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authorMoonchild <moonchild@palemoon.org>2021-02-25 01:03:57 +0000
committerMoonchild <moonchild@palemoon.org>2021-02-25 01:03:57 +0000
commitceadffab6b357723981a429e11222daf6cd6dcfb (patch)
tree5603053048d6a460f79b22bdf165fb74d32d39b0 /testing/web-platform/tests/webaudio
parent14fb2f966e9b54598c451e3cb35b4aa0480dafed (diff)
parentad5a13bd501e379517da1a944c104a11d951a3f5 (diff)
downloadUXP-RC_20210225.tar
UXP-RC_20210225.tar.gz
UXP-RC_20210225.tar.lz
UXP-RC_20210225.tar.xz
UXP-RC_20210225.zip
Merge branch 'master' into releaseRC_20210225
Diffstat (limited to 'testing/web-platform/tests/webaudio')
-rw-r--r--testing/web-platform/tests/webaudio/.gitignore1
-rw-r--r--testing/web-platform/tests/webaudio/OWNERS1
-rw-r--r--testing/web-platform/tests/webaudio/README.md5
-rw-r--r--testing/web-platform/tests/webaudio/js/buffer-loader.js44
-rw-r--r--testing/web-platform/tests/webaudio/js/helpers.js33
-rw-r--r--testing/web-platform/tests/webaudio/js/lodash.js4282
-rw-r--r--testing/web-platform/tests/webaudio/js/vendor-prefixes.js2
-rwxr-xr-xtesting/web-platform/tests/webaudio/refresh_idl.rb57
-rw-r--r--testing/web-platform/tests/webaudio/resources/sin_440Hz_-6dBFS_1s.wavbin88246 -> 0 bytes
-rw-r--r--testing/web-platform/tests/webaudio/specification.html5911
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-analysernode-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffer-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffer-interface/idl-test.html107
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffersourcenode-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-audiocontext-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-audiodestinationnode-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-audiodestinationnode-interface/idl-test.html128
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-audiolistener-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-audionode-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-audionode-interface/audionode-connect-return-value.html15
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-audioparam-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-audioparam-interface/retrospective-setValueAtTime.html71
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-audioparam-interface/setTargetAtTime-after-event-within-block.html54
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-audioparam-interface/setValueAtTime-within-block.html48
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-audioprocessingevent-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-biquadfilternode-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-channelmergernode-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-channelsplitternode-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-constantsourcenode-interface/test-constantsourcenode.html135
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-convolvernode-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-delaynode-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-delaynode-interface/idl-test.html152
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-dynamicscompressornode-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-gainnode-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-gainnode-interface/gain-expected.wavbin281400 -> 0 bytes
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-gainnode-interface/idl-test.html152
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-gainnode-interface/test-gainnode.html121
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-iirfilternode-interface/test-iirfilternode.html59
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-mediaelementaudiosourcenode-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-mediaelementaudiosourcenode-interface/mediaElementAudioSourceToScriptProcessorTest.html124
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-mediastreamaudiodestinationnode-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-mediastreamaudiosourcenode-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-offlineaudiocontext-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-offlineaudiocontext-interface/current-time-block-size.html17
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-oscillatornode-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-pannernode-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-pannernode-interface/test-pannernode-automation.html31
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-periodicwave-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-scriptprocessornode-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-waveshapernode-interface/.gitkeep0
-rw-r--r--testing/web-platform/tests/webaudio/the-audio-api/the-waveshapernode-interface/curve-tests.html212
51 files changed, 0 insertions, 11762 deletions
diff --git a/testing/web-platform/tests/webaudio/.gitignore b/testing/web-platform/tests/webaudio/.gitignore
deleted file mode 100644
index 068fd1ef0..000000000
--- a/testing/web-platform/tests/webaudio/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-idl/* \ No newline at end of file
diff --git a/testing/web-platform/tests/webaudio/OWNERS b/testing/web-platform/tests/webaudio/OWNERS
deleted file mode 100644
index d4865fcd0..000000000
--- a/testing/web-platform/tests/webaudio/OWNERS
+++ /dev/null
@@ -1 +0,0 @@
-@chrislo
diff --git a/testing/web-platform/tests/webaudio/README.md b/testing/web-platform/tests/webaudio/README.md
deleted file mode 100644
index e1afecd83..000000000
--- a/testing/web-platform/tests/webaudio/README.md
+++ /dev/null
@@ -1,5 +0,0 @@
-Our test suite is currently tracking the [editor's draft](https://dvcs.w3.org/hg/audio/raw-file/tip/webaudio/specification.html) of the Web Audio API.
-
-The tests are arranged in subdirectories, corresponding to different
-sections of the spec. So, for example, tests for the `DelayNode` are
-in `the-audio-api/the-delaynode-interface`.
diff --git a/testing/web-platform/tests/webaudio/js/buffer-loader.js b/testing/web-platform/tests/webaudio/js/buffer-loader.js
deleted file mode 100644
index 453dc4a52..000000000
--- a/testing/web-platform/tests/webaudio/js/buffer-loader.js
+++ /dev/null
@@ -1,44 +0,0 @@
-/* Taken from
- https://raw.github.com/WebKit/webkit/master/LayoutTests/webaudio/resources/buffer-loader.js */
-
-function BufferLoader(context, urlList, callback) {
- this.context = context;
- this.urlList = urlList;
- this.onload = callback;
- this.bufferList = new Array();
- this.loadCount = 0;
-}
-
-BufferLoader.prototype.loadBuffer = function(url, index) {
- // Load buffer asynchronously
- var request = new XMLHttpRequest();
- request.open("GET", url, true);
- request.responseType = "arraybuffer";
-
- var loader = this;
-
- request.onload = function() {
- loader.context.decodeAudioData(request.response, decodeSuccessCallback, decodeErrorCallback);
- };
-
- request.onerror = function() {
- alert('BufferLoader: XHR error');
- };
-
- var decodeSuccessCallback = function(buffer) {
- loader.bufferList[index] = buffer;
- if (++loader.loadCount == loader.urlList.length)
- loader.onload(loader.bufferList);
- };
-
- var decodeErrorCallback = function() {
- alert('decodeErrorCallback: decode error');
- };
-
- request.send();
-}
-
-BufferLoader.prototype.load = function() {
- for (var i = 0; i < this.urlList.length; ++i)
- this.loadBuffer(this.urlList[i], i);
-}
diff --git a/testing/web-platform/tests/webaudio/js/helpers.js b/testing/web-platform/tests/webaudio/js/helpers.js
deleted file mode 100644
index 9e4ee6fa3..000000000
--- a/testing/web-platform/tests/webaudio/js/helpers.js
+++ /dev/null
@@ -1,33 +0,0 @@
-function assert_array_approx_equals(actual, expected, epsilon, description)
-{
- assert_true(actual.length === expected.length,
- (description + ": lengths differ, expected " + expected.length + " got " + actual.length))
-
- for (var i=0; i < actual.length; i++) {
- assert_approx_equals(actual[i], expected[i], epsilon, (description + ": element " + i))
- }
-}
-
-/*
- Returns an array (typed or not), of the passed array with removed trailing and ending
- zero-valued elements
- */
-function trimEmptyElements(array) {
- var start = 0;
- var end = array.length;
-
- while (start < array.length) {
- if (array[start] !== 0) {
- break;
- }
- start++;
- }
-
- while (end > 0) {
- end--;
- if (array[end] !== 0) {
- break;
- }
- }
- return array.subarray(start, end);
-}
diff --git a/testing/web-platform/tests/webaudio/js/lodash.js b/testing/web-platform/tests/webaudio/js/lodash.js
deleted file mode 100644
index 3813d2af2..000000000
--- a/testing/web-platform/tests/webaudio/js/lodash.js
+++ /dev/null
@@ -1,4282 +0,0 @@
-/*!
- * Lo-Dash 0.10.0 <http://lodash.com>
- * (c) 2012 John-David Dalton <http://allyoucanleet.com/>
- * Based on Underscore.js 1.4.2 <http://underscorejs.org>
- * (c) 2009-2012 Jeremy Ashkenas, DocumentCloud Inc.
- * Available under MIT license <http://lodash.com/license>
- */
-;(function(window, undefined) {
-
- /** Detect free variable `exports` */
- var freeExports = typeof exports == 'object' && exports;
-
- /** Detect free variable `global` and use it as `window` */
- var freeGlobal = typeof global == 'object' && global;
- if (freeGlobal.global === freeGlobal) {
- window = freeGlobal;
- }
-
- /** Used for array and object method references */
- var arrayRef = [],
- // avoid a Closure Compiler bug by creatively creating an object
- objectRef = new function(){};
-
- /** Used to generate unique IDs */
- var idCounter = 0;
-
- /** Used internally to indicate various things */
- var indicatorObject = objectRef;
-
- /** Used by `cachedContains` as the default size when optimizations are enabled for large arrays */
- var largeArraySize = 30;
-
- /** Used to restore the original `_` reference in `noConflict` */
- var oldDash = window._;
-
- /** Used to detect template delimiter values that require a with-statement */
- var reComplexDelimiter = /[-?+=!~*%&^<>|{(\/]|\[\D|\b(?:delete|in|instanceof|new|typeof|void)\b/;
-
- /** Used to match HTML entities */
- var reEscapedHtml = /&(?:amp|lt|gt|quot|#x27);/g;
-
- /** Used to match empty string literals in compiled template source */
- var reEmptyStringLeading = /\b__p \+= '';/g,
- reEmptyStringMiddle = /\b(__p \+=) '' \+/g,
- reEmptyStringTrailing = /(__e\(.*?\)|\b__t\)) \+\n'';/g;
-
- /** Used to match regexp flags from their coerced string values */
- var reFlags = /\w*$/;
-
- /** Used to insert the data object variable into compiled template source */
- var reInsertVariable = /(?:__e|__t = )\(\s*(?![\d\s"']|this\.)/g;
-
- /** Used to detect if a method is native */
- var reNative = RegExp('^' +
- (objectRef.valueOf + '')
- .replace(/[.*+?^=!:${}()|[\]\/\\]/g, '\\$&')
- .replace(/valueOf|for [^\]]+/g, '.+?') + '$'
- );
-
- /**
- * Used to match ES6 template delimiters
- * http://people.mozilla.org/~jorendorff/es6-draft.html#sec-7.8.6
- */
- var reEsTemplate = /\$\{((?:(?=\\?)\\?[\s\S])*?)}/g;
-
- /** Used to match "interpolate" template delimiters */
- var reInterpolate = /<%=([\s\S]+?)%>/g;
-
- /** Used to ensure capturing order of template delimiters */
- var reNoMatch = /($^)/;
-
- /** Used to match HTML characters */
- var reUnescapedHtml = /[&<>"']/g;
-
- /** Used to match unescaped characters in compiled string literals */
- var reUnescapedString = /['\n\r\t\u2028\u2029\\]/g;
-
- /** Used to fix the JScript [[DontEnum]] bug */
- var shadowed = [
- 'constructor', 'hasOwnProperty', 'isPrototypeOf', 'propertyIsEnumerable',
- 'toLocaleString', 'toString', 'valueOf'
- ];
-
- /** Used to make template sourceURLs easier to identify */
- var templateCounter = 0;
-
- /** Native method shortcuts */
- var ceil = Math.ceil,
- concat = arrayRef.concat,
- floor = Math.floor,
- getPrototypeOf = reNative.test(getPrototypeOf = Object.getPrototypeOf) && getPrototypeOf,
- hasOwnProperty = objectRef.hasOwnProperty,
- push = arrayRef.push,
- propertyIsEnumerable = objectRef.propertyIsEnumerable,
- slice = arrayRef.slice,
- toString = objectRef.toString;
-
- /* Native method shortcuts for methods with the same name as other `lodash` methods */
- var nativeBind = reNative.test(nativeBind = slice.bind) && nativeBind,
- nativeIsArray = reNative.test(nativeIsArray = Array.isArray) && nativeIsArray,
- nativeIsFinite = window.isFinite,
- nativeIsNaN = window.isNaN,
- nativeKeys = reNative.test(nativeKeys = Object.keys) && nativeKeys,
- nativeMax = Math.max,
- nativeMin = Math.min,
- nativeRandom = Math.random;
-
- /** `Object#toString` result shortcuts */
- var argsClass = '[object Arguments]',
- arrayClass = '[object Array]',
- boolClass = '[object Boolean]',
- dateClass = '[object Date]',
- funcClass = '[object Function]',
- numberClass = '[object Number]',
- objectClass = '[object Object]',
- regexpClass = '[object RegExp]',
- stringClass = '[object String]';
-
- /**
- * Detect the JScript [[DontEnum]] bug:
- *
- * In IE < 9 an objects own properties, shadowing non-enumerable ones, are
- * made non-enumerable as well.
- */
- var hasDontEnumBug;
-
- /** Detect if own properties are iterated after inherited properties (IE < 9) */
- var iteratesOwnLast;
-
- /**
- * Detect if `Array#shift` and `Array#splice` augment array-like objects
- * incorrectly:
- *
- * Firefox < 10, IE compatibility mode, and IE < 9 have buggy Array `shift()`
- * and `splice()` functions that fail to remove the last element, `value[0]`,
- * of array-like objects even though the `length` property is set to `0`.
- * The `shift()` method is buggy in IE 8 compatibility mode, while `splice()`
- * is buggy regardless of mode in IE < 9 and buggy in compatibility mode in IE 9.
- */
- var hasObjectSpliceBug = (hasObjectSpliceBug = { '0': 1, 'length': 1 },
- arrayRef.splice.call(hasObjectSpliceBug, 0, 1), hasObjectSpliceBug[0]);
-
- /** Detect if an `arguments` object's indexes are non-enumerable (IE < 9) */
- var noArgsEnum = true;
-
- (function() {
- var props = [];
- function ctor() { this.x = 1; }
- ctor.prototype = { 'valueOf': 1, 'y': 1 };
- for (var prop in new ctor) { props.push(prop); }
- for (prop in arguments) { noArgsEnum = !prop; }
-
- hasDontEnumBug = !/valueOf/.test(props);
- iteratesOwnLast = props[0] != 'x';
- }(1));
-
- /** Detect if an `arguments` object's [[Class]] is unresolvable (Firefox < 4, IE < 9) */
- var noArgsClass = !isArguments(arguments);
-
- /** Detect if `Array#slice` cannot be used to convert strings to arrays (Opera < 10.52) */
- var noArraySliceOnStrings = slice.call('x')[0] != 'x';
-
- /**
- * Detect lack of support for accessing string characters by index:
- *
- * IE < 8 can't access characters by index and IE 8 can only access
- * characters by index on string literals.
- */
- var noCharByIndex = ('x'[0] + Object('x')[0]) != 'xx';
-
- /**
- * Detect if a node's [[Class]] is unresolvable (IE < 9)
- * and that the JS engine won't error when attempting to coerce an object to
- * a string without a `toString` property value of `typeof` "function".
- */
- try {
- var noNodeClass = ({ 'toString': 0 } + '', toString.call(window.document || 0) == objectClass);
- } catch(e) { }
-
- /* Detect if `Function#bind` exists and is inferred to be fast (all but V8) */
- var isBindFast = nativeBind && /\n|Opera/.test(nativeBind + toString.call(window.opera));
-
- /* Detect if `Object.keys` exists and is inferred to be fast (IE, Opera, V8) */
- var isKeysFast = nativeKeys && /^.+$|true/.test(nativeKeys + !!window.attachEvent);
-
- /**
- * Detect if sourceURL syntax is usable without erroring:
- *
- * The JS engine in Adobe products, like InDesign, will throw a syntax error
- * when it encounters a single line comment beginning with the `@` symbol.
- *
- * The JS engine in Narwhal will generate the function `function anonymous(){//}`
- * and throw a syntax error.
- *
- * Avoid comments beginning `@` symbols in IE because they are part of its
- * non-standard conditional compilation support.
- * http://msdn.microsoft.com/en-us/library/121hztk3(v=vs.94).aspx
- */
- try {
- var useSourceURL = (Function('//@')(), !window.attachEvent);
- } catch(e) { }
-
- /** Used to identify object classifications that `_.clone` supports */
- var cloneableClasses = {};
- cloneableClasses[argsClass] = cloneableClasses[funcClass] = false;
- cloneableClasses[arrayClass] = cloneableClasses[boolClass] = cloneableClasses[dateClass] =
- cloneableClasses[numberClass] = cloneableClasses[objectClass] = cloneableClasses[regexpClass] =
- cloneableClasses[stringClass] = true;
-
- /** Used to determine if values are of the language type Object */
- var objectTypes = {
- 'boolean': false,
- 'function': true,
- 'object': true,
- 'number': false,
- 'string': false,
- 'undefined': false
- };
-
- /** Used to escape characters for inclusion in compiled string literals */
- var stringEscapes = {
- '\\': '\\',
- "'": "'",
- '\n': 'n',
- '\r': 'r',
- '\t': 't',
- '\u2028': 'u2028',
- '\u2029': 'u2029'
- };
-
- /*--------------------------------------------------------------------------*/
-
- /**
- * The `lodash` function.
- *
- * @name _
- * @constructor
- * @category Chaining
- * @param {Mixed} value The value to wrap in a `lodash` instance.
- * @returns {Object} Returns a `lodash` instance.
- */
- function lodash(value) {
- // exit early if already wrapped
- if (value && value.__wrapped__) {
- return value;
- }
- // allow invoking `lodash` without the `new` operator
- if (!(this instanceof lodash)) {
- return new lodash(value);
- }
- this.__wrapped__ = value;
- }
-
- /**
- * By default, the template delimiters used by Lo-Dash are similar to those in
- * embedded Ruby (ERB). Change the following template settings to use alternative
- * delimiters.
- *
- * @static
- * @memberOf _
- * @type Object
- */
- lodash.templateSettings = {
-
- /**
- * Used to detect `data` property values to be HTML-escaped.
- *
- * @static
- * @memberOf _.templateSettings
- * @type RegExp
- */
- 'escape': /<%-([\s\S]+?)%>/g,
-
- /**
- * Used to detect code to be evaluated.
- *
- * @static
- * @memberOf _.templateSettings
- * @type RegExp
- */
- 'evaluate': /<%([\s\S]+?)%>/g,
-
- /**
- * Used to detect `data` property values to inject.
- *
- * @static
- * @memberOf _.templateSettings
- * @type RegExp
- */
- 'interpolate': reInterpolate,
-
- /**
- * Used to reference the data object in the template text.
- *
- * @static
- * @memberOf _.templateSettings
- * @type String
- */
- 'variable': ''
- };
-
- /*--------------------------------------------------------------------------*/
-
- /**
- * The template used to create iterator functions.
- *
- * @private
- * @param {Obect} data The data object used to populate the text.
- * @returns {String} Returns the interpolated text.
- */
- var iteratorTemplate = template(
- // conditional strict mode
- '<% if (obj.useStrict) { %>\'use strict\';\n<% } %>' +
-
- // the `iteratee` may be reassigned by the `top` snippet
- 'var index, value, iteratee = <%= firstArg %>, ' +
- // assign the `result` variable an initial value
- 'result = <%= firstArg %>;\n' +
- // exit early if the first argument is falsey
- 'if (!<%= firstArg %>) return result;\n' +
- // add code before the iteration branches
- '<%= top %>;\n' +
-
- // array-like iteration:
- '<% if (arrayLoop) { %>' +
- 'var length = iteratee.length; index = -1;\n' +
- 'if (typeof length == \'number\') {' +
-
- // add support for accessing string characters by index if needed
- ' <% if (noCharByIndex) { %>\n' +
- ' if (isString(iteratee)) {\n' +
- ' iteratee = iteratee.split(\'\')\n' +
- ' }' +
- ' <% } %>\n' +
-
- // iterate over the array-like value
- ' while (++index < length) {\n' +
- ' value = iteratee[index];\n' +
- ' <%= arrayLoop %>\n' +
- ' }\n' +
- '}\n' +
- 'else {' +
-
- // object iteration:
- // add support for iterating over `arguments` objects if needed
- ' <% } else if (noArgsEnum) { %>\n' +
- ' var length = iteratee.length; index = -1;\n' +
- ' if (length && isArguments(iteratee)) {\n' +
- ' while (++index < length) {\n' +
- ' value = iteratee[index += \'\'];\n' +
- ' <%= objectLoop %>\n' +
- ' }\n' +
- ' } else {' +
- ' <% } %>' +
-
- // Firefox < 3.6, Opera > 9.50 - Opera < 11.60, and Safari < 5.1
- // (if the prototype or a property on the prototype has been set)
- // incorrectly sets a function's `prototype` property [[Enumerable]]
- // value to `true`. Because of this Lo-Dash standardizes on skipping
- // the the `prototype` property of functions regardless of its
- // [[Enumerable]] value.
- ' <% if (!hasDontEnumBug) { %>\n' +
- ' var skipProto = typeof iteratee == \'function\' && \n' +
- ' propertyIsEnumerable.call(iteratee, \'prototype\');\n' +
- ' <% } %>' +
-
- // iterate own properties using `Object.keys` if it's fast
- ' <% if (isKeysFast && useHas) { %>\n' +
- ' var ownIndex = -1,\n' +
- ' ownProps = objectTypes[typeof iteratee] ? nativeKeys(iteratee) : [],\n' +
- ' length = ownProps.length;\n\n' +
- ' while (++ownIndex < length) {\n' +
- ' index = ownProps[ownIndex];\n' +
- ' <% if (!hasDontEnumBug) { %>if (!(skipProto && index == \'prototype\')) {\n <% } %>' +
- ' value = iteratee[index];\n' +
- ' <%= objectLoop %>\n' +
- ' <% if (!hasDontEnumBug) { %>}\n<% } %>' +
- ' }' +
-
- // else using a for-in loop
- ' <% } else { %>\n' +
- ' for (index in iteratee) {<%' +
- ' if (!hasDontEnumBug || useHas) { %>\n if (<%' +
- ' if (!hasDontEnumBug) { %>!(skipProto && index == \'prototype\')<% }' +
- ' if (!hasDontEnumBug && useHas) { %> && <% }' +
- ' if (useHas) { %>hasOwnProperty.call(iteratee, index)<% }' +
- ' %>) {' +
- ' <% } %>\n' +
- ' value = iteratee[index];\n' +
- ' <%= objectLoop %>;' +
- ' <% if (!hasDontEnumBug || useHas) { %>\n }<% } %>\n' +
- ' }' +
- ' <% } %>' +
-
- // Because IE < 9 can't set the `[[Enumerable]]` attribute of an
- // existing property and the `constructor` property of a prototype
- // defaults to non-enumerable, Lo-Dash skips the `constructor`
- // property when it infers it's iterating over a `prototype` object.
- ' <% if (hasDontEnumBug) { %>\n\n' +
- ' var ctor = iteratee.constructor;\n' +
- ' <% for (var k = 0; k < 7; k++) { %>\n' +
- ' index = \'<%= shadowed[k] %>\';\n' +
- ' if (<%' +
- ' if (shadowed[k] == \'constructor\') {' +
- ' %>!(ctor && ctor.prototype === iteratee) && <%' +
- ' } %>hasOwnProperty.call(iteratee, index)) {\n' +
- ' value = iteratee[index];\n' +
- ' <%= objectLoop %>\n' +
- ' }' +
- ' <% } %>' +
- ' <% } %>' +
- ' <% if (arrayLoop || noArgsEnum) { %>\n}<% } %>\n' +
-
- // add code to the bottom of the iteration function
- '<%= bottom %>;\n' +
- // finally, return the `result`
- 'return result'
- );
-
- /** Reusable iterator options for `assign` and `defaults` */
- var assignIteratorOptions = {
- 'args': 'object, source, guard',
- 'top':
- 'for (var argsIndex = 1, argsLength = typeof guard == \'number\' ? 2 : arguments.length; argsIndex < argsLength; argsIndex++) {\n' +
- ' if ((iteratee = arguments[argsIndex])) {',
- 'objectLoop': 'result[index] = value',
- 'bottom': ' }\n}'
- };
-
- /**
- * Reusable iterator options shared by `forEach`, `forIn`, and `forOwn`.
- */
- var forEachIteratorOptions = {
- 'args': 'collection, callback, thisArg',
- 'top': 'callback = createCallback(callback, thisArg)',
- 'arrayLoop': 'if (callback(value, index, collection) === false) return result',
- 'objectLoop': 'if (callback(value, index, collection) === false) return result'
- };
-
- /** Reusable iterator options for `forIn` and `forOwn` */
- var forOwnIteratorOptions = {
- 'arrayLoop': null
- };
-
- /*--------------------------------------------------------------------------*/
-
- /**
- * Creates a function optimized to search large arrays for a given `value`,
- * starting at `fromIndex`, using strict equality for comparisons, i.e. `===`.
- *
- * @private
- * @param {Array} array The array to search.
- * @param {Mixed} value The value to search for.
- * @param {Number} [fromIndex=0] The index to search from.
- * @param {Number} [largeSize=30] The length at which an array is considered large.
- * @returns {Boolean} Returns `true` if `value` is found, else `false`.
- */
- function cachedContains(array, fromIndex, largeSize) {
- fromIndex || (fromIndex = 0);
-
- var length = array.length,
- isLarge = (length - fromIndex) >= (largeSize || largeArraySize);
-
- if (isLarge) {
- var cache = {},
- index = fromIndex - 1;
-
- while (++index < length) {
- // manually coerce `value` to a string because `hasOwnProperty`, in some
- // older versions of Firefox, coerces objects incorrectly
- var key = array[index] + '';
- (hasOwnProperty.call(cache, key) ? cache[key] : (cache[key] = [])).push(array[index]);
- }
- }
- return function(value) {
- if (isLarge) {
- var key = value + '';
- return hasOwnProperty.call(cache, key) && indexOf(cache[key], value) > -1;
- }
- return indexOf(array, value, fromIndex) > -1;
- }
- }
-
- /**
- * Used by `_.max` and `_.min` as the default `callback` when a given
- * `collection` is a string value.
- *
- * @private
- * @param {String} value The character to inspect.
- * @returns {Number} Returns the code unit of given character.
- */
- function charAtCallback(value) {
- return value.charCodeAt(0);
- }
-
- /**
- * Used by `sortBy` to compare transformed `collection` values, stable sorting
- * them in ascending order.
- *
- * @private
- * @param {Object} a The object to compare to `b`.
- * @param {Object} b The object to compare to `a`.
- * @returns {Number} Returns the sort order indicator of `1` or `-1`.
- */
- function compareAscending(a, b) {
- var ai = a.index,
- bi = b.index;
-
- a = a.criteria;
- b = b.criteria;
-
- // ensure a stable sort in V8 and other engines
- // http://code.google.com/p/v8/issues/detail?id=90
- if (a !== b) {
- if (a > b || a === undefined) {
- return 1;
- }
- if (a < b || b === undefined) {
- return -1;
- }
- }
- return ai < bi ? -1 : 1;
- }
-
- /**
- * Creates a function that, when called, invokes `func` with the `this`
- * binding of `thisArg` and prepends any `partailArgs` to the arguments passed
- * to the bound function.
- *
- * @private
- * @param {Function|String} func The function to bind or the method name.
- * @param {Mixed} [thisArg] The `this` binding of `func`.
- * @param {Array} partialArgs An array of arguments to be partially applied.
- * @returns {Function} Returns the new bound function.
- */
- function createBound(func, thisArg, partialArgs) {
- var isFunc = isFunction(func),
- isPartial = !partialArgs,
- key = thisArg;
-
- // juggle arguments
- if (isPartial) {
- partialArgs = thisArg;
- }
- if (!isFunc) {
- thisArg = func;
- }
-
- function bound() {
- // `Function#bind` spec
- // http://es5.github.com/#x15.3.4.5
- var args = arguments,
- thisBinding = isPartial ? this : thisArg;
-
- if (!isFunc) {
- func = thisArg[key];
- }
- if (partialArgs.length) {
- args = args.length
- ? partialArgs.concat(slice.call(args))
- : partialArgs;
- }
- if (this instanceof bound) {
- // get `func` instance if `bound` is invoked in a `new` expression
- noop.prototype = func.prototype;
- thisBinding = new noop;
-
- // mimic the constructor's `return` behavior
- // http://es5.github.com/#x13.2.2
- var result = func.apply(thisBinding, args);
- return isObject(result)
- ? result
- : thisBinding
- }
- return func.apply(thisBinding, args);
- }
- return bound;
- }
-
- /**
- * Produces an iteration callback bound to an optional `thisArg`. If `func` is
- * a property name, the callback will return the property value for a given element.
- *
- * @private
- * @param {Function|String} [func=identity|property] The function called per
- * iteration or property name to query.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Function} Returns a callback function.
- */
- function createCallback(func, thisArg) {
- if (!func) {
- return identity;
- }
- if (typeof func != 'function') {
- return function(object) {
- return object[func];
- };
- }
- if (thisArg !== undefined) {
- return function(value, index, object) {
- return func.call(thisArg, value, index, object);
- };
- }
- return func;
- }
-
- /**
- * Creates compiled iteration functions.
- *
- * @private
- * @param {Object} [options1, options2, ...] The compile options object(s).
- * useHas - A boolean to specify using `hasOwnProperty` checks in the object loop.
- * args - A string of comma separated arguments the iteration function will accept.
- * top - A string of code to execute before the iteration branches.
- * arrayLoop - A string of code to execute in the array loop.
- * objectLoop - A string of code to execute in the object loop.
- * bottom - A string of code to execute after the iteration branches.
- *
- * @returns {Function} Returns the compiled function.
- */
- function createIterator() {
- var data = {
- 'arrayLoop': '',
- 'bottom': '',
- 'hasDontEnumBug': hasDontEnumBug,
- 'isKeysFast': isKeysFast,
- 'objectLoop': '',
- 'noArgsEnum': noArgsEnum,
- 'noCharByIndex': noCharByIndex,
- 'shadowed': shadowed,
- 'top': '',
- 'useHas': true
- };
-
- // merge options into a template data object
- for (var object, index = 0; object = arguments[index]; index++) {
- for (var key in object) {
- data[key] = object[key];
- }
- }
- var args = data.args;
- data.firstArg = /^[^,]+/.exec(args)[0];
-
- // create the function factory
- var factory = Function(
- 'createCallback, hasOwnProperty, isArguments, isString, objectTypes, ' +
- 'nativeKeys, propertyIsEnumerable',
- 'return function(' + args + ') {\n' + iteratorTemplate(data) + '\n}'
- );
- // return the compiled function
- return factory(
- createCallback, hasOwnProperty, isArguments, isString, objectTypes,
- nativeKeys, propertyIsEnumerable
- );
- }
-
- /**
- * Used by `template` to escape characters for inclusion in compiled
- * string literals.
- *
- * @private
- * @param {String} match The matched character to escape.
- * @returns {String} Returns the escaped character.
- */
- function escapeStringChar(match) {
- return '\\' + stringEscapes[match];
- }
-
- /**
- * Used by `escape` to convert characters to HTML entities.
- *
- * @private
- * @param {String} match The matched character to escape.
- * @returns {String} Returns the escaped character.
- */
- function escapeHtmlChar(match) {
- return htmlEscapes[match];
- }
-
- /**
- * A no-operation function.
- *
- * @private
- */
- function noop() {
- // no operation performed
- }
-
- /**
- * Used by `unescape` to convert HTML entities to characters.
- *
- * @private
- * @param {String} match The matched character to unescape.
- * @returns {String} Returns the unescaped character.
- */
- function unescapeHtmlChar(match) {
- return htmlUnescapes[match];
- }
-
- /*--------------------------------------------------------------------------*/
-
- /**
- * Assigns own enumerable properties of source object(s) to the `destination`
- * object. Subsequent sources will overwrite propery assignments of previous
- * sources.
- *
- * @static
- * @memberOf _
- * @alias extend
- * @category Objects
- * @param {Object} object The destination object.
- * @param {Object} [source1, source2, ...] The source objects.
- * @returns {Object} Returns the destination object.
- * @example
- *
- * _.assign({ 'name': 'moe' }, { 'age': 40 });
- * // => { 'name': 'moe', 'age': 40 }
- */
- var assign = createIterator(assignIteratorOptions);
-
- /**
- * Checks if `value` is an `arguments` object.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Mixed} value The value to check.
- * @returns {Boolean} Returns `true` if the `value` is an `arguments` object, else `false`.
- * @example
- *
- * (function() { return _.isArguments(arguments); })(1, 2, 3);
- * // => true
- *
- * _.isArguments([1, 2, 3]);
- * // => false
- */
- function isArguments(value) {
- return toString.call(value) == argsClass;
- }
- // fallback for browsers that can't detect `arguments` objects by [[Class]]
- if (noArgsClass) {
- isArguments = function(value) {
- return value ? hasOwnProperty.call(value, 'callee') : false;
- };
- }
-
- /**
- * Iterates over `object`'s own and inherited enumerable properties, executing
- * the `callback` for each property. The `callback` is bound to `thisArg` and
- * invoked with three arguments; (value, key, object). Callbacks may exit iteration
- * early by explicitly returning `false`.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Object} object The object to iterate over.
- * @param {Function} callback The function called per iteration.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Object} Returns `object`.
- * @example
- *
- * function Dog(name) {
- * this.name = name;
- * }
- *
- * Dog.prototype.bark = function() {
- * alert('Woof, woof!');
- * };
- *
- * _.forIn(new Dog('Dagny'), function(value, key) {
- * alert(key);
- * });
- * // => alerts 'name' and 'bark' (order is not guaranteed)
- */
- var forIn = createIterator(forEachIteratorOptions, forOwnIteratorOptions, {
- 'useHas': false
- });
-
- /**
- * Iterates over an object's own enumerable properties, executing the `callback`
- * for each property. The `callback` is bound to `thisArg` and invoked with three
- * arguments; (value, key, object). Callbacks may exit iteration early by explicitly
- * returning `false`.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Object} object The object to iterate over.
- * @param {Function} callback The function called per iteration.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Object} Returns `object`.
- * @example
- *
- * _.forOwn({ '0': 'zero', '1': 'one', 'length': 2 }, function(num, key) {
- * alert(key);
- * });
- * // => alerts '0', '1', and 'length' (order is not guaranteed)
- */
- var forOwn = createIterator(forEachIteratorOptions, forOwnIteratorOptions);
-
- /**
- * A fallback implementation of `isPlainObject` that checks if a given `value`
- * is an object created by the `Object` constructor, assuming objects created
- * by the `Object` constructor have no inherited enumerable properties and that
- * there are no `Object.prototype` extensions.
- *
- * @private
- * @param {Mixed} value The value to check.
- * @returns {Boolean} Returns `true` if `value` is a plain object, else `false`.
- */
- function shimIsPlainObject(value) {
- // avoid non-objects and false positives for `arguments` objects
- var result = false;
- if (!(value && typeof value == 'object') || isArguments(value)) {
- return result;
- }
- // IE < 9 presents DOM nodes as `Object` objects except they have `toString`
- // methods that are `typeof` "string" and still can coerce nodes to strings.
- // Also check that the constructor is `Object` (i.e. `Object instanceof Object`)
- var ctor = value.constructor;
- if ((!noNodeClass || !(typeof value.toString != 'function' && typeof (value + '') == 'string')) &&
- (!isFunction(ctor) || ctor instanceof ctor)) {
- // IE < 9 iterates inherited properties before own properties. If the first
- // iterated property is an object's own property then there are no inherited
- // enumerable properties.
- if (iteratesOwnLast) {
- forIn(value, function(value, key, object) {
- result = !hasOwnProperty.call(object, key);
- return false;
- });
- return result === false;
- }
- // In most environments an object's own properties are iterated before
- // its inherited properties. If the last iterated property is an object's
- // own property then there are no inherited enumerable properties.
- forIn(value, function(value, key) {
- result = key;
- });
- return result === false || hasOwnProperty.call(value, result);
- }
- return result;
- }
-
- /**
- * A fallback implementation of `Object.keys` that produces an array of the
- * given object's own enumerable property names.
- *
- * @private
- * @param {Object} object The object to inspect.
- * @returns {Array} Returns a new array of property names.
- */
- function shimKeys(object) {
- var result = [];
- forOwn(object, function(value, key) {
- result.push(key);
- });
- return result;
- }
-
- /**
- * Used to convert characters to HTML entities:
- *
- * Though the `>` character is escaped for symmetry, characters like `>` and `/`
- * don't require escaping in HTML and have no special meaning unless they're part
- * of a tag or an unquoted attribute value.
- * http://mathiasbynens.be/notes/ambiguous-ampersands (under "semi-related fun fact")
- */
- var htmlEscapes = {
- '&': '&amp;',
- '<': '&lt;',
- '>': '&gt;',
- '"': '&quot;',
- "'": '&#x27;'
- };
-
- /** Used to convert HTML entities to characters */
- var htmlUnescapes = invert(htmlEscapes);
-
- /*--------------------------------------------------------------------------*/
-
- /**
- * Creates a clone of `value`. If `deep` is `true`, all nested objects will
- * also be cloned otherwise they will be assigned by reference. Functions, DOM
- * nodes, `arguments` objects, and objects created by constructors other than
- * `Object` are **not** cloned.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Mixed} value The value to clone.
- * @param {Boolean} deep A flag to indicate a deep clone.
- * @param- {Object} [guard] Internally used to allow this method to work with
- * others like `_.map` without using their callback `index` argument for `deep`.
- * @param- {Array} [stackA=[]] Internally used to track traversed source objects.
- * @param- {Array} [stackB=[]] Internally used to associate clones with their
- * source counterparts.
- * @returns {Mixed} Returns the cloned `value`.
- * @example
- *
- * var stooges = [
- * { 'name': 'moe', 'age': 40 },
- * { 'name': 'larry', 'age': 50 },
- * { 'name': 'curly', 'age': 60 }
- * ];
- *
- * _.clone({ 'name': 'moe' });
- * // => { 'name': 'moe' }
- *
- * var shallow = _.clone(stooges);
- * shallow[0] === stooges[0];
- * // => true
- *
- * var deep = _.clone(stooges, true);
- * shallow[0] === stooges[0];
- * // => false
- */
- function clone(value, deep, guard, stackA, stackB) {
- if (value == null) {
- return value;
- }
- if (guard) {
- deep = false;
- }
- // inspect [[Class]]
- var isObj = isObject(value);
- if (isObj) {
- // don't clone `arguments` objects, functions, or non-object Objects
- var className = toString.call(value);
- if (!cloneableClasses[className] || (noArgsClass && isArguments(value))) {
- return value;
- }
- var isArr = className == arrayClass;
- isObj = isArr || (className == objectClass ? isPlainObject(value) : isObj);
- }
- // shallow clone
- if (!isObj || !deep) {
- // don't clone functions
- return isObj
- ? (isArr ? slice.call(value) : assign({}, value))
- : value;
- }
-
- var ctor = value.constructor;
- switch (className) {
- case boolClass:
- case dateClass:
- return new ctor(+value);
-
- case numberClass:
- case stringClass:
- return new ctor(value);
-
- case regexpClass:
- return ctor(value.source, reFlags.exec(value));
- }
- // check for circular references and return corresponding clone
- stackA || (stackA = []);
- stackB || (stackB = []);
-
- var length = stackA.length;
- while (length--) {
- if (stackA[length] == value) {
- return stackB[length];
- }
- }
- // init cloned object
- var result = isArr ? ctor(value.length) : {};
-
- // add the source value to the stack of traversed objects
- // and associate it with its clone
- stackA.push(value);
- stackB.push(result);
-
- // recursively populate clone (susceptible to call stack limits)
- (isArr ? forEach : forOwn)(value, function(objValue, key) {
- result[key] = clone(objValue, deep, null, stackA, stackB);
- });
-
- return result;
- }
-
- /**
- * Assigns own enumerable properties of source object(s) to the `destination`
- * object for all `destination` properties that resolve to `null`/`undefined`.
- * Once a property is set, additional defaults of the same property will be
- * ignored.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Object} object The destination object.
- * @param {Object} [default1, default2, ...] The default objects.
- * @returns {Object} Returns the destination object.
- * @example
- *
- * var iceCream = { 'flavor': 'chocolate' };
- * _.defaults(iceCream, { 'flavor': 'vanilla', 'sprinkles': 'rainbow' });
- * // => { 'flavor': 'chocolate', 'sprinkles': 'rainbow' }
- */
- var defaults = createIterator(assignIteratorOptions, {
- 'objectLoop': 'if (result[index] == null) ' + assignIteratorOptions.objectLoop
- });
-
- /**
- * Creates a sorted array of all enumerable properties, own and inherited,
- * of `object` that have function values.
- *
- * @static
- * @memberOf _
- * @alias methods
- * @category Objects
- * @param {Object} object The object to inspect.
- * @returns {Array} Returns a new array of property names that have function values.
- * @example
- *
- * _.functions(_);
- * // => ['all', 'any', 'bind', 'bindAll', 'clone', 'compact', 'compose', ...]
- */
- function functions(object) {
- var result = [];
- forIn(object, function(value, key) {
- if (isFunction(value)) {
- result.push(key);
- }
- });
- return result.sort();
- }
-
- /**
- * Checks if the specified object `property` exists and is a direct property,
- * instead of an inherited property.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Object} object The object to check.
- * @param {String} property The property to check for.
- * @returns {Boolean} Returns `true` if key is a direct property, else `false`.
- * @example
- *
- * _.has({ 'a': 1, 'b': 2, 'c': 3 }, 'b');
- * // => true
- */
- function has(object, property) {
- return object ? hasOwnProperty.call(object, property) : false;
- }
-
- /**
- * Creates an object composed of the inverted keys and values of the given `object`.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Object} object The object to invert.
- * @returns {Object} Returns the created inverted object.
- * @example
- *
- * _.invert({ 'first': 'Moe', 'second': 'Larry', 'third': 'Curly' });
- * // => { 'Moe': 'first', 'Larry': 'second', 'Curly': 'third' } (order is not guaranteed)
- */
- function invert(object) {
- var result = {};
- forOwn(object, function(value, key) {
- result[value] = key;
- });
- return result;
- }
-
- /**
- * Checks if `value` is an array.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Mixed} value The value to check.
- * @returns {Boolean} Returns `true` if the `value` is an array, else `false`.
- * @example
- *
- * (function() { return _.isArray(arguments); })();
- * // => false
- *
- * _.isArray([1, 2, 3]);
- * // => true
- */
- var isArray = nativeIsArray || function(value) {
- return toString.call(value) == arrayClass;
- };
-
- /**
- * Checks if `value` is a boolean (`true` or `false`) value.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Mixed} value The value to check.
- * @returns {Boolean} Returns `true` if the `value` is a boolean value, else `false`.
- * @example
- *
- * _.isBoolean(null);
- * // => false
- */
- function isBoolean(value) {
- return value === true || value === false || toString.call(value) == boolClass;
- }
-
- /**
- * Checks if `value` is a date.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Mixed} value The value to check.
- * @returns {Boolean} Returns `true` if the `value` is a date, else `false`.
- * @example
- *
- * _.isDate(new Date);
- * // => true
- */
- function isDate(value) {
- return toString.call(value) == dateClass;
- }
-
- /**
- * Checks if `value` is a DOM element.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Mixed} value The value to check.
- * @returns {Boolean} Returns `true` if the `value` is a DOM element, else `false`.
- * @example
- *
- * _.isElement(document.body);
- * // => true
- */
- function isElement(value) {
- return value ? value.nodeType === 1 : false;
- }
-
- /**
- * Checks if `value` is empty. Arrays, strings, or `arguments` objects with a
- * length of `0` and objects with no own enumerable properties are considered
- * "empty".
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Array|Object|String} value The value to inspect.
- * @returns {Boolean} Returns `true` if the `value` is empty, else `false`.
- * @example
- *
- * _.isEmpty([1, 2, 3]);
- * // => false
- *
- * _.isEmpty({});
- * // => true
- *
- * _.isEmpty('');
- * // => true
- */
- function isEmpty(value) {
- var result = true;
- if (!value) {
- return result;
- }
- var className = toString.call(value),
- length = value.length;
-
- if ((className == arrayClass || className == stringClass ||
- className == argsClass || (noArgsClass && isArguments(value))) ||
- (className == objectClass && typeof length == 'number' && isFunction(value.splice))) {
- return !length;
- }
- forOwn(value, function() {
- return (result = false);
- });
- return result;
- }
-
- /**
- * Performs a deep comparison between two values to determine if they are
- * equivalent to each other.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Mixed} a The value to compare.
- * @param {Mixed} b The other value to compare.
- * @param- {Object} [stackA=[]] Internally used track traversed `a` objects.
- * @param- {Object} [stackB=[]] Internally used track traversed `b` objects.
- * @returns {Boolean} Returns `true` if the values are equvalent, else `false`.
- * @example
- *
- * var moe = { 'name': 'moe', 'luckyNumbers': [13, 27, 34] };
- * var clone = { 'name': 'moe', 'luckyNumbers': [13, 27, 34] };
- *
- * moe == clone;
- * // => false
- *
- * _.isEqual(moe, clone);
- * // => true
- */
- function isEqual(a, b, stackA, stackB) {
- // exit early for identical values
- if (a === b) {
- // treat `+0` vs. `-0` as not equal
- return a !== 0 || (1 / a == 1 / b);
- }
- // a strict comparison is necessary because `null == undefined`
- if (a == null || b == null) {
- return a === b;
- }
- // compare [[Class]] names
- var className = toString.call(a);
- if (className != toString.call(b)) {
- return false;
- }
- switch (className) {
- case boolClass:
- case dateClass:
- // coerce dates and booleans to numbers, dates to milliseconds and booleans
- // to `1` or `0`, treating invalid dates coerced to `NaN` as not equal
- return +a == +b;
-
- case numberClass:
- // treat `NaN` vs. `NaN` as equal
- return a != +a
- ? b != +b
- // but treat `+0` vs. `-0` as not equal
- : (a == 0 ? (1 / a == 1 / b) : a == +b);
-
- case regexpClass:
- case stringClass:
- // coerce regexes to strings (http://es5.github.com/#x15.10.6.4)
- // treat string primitives and their corresponding object instances as equal
- return a == b + '';
- }
- // exit early, in older browsers, if `a` is array-like but not `b`
- var isArr = className == arrayClass || className == argsClass;
- if (noArgsClass && !isArr && (isArr = isArguments(a)) && !isArguments(b)) {
- return false;
- }
- if (!isArr) {
- // unwrap any `lodash` wrapped values
- if (a.__wrapped__ || b.__wrapped__) {
- return isEqual(a.__wrapped__ || a, b.__wrapped__ || b);
- }
- // exit for functions and DOM nodes
- if (className != objectClass || (noNodeClass && (
- (typeof a.toString != 'function' && typeof (a + '') == 'string') ||
- (typeof b.toString != 'function' && typeof (b + '') == 'string')))) {
- return false;
- }
- var ctorA = a.constructor,
- ctorB = b.constructor;
-
- // non `Object` object instances with different constructors are not equal
- if (ctorA != ctorB && !(
- isFunction(ctorA) && ctorA instanceof ctorA &&
- isFunction(ctorB) && ctorB instanceof ctorB
- )) {
- return false;
- }
- }
- // assume cyclic structures are equal
- // the algorithm for detecting cyclic structures is adapted from ES 5.1
- // section 15.12.3, abstract operation `JO` (http://es5.github.com/#x15.12.3)
- stackA || (stackA = []);
- stackB || (stackB = []);
-
- var length = stackA.length;
- while (length--) {
- if (stackA[length] == a) {
- return stackB[length] == b;
- }
- }
-
- var index = -1,
- result = true,
- size = 0;
-
- // add `a` and `b` to the stack of traversed objects
- stackA.push(a);
- stackB.push(b);
-
- // recursively compare objects and arrays (susceptible to call stack limits)
- if (isArr) {
- // compare lengths to determine if a deep comparison is necessary
- size = a.length;
- result = size == b.length;
-
- if (result) {
- // deep compare the contents, ignoring non-numeric properties
- while (size--) {
- if (!(result = isEqual(a[size], b[size], stackA, stackB))) {
- break;
- }
- }
- }
- return result;
- }
- // deep compare objects
- for (var key in a) {
- if (hasOwnProperty.call(a, key)) {
- // count the number of properties.
- size++;
- // deep compare each property value.
- if (!(hasOwnProperty.call(b, key) && isEqual(a[key], b[key], stackA, stackB))) {
- return false;
- }
- }
- }
- // ensure both objects have the same number of properties
- for (key in b) {
- // The JS engine in Adobe products, like InDesign, has a bug that causes
- // `!size--` to throw an error so it must be wrapped in parentheses.
- // https://github.com/documentcloud/underscore/issues/355
- if (hasOwnProperty.call(b, key) && !(size--)) {
- // `size` will be `-1` if `b` has more properties than `a`
- return false;
- }
- }
- // handle JScript [[DontEnum]] bug
- if (hasDontEnumBug) {
- while (++index < 7) {
- key = shadowed[index];
- if (hasOwnProperty.call(a, key) &&
- !(hasOwnProperty.call(b, key) && isEqual(a[key], b[key], stackA, stackB))) {
- return false;
- }
- }
- }
- return true;
- }
-
- /**
- * Checks if `value` is, or can be coerced to, a finite number.
- *
- * Note: This is not the same as native `isFinite`, which will return true for
- * booleans and empty strings. See http://es5.github.com/#x15.1.2.5.
- *
- * @deprecated
- * @static
- * @memberOf _
- * @category Objects
- * @param {Mixed} value The value to check.
- * @returns {Boolean} Returns `true` if the `value` is a finite number, else `false`.
- * @example
- *
- * _.isFinite(-101);
- * // => true
- *
- * _.isFinite('10');
- * // => true
- *
- * _.isFinite(true);
- * // => false
- *
- * _.isFinite('');
- * // => false
- *
- * _.isFinite(Infinity);
- * // => false
- */
- function isFinite(value) {
- return nativeIsFinite(value) && !nativeIsNaN(parseFloat(value));
- }
-
- /**
- * Checks if `value` is a function.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Mixed} value The value to check.
- * @returns {Boolean} Returns `true` if the `value` is a function, else `false`.
- * @example
- *
- * _.isFunction(_);
- * // => true
- */
- function isFunction(value) {
- return typeof value == 'function';
- }
- // fallback for older versions of Chrome and Safari
- if (isFunction(/x/)) {
- isFunction = function(value) {
- return toString.call(value) == funcClass;
- };
- }
-
- /**
- * Checks if `value` is the language type of Object.
- * (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Mixed} value The value to check.
- * @returns {Boolean} Returns `true` if the `value` is an object, else `false`.
- * @example
- *
- * _.isObject({});
- * // => true
- *
- * _.isObject([1, 2, 3]);
- * // => true
- *
- * _.isObject(1);
- * // => false
- */
- function isObject(value) {
- // check if the value is the ECMAScript language type of Object
- // http://es5.github.com/#x8
- // and avoid a V8 bug
- // http://code.google.com/p/v8/issues/detail?id=2291
- return value ? objectTypes[typeof value] : false;
- }
-
- /**
- * Checks if `value` is `NaN`.
- *
- * Note: This is not the same as native `isNaN`, which will return true for
- * `undefined` and other values. See http://es5.github.com/#x15.1.2.4.
- *
- * @deprecated
- * @static
- * @memberOf _
- * @category Objects
- * @param {Mixed} value The value to check.
- * @returns {Boolean} Returns `true` if the `value` is `NaN`, else `false`.
- * @example
- *
- * _.isNaN(NaN);
- * // => true
- *
- * _.isNaN(new Number(NaN));
- * // => true
- *
- * isNaN(undefined);
- * // => true
- *
- * _.isNaN(undefined);
- * // => false
- */
- function isNaN(value) {
- // `NaN` as a primitive is the only value that is not equal to itself
- // (perform the [[Class]] check first to avoid errors with some host objects in IE)
- return toString.call(value) == numberClass && value != +value
- }
-
- /**
- * Checks if `value` is `null`.
- *
- * @deprecated
- * @static
- * @memberOf _
- * @category Objects
- * @param {Mixed} value The value to check.
- * @returns {Boolean} Returns `true` if the `value` is `null`, else `false`.
- * @example
- *
- * _.isNull(null);
- * // => true
- *
- * _.isNull(undefined);
- * // => false
- */
- function isNull(value) {
- return value === null;
- }
-
- /**
- * Checks if `value` is a number.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Mixed} value The value to check.
- * @returns {Boolean} Returns `true` if the `value` is a number, else `false`.
- * @example
- *
- * _.isNumber(8.4 * 5);
- * // => true
- */
- function isNumber(value) {
- return toString.call(value) == numberClass;
- }
-
- /**
- * Checks if a given `value` is an object created by the `Object` constructor.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Mixed} value The value to check.
- * @returns {Boolean} Returns `true` if `value` is a plain object, else `false`.
- * @example
- *
- * function Stooge(name, age) {
- * this.name = name;
- * this.age = age;
- * }
- *
- * _.isPlainObject(new Stooge('moe', 40));
- * // => false
- *
- * _.isPlainObject([1, 2, 3]);
- * // => false
- *
- * _.isPlainObject({ 'name': 'moe', 'age': 40 });
- * // => true
- */
- var isPlainObject = !getPrototypeOf ? shimIsPlainObject : function(value) {
- if (!(value && typeof value == 'object')) {
- return false;
- }
- var valueOf = value.valueOf,
- objProto = typeof valueOf == 'function' && (objProto = getPrototypeOf(valueOf)) && getPrototypeOf(objProto);
-
- return objProto
- ? value == objProto || (getPrototypeOf(value) == objProto && !isArguments(value))
- : shimIsPlainObject(value);
- };
-
- /**
- * Checks if `value` is a regular expression.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Mixed} value The value to check.
- * @returns {Boolean} Returns `true` if the `value` is a regular expression, else `false`.
- * @example
- *
- * _.isRegExp(/moe/);
- * // => true
- */
- function isRegExp(value) {
- return toString.call(value) == regexpClass;
- }
-
- /**
- * Checks if `value` is a string.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Mixed} value The value to check.
- * @returns {Boolean} Returns `true` if the `value` is a string, else `false`.
- * @example
- *
- * _.isString('moe');
- * // => true
- */
- function isString(value) {
- return toString.call(value) == stringClass;
- }
-
- /**
- * Checks if `value` is `undefined`.
- *
- * @deprecated
- * @static
- * @memberOf _
- * @category Objects
- * @param {Mixed} value The value to check.
- * @returns {Boolean} Returns `true` if the `value` is `undefined`, else `false`.
- * @example
- *
- * _.isUndefined(void 0);
- * // => true
- */
- function isUndefined(value) {
- return value === undefined;
- }
-
- /**
- * Creates an array composed of the own enumerable property names of `object`.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Object} object The object to inspect.
- * @returns {Array} Returns a new array of property names.
- * @example
- *
- * _.keys({ 'one': 1, 'two': 2, 'three': 3 });
- * // => ['one', 'two', 'three'] (order is not guaranteed)
- */
- var keys = !nativeKeys ? shimKeys : function(object) {
- // avoid iterating over the `prototype` property
- return typeof object == 'function' && propertyIsEnumerable.call(object, 'prototype')
- ? shimKeys(object)
- : (isObject(object) ? nativeKeys(object) : []);
- };
-
- /**
- * Merges enumerable properties of the source object(s) into the `destination`
- * object. Subsequent sources will overwrite propery assignments of previous
- * sources.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Object} object The destination object.
- * @param {Object} [source1, source2, ...] The source objects.
- * @param- {Object} [indicator] Internally used to indicate that the `stack`
- * argument is an array of traversed objects instead of another source object.
- * @param- {Array} [stackA=[]] Internally used to track traversed source objects.
- * @param- {Array} [stackB=[]] Internally used to associate values with their
- * source counterparts.
- * @returns {Object} Returns the destination object.
- * @example
- *
- * var stooges = [
- * { 'name': 'moe' },
- * { 'name': 'larry' }
- * ];
- *
- * var ages = [
- * { 'age': 40 },
- * { 'age': 50 }
- * ];
- *
- * _.merge(stooges, ages);
- * // => [{ 'name': 'moe', 'age': 40 }, { 'name': 'larry', 'age': 50 }]
- */
- function merge(object, source, indicator) {
- var args = arguments,
- index = 0,
- length = 2,
- stackA = args[3],
- stackB = args[4];
-
- if (indicator !== indicatorObject) {
- stackA = [];
- stackB = [];
-
- // work with `_.reduce` by only using its callback `accumulator` and `value` arguments
- if (typeof indicator != 'number') {
- length = args.length;
- }
- }
- while (++index < length) {
- forOwn(args[index], function(source, key) {
- var found, isArr, value;
- if (source && ((isArr = isArray(source)) || isPlainObject(source))) {
- // avoid merging previously merged cyclic sources
- var stackLength = stackA.length;
- while (stackLength--) {
- found = stackA[stackLength] == source;
- if (found) {
- break;
- }
- }
- if (found) {
- object[key] = stackB[stackLength];
- }
- else {
- // add `source` and associated `value` to the stack of traversed objects
- stackA.push(source);
- stackB.push(value = (value = object[key], isArr)
- ? (isArray(value) ? value : [])
- : (isPlainObject(value) ? value : {})
- );
- // recursively merge objects and arrays (susceptible to call stack limits)
- object[key] = merge(value, source, indicatorObject, stackA, stackB);
- }
- } else if (source != null) {
- object[key] = source;
- }
- });
- }
- return object;
- }
-
- /**
- * Creates a shallow clone of `object` excluding the specified properties.
- * Property names may be specified as individual arguments or as arrays of
- * property names. If `callback` is passed, it will be executed for each property
- * in the `object`, omitting the properties `callback` returns truthy for. The
- * `callback` is bound to `thisArg` and invoked with three arguments; (value, key, object).
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Object} object The source object.
- * @param {Function|String} callback|[prop1, prop2, ...] The properties to omit
- * or the function called per iteration.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Object} Returns an object without the omitted properties.
- * @example
- *
- * _.omit({ 'name': 'moe', 'age': 40, 'userid': 'moe1' }, 'userid');
- * // => { 'name': 'moe', 'age': 40 }
- *
- * _.omit({ 'name': 'moe', '_hint': 'knucklehead', '_seed': '96c4eb' }, function(value, key) {
- * return key.charAt(0) == '_';
- * });
- * // => { 'name': 'moe' }
- */
- function omit(object, callback, thisArg) {
- var isFunc = typeof callback == 'function',
- result = {};
-
- if (isFunc) {
- callback = createCallback(callback, thisArg);
- } else {
- var props = concat.apply(arrayRef, arguments);
- }
- forIn(object, function(value, key, object) {
- if (isFunc
- ? !callback(value, key, object)
- : indexOf(props, key, 1) < 0
- ) {
- result[key] = value;
- }
- });
- return result;
- }
-
- /**
- * Creates a two dimensional array of the given object's key-value pairs,
- * i.e. `[[key1, value1], [key2, value2]]`.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Object} object The object to inspect.
- * @returns {Array} Returns new array of key-value pairs.
- * @example
- *
- * _.pairs({ 'moe': 30, 'larry': 40, 'curly': 50 });
- * // => [['moe', 30], ['larry', 40], ['curly', 50]] (order is not guaranteed)
- */
- function pairs(object) {
- var result = [];
- forOwn(object, function(value, key) {
- result.push([key, value]);
- });
- return result;
- }
-
- /**
- * Creates a shallow clone of `object` composed of the specified properties.
- * Property names may be specified as individual arguments or as arrays of
- * property names. If `callback` is passed, it will be executed for each property
- * in the `object`, picking the properties `callback` returns truthy for. The
- * `callback` is bound to `thisArg` and invoked with three arguments; (value, key, object).
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Object} object The source object.
- * @param {Function|String} callback|[prop1, prop2, ...] The properties to pick
- * or the function called per iteration.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Object} Returns an object composed of the picked properties.
- * @example
- *
- * _.pick({ 'name': 'moe', 'age': 40, 'userid': 'moe1' }, 'name', 'age');
- * // => { 'name': 'moe', 'age': 40 }
- *
- * _.pick({ 'name': 'moe', '_hint': 'knucklehead', '_seed': '96c4eb' }, function(value, key) {
- * return key.charAt(0) != '_';
- * });
- * // => { 'name': 'moe' }
- */
- function pick(object, callback, thisArg) {
- var result = {};
- if (typeof callback != 'function') {
- var index = 0,
- props = concat.apply(arrayRef, arguments),
- length = props.length;
-
- while (++index < length) {
- var key = props[index];
- if (key in object) {
- result[key] = object[key];
- }
- }
- } else {
- callback = createCallback(callback, thisArg);
- forIn(object, function(value, key, object) {
- if (callback(value, key, object)) {
- result[key] = value;
- }
- });
- }
- return result;
- }
-
- /**
- * Creates an array composed of the own enumerable property values of `object`.
- *
- * @static
- * @memberOf _
- * @category Objects
- * @param {Object} object The object to inspect.
- * @returns {Array} Returns a new array of property values.
- * @example
- *
- * _.values({ 'one': 1, 'two': 2, 'three': 3 });
- * // => [1, 2, 3]
- */
- function values(object) {
- var result = [];
- forOwn(object, function(value) {
- result.push(value);
- });
- return result;
- }
-
- /*--------------------------------------------------------------------------*/
-
- /**
- * Checks if a given `target` element is present in a `collection` using strict
- * equality for comparisons, i.e. `===`. If `fromIndex` is negative, it is used
- * as the offset from the end of the collection.
- *
- * @static
- * @memberOf _
- * @alias include
- * @category Collections
- * @param {Array|Object|String} collection The collection to iterate over.
- * @param {Mixed} target The value to check for.
- * @param {Number} [fromIndex=0] The index to search from.
- * @returns {Boolean} Returns `true` if the `target` element is found, else `false`.
- * @example
- *
- * _.contains([1, 2, 3], 1);
- * // => true
- *
- * _.contains([1, 2, 3], 1, 2);
- * // => false
- *
- * _.contains({ 'name': 'moe', 'age': 40 }, 'moe');
- * // => true
- *
- * _.contains('curly', 'ur');
- * // => true
- */
- function contains(collection, target, fromIndex) {
- var index = -1,
- length = collection ? collection.length : 0,
- result = false;
-
- fromIndex = (fromIndex < 0 ? nativeMax(0, length + fromIndex) : fromIndex) || 0;
- if (typeof length == 'number') {
- result = (isString(collection)
- ? collection.indexOf(target, fromIndex)
- : indexOf(collection, target, fromIndex)
- ) > -1;
- } else {
- forEach(collection, function(value) {
- if (++index >= fromIndex) {
- return !(result = value === target);
- }
- });
- }
- return result;
- }
-
- /**
- * Creates an object composed of keys returned from running each element of
- * `collection` through a `callback`. The corresponding value of each key is
- * the number of times the key was returned by `callback`. The `callback` is
- * bound to `thisArg` and invoked with three arguments; (value, index|key, collection).
- * The `callback` argument may also be the name of a property to count by (e.g. 'length').
- *
- * @static
- * @memberOf _
- * @category Collections
- * @param {Array|Object|String} collection The collection to iterate over.
- * @param {Function|String} callback|property The function called per iteration
- * or property name to count by.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Object} Returns the composed aggregate object.
- * @example
- *
- * _.countBy([4.3, 6.1, 6.4], function(num) { return Math.floor(num); });
- * // => { '4': 1, '6': 2 }
- *
- * _.countBy([4.3, 6.1, 6.4], function(num) { return this.floor(num); }, Math);
- * // => { '4': 1, '6': 2 }
- *
- * _.countBy(['one', 'two', 'three'], 'length');
- * // => { '3': 2, '5': 1 }
- */
- function countBy(collection, callback, thisArg) {
- var result = {};
- callback = createCallback(callback, thisArg);
- forEach(collection, function(value, key, collection) {
- key = callback(value, key, collection);
- (hasOwnProperty.call(result, key) ? result[key]++ : result[key] = 1);
- });
- return result;
- }
-
- /**
- * Checks if the `callback` returns a truthy value for **all** elements of a
- * `collection`. The `callback` is bound to `thisArg` and invoked with three
- * arguments; (value, index|key, collection).
- *
- * @static
- * @memberOf _
- * @alias all
- * @category Collections
- * @param {Array|Object|String} collection The collection to iterate over.
- * @param {Function} [callback=identity] The function called per iteration.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Boolean} Returns `true` if all elements pass the callback check,
- * else `false`.
- * @example
- *
- * _.every([true, 1, null, 'yes'], Boolean);
- * // => false
- */
- function every(collection, callback, thisArg) {
- var result = true;
- callback = createCallback(callback, thisArg);
-
- if (isArray(collection)) {
- var index = -1,
- length = collection.length;
-
- while (++index < length) {
- if (!(result = !!callback(collection[index], index, collection))) {
- break;
- }
- }
- } else {
- forEach(collection, function(value, index, collection) {
- return (result = !!callback(value, index, collection));
- });
- }
- return result;
- }
-
- /**
- * Examines each element in a `collection`, returning an array of all elements
- * the `callback` returns truthy for. The `callback` is bound to `thisArg` and
- * invoked with three arguments; (value, index|key, collection).
- *
- * @static
- * @memberOf _
- * @alias select
- * @category Collections
- * @param {Array|Object|String} collection The collection to iterate over.
- * @param {Function} [callback=identity] The function called per iteration.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Array} Returns a new array of elements that passed the callback check.
- * @example
- *
- * var evens = _.filter([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; });
- * // => [2, 4, 6]
- */
- function filter(collection, callback, thisArg) {
- var result = [];
- callback = createCallback(callback, thisArg);
-
- if (isArray(collection)) {
- var index = -1,
- length = collection.length;
-
- while (++index < length) {
- var value = collection[index];
- if (callback(value, index, collection)) {
- result.push(value);
- }
- }
- } else {
- forEach(collection, function(value, index, collection) {
- if (callback(value, index, collection)) {
- result.push(value);
- }
- });
- }
- return result;
- }
-
- /**
- * Examines each element in a `collection`, returning the first one the `callback`
- * returns truthy for. The function returns as soon as it finds an acceptable
- * element, and does not iterate over the entire `collection`. The `callback` is
- * bound to `thisArg` and invoked with three arguments; (value, index|key, collection).
- *
- * @static
- * @memberOf _
- * @alias detect
- * @category Collections
- * @param {Array|Object|String} collection The collection to iterate over.
- * @param {Function} callback The function called per iteration.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Mixed} Returns the element that passed the callback check,
- * else `undefined`.
- * @example
- *
- * var even = _.find([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; });
- * // => 2
- */
- function find(collection, callback, thisArg) {
- var result;
- callback = createCallback(callback, thisArg);
- forEach(collection, function(value, index, collection) {
- if (callback(value, index, collection)) {
- result = value;
- return false;
- }
- });
- return result;
- }
-
- /**
- * Iterates over a `collection`, executing the `callback` for each element in
- * the `collection`. The `callback` is bound to `thisArg` and invoked with three
- * arguments; (value, index|key, collection). Callbacks may exit iteration early
- * by explicitly returning `false`.
- *
- * @static
- * @memberOf _
- * @alias each
- * @category Collections
- * @param {Array|Object|String} collection The collection to iterate over.
- * @param {Function} callback The function called per iteration.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Array|Object|String} Returns `collection`.
- * @example
- *
- * _([1, 2, 3]).forEach(alert).join(',');
- * // => alerts each number and returns '1,2,3'
- *
- * _.forEach({ 'one': 1, 'two': 2, 'three': 3 }, alert);
- * // => alerts each number (order is not guaranteed)
- */
- var forEach = createIterator(forEachIteratorOptions);
-
- /**
- * Creates an object composed of keys returned from running each element of
- * `collection` through a `callback`. The corresponding value of each key is an
- * array of elements passed to `callback` that returned the key. The `callback`
- * is bound to `thisArg` and invoked with three arguments; (value, index|key, collection).
- * The `callback` argument may also be the name of a property to group by (e.g. 'length').
- *
- * @static
- * @memberOf _
- * @category Collections
- * @param {Array|Object|String} collection The collection to iterate over.
- * @param {Function|String} callback|property The function called per iteration
- * or property name to group by.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Object} Returns the composed aggregate object.
- * @example
- *
- * _.groupBy([4.2, 6.1, 6.4], function(num) { return Math.floor(num); });
- * // => { '4': [4.2], '6': [6.1, 6.4] }
- *
- * _.groupBy([4.2, 6.1, 6.4], function(num) { return this.floor(num); }, Math);
- * // => { '4': [4.2], '6': [6.1, 6.4] }
- *
- * _.groupBy(['one', 'two', 'three'], 'length');
- * // => { '3': ['one', 'two'], '5': ['three'] }
- */
- function groupBy(collection, callback, thisArg) {
- var result = {};
- callback = createCallback(callback, thisArg);
- forEach(collection, function(value, key, collection) {
- key = callback(value, key, collection);
- (hasOwnProperty.call(result, key) ? result[key] : result[key] = []).push(value);
- });
- return result;
- }
-
- /**
- * Invokes the method named by `methodName` on each element in the `collection`,
- * returning an array of the results of each invoked method. Additional arguments
- * will be passed to each invoked method. If `methodName` is a function it will
- * be invoked for, and `this` bound to, each element in the `collection`.
- *
- * @static
- * @memberOf _
- * @category Collections
- * @param {Array|Object|String} collection The collection to iterate over.
- * @param {Function|String} methodName The name of the method to invoke or
- * the function invoked per iteration.
- * @param {Mixed} [arg1, arg2, ...] Arguments to invoke the method with.
- * @returns {Array} Returns a new array of the results of each invoked method.
- * @example
- *
- * _.invoke([[5, 1, 7], [3, 2, 1]], 'sort');
- * // => [[1, 5, 7], [1, 2, 3]]
- *
- * _.invoke([123, 456], String.prototype.split, '');
- * // => [['1', '2', '3'], ['4', '5', '6']]
- */
- function invoke(collection, methodName) {
- var args = slice.call(arguments, 2),
- isFunc = typeof methodName == 'function',
- result = [];
-
- forEach(collection, function(value) {
- result.push((isFunc ? methodName : value[methodName]).apply(value, args));
- });
- return result;
- }
-
- /**
- * Creates an array of values by running each element in the `collection`
- * through a `callback`. The `callback` is bound to `thisArg` and invoked with
- * three arguments; (value, index|key, collection).
- *
- * @static
- * @memberOf _
- * @alias collect
- * @category Collections
- * @param {Array|Object|String} collection The collection to iterate over.
- * @param {Function} [callback=identity] The function called per iteration.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Array} Returns a new array of the results of each `callback` execution.
- * @example
- *
- * _.map([1, 2, 3], function(num) { return num * 3; });
- * // => [3, 6, 9]
- *
- * _.map({ 'one': 1, 'two': 2, 'three': 3 }, function(num) { return num * 3; });
- * // => [3, 6, 9] (order is not guaranteed)
- */
- function map(collection, callback, thisArg) {
- var index = -1,
- length = collection ? collection.length : 0,
- result = Array(typeof length == 'number' ? length : 0);
-
- callback = createCallback(callback, thisArg);
- if (isArray(collection)) {
- while (++index < length) {
- result[index] = callback(collection[index], index, collection);
- }
- } else {
- forEach(collection, function(value, key, collection) {
- result[++index] = callback(value, key, collection);
- });
- }
- return result;
- }
-
- /**
- * Retrieves the maximum value of an `array`. If `callback` is passed,
- * it will be executed for each value in the `array` to generate the
- * criterion by which the value is ranked. The `callback` is bound to
- * `thisArg` and invoked with three arguments; (value, index, collection).
- *
- * @static
- * @memberOf _
- * @category Collections
- * @param {Array|Object|String} collection The collection to iterate over.
- * @param {Function} [callback] The function called per iteration.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Mixed} Returns the maximum value.
- * @example
- *
- * var stooges = [
- * { 'name': 'moe', 'age': 40 },
- * { 'name': 'larry', 'age': 50 },
- * { 'name': 'curly', 'age': 60 }
- * ];
- *
- * _.max(stooges, function(stooge) { return stooge.age; });
- * // => { 'name': 'curly', 'age': 60 };
- */
- function max(collection, callback, thisArg) {
- var computed = -Infinity,
- index = -1,
- length = collection ? collection.length : 0,
- result = computed;
-
- if (callback || !isArray(collection)) {
- callback = !callback && isString(collection)
- ? charAtCallback
- : createCallback(callback, thisArg);
-
- forEach(collection, function(value, index, collection) {
- var current = callback(value, index, collection);
- if (current > computed) {
- computed = current;
- result = value;
- }
- });
- } else {
- while (++index < length) {
- if (collection[index] > result) {
- result = collection[index];
- }
- }
- }
- return result;
- }
-
- /**
- * Retrieves the minimum value of an `array`. If `callback` is passed,
- * it will be executed for each value in the `array` to generate the
- * criterion by which the value is ranked. The `callback` is bound to `thisArg`
- * and invoked with three arguments; (value, index, collection).
- *
- * @static
- * @memberOf _
- * @category Collections
- * @param {Array|Object|String} collection The collection to iterate over.
- * @param {Function} [callback] The function called per iteration.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Mixed} Returns the minimum value.
- * @example
- *
- * _.min([10, 5, 100, 2, 1000]);
- * // => 2
- */
- function min(collection, callback, thisArg) {
- var computed = Infinity,
- index = -1,
- length = collection ? collection.length : 0,
- result = computed;
-
- if (callback || !isArray(collection)) {
- callback = !callback && isString(collection)
- ? charAtCallback
- : createCallback(callback, thisArg);
-
- forEach(collection, function(value, index, collection) {
- var current = callback(value, index, collection);
- if (current < computed) {
- computed = current;
- result = value;
- }
- });
- } else {
- while (++index < length) {
- if (collection[index] < result) {
- result = collection[index];
- }
- }
- }
- return result;
- }
-
- /**
- * Retrieves the value of a specified property from all elements in
- * the `collection`.
- *
- * @static
- * @memberOf _
- * @category Collections
- * @param {Array|Object|String} collection The collection to iterate over.
- * @param {String} property The property to pluck.
- * @returns {Array} Returns a new array of property values.
- * @example
- *
- * var stooges = [
- * { 'name': 'moe', 'age': 40 },
- * { 'name': 'larry', 'age': 50 },
- * { 'name': 'curly', 'age': 60 }
- * ];
- *
- * _.pluck(stooges, 'name');
- * // => ['moe', 'larry', 'curly']
- */
- function pluck(collection, property) {
- var result = [];
- forEach(collection, function(value) {
- result.push(value[property]);
- });
- return result;
- }
-
- /**
- * Boils down a `collection` to a single value. The initial state of the
- * reduction is `accumulator` and each successive step of it should be returned
- * by the `callback`. The `callback` is bound to `thisArg` and invoked with 4
- * arguments; for arrays they are (accumulator, value, index|key, collection).
- *
- * @static
- * @memberOf _
- * @alias foldl, inject
- * @category Collections
- * @param {Array|Object|String} collection The collection to iterate over.
- * @param {Function} callback The function called per iteration.
- * @param {Mixed} [accumulator] Initial value of the accumulator.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Mixed} Returns the accumulated value.
- * @example
- *
- * var sum = _.reduce([1, 2, 3], function(memo, num) { return memo + num; });
- * // => 6
- */
- function reduce(collection, callback, accumulator, thisArg) {
- var noaccum = arguments.length < 3;
- callback = createCallback(callback, thisArg);
- forEach(collection, function(value, index, collection) {
- accumulator = noaccum
- ? (noaccum = false, value)
- : callback(accumulator, value, index, collection)
- });
- return accumulator;
- }
-
- /**
- * The right-associative version of `_.reduce`.
- *
- * @static
- * @memberOf _
- * @alias foldr
- * @category Collections
- * @param {Array|Object|String} collection The collection to iterate over.
- * @param {Function} callback The function called per iteration.
- * @param {Mixed} [accumulator] Initial value of the accumulator.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Mixed} Returns the accumulated value.
- * @example
- *
- * var list = [[0, 1], [2, 3], [4, 5]];
- * var flat = _.reduceRight(list, function(a, b) { return a.concat(b); }, []);
- * // => [4, 5, 2, 3, 0, 1]
- */
- function reduceRight(collection, callback, accumulator, thisArg) {
- var iteratee = collection,
- length = collection ? collection.length : 0,
- noaccum = arguments.length < 3;
-
- if (typeof length != 'number') {
- var props = keys(collection);
- length = props.length;
- } else if (noCharByIndex && isString(collection)) {
- iteratee = collection.split('');
- }
- forEach(collection, function(value, index, collection) {
- index = props ? props[--length] : --length;
- accumulator = noaccum
- ? (noaccum = false, iteratee[index])
- : callback.call(thisArg, accumulator, iteratee[index], index, collection);
- });
- return accumulator;
- }
-
- /**
- * The opposite of `_.filter`, this method returns the values of a
- * `collection` that `callback` does **not** return truthy for.
- *
- * @static
- * @memberOf _
- * @category Collections
- * @param {Array|Object|String} collection The collection to iterate over.
- * @param {Function} [callback=identity] The function called per iteration.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Array} Returns a new array of elements that did **not** pass the
- * callback check.
- * @example
- *
- * var odds = _.reject([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; });
- * // => [1, 3, 5]
- */
- function reject(collection, callback, thisArg) {
- callback = createCallback(callback, thisArg);
- return filter(collection, function(value, index, collection) {
- return !callback(value, index, collection);
- });
- }
-
- /**
- * Creates an array of shuffled `array` values, using a version of the
- * Fisher-Yates shuffle. See http://en.wikipedia.org/wiki/Fisher-Yates_shuffle.
- *
- * @static
- * @memberOf _
- * @category Collections
- * @param {Array|Object|String} collection The collection to shuffle.
- * @returns {Array} Returns a new shuffled collection.
- * @example
- *
- * _.shuffle([1, 2, 3, 4, 5, 6]);
- * // => [4, 1, 6, 3, 5, 2]
- */
- function shuffle(collection) {
- var index = -1,
- result = Array(collection ? collection.length : 0);
-
- forEach(collection, function(value) {
- var rand = floor(nativeRandom() * (++index + 1));
- result[index] = result[rand];
- result[rand] = value;
- });
- return result;
- }
-
- /**
- * Gets the size of the `collection` by returning `collection.length` for arrays
- * and array-like objects or the number of own enumerable properties for objects.
- *
- * @static
- * @memberOf _
- * @category Collections
- * @param {Array|Object|String} collection The collection to inspect.
- * @returns {Number} Returns `collection.length` or number of own enumerable properties.
- * @example
- *
- * _.size([1, 2]);
- * // => 2
- *
- * _.size({ 'one': 1, 'two': 2, 'three': 3 });
- * // => 3
- *
- * _.size('curly');
- * // => 5
- */
- function size(collection) {
- var length = collection ? collection.length : 0;
- return typeof length == 'number' ? length : keys(collection).length;
- }
-
- /**
- * Checks if the `callback` returns a truthy value for **any** element of a
- * `collection`. The function returns as soon as it finds passing value, and
- * does not iterate over the entire `collection`. The `callback` is bound to
- * `thisArg` and invoked with three arguments; (value, index|key, collection).
- *
- * @static
- * @memberOf _
- * @alias any
- * @category Collections
- * @param {Array|Object|String} collection The collection to iterate over.
- * @param {Function} [callback=identity] The function called per iteration.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Boolean} Returns `true` if any element passes the callback check,
- * else `false`.
- * @example
- *
- * _.some([null, 0, 'yes', false], Boolean);
- * // => true
- */
- function some(collection, callback, thisArg) {
- var result;
- callback = createCallback(callback, thisArg);
-
- if (isArray(collection)) {
- var index = -1,
- length = collection.length;
-
- while (++index < length) {
- if ((result = callback(collection[index], index, collection))) {
- break;
- }
- }
- } else {
- forEach(collection, function(value, index, collection) {
- return !(result = callback(value, index, collection));
- });
- }
- return !!result;
- }
-
- /**
- * Creates an array, stable sorted in ascending order by the results of
- * running each element of `collection` through a `callback`. The `callback`
- * is bound to `thisArg` and invoked with three arguments; (value, index|key, collection).
- * The `callback` argument may also be the name of a property to sort by (e.g. 'length').
- *
- * @static
- * @memberOf _
- * @category Collections
- * @param {Array|Object|String} collection The collection to iterate over.
- * @param {Function|String} callback|property The function called per iteration
- * or property name to sort by.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Array} Returns a new array of sorted elements.
- * @example
- *
- * _.sortBy([1, 2, 3], function(num) { return Math.sin(num); });
- * // => [3, 1, 2]
- *
- * _.sortBy([1, 2, 3], function(num) { return this.sin(num); }, Math);
- * // => [3, 1, 2]
- *
- * _.sortBy(['larry', 'brendan', 'moe'], 'length');
- * // => ['moe', 'larry', 'brendan']
- */
- function sortBy(collection, callback, thisArg) {
- var result = [];
- callback = createCallback(callback, thisArg);
- forEach(collection, function(value, index, collection) {
- result.push({
- 'criteria': callback(value, index, collection),
- 'index': index,
- 'value': value
- });
- });
-
- var length = result.length;
- result.sort(compareAscending);
- while (length--) {
- result[length] = result[length].value;
- }
- return result;
- }
-
- /**
- * Converts the `collection`, to an array.
- *
- * @static
- * @memberOf _
- * @category Collections
- * @param {Array|Object|String} collection The collection to convert.
- * @returns {Array} Returns the new converted array.
- * @example
- *
- * (function() { return _.toArray(arguments).slice(1); })(1, 2, 3, 4);
- * // => [2, 3, 4]
- */
- function toArray(collection) {
- if (collection && typeof collection.length == 'number') {
- return (noArraySliceOnStrings ? isString(collection) : typeof collection == 'string')
- ? collection.split('')
- : slice.call(collection);
- }
- return values(collection);
- }
-
- /**
- * Examines each element in a `collection`, returning an array of all elements
- * that contain the given `properties`.
- *
- * @static
- * @memberOf _
- * @category Collections
- * @param {Array|Object|String} collection The collection to iterate over.
- * @param {Object} properties The object of property values to filter by.
- * @returns {Array} Returns a new array of elements that contain the given `properties`.
- * @example
- *
- * var stooges = [
- * { 'name': 'moe', 'age': 40 },
- * { 'name': 'larry', 'age': 50 },
- * { 'name': 'curly', 'age': 60 }
- * ];
- *
- * _.where(stooges, { 'age': 40 });
- * // => [{ 'name': 'moe', 'age': 40 }]
- */
- function where(collection, properties) {
- var props = keys(properties);
- return filter(collection, function(object) {
- var length = props.length;
- while (length--) {
- var result = object[props[length]] === properties[props[length]];
- if (!result) {
- break;
- }
- }
- return !!result;
- });
- }
-
- /*--------------------------------------------------------------------------*/
-
- /**
- * Creates an array with all falsey values of `array` removed. The values
- * `false`, `null`, `0`, `""`, `undefined` and `NaN` are all falsey.
- *
- * @static
- * @memberOf _
- * @category Arrays
- * @param {Array} array The array to compact.
- * @returns {Array} Returns a new filtered array.
- * @example
- *
- * _.compact([0, 1, false, 2, '', 3]);
- * // => [1, 2, 3]
- */
- function compact(array) {
- var index = -1,
- length = array ? array.length : 0,
- result = [];
-
- while (++index < length) {
- var value = array[index];
- if (value) {
- result.push(value);
- }
- }
- return result;
- }
-
- /**
- * Creates an array of `array` elements not present in the other arrays
- * using strict equality for comparisons, i.e. `===`.
- *
- * @static
- * @memberOf _
- * @category Arrays
- * @param {Array} array The array to process.
- * @param {Array} [array1, array2, ...] Arrays to check.
- * @returns {Array} Returns a new array of `array` elements not present in the
- * other arrays.
- * @example
- *
- * _.difference([1, 2, 3, 4, 5], [5, 2, 10]);
- * // => [1, 3, 4]
- */
- function difference(array) {
- var index = -1,
- length = array ? array.length : 0,
- flattened = concat.apply(arrayRef, arguments),
- contains = cachedContains(flattened, length),
- result = [];
-
- while (++index < length) {
- var value = array[index];
- if (!contains(value)) {
- result.push(value);
- }
- }
- return result;
- }
-
- /**
- * Gets the first element of the `array`. Pass `n` to return the first `n`
- * elements of the `array`.
- *
- * @static
- * @memberOf _
- * @alias head, take
- * @category Arrays
- * @param {Array} array The array to query.
- * @param {Number} [n] The number of elements to return.
- * @param- {Object} [guard] Internally used to allow this method to work with
- * others like `_.map` without using their callback `index` argument for `n`.
- * @returns {Mixed} Returns the first element or an array of the first `n`
- * elements of `array`.
- * @example
- *
- * _.first([5, 4, 3, 2, 1]);
- * // => 5
- */
- function first(array, n, guard) {
- if (array) {
- return (n == null || guard) ? array[0] : slice.call(array, 0, n);
- }
- }
-
- /**
- * Flattens a nested array (the nesting can be to any depth). If `shallow` is
- * truthy, `array` will only be flattened a single level.
- *
- * @static
- * @memberOf _
- * @category Arrays
- * @param {Array} array The array to compact.
- * @param {Boolean} shallow A flag to indicate only flattening a single level.
- * @returns {Array} Returns a new flattened array.
- * @example
- *
- * _.flatten([1, [2], [3, [[4]]]]);
- * // => [1, 2, 3, 4];
- *
- * _.flatten([1, [2], [3, [[4]]]], true);
- * // => [1, 2, 3, [[4]]];
- */
- function flatten(array, shallow) {
- var index = -1,
- length = array ? array.length : 0,
- result = [];
-
- while (++index < length) {
- var value = array[index];
-
- // recursively flatten arrays (susceptible to call stack limits)
- if (isArray(value)) {
- push.apply(result, shallow ? value : flatten(value));
- } else {
- result.push(value);
- }
- }
- return result;
- }
-
- /**
- * Gets the index at which the first occurrence of `value` is found using
- * strict equality for comparisons, i.e. `===`. If the `array` is already
- * sorted, passing `true` for `fromIndex` will run a faster binary search.
- *
- * @static
- * @memberOf _
- * @category Arrays
- * @param {Array} array The array to search.
- * @param {Mixed} value The value to search for.
- * @param {Boolean|Number} [fromIndex=0] The index to search from or `true` to
- * perform a binary search on a sorted `array`.
- * @returns {Number} Returns the index of the matched value or `-1`.
- * @example
- *
- * _.indexOf([1, 2, 3, 1, 2, 3], 2);
- * // => 1
- *
- * _.indexOf([1, 2, 3, 1, 2, 3], 2, 3);
- * // => 4
- *
- * _.indexOf([1, 1, 2, 2, 3, 3], 2, true);
- * // => 2
- */
- function indexOf(array, value, fromIndex) {
- var index = -1,
- length = array ? array.length : 0;
-
- if (typeof fromIndex == 'number') {
- index = (fromIndex < 0 ? nativeMax(0, length + fromIndex) : fromIndex || 0) - 1;
- } else if (fromIndex) {
- index = sortedIndex(array, value);
- return array[index] === value ? index : -1;
- }
- while (++index < length) {
- if (array[index] === value) {
- return index;
- }
- }
- return -1;
- }
-
- /**
- * Gets all but the last element of `array`. Pass `n` to exclude the last `n`
- * elements from the result.
- *
- * @static
- * @memberOf _
- * @category Arrays
- * @param {Array} array The array to query.
- * @param {Number} [n=1] The number of elements to exclude.
- * @param- {Object} [guard] Internally used to allow this method to work with
- * others like `_.map` without using their callback `index` argument for `n`.
- * @returns {Array} Returns all but the last element or `n` elements of `array`.
- * @example
- *
- * _.initial([3, 2, 1]);
- * // => [3, 2]
- */
- function initial(array, n, guard) {
- return array
- ? slice.call(array, 0, -((n == null || guard) ? 1 : n))
- : [];
- }
-
- /**
- * Computes the intersection of all the passed-in arrays using strict equality
- * for comparisons, i.e. `===`.
- *
- * @static
- * @memberOf _
- * @category Arrays
- * @param {Array} [array1, array2, ...] Arrays to process.
- * @returns {Array} Returns a new array of unique elements, in order, that are
- * present in **all** of the arrays.
- * @example
- *
- * _.intersection([1, 2, 3], [101, 2, 1, 10], [2, 1]);
- * // => [1, 2]
- */
- function intersection(array) {
- var args = arguments,
- argsLength = args.length,
- cache = {},
- result = [];
-
- forEach(array, function(value) {
- if (indexOf(result, value) < 0) {
- var length = argsLength;
- while (--length) {
- if (!(cache[length] || (cache[length] = cachedContains(args[length])))(value)) {
- return;
- }
- }
- result.push(value);
- }
- });
- return result;
- }
-
- /**
- * Gets the last element of the `array`. Pass `n` to return the last `n`
- * elements of the `array`.
- *
- * @static
- * @memberOf _
- * @category Arrays
- * @param {Array} array The array to query.
- * @param {Number} [n] The number of elements to return.
- * @param- {Object} [guard] Internally used to allow this method to work with
- * others like `_.map` without using their callback `index` argument for `n`.
- * @returns {Mixed} Returns the last element or an array of the last `n`
- * elements of `array`.
- * @example
- *
- * _.last([3, 2, 1]);
- * // => 1
- */
- function last(array, n, guard) {
- if (array) {
- var length = array.length;
- return (n == null || guard) ? array[length - 1] : slice.call(array, -n || length);
- }
- }
-
- /**
- * Gets the index at which the last occurrence of `value` is found using strict
- * equality for comparisons, i.e. `===`. If `fromIndex` is negative, it is used
- * as the offset from the end of the collection.
- *
- * @static
- * @memberOf _
- * @category Arrays
- * @param {Array} array The array to search.
- * @param {Mixed} value The value to search for.
- * @param {Number} [fromIndex=array.length-1] The index to search from.
- * @returns {Number} Returns the index of the matched value or `-1`.
- * @example
- *
- * _.lastIndexOf([1, 2, 3, 1, 2, 3], 2);
- * // => 4
- *
- * _.lastIndexOf([1, 2, 3, 1, 2, 3], 2, 3);
- * // => 1
- */
- function lastIndexOf(array, value, fromIndex) {
- var index = array ? array.length : 0;
- if (typeof fromIndex == 'number') {
- index = (fromIndex < 0 ? nativeMax(0, index + fromIndex) : nativeMin(fromIndex, index - 1)) + 1;
- }
- while (index--) {
- if (array[index] === value) {
- return index;
- }
- }
- return -1;
- }
-
- /**
- * Creates an object composed from arrays of `keys` and `values`. Pass either
- * a single two dimensional array, i.e. `[[key1, value1], [key2, value2]]`, or
- * two arrays, one of `keys` and one of corresponding `values`.
- *
- * @static
- * @memberOf _
- * @category Arrays
- * @param {Array} keys The array of keys.
- * @param {Array} [values=[]] The array of values.
- * @returns {Object} Returns an object composed of the given keys and
- * corresponding values.
- * @example
- *
- * _.object(['moe', 'larry', 'curly'], [30, 40, 50]);
- * // => { 'moe': 30, 'larry': 40, 'curly': 50 }
- */
- function object(keys, values) {
- var index = -1,
- length = keys ? keys.length : 0,
- result = {};
-
- while (++index < length) {
- var key = keys[index];
- if (values) {
- result[key] = values[index];
- } else {
- result[key[0]] = key[1];
- }
- }
- return result;
- }
-
- /**
- * Creates an array of numbers (positive and/or negative) progressing from
- * `start` up to but not including `stop`. This method is a port of Python's
- * `range()` function. See http://docs.python.org/library/functions.html#range.
- *
- * @static
- * @memberOf _
- * @category Arrays
- * @param {Number} [start=0] The start of the range.
- * @param {Number} end The end of the range.
- * @param {Number} [step=1] The value to increment or descrement by.
- * @returns {Array} Returns a new range array.
- * @example
- *
- * _.range(10);
- * // => [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
- *
- * _.range(1, 11);
- * // => [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
- *
- * _.range(0, 30, 5);
- * // => [0, 5, 10, 15, 20, 25]
- *
- * _.range(0, -10, -1);
- * // => [0, -1, -2, -3, -4, -5, -6, -7, -8, -9]
- *
- * _.range(0);
- * // => []
- */
- function range(start, end, step) {
- start = +start || 0;
- step = +step || 1;
-
- if (end == null) {
- end = start;
- start = 0;
- }
- // use `Array(length)` so V8 will avoid the slower "dictionary" mode
- // http://www.youtube.com/watch?v=XAqIpGU8ZZk#t=16m27s
- var index = -1,
- length = nativeMax(0, ceil((end - start) / step)),
- result = Array(length);
-
- while (++index < length) {
- result[index] = start;
- start += step;
- }
- return result;
- }
-
- /**
- * The opposite of `_.initial`, this method gets all but the first value of
- * `array`. Pass `n` to exclude the first `n` values from the result.
- *
- * @static
- * @memberOf _
- * @alias drop, tail
- * @category Arrays
- * @param {Array} array The array to query.
- * @param {Number} [n=1] The number of elements to exclude.
- * @param- {Object} [guard] Internally used to allow this method to work with
- * others like `_.map` without using their callback `index` argument for `n`.
- * @returns {Array} Returns all but the first value or `n` values of `array`.
- * @example
- *
- * _.rest([3, 2, 1]);
- * // => [2, 1]
- */
- function rest(array, n, guard) {
- return array
- ? slice.call(array, (n == null || guard) ? 1 : n)
- : [];
- }
-
- /**
- * Uses a binary search to determine the smallest index at which the `value`
- * should be inserted into `array` in order to maintain the sort order of the
- * sorted `array`. If `callback` is passed, it will be executed for `value` and
- * each element in `array` to compute their sort ranking. The `callback` is
- * bound to `thisArg` and invoked with one argument; (value). The `callback`
- * argument may also be the name of a property to order by.
- *
- * @static
- * @memberOf _
- * @category Arrays
- * @param {Array} array The array to iterate over.
- * @param {Mixed} value The value to evaluate.
- * @param {Function|String} [callback=identity|property] The function called
- * per iteration or property name to order by.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Number} Returns the index at which the value should be inserted
- * into `array`.
- * @example
- *
- * _.sortedIndex([20, 30, 50], 40);
- * // => 2
- *
- * _.sortedIndex([{ 'x': 20 }, { 'x': 30 }, { 'x': 50 }], { 'x': 40 }, 'x');
- * // => 2
- *
- * var dict = {
- * 'wordToNumber': { 'twenty': 20, 'thirty': 30, 'fourty': 40, 'fifty': 50 }
- * };
- *
- * _.sortedIndex(['twenty', 'thirty', 'fifty'], 'fourty', function(word) {
- * return dict.wordToNumber[word];
- * });
- * // => 2
- *
- * _.sortedIndex(['twenty', 'thirty', 'fifty'], 'fourty', function(word) {
- * return this.wordToNumber[word];
- * }, dict);
- * // => 2
- */
- function sortedIndex(array, value, callback, thisArg) {
- var low = 0,
- high = array ? array.length : low;
-
- // explicitly reference `identity` for better engine inlining
- callback = callback ? createCallback(callback, thisArg) : identity;
- value = callback(value);
- while (low < high) {
- var mid = (low + high) >>> 1;
- callback(array[mid]) < value
- ? low = mid + 1
- : high = mid;
- }
- return low;
- }
-
- /**
- * Computes the union of the passed-in arrays using strict equality for
- * comparisons, i.e. `===`.
- *
- * @static
- * @memberOf _
- * @category Arrays
- * @param {Array} [array1, array2, ...] Arrays to process.
- * @returns {Array} Returns a new array of unique values, in order, that are
- * present in one or more of the arrays.
- * @example
- *
- * _.union([1, 2, 3], [101, 2, 1, 10], [2, 1]);
- * // => [1, 2, 3, 101, 10]
- */
- function union() {
- return uniq(concat.apply(arrayRef, arguments));
- }
-
- /**
- * Creates a duplicate-value-free version of the `array` using strict equality
- * for comparisons, i.e. `===`. If the `array` is already sorted, passing `true`
- * for `isSorted` will run a faster algorithm. If `callback` is passed, each
- * element of `array` is passed through a callback` before uniqueness is computed.
- * The `callback` is bound to `thisArg` and invoked with three arguments; (value, index, array).
- *
- * @static
- * @memberOf _
- * @alias unique
- * @category Arrays
- * @param {Array} array The array to process.
- * @param {Boolean} [isSorted=false] A flag to indicate that the `array` is already sorted.
- * @param {Function} [callback=identity] The function called per iteration.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Array} Returns a duplicate-value-free array.
- * @example
- *
- * _.uniq([1, 2, 1, 3, 1]);
- * // => [1, 2, 3]
- *
- * _.uniq([1, 1, 2, 2, 3], true);
- * // => [1, 2, 3]
- *
- * _.uniq([1, 2, 1.5, 3, 2.5], function(num) { return Math.floor(num); });
- * // => [1, 2, 3]
- *
- * _.uniq([1, 2, 1.5, 3, 2.5], function(num) { return this.floor(num); }, Math);
- * // => [1, 2, 3]
- */
- function uniq(array, isSorted, callback, thisArg) {
- var index = -1,
- length = array ? array.length : 0,
- result = [],
- seen = result;
-
- // juggle arguments
- if (typeof isSorted == 'function') {
- thisArg = callback;
- callback = isSorted;
- isSorted = false;
- }
- // init value cache for large arrays
- var isLarge = !isSorted && length > 74;
- if (isLarge) {
- var cache = {};
- }
- if (callback) {
- seen = [];
- callback = createCallback(callback, thisArg);
- }
- while (++index < length) {
- var value = array[index],
- computed = callback ? callback(value, index, array) : value;
-
- if (isLarge) {
- // manually coerce `computed` to a string because `hasOwnProperty`, in
- // some older versions of Firefox, coerces objects incorrectly
- seen = hasOwnProperty.call(cache, computed + '') ? cache[computed] : (cache[computed] = []);
- }
- if (isSorted
- ? !index || seen[seen.length - 1] !== computed
- : indexOf(seen, computed) < 0
- ) {
- if (callback || isLarge) {
- seen.push(computed);
- }
- result.push(value);
- }
- }
- return result;
- }
-
- /**
- * Creates an array with all occurrences of the passed values removed using
- * strict equality for comparisons, i.e. `===`.
- *
- * @static
- * @memberOf _
- * @category Arrays
- * @param {Array} array The array to filter.
- * @param {Mixed} [value1, value2, ...] Values to remove.
- * @returns {Array} Returns a new filtered array.
- * @example
- *
- * _.without([1, 2, 1, 0, 3, 1, 4], 0, 1);
- * // => [2, 3, 4]
- */
- function without(array) {
- var index = -1,
- length = array ? array.length : 0,
- contains = cachedContains(arguments, 1, 20),
- result = [];
-
- while (++index < length) {
- var value = array[index];
- if (!contains(value)) {
- result.push(value);
- }
- }
- return result;
- }
-
- /**
- * Groups the elements of each array at their corresponding indexes. Useful for
- * separate data sources that are coordinated through matching array indexes.
- * For a matrix of nested arrays, `_.zip.apply(...)` can transpose the matrix
- * in a similar fashion.
- *
- * @static
- * @memberOf _
- * @category Arrays
- * @param {Array} [array1, array2, ...] Arrays to process.
- * @returns {Array} Returns a new array of grouped elements.
- * @example
- *
- * _.zip(['moe', 'larry', 'curly'], [30, 40, 50], [true, false, false]);
- * // => [['moe', 30, true], ['larry', 40, false], ['curly', 50, false]]
- */
- function zip(array) {
- var index = -1,
- length = array ? max(pluck(arguments, 'length')) : 0,
- result = Array(length);
-
- while (++index < length) {
- result[index] = pluck(arguments, index);
- }
- return result;
- }
-
- /*--------------------------------------------------------------------------*/
-
- /**
- * Creates a function that is restricted to executing `func` only after it is
- * called `n` times. The `func` is executed with the `this` binding of the
- * created function.
- *
- * @static
- * @memberOf _
- * @category Functions
- * @param {Number} n The number of times the function must be called before
- * it is executed.
- * @param {Function} func The function to restrict.
- * @returns {Function} Returns the new restricted function.
- * @example
- *
- * var renderNotes = _.after(notes.length, render);
- * _.forEach(notes, function(note) {
- * note.asyncSave({ 'success': renderNotes });
- * });
- * // `renderNotes` is run once, after all notes have saved
- */
- function after(n, func) {
- if (n < 1) {
- return func();
- }
- return function() {
- if (--n < 1) {
- return func.apply(this, arguments);
- }
- };
- }
-
- /**
- * Creates a function that, when called, invokes `func` with the `this`
- * binding of `thisArg` and prepends any additional `bind` arguments to those
- * passed to the bound function.
- *
- * @static
- * @memberOf _
- * @category Functions
- * @param {Function} func The function to bind.
- * @param {Mixed} [thisArg] The `this` binding of `func`.
- * @param {Mixed} [arg1, arg2, ...] Arguments to be partially applied.
- * @returns {Function} Returns the new bound function.
- * @example
- *
- * var func = function(greeting) {
- * return greeting + ' ' + this.name;
- * };
- *
- * func = _.bind(func, { 'name': 'moe' }, 'hi');
- * func();
- * // => 'hi moe'
- */
- function bind(func, thisArg) {
- // use `Function#bind` if it exists and is fast
- // (in V8 `Function#bind` is slower except when partially applied)
- return isBindFast || (nativeBind && arguments.length > 2)
- ? nativeBind.call.apply(nativeBind, arguments)
- : createBound(func, thisArg, slice.call(arguments, 2));
- }
-
- /**
- * Binds methods on `object` to `object`, overwriting the existing method.
- * If no method names are provided, all the function properties of `object`
- * will be bound.
- *
- * @static
- * @memberOf _
- * @category Functions
- * @param {Object} object The object to bind and assign the bound methods to.
- * @param {String} [methodName1, methodName2, ...] Method names on the object to bind.
- * @returns {Object} Returns `object`.
- * @example
- *
- * var buttonView = {
- * 'label': 'lodash',
- * 'onClick': function() { alert('clicked: ' + this.label); }
- * };
- *
- * _.bindAll(buttonView);
- * jQuery('#lodash_button').on('click', buttonView.onClick);
- * // => When the button is clicked, `this.label` will have the correct value
- */
- function bindAll(object) {
- var funcs = arguments,
- index = funcs.length > 1 ? 0 : (funcs = functions(object), -1),
- length = funcs.length;
-
- while (++index < length) {
- var key = funcs[index];
- object[key] = bind(object[key], object);
- }
- return object;
- }
-
- /**
- * Creates a function that, when called, invokes the method at `object[key]`
- * and prepends any additional `bindKey` arguments to those passed to the bound
- * function. This method differs from `_.bind` by allowing bound functions to
- * reference methods that will be redefined or don't yet exist.
- * See http://michaux.ca/articles/lazy-function-definition-pattern.
- *
- * @static
- * @memberOf _
- * @category Functions
- * @param {Object} object The object the method belongs to.
- * @param {String} key The key of the method.
- * @param {Mixed} [arg1, arg2, ...] Arguments to be partially applied.
- * @returns {Function} Returns the new bound function.
- * @example
- *
- * var object = {
- * 'name': 'moe',
- * 'greet': function(greeting) {
- * return greeting + ' ' + this.name;
- * }
- * };
- *
- * var func = _.bindKey(object, 'greet', 'hi');
- * func();
- * // => 'hi moe'
- *
- * object.greet = function(greeting) {
- * return greeting + ', ' + this.name + '!';
- * };
- *
- * func();
- * // => 'hi, moe!'
- */
- function bindKey(object, key) {
- return createBound(object, key, slice.call(arguments, 2));
- }
-
- /**
- * Creates a function that is the composition of the passed functions,
- * where each function consumes the return value of the function that follows.
- * In math terms, composing the functions `f()`, `g()`, and `h()` produces `f(g(h()))`.
- * Each function is executed with the `this` binding of the composed function.
- *
- * @static
- * @memberOf _
- * @category Functions
- * @param {Function} [func1, func2, ...] Functions to compose.
- * @returns {Function} Returns the new composed function.
- * @example
- *
- * var greet = function(name) { return 'hi: ' + name; };
- * var exclaim = function(statement) { return statement + '!'; };
- * var welcome = _.compose(exclaim, greet);
- * welcome('moe');
- * // => 'hi: moe!'
- */
- function compose() {
- var funcs = arguments;
- return function() {
- var args = arguments,
- length = funcs.length;
-
- while (length--) {
- args = [funcs[length].apply(this, args)];
- }
- return args[0];
- };
- }
-
- /**
- * Creates a function that will delay the execution of `func` until after
- * `wait` milliseconds have elapsed since the last time it was invoked. Pass
- * `true` for `immediate` to cause debounce to invoke `func` on the leading,
- * instead of the trailing, edge of the `wait` timeout. Subsequent calls to
- * the debounced function will return the result of the last `func` call.
- *
- * @static
- * @memberOf _
- * @category Functions
- * @param {Function} func The function to debounce.
- * @param {Number} wait The number of milliseconds to delay.
- * @param {Boolean} immediate A flag to indicate execution is on the leading
- * edge of the timeout.
- * @returns {Function} Returns the new debounced function.
- * @example
- *
- * var lazyLayout = _.debounce(calculateLayout, 300);
- * jQuery(window).on('resize', lazyLayout);
- */
- function debounce(func, wait, immediate) {
- var args,
- result,
- thisArg,
- timeoutId;
-
- function delayed() {
- timeoutId = null;
- if (!immediate) {
- result = func.apply(thisArg, args);
- }
- }
- return function() {
- var isImmediate = immediate && !timeoutId;
- args = arguments;
- thisArg = this;
-
- clearTimeout(timeoutId);
- timeoutId = setTimeout(delayed, wait);
-
- if (isImmediate) {
- result = func.apply(thisArg, args);
- }
- return result;
- };
- }
-
- /**
- * Executes the `func` function after `wait` milliseconds. Additional arguments
- * will be passed to `func` when it is invoked.
- *
- * @static
- * @memberOf _
- * @category Functions
- * @param {Function} func The function to delay.
- * @param {Number} wait The number of milliseconds to delay execution.
- * @param {Mixed} [arg1, arg2, ...] Arguments to invoke the function with.
- * @returns {Number} Returns the `setTimeout` timeout id.
- * @example
- *
- * var log = _.bind(console.log, console);
- * _.delay(log, 1000, 'logged later');
- * // => 'logged later' (Appears after one second.)
- */
- function delay(func, wait) {
- var args = slice.call(arguments, 2);
- return setTimeout(function() { func.apply(undefined, args); }, wait);
- }
-
- /**
- * Defers executing the `func` function until the current call stack has cleared.
- * Additional arguments will be passed to `func` when it is invoked.
- *
- * @static
- * @memberOf _
- * @category Functions
- * @param {Function} func The function to defer.
- * @param {Mixed} [arg1, arg2, ...] Arguments to invoke the function with.
- * @returns {Number} Returns the `setTimeout` timeout id.
- * @example
- *
- * _.defer(function() { alert('deferred'); });
- * // returns from the function before `alert` is called
- */
- function defer(func) {
- var args = slice.call(arguments, 1);
- return setTimeout(function() { func.apply(undefined, args); }, 1);
- }
-
- /**
- * Creates a function that memoizes the result of `func`. If `resolver` is
- * passed, it will be used to determine the cache key for storing the result
- * based on the arguments passed to the memoized function. By default, the first
- * argument passed to the memoized function is used as the cache key. The `func`
- * is executed with the `this` binding of the memoized function.
- *
- * @static
- * @memberOf _
- * @category Functions
- * @param {Function} func The function to have its output memoized.
- * @param {Function} [resolver] A function used to resolve the cache key.
- * @returns {Function} Returns the new memoizing function.
- * @example
- *
- * var fibonacci = _.memoize(function(n) {
- * return n < 2 ? n : fibonacci(n - 1) + fibonacci(n - 2);
- * });
- */
- function memoize(func, resolver) {
- var cache = {};
- return function() {
- var key = resolver ? resolver.apply(this, arguments) : arguments[0];
- return hasOwnProperty.call(cache, key)
- ? cache[key]
- : (cache[key] = func.apply(this, arguments));
- };
- }
-
- /**
- * Creates a function that is restricted to execute `func` once. Repeat calls to
- * the function will return the value of the first call. The `func` is executed
- * with the `this` binding of the created function.
- *
- * @static
- * @memberOf _
- * @category Functions
- * @param {Function} func The function to restrict.
- * @returns {Function} Returns the new restricted function.
- * @example
- *
- * var initialize = _.once(createApplication);
- * initialize();
- * initialize();
- * // Application is only created once.
- */
- function once(func) {
- var result,
- ran = false;
-
- return function() {
- if (ran) {
- return result;
- }
- ran = true;
- result = func.apply(this, arguments);
-
- // clear the `func` variable so the function may be garbage collected
- func = null;
- return result;
- };
- }
-
- /**
- * Creates a function that, when called, invokes `func` with any additional
- * `partial` arguments prepended to those passed to the new function. This
- * method is similar to `bind`, except it does **not** alter the `this` binding.
- *
- * @static
- * @memberOf _
- * @category Functions
- * @param {Function} func The function to partially apply arguments to.
- * @param {Mixed} [arg1, arg2, ...] Arguments to be partially applied.
- * @returns {Function} Returns the new partially applied function.
- * @example
- *
- * var greet = function(greeting, name) { return greeting + ': ' + name; };
- * var hi = _.partial(greet, 'hi');
- * hi('moe');
- * // => 'hi: moe'
- */
- function partial(func) {
- return createBound(func, slice.call(arguments, 1));
- }
-
- /**
- * Creates a function that, when executed, will only call the `func`
- * function at most once per every `wait` milliseconds. If the throttled
- * function is invoked more than once during the `wait` timeout, `func` will
- * also be called on the trailing edge of the timeout. Subsequent calls to the
- * throttled function will return the result of the last `func` call.
- *
- * @static
- * @memberOf _
- * @category Functions
- * @param {Function} func The function to throttle.
- * @param {Number} wait The number of milliseconds to throttle executions to.
- * @returns {Function} Returns the new throttled function.
- * @example
- *
- * var throttled = _.throttle(updatePosition, 100);
- * jQuery(window).on('scroll', throttled);
- */
- function throttle(func, wait) {
- var args,
- result,
- thisArg,
- timeoutId,
- lastCalled = 0;
-
- function trailingCall() {
- lastCalled = new Date;
- timeoutId = null;
- result = func.apply(thisArg, args);
- }
- return function() {
- var now = new Date,
- remaining = wait - (now - lastCalled);
-
- args = arguments;
- thisArg = this;
-
- if (remaining <= 0) {
- clearTimeout(timeoutId);
- lastCalled = now;
- result = func.apply(thisArg, args);
- }
- else if (!timeoutId) {
- timeoutId = setTimeout(trailingCall, remaining);
- }
- return result;
- };
- }
-
- /**
- * Creates a function that passes `value` to the `wrapper` function as its
- * first argument. Additional arguments passed to the function are appended
- * to those passed to the `wrapper` function. The `wrapper` is executed with
- * the `this` binding of the created function.
- *
- * @static
- * @memberOf _
- * @category Functions
- * @param {Mixed} value The value to wrap.
- * @param {Function} wrapper The wrapper function.
- * @returns {Function} Returns the new function.
- * @example
- *
- * var hello = function(name) { return 'hello ' + name; };
- * hello = _.wrap(hello, function(func) {
- * return 'before, ' + func('moe') + ', after';
- * });
- * hello();
- * // => 'before, hello moe, after'
- */
- function wrap(value, wrapper) {
- return function() {
- var args = [value];
- push.apply(args, arguments);
- return wrapper.apply(this, args);
- };
- }
-
- /*--------------------------------------------------------------------------*/
-
- /**
- * Converts the characters `&`, `<`, `>`, `"`, and `'` in `string` to their
- * corresponding HTML entities.
- *
- * @static
- * @memberOf _
- * @category Utilities
- * @param {String} string The string to escape.
- * @returns {String} Returns the escaped string.
- * @example
- *
- * _.escape('Moe, Larry & Curly');
- * // => "Moe, Larry &amp; Curly"
- */
- function escape(string) {
- return string == null ? '' : (string + '').replace(reUnescapedHtml, escapeHtmlChar);
- }
-
- /**
- * This function returns the first argument passed to it.
- *
- * Note: It is used throughout Lo-Dash as a default callback.
- *
- * @static
- * @memberOf _
- * @category Utilities
- * @param {Mixed} value Any value.
- * @returns {Mixed} Returns `value`.
- * @example
- *
- * var moe = { 'name': 'moe' };
- * moe === _.identity(moe);
- * // => true
- */
- function identity(value) {
- return value;
- }
-
- /**
- * Adds functions properties of `object` to the `lodash` function and chainable
- * wrapper.
- *
- * @static
- * @memberOf _
- * @category Utilities
- * @param {Object} object The object of function properties to add to `lodash`.
- * @example
- *
- * _.mixin({
- * 'capitalize': function(string) {
- * return string.charAt(0).toUpperCase() + string.slice(1).toLowerCase();
- * }
- * });
- *
- * _.capitalize('larry');
- * // => 'Larry'
- *
- * _('curly').capitalize();
- * // => 'Curly'
- */
- function mixin(object) {
- forEach(functions(object), function(methodName) {
- var func = lodash[methodName] = object[methodName];
-
- lodash.prototype[methodName] = function() {
- var args = [this.__wrapped__];
- push.apply(args, arguments);
-
- var result = func.apply(lodash, args);
- if (this.__chain__) {
- result = new lodash(result);
- result.__chain__ = true;
- }
- return result;
- };
- });
- }
-
- /**
- * Reverts the '_' variable to its previous value and returns a reference to
- * the `lodash` function.
- *
- * @static
- * @memberOf _
- * @category Utilities
- * @returns {Function} Returns the `lodash` function.
- * @example
- *
- * var lodash = _.noConflict();
- */
- function noConflict() {
- window._ = oldDash;
- return this;
- }
-
- /**
- * Produces a random number between `min` and `max` (inclusive). If only one
- * argument is passed, a number between `0` and the given number will be returned.
- *
- * @static
- * @memberOf _
- * @category Utilities
- * @param {Number} [min=0] The minimum possible value.
- * @param {Number} [max=1] The maximum possible value.
- * @returns {Number} Returns a random number.
- * @example
- *
- * _.random(0, 5);
- * // => a number between 1 and 5
- *
- * _.random(5);
- * // => also a number between 1 and 5
- */
- function random(min, max) {
- if (min == null && max == null) {
- max = 1;
- }
- min = +min || 0;
- if (max == null) {
- max = min;
- min = 0;
- }
- return min + floor(nativeRandom() * ((+max || 0) - min + 1));
- }
-
- /**
- * Resolves the value of `property` on `object`. If `property` is a function
- * it will be invoked and its result returned, else the property value is
- * returned. If `object` is falsey, then `null` is returned.
- *
- * @deprecated
- * @static
- * @memberOf _
- * @category Utilities
- * @param {Object} object The object to inspect.
- * @param {String} property The property to get the value of.
- * @returns {Mixed} Returns the resolved value.
- * @example
- *
- * var object = {
- * 'cheese': 'crumpets',
- * 'stuff': function() {
- * return 'nonsense';
- * }
- * };
- *
- * _.result(object, 'cheese');
- * // => 'crumpets'
- *
- * _.result(object, 'stuff');
- * // => 'nonsense'
- */
- function result(object, property) {
- // based on Backbone's private `getValue` function
- // https://github.com/documentcloud/backbone/blob/0.9.2/backbone.js#L1419-1424
- var value = object ? object[property] : null;
- return isFunction(value) ? object[property]() : value;
- }
-
- /**
- * A micro-templating method that handles arbitrary delimiters, preserves
- * whitespace, and correctly escapes quotes within interpolated code.
- *
- * Note: In the development build `_.template` utilizes sourceURLs for easier
- * debugging. See http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl
- *
- * Note: Lo-Dash may be used in Chrome extensions by either creating a `lodash csp`
- * build and avoiding `_.template` use, or loading Lo-Dash in a sandboxed page.
- * See http://developer.chrome.com/trunk/extensions/sandboxingEval.html
- *
- * @static
- * @memberOf _
- * @category Utilities
- * @param {String} text The template text.
- * @param {Obect} data The data object used to populate the text.
- * @param {Object} options The options object.
- * escape - The "escape" delimiter regexp.
- * evaluate - The "evaluate" delimiter regexp.
- * interpolate - The "interpolate" delimiter regexp.
- * sourceURL - The sourceURL of the template's compiled source.
- * variable - The data object variable name.
- *
- * @returns {Function|String} Returns a compiled function when no `data` object
- * is given, else it returns the interpolated text.
- * @example
- *
- * // using a compiled template
- * var compiled = _.template('hello <%= name %>');
- * compiled({ 'name': 'moe' });
- * // => 'hello moe'
- *
- * var list = '<% _.forEach(people, function(name) { %><li><%= name %></li><% }); %>';
- * _.template(list, { 'people': ['moe', 'larry', 'curly'] });
- * // => '<li>moe</li><li>larry</li><li>curly</li>'
- *
- * // using the "escape" delimiter to escape HTML in data property values
- * _.template('<b><%- value %></b>', { 'value': '<script>' });
- * // => '<b>&lt;script&gt;</b>'
- *
- * // using the ES6 delimiter as an alternative to the default "interpolate" delimiter
- * _.template('hello ${ name }', { 'name': 'curly' });
- * // => 'hello curly'
- *
- * // using the internal `print` function in "evaluate" delimiters
- * _.template('<% print("hello " + epithet); %>!', { 'epithet': 'stooge' });
- * // => 'hello stooge!'
- *
- * // using custom template delimiters
- * _.templateSettings = {
- * 'interpolate': /{{([\s\S]+?)}}/g
- * };
- *
- * _.template('hello {{ name }}!', { 'name': 'mustache' });
- * // => 'hello mustache!'
- *
- * // using the `sourceURL` option to specify a custom sourceURL for the template
- * var compiled = _.template('hello <%= name %>', null, { 'sourceURL': '/basic/greeting.jst' });
- * compiled(data);
- * // => find the source of "greeting.jst" under the Sources tab or Resources panel of the web inspector
- *
- * // using the `variable` option to ensure a with-statement isn't used in the compiled template
- * var compiled = _.template('hello <%= data.name %>!', null, { 'variable': 'data' });
- * compiled.source;
- * // => function(data) {
- * var __t, __p = '', __e = _.escape;
- * __p += 'hello ' + ((__t = ( data.name )) == null ? '' : __t) + '!';
- * return __p;
- * }
- *
- * // using the `source` property to inline compiled templates for meaningful
- * // line numbers in error messages and a stack trace
- * fs.writeFileSync(path.join(cwd, 'jst.js'), '\
- * var JST = {\
- * "main": ' + _.template(mainText).source + '\
- * };\
- * ');
- */
- function template(text, data, options) {
- // based on John Resig's `tmpl` implementation
- // http://ejohn.org/blog/javascript-micro-templating/
- // and Laura Doktorova's doT.js
- // https://github.com/olado/doT
- text || (text = '');
- options || (options = {});
-
- var isEvaluating,
- result,
- settings = lodash.templateSettings,
- index = 0,
- interpolate = options.interpolate || settings.interpolate || reNoMatch,
- source = "__p += '",
- variable = options.variable || settings.variable,
- hasVariable = variable;
-
- // compile regexp to match each delimiter
- var reDelimiters = RegExp(
- (options.escape || settings.escape || reNoMatch).source + '|' +
- interpolate.source + '|' +
- (interpolate === reInterpolate ? reEsTemplate : reNoMatch).source + '|' +
- (options.evaluate || settings.evaluate || reNoMatch).source + '|$'
- , 'g');
-
- text.replace(reDelimiters, function(match, escapeValue, interpolateValue, esTemplateValue, evaluateValue, offset) {
- interpolateValue || (interpolateValue = esTemplateValue);
-
- // escape characters that cannot be included in string literals
- source += text.slice(index, offset).replace(reUnescapedString, escapeStringChar);
-
- // replace delimiters with snippets
- source +=
- escapeValue ? "' +\n__e(" + escapeValue + ") +\n'" :
- evaluateValue ? "';\n" + evaluateValue + ";\n__p += '" :
- interpolateValue ? "' +\n((__t = (" + interpolateValue + ")) == null ? '' : __t) +\n'" : '';
-
- isEvaluating || (isEvaluating = evaluateValue || reComplexDelimiter.test(escapeValue || interpolateValue));
- index = offset + match.length;
- });
-
- source += "';\n";
-
- // if `variable` is not specified and the template contains "evaluate"
- // delimiters, wrap a with-statement around the generated code to add the
- // data object to the top of the scope chain
- if (!hasVariable) {
- variable = 'obj';
- if (isEvaluating) {
- source = 'with (' + variable + ') {\n' + source + '\n}\n';
- }
- else {
- // avoid a with-statement by prepending data object references to property names
- var reDoubleVariable = RegExp('(\\(\\s*)' + variable + '\\.' + variable + '\\b', 'g');
- source = source
- .replace(reInsertVariable, '$&' + variable + '.')
- .replace(reDoubleVariable, '$1__d');
- }
- }
-
- // cleanup code by stripping empty strings
- source = (isEvaluating ? source.replace(reEmptyStringLeading, '') : source)
- .replace(reEmptyStringMiddle, '$1')
- .replace(reEmptyStringTrailing, '$1;');
-
- // frame code as the function body
- source = 'function(' + variable + ') {\n' +
- (hasVariable ? '' : variable + ' || (' + variable + ' = {});\n') +
- 'var __t, __p = \'\', __e = _.escape' +
- (isEvaluating
- ? ', __j = Array.prototype.join;\n' +
- 'function print() { __p += __j.call(arguments, \'\') }\n'
- : (hasVariable ? '' : ', __d = ' + variable + '.' + variable + ' || ' + variable) + ';\n'
- ) +
- source +
- 'return __p\n}';
-
- // use a sourceURL for easier debugging
- // http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl
- var sourceURL = useSourceURL
- ? '\n//@ sourceURL=' + (options.sourceURL || '/lodash/template/source[' + (templateCounter++) + ']')
- : '';
-
- try {
- result = Function('_', 'return ' + source + sourceURL)(lodash);
- } catch(e) {
- e.source = source;
- throw e;
- }
-
- if (data) {
- return result(data);
- }
- // provide the compiled function's source via its `toString` method, in
- // supported environments, or the `source` property as a convenience for
- // inlining compiled templates during the build process
- result.source = source;
- return result;
- }
-
- /**
- * Executes the `callback` function `n` times, returning an array of the results
- * of each `callback` execution. The `callback` is bound to `thisArg` and invoked
- * with one argument; (index).
- *
- * @static
- * @memberOf _
- * @category Utilities
- * @param {Number} n The number of times to execute the callback.
- * @param {Function} callback The function called per iteration.
- * @param {Mixed} [thisArg] The `this` binding of `callback`.
- * @returns {Array} Returns a new array of the results of each `callback` execution.
- * @example
- *
- * var diceRolls = _.times(3, _.partial(_.random, 1, 6));
- * // => [3, 6, 4]
- *
- * _.times(3, function(n) { mage.castSpell(n); });
- * // => calls `mage.castSpell(n)` three times, passing `n` of `0`, `1`, and `2` respectively
- *
- * _.times(3, function(n) { this.cast(n); }, mage);
- * // => also calls `mage.castSpell(n)` three times
- */
- function times(n, callback, thisArg) {
- n = +n || 0;
- var index = -1,
- result = Array(n);
-
- while (++index < n) {
- result[index] = callback.call(thisArg, index);
- }
- return result;
- }
-
- /**
- * The opposite of `_.escape`, this method converts the HTML entities
- * `&amp;`, `&lt;`, `&gt;`, `&quot;`, and `&#x27;` in `string` to their
- * corresponding characters.
- *
- * @static
- * @memberOf _
- * @category Utilities
- * @param {String} string The string to unescape.
- * @returns {String} Returns the unescaped string.
- * @example
- *
- * _.unescape('Moe, Larry &amp; Curly');
- * // => "Moe, Larry & Curly"
- */
- function unescape(string) {
- return string == null ? '' : (string + '').replace(reEscapedHtml, unescapeHtmlChar);
- }
-
- /**
- * Generates a unique id. If `prefix` is passed, the id will be appended to it.
- *
- * @static
- * @memberOf _
- * @category Utilities
- * @param {String} [prefix] The value to prefix the id with.
- * @returns {Number|String} Returns a numeric id if no prefix is passed, else
- * a string id may be returned.
- * @example
- *
- * _.uniqueId('contact_');
- * // => 'contact_104'
- */
- function uniqueId(prefix) {
- var id = idCounter++;
- return prefix ? prefix + id : id;
- }
-
- /*--------------------------------------------------------------------------*/
-
- /**
- * Wraps the value in a `lodash` wrapper object.
- *
- * @static
- * @memberOf _
- * @category Chaining
- * @param {Mixed} value The value to wrap.
- * @returns {Object} Returns the wrapper object.
- * @example
- *
- * var stooges = [
- * { 'name': 'moe', 'age': 40 },
- * { 'name': 'larry', 'age': 50 },
- * { 'name': 'curly', 'age': 60 }
- * ];
- *
- * var youngest = _.chain(stooges)
- * .sortBy(function(stooge) { return stooge.age; })
- * .map(function(stooge) { return stooge.name + ' is ' + stooge.age; })
- * .first()
- * .value();
- * // => 'moe is 40'
- */
- function chain(value) {
- value = new lodash(value);
- value.__chain__ = true;
- return value;
- }
-
- /**
- * Invokes `interceptor` with the `value` as the first argument, and then
- * returns `value`. The purpose of this method is to "tap into" a method chain,
- * in order to perform operations on intermediate results within the chain.
- *
- * @static
- * @memberOf _
- * @category Chaining
- * @param {Mixed} value The value to pass to `interceptor`.
- * @param {Function} interceptor The function to invoke.
- * @returns {Mixed} Returns `value`.
- * @example
- *
- * _.chain([1, 2, 3, 200])
- * .filter(function(num) { return num % 2 == 0; })
- * .tap(alert)
- * .map(function(num) { return num * num })
- * .value();
- * // => // [2, 200] (alerted)
- * // => [4, 40000]
- */
- function tap(value, interceptor) {
- interceptor(value);
- return value;
- }
-
- /**
- * Enables method chaining on the wrapper object.
- *
- * @name chain
- * @deprecated
- * @memberOf _
- * @category Chaining
- * @returns {Mixed} Returns the wrapper object.
- * @example
- *
- * _([1, 2, 3]).value();
- * // => [1, 2, 3]
- */
- function wrapperChain() {
- this.__chain__ = true;
- return this;
- }
-
- /**
- * Extracts the wrapped value.
- *
- * @name value
- * @memberOf _
- * @category Chaining
- * @returns {Mixed} Returns the wrapped value.
- * @example
- *
- * _([1, 2, 3]).value();
- * // => [1, 2, 3]
- */
- function wrapperValue() {
- return this.__wrapped__;
- }
-
- /*--------------------------------------------------------------------------*/
-
- /**
- * The semantic version number.
- *
- * @static
- * @memberOf _
- * @type String
- */
- lodash.VERSION = '0.10.0';
-
- // assign static methods
- lodash.assign = assign;
- lodash.after = after;
- lodash.bind = bind;
- lodash.bindAll = bindAll;
- lodash.bindKey = bindKey;
- lodash.chain = chain;
- lodash.clone = clone;
- lodash.compact = compact;
- lodash.compose = compose;
- lodash.contains = contains;
- lodash.countBy = countBy;
- lodash.debounce = debounce;
- lodash.defaults = defaults;
- lodash.defer = defer;
- lodash.delay = delay;
- lodash.difference = difference;
- lodash.escape = escape;
- lodash.every = every;
- lodash.filter = filter;
- lodash.find = find;
- lodash.first = first;
- lodash.flatten = flatten;
- lodash.forEach = forEach;
- lodash.forIn = forIn;
- lodash.forOwn = forOwn;
- lodash.functions = functions;
- lodash.groupBy = groupBy;
- lodash.has = has;
- lodash.identity = identity;
- lodash.indexOf = indexOf;
- lodash.initial = initial;
- lodash.intersection = intersection;
- lodash.invert = invert;
- lodash.invoke = invoke;
- lodash.isArguments = isArguments;
- lodash.isArray = isArray;
- lodash.isBoolean = isBoolean;
- lodash.isDate = isDate;
- lodash.isElement = isElement;
- lodash.isEmpty = isEmpty;
- lodash.isEqual = isEqual;
- lodash.isFinite = isFinite;
- lodash.isFunction = isFunction;
- lodash.isNaN = isNaN;
- lodash.isNull = isNull;
- lodash.isNumber = isNumber;
- lodash.isObject = isObject;
- lodash.isPlainObject = isPlainObject;
- lodash.isRegExp = isRegExp;
- lodash.isString = isString;
- lodash.isUndefined = isUndefined;
- lodash.keys = keys;
- lodash.last = last;
- lodash.lastIndexOf = lastIndexOf;
- lodash.map = map;
- lodash.max = max;
- lodash.memoize = memoize;
- lodash.merge = merge;
- lodash.min = min;
- lodash.mixin = mixin;
- lodash.noConflict = noConflict;
- lodash.object = object;
- lodash.omit = omit;
- lodash.once = once;
- lodash.pairs = pairs;
- lodash.partial = partial;
- lodash.pick = pick;
- lodash.pluck = pluck;
- lodash.random = random;
- lodash.range = range;
- lodash.reduce = reduce;
- lodash.reduceRight = reduceRight;
- lodash.reject = reject;
- lodash.rest = rest;
- lodash.result = result;
- lodash.shuffle = shuffle;
- lodash.size = size;
- lodash.some = some;
- lodash.sortBy = sortBy;
- lodash.sortedIndex = sortedIndex;
- lodash.tap = tap;
- lodash.template = template;
- lodash.throttle = throttle;
- lodash.times = times;
- lodash.toArray = toArray;
- lodash.unescape = unescape;
- lodash.union = union;
- lodash.uniq = uniq;
- lodash.uniqueId = uniqueId;
- lodash.values = values;
- lodash.where = where;
- lodash.without = without;
- lodash.wrap = wrap;
- lodash.zip = zip;
-
- // assign aliases
- lodash.all = every;
- lodash.any = some;
- lodash.collect = map;
- lodash.detect = find;
- lodash.drop = rest;
- lodash.each = forEach;
- lodash.extend = assign;
- lodash.foldl = reduce;
- lodash.foldr = reduceRight;
- lodash.head = first;
- lodash.include = contains;
- lodash.inject = reduce;
- lodash.methods = functions;
- lodash.select = filter;
- lodash.tail = rest;
- lodash.take = first;
- lodash.unique = uniq;
-
- // add pseudo private property to be used and removed during the build process
- lodash._iteratorTemplate = iteratorTemplate;
-
- /*--------------------------------------------------------------------------*/
-
- // add all static functions to `lodash.prototype`
- mixin(lodash);
-
- // add `lodash.prototype.chain` after calling `mixin()` to avoid overwriting
- // it with the wrapped `lodash.chain`
- lodash.prototype.chain = wrapperChain;
- lodash.prototype.value = wrapperValue;
-
- // add all mutator Array functions to the wrapper.
- forEach(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(methodName) {
- var func = arrayRef[methodName];
-
- lodash.prototype[methodName] = function() {
- var value = this.__wrapped__;
- func.apply(value, arguments);
-
- // avoid array-like object bugs with `Array#shift` and `Array#splice` in
- // Firefox < 10 and IE < 9
- if (hasObjectSpliceBug && value.length === 0) {
- delete value[0];
- }
- if (this.__chain__) {
- value = new lodash(value);
- value.__chain__ = true;
- }
- return value;
- };
- });
-
- // add all accessor Array functions to the wrapper.
- forEach(['concat', 'join', 'slice'], function(methodName) {
- var func = arrayRef[methodName];
-
- lodash.prototype[methodName] = function() {
- var value = this.__wrapped__,
- result = func.apply(value, arguments);
-
- if (this.__chain__) {
- result = new lodash(result);
- result.__chain__ = true;
- }
- return result;
- };
- });
-
- /*--------------------------------------------------------------------------*/
-
- // expose Lo-Dash
- // some AMD build optimizers, like r.js, check for specific condition patterns like the following:
- if (typeof define == 'function' && typeof define.amd == 'object' && define.amd) {
- // Expose Lo-Dash to the global object even when an AMD loader is present in
- // case Lo-Dash was injected by a third-party script and not intended to be
- // loaded as a module. The global assignment can be reverted in the Lo-Dash
- // module via its `noConflict()` method.
- window._ = lodash;
-
- // define as an anonymous module so, through path mapping, it can be
- // referenced as the "underscore" module
- define(function() {
- return lodash;
- });
- }
- // check for `exports` after `define` in case a build optimizer adds an `exports` object
- else if (freeExports) {
- // in Node.js or RingoJS v0.8.0+
- if (typeof module == 'object' && module && module.exports == freeExports) {
- (module.exports = lodash)._ = lodash;
- }
- // in Narwhal or RingoJS v0.7.0-
- else {
- freeExports._ = lodash;
- }
- }
- else {
- // in a browser or Rhino
- window._ = lodash;
- }
-}(this));
diff --git a/testing/web-platform/tests/webaudio/js/vendor-prefixes.js b/testing/web-platform/tests/webaudio/js/vendor-prefixes.js
deleted file mode 100644
index 287d692b3..000000000
--- a/testing/web-platform/tests/webaudio/js/vendor-prefixes.js
+++ /dev/null
@@ -1,2 +0,0 @@
-window.AudioContext = window.AudioContext || window.webkitAudioContext;
-window.OfflineAudioContext = window.OfflineAudioContext || window.webkitOfflineAudioContext;
diff --git a/testing/web-platform/tests/webaudio/refresh_idl.rb b/testing/web-platform/tests/webaudio/refresh_idl.rb
deleted file mode 100755
index a07847535..000000000
--- a/testing/web-platform/tests/webaudio/refresh_idl.rb
+++ /dev/null
@@ -1,57 +0,0 @@
-#!/usr/bin/env ruby
-require 'nokogiri'
-
-def base_dir
- File.dirname(__FILE__)
-end
-
-def output_directory
- File.join(base_dir, 'idl')
-end
-
-def specification
- file = File.open(File.join(base_dir, 'specification.html'))
- doc = Nokogiri::XML(file)
- file.close
- doc
-end
-
-def write_node_inner_text_to_file(filename, node)
- File.open(filename, 'w') { |file| file.write(node.inner_text.strip) }
- puts "Wrote: #{filename}"
-end
-
-def load_idl(id)
- file = File.join(output_directory, id)
- return false if !File.exist?(file)
- File.read(file)
-end
-
-# Parse the specification writing each block of idl to its own file
-specification.css(".idl-code").each do |idl_block|
- id = idl_block["id"]
- write_node_inner_text_to_file(File.join(output_directory, id), idl_block) if id
-end
-
-# Update the idl in the pre blocks for each idl test
-idl_test_files = [
- File.join(base_dir, 'the-audio-api', 'the-gainnode-interface', 'idl-test.html'),
- File.join(base_dir, 'the-audio-api', 'the-audiodestinationnode-interface', 'idl-test.html'),
- File.join(base_dir, 'the-audio-api', 'the-delaynode-interface', 'idl-test.html'),
- File.join(base_dir, 'the-audio-api', 'the-audiobuffer-interface', 'idl-test.html'),
-]
-
-idl_test_files.each do |fn|
- file = File.open(fn)
- doc = Nokogiri::HTML(file)
- file.close
-
- doc.css('pre').each do |node|
- node_id = node["id"]
- if idl = load_idl(node_id)
- node.content = idl
- end
- end
-
- File.open(fn, 'w') { |file| file.write(doc.to_html)}
-end
diff --git a/testing/web-platform/tests/webaudio/resources/sin_440Hz_-6dBFS_1s.wav b/testing/web-platform/tests/webaudio/resources/sin_440Hz_-6dBFS_1s.wav
deleted file mode 100644
index f660c3c4b..000000000
--- a/testing/web-platform/tests/webaudio/resources/sin_440Hz_-6dBFS_1s.wav
+++ /dev/null
Binary files differ
diff --git a/testing/web-platform/tests/webaudio/specification.html b/testing/web-platform/tests/webaudio/specification.html
deleted file mode 100644
index 3178c5e10..000000000
--- a/testing/web-platform/tests/webaudio/specification.html
+++ /dev/null
@@ -1,5911 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
- "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
-<head>
- <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
- <title>Web Audio API</title>
- <meta name="revision"
- content="$Id: Overview.html,v 1.4 2012/07/30 11:44:57 tmichel Exp $" />
- <link rel="stylesheet" href="style.css" type="text/css" />
- <!--
- <script src="section-links.js" type="application/ecmascript"></script>
- <script src="dfn.js" type="application/ecmascript"></script>
- -->
- <!--[if IE]>
- <style type='text/css'>
- .ignore {
- -ms-filter:"progid:DXImageTransform.Microsoft.Alpha(Opacity=50)";
- filter: alpha(opacity=50);
- }
- </style>
- <![endif]-->
- <link rel="stylesheet" href="//www.w3.org/StyleSheets/TR/W3C-ED"
- type="text/css" />
-</head>
-
-<body>
-
-<div class="head">
-<p><a href="http://www.w3.org/"><img width="72" height="48" alt="W3C"
-src="http://www.w3.org/Icons/w3c_home" /></a> </p>
-
-<h1 id="title" class="title">Web Audio API </h1>
-
-<h2 id="w3c-date-document"><acronym
-title="World Wide Web Consortium">W3C</acronym> Editor's Draft
-</h2>
-<dl>
- <dt>This version: </dt>
- <dd><a
- href="https://dvcs.w3.org/hg/audio/raw-file/tip/webaudio/specification.html">https://dvcs.w3.org/hg/audio/raw-file/tip/webaudio/specification.html</a>
- </dd>
- <dt>Latest published version: </dt>
- <dd><a
- href="http://www.w3.org/TR/webaudio/">http://www.w3.org/TR/webaudio/</a>
- </dd>
- <dt>Previous version: </dt>
- <dd><a
- href="http://www.w3.org/TR/2012/WD-webaudio-20120315/">http://www.w3.org/TR/2012/WD-webaudio-20120315/</a>
- </dd>
-</dl>
-
-<dl>
- <dt>Editor: </dt>
- <dd>Chris Rogers, Google &lt;crogers@google.com&gt;</dd>
-</dl>
-
-<p class="copyright"><a
-href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> ©
-2012 <a href="http://www.w3.org/"><acronym
-title="World Wide Web Consortium">W3C</acronym></a><sup>®</sup> (<a
-href="http://www.csail.mit.edu/"><acronym
-title="Massachusetts Institute of Technology">MIT</acronym></a>, <a
-href="http://www.ercim.eu/"><acronym
-title="European Research Consortium for Informatics and Mathematics">ERCIM</acronym></a>,
-<a href="http://www.keio.ac.jp/">Keio</a>), All Rights Reserved. W3C <a
-href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>,
-<a
-href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a>
-and <a href="http://www.w3.org/Consortium/Legal/copyright-documents">document
-use</a> rules apply.</p>
-<hr />
-</div>
-
-<div id="abstract-section" class="section">
-<h2 id="abstract">Abstract</h2>
-
-<p>This specification describes a high-level JavaScript <acronym
-title="Application Programming Interface">API</acronym> for processing and
-synthesizing audio in web applications. The primary paradigm is of an audio
-routing graph, where a number of <a
-href="#AudioNode-section"><code>AudioNode</code></a> objects are connected
-together to define the overall audio rendering. The actual processing will
-primarily take place in the underlying implementation (typically optimized
-Assembly / C / C++ code), but <a href="#JavaScriptProcessing-section">direct
-JavaScript processing and synthesis</a> is also supported. </p>
-
-<p>The <a href="#introduction">introductory</a> section covers the motivation
-behind this specification.</p>
-
-<p>This API is designed to be used in conjunction with other APIs and elements
-on the web platform, notably: XMLHttpRequest
-(using the <code>responseType</code> and <code>response</code> attributes). For
-games and interactive applications, it is anticipated to be used with the
-<code>canvas</code> 2D and WebGL 3D graphics APIs. </p>
-</div>
-
-<div id="sotd-section" class="section">
-<h2 id="sotd">Status of this Document</h2>
-
-
-<p><em>This section describes the status of this document at the time of its
-publication. Other documents may supersede this document. A list of current W3C
-publications and the latest revision of this technical report can be found in
-the <a href="http://www.w3.org/TR/">W3C technical reports index</a> at
-http://www.w3.org/TR/. </em></p>
-
-<p>This is the Editor's Draft of the <cite>Web Audio API</cite>
-specification. It has been produced by the <a
-href="http://www.w3.org/2011/audio/"><b>W3C Audio Working Group</b></a> , which
-is part of the W3C WebApps Activity.</p>
-
-<p></p>
-
-<p>Please send comments about this document to &lt;<a
-href="mailto:public-audio@w3.org">public-audio@w3.org</a>&gt; (<a
-href="http://lists.w3.org/Archives/Public/public-audio/">public archives</a> of
-the W3C audio mailing list). Web content and browser developers are encouraged
-to review this draft. </p>
-
-<p>Publication as a Working Draft does not imply endorsement by the W3C
-Membership. This is a draft document and may be updated, replaced or obsoleted
-by other documents at any time. It is inappropriate to cite this document as
-other than work in progress.</p>
-
-<p> This document was produced by a group operating under the <a href="http://www.w3.org/Consortium/Patent-Policy-20040205/">5 February 2004 W3C Patent Policy</a>. W3C maintains a <a rel="disclosure" href="http://www.w3.org/2004/01/pp-impl/46884/status">public list of any patent disclosures</a> made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains <a href="http://www.w3.org/Consortium/Patent-Policy-20040205/#def-essential">Essential Claim(s)</a> must disclose the information in accordance with <a href="http://www.w3.org/Consortium/Patent-Policy-20040205/#sec-Disclosure">section 6 of the W3C Patent Policy</a>. </p>
-</div>
-
-<div id="toc">
-<h2 id="L13522">Table of Contents</h2>
-
-<div class="toc">
-<ul>
- <li><a href="#introduction">1. Introduction</a>
- <ul>
- <li><a href="#Features">1.1. Features</a></li>
- <li><a href="#ModularRouting">1.2. Modular Routing</a></li>
- <li><a href="#APIOverview">1.3. API Overview</a></li>
- </ul>
- </li>
- <li><a href="#conformance">2. Conformance</a></li>
- <li><a href="#API-section">4. The Audio API</a>
- <ul>
- <li><a href="#AudioContext-section">4.1. The AudioContext Interface</a>
- <ul>
- <li><a href="#attributes-AudioContext">4.1.1. Attributes</a></li>
- <li><a href="#methodsandparams-AudioContext">4.1.2. Methods and
- Parameters</a></li>
- <li><a href="#lifetime-AudioContext">4.1.3. Lifetime</a></li>
- </ul>
- </li>
- <li><a href="#OfflineAudioContext-section">4.1b. The OfflineAudioContext Interface</a>
- </li>
-
- <li><a href="#AudioNode-section">4.2. The AudioNode Interface</a>
- <ul>
- <li><a href="#attributes-AudioNode">4.2.1. Attributes</a></li>
- <li><a href="#methodsandparams-AudioNode">4.2.2. Methods and
- Parameters</a></li>
- <li><a href="#lifetime-AudioNode">4.2.3. Lifetime</a></li>
- </ul>
- </li>
- <li><a href="#AudioDestinationNode">4.4. The AudioDestinationNode
- Interface</a>
- <ul>
- <li><a href="#attributes-AudioDestinationNode">4.4.1. Attributes</a></li>
- </ul>
- </li>
- <li><a href="#AudioParam">4.5. The AudioParam Interface</a>
- <ul>
- <li><a href="#attributes-AudioParam">4.5.1. Attributes</a></li>
- <li><a href="#methodsandparams-AudioParam">4.5.2. Methods and
- Parameters</a></li>
- <li><a href="#computedValue-AudioParam-section">4.5.3. Computation of Value</a></li>
- <li><a href="#example1-AudioParam-section">4.5.4. AudioParam Automation Example</a></li>
- </ul>
- </li>
- <li><a href="#GainNode">4.7. The GainNode Interface</a>
- <ul>
- <li><a href="#attributes-GainNode">4.7.1. Attributes</a></li>
- </ul>
- </li>
- <li><a href="#DelayNode">4.8. The DelayNode Interface</a>
- <ul>
- <li><a href="#attributes-GainNode_2">4.8.1. Attributes</a></li>
- </ul>
- </li>
- <li><a href="#AudioBuffer">4.9. The AudioBuffer Interface</a>
- <ul>
- <li><a href="#attributes-AudioBuffer">4.9.1. Attributes</a></li>
- <li><a href="#methodsandparams-AudioBuffer">4.9.2. Methods and
- Parameters</a></li>
- </ul>
- </li>
- <li><a href="#AudioBufferSourceNode">4.10. The AudioBufferSourceNode
- Interface</a>
- <ul>
- <li><a href="#attributes-AudioBufferSourceNode">4.10.1.
- Attributes</a></li>
- <li><a href="#methodsandparams-AudioBufferSourceNode">4.10.2. Methods and
- Parameters</a></li>
- </ul>
- </li>
- <li><a href="#MediaElementAudioSourceNode">4.11. The
- MediaElementAudioSourceNode Interface</a></li>
- <li><a href="#ScriptProcessorNode">4.12. The ScriptProcessorNode
- Interface</a>
- <ul>
- <li><a href="#attributes-ScriptProcessorNode">4.12.1. Attributes</a></li>
- </ul>
- </li>
- <li><a href="#AudioProcessingEvent">4.13. The AudioProcessingEvent
- Interface</a>
- <ul>
- <li><a href="#attributes-AudioProcessingEvent">4.13.1. Attributes</a></li>
- </ul>
- </li>
- <li><a href="#PannerNode">4.14. The PannerNode Interface</a>
- <ul>
- <li><a href="#attributes-PannerNode_attributes">4.14.2.
- Attributes</a></li>
- <li><a href="#Methods_and_Parameters">4.14.3. Methods and
- Parameters</a></li>
- </ul>
- </li>
- <li><a href="#AudioListener">4.15. The AudioListener Interface</a>
- <ul>
- <li><a href="#attributes-AudioListener">4.15.1. Attributes</a></li>
- <li><a href="#L15842">4.15.2. Methods and Parameters</a></li>
- </ul>
- </li>
- <li><a href="#ConvolverNode">4.16. The ConvolverNode Interface</a>
- <ul>
- <li><a href="#attributes-ConvolverNode">4.16.1. Attributes</a></li>
- </ul>
- </li>
- <li><a href="#AnalyserNode">4.17. The AnalyserNode
- Interface</a>
- <ul>
- <li><a href="#attributes-ConvolverNode_2">4.17.1. Attributes</a></li>
- <li><a href="#methods-and-parameters">4.17.2. Methods and
- Parameters</a></li>
- </ul>
- </li>
- <li><a href="#ChannelSplitterNode">4.18. The ChannelSplitterNode
- Interface</a>
- <ul>
- <li><a href="#example-1">Example:</a></li>
- </ul>
- </li>
- <li><a href="#ChannelMergerNode">4.19. The ChannelMergerNode Interface</a>
- <ul>
- <li><a href="#example-2">Example:</a></li>
- </ul>
- </li>
- <li><a href="#DynamicsCompressorNode">4.20. The DynamicsCompressorNode
- Interface</a>
- <ul>
- <li><a href="#attributes-DynamicsCompressorNode">4.20.1.
- Attributes</a></li>
- </ul>
- </li>
- <li><a href="#BiquadFilterNode">4.21. The BiquadFilterNode Interface</a>
- <ul>
- <li><a href="#BiquadFilterNode-description">4.21.1 Lowpass</a></li>
- <li><a href="#HIGHPASS">4.21.2 Highpass</a></li>
- <li><a href="#BANDPASS">4.21.3 Bandpass</a></li>
- <li><a href="#LOWSHELF">4.21.4 Lowshelf</a></li>
- <li><a href="#L16352">4.21.5 Highshelf</a></li>
- <li><a href="#PEAKING">4.21.6 Peaking</a></li>
- <li><a href="#NOTCH">4.21.7 Notch</a></li>
- <li><a href="#ALLPASS">4.21.8 Allpass</a></li>
- <li><a href="#Methods">4.21.9. Methods</a></li>
- </ul>
- </li>
- <li><a href="#WaveShaperNode">4.22. The WaveShaperNode Interface</a>
- <ul>
- <li><a href="#attributes-WaveShaperNode">4.22.1.
- Attributes</a></li>
- </ul>
- </li>
- <li><a href="#OscillatorNode">4.23. The OscillatorNode Interface</a>
- <ul>
- <li><a href="#attributes-OscillatorNode">4.23.1.
- Attributes</a></li>
- <li><a href="#methodsandparams-OscillatorNode-section">4.23.2. Methods and
- Parameters</a></li>
- </ul>
- </li>
- <li><a href="#PeriodicWave">4.24. The PeriodicWave Interface</a>
- </li>
- <li><a href="#MediaStreamAudioSourceNode">4.25. The
- MediaStreamAudioSourceNode Interface</a></li>
- <li><a href="#MediaStreamAudioDestinationNode">4.26. The
- MediaStreamAudioDestinationNode Interface</a></li>
- </ul>
- </li>
- <li><a href="#MixerGainStructure">6. Mixer Gain Structure</a>
- <ul>
- <li><a href="#background">Background</a></li>
- <li><a href="#SummingJunction">Summing Inputs</a></li>
- <li><a href="#gain-Control">Gain Control</a></li>
- <li><a href="#Example-mixer-with-send-busses">Example: Mixer with Send
- Busses</a></li>
- </ul>
- </li>
- <li><a href="#DynamicLifetime">7. Dynamic Lifetime</a>
- <ul>
- <li><a href="#DynamicLifetime-background">Background</a></li>
- <li><a href="#Example-DynamicLifetime">Example</a></li>
- </ul>
- </li>
- <li><a href="#UpMix">9. Channel up-mixing and down-mixing</a>
- <ul>
- <li><a href="#ChannelLayouts">9.1. Speaker Channel Layouts</a>
- <ul>
- <li><a href="#ChannelOrdering">9.1.1. Channel Ordering</a></li>
- <li><a href="#UpMix-sub">9.1.2. Up Mixing</a></li>
- <li><a href="#down-mix">9.1.3. Down Mixing</a></li>
- </ul>
- </li>
-
- <li><a href="#ChannelRules-section">9.2. Channel Rules Examples</a>
-
- </ul>
- </li>
- <li><a href="#Spatialization">11. Spatialization / Panning </a>
- <ul>
- <li><a href="#Spatialization-background">Background</a></li>
- <li><a href="#Spatialization-panning-algorithm">Panning Algorithm</a></li>
- <li><a href="#Spatialization-distance-effects">Distance Effects</a></li>
- <li><a href="#Spatialization-sound-cones">Sound Cones</a></li>
- <li><a href="#Spatialization-doppler-shift">Doppler Shift</a></li>
- </ul>
- </li>
- <li><a href="#Convolution">12. Linear Effects using Convolution</a>
- <ul>
- <li><a href="#Convolution-background">Background</a></li>
- <li><a href="#Convolution-motivation">Motivation for use as a
- Standard</a></li>
- <li><a href="#Convolution-implementation-guide">Implementation Guide</a></li>
- <li><a href="#Convolution-reverb-effect">Reverb Effect (with
- matrixing)</a></li>
- <li><a href="#recording-impulse-responses">Recording Impulse
- Responses</a></li>
- <li><a href="#tools">Tools</a></li>
- <li><a href="#recording-setup">Recording Setup</a></li>
- <li><a href="#warehouse">The Warehouse Space</a></li>
- </ul>
- </li>
- <li><a href="#JavaScriptProcessing">13. JavaScript Synthesis and
- Processing</a>
- <ul>
- <li><a href="#custom-DSP-effects">Custom DSP Effects</a></li>
- <li><a href="#educational-applications">Educational Applications</a></li>
- <li><a href="#javaScript-performance">JavaScript Performance</a></li>
- </ul>
- </li>
- <li><a href="#Performance">15. Performance Considerations</a>
- <ul>
- <li><a href="#Latency">15.1. Latency: What it is and Why it's
- Important</a></li>
- <li><a href="#audio-glitching">15.2. Audio Glitching</a></li>
- <li><a href="#hardware-scalability">15.3. Hardware Scalability</a>
- <ul>
- <li><a href="#CPU-monitoring">15.3.1. CPU monitoring</a></li>
- <li><a href="#Voice-dropping">15.3.2. Voice Dropping</a></li>
- <li><a href="#Simplification-of-Effects-Processing">15.3.3.
- Simplification of Effects Processing</a></li>
- <li><a href="#Sample-rate">15.3.4. Sample Rate</a></li>
- <li><a href="#pre-flighting">15.3.5. Pre-flighting</a></li>
- <li><a href="#Authoring-for-different-user-agents">15.3.6. Authoring
- for different user agents</a></li>
- <li><a href="#Scalability-of-Direct-JavaScript-Synthesis">15.3.7.
- Scalability of Direct JavaScript Synthesis / Processing</a></li>
- </ul>
- </li>
- <li><a href="#JavaScriptPerformance">15.4. JavaScript Issues with
- real-time Processing and Synthesis: </a></li>
- </ul>
- </li>
- <li><a href="#ExampleApplications">16. Example Applications</a>
- <ul>
- <li><a href="#basic-sound-playback">Basic Sound Playback</a></li>
- <li><a href="#threeD-environmentse-and-games">3D Environments and
- Games</a></li>
- <li><a href="#musical-applications">Musical Applications</a></li>
- <li><a href="#music-visualizers">Music Visualizers</a></li>
- <li><a href="#educational-applications_2">Educational
- Applications</a></li>
- <li><a href="#artistic-audio-exploration">Artistic Audio
- Exploration</a></li>
- </ul>
- </li>
- <li><a href="#SecurityConsiderations">17. Security Considerations</a></li>
- <li><a href="#PrivacyConsiderations">18. Privacy Considerations</a></li>
- <li><a href="#requirements">19. Requirements and Use Cases</a></li>
- <li><a href="#OldNames">20. Old Names</a></li>
- <li><a href="#L17310">A.References</a>
- <ul>
- <li><a href="#Normative-references">A.1 Normative references</a></li>
- <li><a href="#Informative-references">A.2 Informative references</a></li>
- </ul>
- </li>
- <li><a href="#L17335">B.Acknowledgements</a></li>
- <li><a href="#ChangeLog">C. Web Audio API Change Log</a></li>
-</ul>
-</div>
-</div>
-
-<div id="sections">
-
-<div id="div-introduction" class="section">
-<h2 id="introduction">1. Introduction</h2>
-
-<p class="norm">This section is informative.</p>
-
-<p>Audio on the web has been fairly primitive up to this point and until very
-recently has had to be delivered through plugins such as Flash and QuickTime.
-The introduction of the <code>audio</code> element in HTML5 is very important,
-allowing for basic streaming audio playback. But, it is not powerful enough to
-handle more complex audio applications. For sophisticated web-based games or
-interactive applications, another solution is required. It is a goal of this
-specification to include the capabilities found in modern game audio engines as
-well as some of the mixing, processing, and filtering tasks that are found in
-modern desktop audio production applications. </p>
-
-<p>The APIs have been designed with a wide variety of <a
-href="#ExampleApplications-section">use cases</a> in mind. Ideally, it should
-be able to support <i>any</i> use case which could reasonably be implemented
-with an optimized C++ engine controlled via JavaScript and run in a browser.
-That said, modern desktop audio software can have very advanced capabilities,
-some of which would be difficult or impossible to build with this system.
-Apple's Logic Audio is one such application which has support for external MIDI
-controllers, arbitrary plugin audio effects and synthesizers, highly optimized
-direct-to-disk audio file reading/writing, tightly integrated time-stretching,
-and so on. Nevertheless, the proposed system will be quite capable of
-supporting a large range of reasonably complex games and interactive
-applications, including musical ones. And it can be a very good complement to
-the more advanced graphics features offered by WebGL. The API has been designed
-so that more advanced capabilities can be added at a later time. </p>
-
-<div id="Features-section" class="section">
-<h2 id="Features">1.1. Features</h2>
-</div>
-
-<p>The API supports these primary features: </p>
-<ul>
- <li><a href="#ModularRouting-section">Modular routing</a> for simple or
- complex mixing/effect architectures, including <a
- href="#MixerGainStructure-section">multiple sends and submixes</a>.</li>
- <li><a href="#AudioParam">Sample-accurate scheduled sound
- playback</a> with low <a href="#Latency-section">latency</a> for musical
- applications requiring a very high degree of rhythmic precision such as
- drum machines and sequencers. This also includes the possibility of <a
- href="#DynamicLifetime-section">dynamic creation</a> of effects. </li>
- <li>Automation of audio parameters for envelopes, fade-ins / fade-outs,
- granular effects, filter sweeps, LFOs etc. </li>
- <li>Flexible handling of channels in an audio stream, allowing them to be split and merged.</li>
-
- <li>Processing of audio sources from an <code>audio</code> or
- <code>video</code> <a href="#MediaElementAudioSourceNode">media
- element</a>. </li>
-
- <li>Processing live audio input using a <a href="#MediaStreamAudioSourceNode">MediaStream</a>
- from getUserMedia().
- </li>
-
- <li>Integration with WebRTC
- <ul>
-
-
- <li>Processing audio received from a remote peer using a <a href="#MediaStreamAudioSourceNode">MediaStream</a>.
- </li>
-
- <li>Sending a generated or processed audio stream to a remote peer using a <a href="#MediaStreamAudioDestinationNode">MediaStream</a>.
- </li>
-
- </ul>
- </li>
-
- <li>Audio stream synthesis and processing <a
- href="#JavaScriptProcessing-section">directly in JavaScript</a>. </li>
- <li><a href="#Spatialization-section">Spatialized audio</a> supporting a wide
- range of 3D games and immersive environments:
- <ul>
- <li>Panning models: equal-power, HRTF, pass-through </li>
- <li>Distance Attenuation </li>
- <li>Sound Cones </li>
- <li>Obstruction / Occlusion </li>
- <li>Doppler Shift </li>
- <li>Source / Listener based</li>
- </ul>
- </li>
- <li>A <a href="#Convolution-section">convolution engine</a> for a wide range
- of linear effects, especially very high-quality room effects. Here are some
- examples of possible effects:
- <ul>
- <li>Small / large room </li>
- <li>Cathedral </li>
- <li>Concert hall </li>
- <li>Cave </li>
- <li>Tunnel </li>
- <li>Hallway </li>
- <li>Forest </li>
- <li>Amphitheater </li>
- <li>Sound of a distant room through a doorway </li>
- <li>Extreme filters</li>
- <li>Strange backwards effects</li>
- <li>Extreme comb filter effects </li>
- </ul>
- </li>
- <li>Dynamics compression for overall control and sweetening of the mix </li>
- <li>Efficient <a href="#AnalyserNode">real-time time-domain and
- frequency analysis / music visualizer support</a></li>
- <li>Efficient biquad filters for lowpass, highpass, and other common filters.
- </li>
- <li>A Waveshaping effect for distortion and other non-linear effects</li>
- <li>Oscillators</li>
-
-</ul>
-
-<div id="ModularRouting-section">
-<h2 id="ModularRouting">1.2. Modular Routing</h2>
-
-<p>Modular routing allows arbitrary connections between different <a
-href="#AudioNode-section"><code>AudioNode</code></a> objects. Each node can
-have <dfn>inputs</dfn> and/or <dfn>outputs</dfn>. A <dfn>source node</dfn> has no inputs
-and a single output. A <dfn>destination node</dfn> has
-one input and no outputs, the most common example being <a
-href="#AudioDestinationNode-section"><code>AudioDestinationNode</code></a> the final destination to the audio
-hardware. Other nodes such as filters can be placed between the source and destination nodes.
-The developer doesn't have to worry about low-level stream format details
-when two objects are connected together; <a href="#UpMix-section">the right
-thing just happens</a>. For example, if a mono audio stream is connected to a
-stereo input it should just mix to left and right channels <a
-href="#UpMix-section">appropriately</a>. </p>
-
-<p>In the simplest case, a single source can be routed directly to the output.
-All routing occurs within an <a
-href="#AudioContext-section"><code>AudioContext</code></a> containing a single
-<a href="#AudioDestinationNode-section"><code>AudioDestinationNode</code></a>:
-</p>
-<img alt="modular routing" src="images/modular-routing1.png" />
-
-<p>Illustrating this simple routing, here's a simple example playing a single
-sound: </p>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">ECMAScript</span> </div>
-
-<div class="blockContent">
-<pre class="code"><code class="es-code">
-
-var context = new AudioContext();
-
-function playSound() {
- var source = context.createBufferSource();
- source.buffer = dogBarkingBuffer;
- source.connect(context.destination);
- source.start(0);
-}
- </code></pre>
-</div>
-</div>
-
-<p>Here's a more complex example with three sources and a convolution reverb
-send with a dynamics compressor at the final output stage: </p>
-<img alt="modular routing2" src="images/modular-routing2.png" />
-
-<div class="example">
-
-<div class="exampleHeader">
-Example</div>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">ECMAScript</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="es-code">
-
-var context = 0;
-var compressor = 0;
-var reverb = 0;
-
-var source1 = 0;
-var source2 = 0;
-var source3 = 0;
-
-var lowpassFilter = 0;
-var waveShaper = 0;
-var panner = 0;
-
-var dry1 = 0;
-var dry2 = 0;
-var dry3 = 0;
-
-var wet1 = 0;
-var wet2 = 0;
-var wet3 = 0;
-
-var masterDry = 0;
-var masterWet = 0;
-
-function setupRoutingGraph () {
- context = new AudioContext();
-
- // Create the effects nodes.
- lowpassFilter = context.createBiquadFilter();
- waveShaper = context.createWaveShaper();
- panner = context.createPanner();
- compressor = context.createDynamicsCompressor();
- reverb = context.createConvolver();
-
- // Create master wet and dry.
- masterDry = context.createGain();
- masterWet = context.createGain();
-
- // Connect final compressor to final destination.
- compressor.connect(context.destination);
-
- // Connect master dry and wet to compressor.
- masterDry.connect(compressor);
- masterWet.connect(compressor);
-
- // Connect reverb to master wet.
- reverb.connect(masterWet);
-
- // Create a few sources.
- source1 = context.createBufferSource();
- source2 = context.createBufferSource();
- source3 = context.createOscillator();
-
- source1.buffer = manTalkingBuffer;
- source2.buffer = footstepsBuffer;
- source3.frequency.value = 440;
-
- // Connect source1
- dry1 = context.createGain();
- wet1 = context.createGain();
- source1.connect(lowpassFilter);
- lowpassFilter.connect(dry1);
- lowpassFilter.connect(wet1);
- dry1.connect(masterDry);
- wet1.connect(reverb);
-
- // Connect source2
- dry2 = context.createGain();
- wet2 = context.createGain();
- source2.connect(waveShaper);
- waveShaper.connect(dry2);
- waveShaper.connect(wet2);
- dry2.connect(masterDry);
- wet2.connect(reverb);
-
- // Connect source3
- dry3 = context.createGain();
- wet3 = context.createGain();
- source3.connect(panner);
- panner.connect(dry3);
- panner.connect(wet3);
- dry3.connect(masterDry);
- wet3.connect(reverb);
-
- // Start the sources now.
- source1.start(0);
- source2.start(0);
- source3.start(0);
-}
- </code></pre>
-</div>
-</div>
-</div>
-</div>
-
-</div>
-
-<div id="APIOverview-section" class="section">
-<h2 id="APIOverview">1.3. API Overview</h2>
-</div>
-
-<p>The interfaces defined are: </p>
-<ul>
- <li>An <a class="dfnref" href="#AudioContext-section">AudioContext</a>
- interface, which contains an audio signal graph representing connections
- betweens AudioNodes. </li>
- <li>An <a class="dfnref" href="#AudioNode-section">AudioNode</a> interface,
- which represents audio sources, audio outputs, and intermediate processing
- modules. AudioNodes can be dynamically connected together in a <a
- href="#ModularRouting-section">modular fashion</a>. <code>AudioNodes</code>
- exist in the context of an <code>AudioContext</code> </li>
- <li>An <a class="dfnref"
- href="#AudioDestinationNode-section">AudioDestinationNode</a> interface, an
- AudioNode subclass representing the final destination for all rendered
- audio. </li>
- <li>An <a class="dfnref" href="#AudioBuffer-section">AudioBuffer</a>
- interface, for working with memory-resident audio assets. These can
- represent one-shot sounds, or longer audio clips. </li>
- <li>An <a class="dfnref"
- href="#AudioBufferSourceNode-section">AudioBufferSourceNode</a> interface,
- an AudioNode which generates audio from an AudioBuffer. </li>
- <li>A <a class="dfnref"
- href="#MediaElementAudioSourceNode-section">MediaElementAudioSourceNode</a>
- interface, an AudioNode which is the audio source from an
- <code>audio</code>, <code>video</code>, or other media element. </li>
- <li>A <a class="dfnref"
- href="#MediaStreamAudioSourceNode-section">MediaStreamAudioSourceNode</a>
- interface, an AudioNode which is the audio source from a
- MediaStream such as live audio input, or from a remote peer. </li>
- <li>A <a class="dfnref"
- href="#MediaStreamAudioDestinationNode-section">MediaStreamAudioDestinationNode</a>
- interface, an AudioNode which is the audio destination to a
- MediaStream sent to a remote peer. </li>
- <li>A <a class="dfnref"
- href="#ScriptProcessorNode-section">ScriptProcessorNode</a> interface, an
- AudioNode for generating or processing audio directly in JavaScript. </li>
- <li>An <a class="dfnref"
- href="#AudioProcessingEvent-section">AudioProcessingEvent</a> interface,
- which is an event type used with <code>ScriptProcessorNode</code> objects.
- </li>
- <li>An <a class="dfnref" href="#AudioParam-section">AudioParam</a> interface,
- for controlling an individual aspect of an AudioNode's functioning, such as
- volume. </li>
- <li>An <a class="dfnref" href="#GainNode-section">GainNode</a>
- interface, for explicit gain control. Because inputs to AudioNodes support
- multiple connections (as a unity-gain summing junction), mixers can be <a
- href="#MixerGainStructure-section">easily built</a> with GainNodes.
- </li>
- <li>A <a class="dfnref" href="#BiquadFilterNode-section">BiquadFilterNode</a>
- interface, an AudioNode for common low-order filters such as:
- <ul>
- <li>Low Pass</li>
- <li>High Pass </li>
- <li>Band Pass </li>
- <li>Low Shelf </li>
- <li>High Shelf </li>
- <li>Peaking </li>
- <li>Notch </li>
- <li>Allpass </li>
- </ul>
- </li>
- <li>A <a class="dfnref" href="#DelayNode-section">DelayNode</a> interface, an
- AudioNode which applies a dynamically adjustable variable delay. </li>
- <li>An <a class="dfnref" href="#PannerNode-section">PannerNode</a>
- interface, for spatializing / positioning audio in 3D space. </li>
- <li>An <a class="dfnref" href="#AudioListener-section">AudioListener</a>
- interface, which works with an <code>PannerNode</code> for
- spatialization. </li>
- <li>A <a class="dfnref" href="#ConvolverNode-section">ConvolverNode</a>
- interface, an AudioNode for applying a <a
- href="#Convolution-section">real-time linear effect</a> (such as the sound
- of a concert hall). </li>
- <li>A <a class="dfnref"
- href="#AnalyserNode-section">AnalyserNode</a> interface,
- for use with music visualizers, or other visualization applications. </li>
- <li>A <a class="dfnref"
- href="#ChannelSplitterNode-section">ChannelSplitterNode</a> interface,
- for accessing the individual channels of an audio stream in the routing
- graph. </li>
- <li>A <a class="dfnref"
- href="#ChannelMergerNode-section">ChannelMergerNode</a> interface, for
- combining channels from multiple audio streams into a single audio stream.
- </li>
- <li>A <a
- href="#DynamicsCompressorNode-section">DynamicsCompressorNode</a> interface, an
- AudioNode for dynamics compression. </li>
- <li>A <a class="dfnref" href="#dfn-WaveShaperNode">WaveShaperNode</a>
- interface, an AudioNode which applies a non-linear waveshaping effect for
- distortion and other more subtle warming effects. </li>
- <li>A <a class="dfnref" href="#dfn-OscillatorNode">OscillatorNode</a>
- interface, an audio source generating a periodic waveform. </li>
-</ul>
-</div>
-
-<div id="conformance-section" class="section">
-<h2 id="conformance">2. Conformance</h2>
-
-<p>Everything in this specification is normative except for examples and
-sections marked as being informative. </p>
-
-<p>The keywords “<span class="rfc2119">MUST</span>”, “<span
-class="rfc2119">MUST NOT</span>”, “<span
-class="rfc2119">REQUIRED</span>”, “<span class="rfc2119">SHALL</span>”,
-“<span class="rfc2119">SHALL NOT</span>”, “<span
-class="rfc2119">RECOMMENDED</span>”, “<span class="rfc2119">MAY</span>”
-and “<span class="rfc2119">OPTIONAL</span>” in this document are to be
-interpreted as described in <cite><a href="http://www.ietf.org/rfc/rfc2119">Key
-words for use in RFCs to Indicate Requirement Levels</a></cite> <a
-href="#RFC2119">[RFC2119]</a>. </p>
-
-<p>The following conformance classes are defined by this specification: </p>
-<dl>
- <dt><dfn id="dfn-conforming-implementation">conforming
- implementation</dfn></dt>
- <dd><p>A user agent is considered to be a <a class="dfnref"
- href="#dfn-conforming-implementation">conforming implementation</a> if it
- satisfies all of the <span class="rfc2119">MUST</span>-, <span
- class="rfc2119">REQUIRED</span>- and <span
- class="rfc2119">SHALL</span>-level criteria in this specification that
- apply to implementations. </p>
- </dd>
-</dl>
-</div>
-
-<div id="terminology-section" class="section">
-
-<div id="API-section-section" class="section">
-<h2 id="API-section">4. The Audio API</h2>
-</div>
-
-<div id="AudioContext-section-section" class="section">
-<h2 id="AudioContext-section">4.1. The AudioContext Interface</h2>
-
-<p>This interface represents a set of <a
-href="#AudioNode-section"><code>AudioNode</code></a> objects and their
-connections. It allows for arbitrary routing of signals to the <a
-href="#AudioDestinationNode-section"><code>AudioDestinationNode</code></a>
-(what the user ultimately hears). Nodes are created from the context and are
-then <a href="#ModularRouting-section">connected</a> together. In most use
-cases, only a single AudioContext is used per document.</p>
-
-<br>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="audio-context-idl">
-
-callback DecodeSuccessCallback = void (AudioBuffer decodedData);
-callback DecodeErrorCallback = void ();
-
-[Constructor]
-interface <dfn id="dfn-AudioContext">AudioContext</dfn> : EventTarget {
-
- readonly attribute AudioDestinationNode destination;
- readonly attribute float sampleRate;
- readonly attribute double currentTime;
- readonly attribute AudioListener listener;
-
- AudioBuffer createBuffer(unsigned long numberOfChannels, unsigned long length, float sampleRate);
-
- void decodeAudioData(ArrayBuffer audioData,
- DecodeSuccessCallback successCallback,
- optional DecodeErrorCallback errorCallback);
-
-
- <span class="comment">// AudioNode creation </span>
- AudioBufferSourceNode createBufferSource();
-
- MediaElementAudioSourceNode createMediaElementSource(HTMLMediaElement mediaElement);
-
- MediaStreamAudioSourceNode createMediaStreamSource(MediaStream mediaStream);
- MediaStreamAudioDestinationNode createMediaStreamDestination();
-
- ScriptProcessorNode createScriptProcessor(optional unsigned long bufferSize = 0,
- optional unsigned long numberOfInputChannels = 2,
- optional unsigned long numberOfOutputChannels = 2);
-
- AnalyserNode createAnalyser();
- GainNode createGain();
- DelayNode createDelay(optional double maxDelayTime = 1.0);
- BiquadFilterNode createBiquadFilter();
- WaveShaperNode createWaveShaper();
- PannerNode createPanner();
- ConvolverNode createConvolver();
-
- ChannelSplitterNode createChannelSplitter(optional unsigned long numberOfOutputs = 6);
- ChannelMergerNode createChannelMerger(optional unsigned long numberOfInputs = 6);
-
- DynamicsCompressorNode createDynamicsCompressor();
-
- OscillatorNode createOscillator();
- PeriodicWave createPeriodicWave(Float32Array real, Float32Array imag);
-
-};
-</code></pre>
-</div>
-</div>
-
-<div id="attributes-AudioContext-section" class="section">
-<h3 id="attributes-AudioContext">4.1.1. Attributes</h3>
-<dl>
- <dt id="dfn-destination"><code>destination</code></dt>
- <dd><p>An <a
- href="#AudioDestinationNode-section"><code>AudioDestinationNode</code></a>
- with a single input representing the final destination for all audio.
- Usually this will represent the actual audio hardware.
- All AudioNodes actively rendering
- audio will directly or indirectly connect to <code>destination</code>.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-sampleRate"><code>sampleRate</code></dt>
- <dd><p>The sample rate (in sample-frames per second) at which the
- AudioContext handles audio. It is assumed that all AudioNodes in the
- context run at this rate. In making this assumption, sample-rate
- converters or "varispeed" processors are not supported in real-time
- processing.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-currentTime"><code>currentTime</code></dt>
- <dd><p>This is a time in seconds which starts at zero when the context is
- created and increases in real-time. All scheduled times are relative to
- it. This is not a "transport" time which can be started, paused, and
- re-positioned. It is always moving forward. A GarageBand-like timeline
- transport system can be very easily built on top of this (in JavaScript).
- This time corresponds to an ever-increasing hardware timestamp. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-listener"><code>listener</code></dt>
- <dd><p>An <a href="#AudioListener-section"><code>AudioListener</code></a>
- which is used for 3D <a
- href="#Spatialization-section">spatialization</a>.</p>
- </dd>
-</dl>
-</div>
-
-<div id="methodsandparams-AudioContext-section" class="section">
-<h3 id="methodsandparams-AudioContext">4.1.2. Methods and Parameters</h3>
-<dl>
- <dt id="dfn-createBuffer">The <code>createBuffer</code> method</dt>
- <dd><p>Creates an AudioBuffer of the given size. The audio data in the
- buffer will be zero-initialized (silent). An NOT_SUPPORTED_ERR exception will be thrown if
- the <code>numberOfChannels</code> or <code>sampleRate</code> are out-of-bounds,
- or if length is 0.</p>
- <p>The <dfn id="dfn-numberOfChannels">numberOfChannels</dfn> parameter
- determines how many channels the buffer will have. An implementation must support at least 32 channels. </p>
- <p>The <dfn id="dfn-length">length</dfn> parameter determines the size of
- the buffer in sample-frames. </p>
- <p>The <dfn id="dfn-sampleRate_2">sampleRate</dfn> parameter describes
- the sample-rate of the linear PCM audio data in the buffer in
- sample-frames per second. An implementation must support sample-rates in at least the range 22050 to 96000.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-decodeAudioData">The <code>decodeAudioData</code> method</dt>
- <dd><p>Asynchronously decodes the audio file data contained in the
- ArrayBuffer. The ArrayBuffer can, for example, be loaded from an XMLHttpRequest's
- <code>response</code> attribute after setting the <code>responseType</code> to "arraybuffer".
- Audio file data can be in any of the
- formats supported by the <code>audio</code> element. </p>
- <p><dfn id="dfn-audioData">audioData</dfn> is an ArrayBuffer containing
- audio file data.</p>
- <p><dfn id="dfn-successCallback">successCallback</dfn> is a callback
- function which will be invoked when the decoding is finished. The single
- argument to this callback is an AudioBuffer representing the decoded PCM
- audio data.</p>
- <p><dfn id="dfn-errorCallback">errorCallback</dfn> is a callback function
- which will be invoked if there is an error decoding the audio file
- data.</p>
-
- <p>
- The following steps must be performed:
- </p>
- <ol>
-
- <li>Temporarily neuter the <dfn>audioData</dfn> ArrayBuffer in such a way that JavaScript code may not
- access or modify the data.</li>
- <li>Queue a decoding operation to be performed on another thread.</li>
- <li>The decoding thread will attempt to decode the encoded <dfn>audioData</dfn> into linear PCM.
- If a decoding error is encountered due to the audio format not being recognized or supported, or
- because of corrupted/unexpected/inconsistent data then the <dfn>audioData</dfn> neutered state
- will be restored to normal and the <dfn>errorCallback</dfn> will be
- scheduled to run on the main thread's event loop and these steps will be terminated.</li>
- <li>The decoding thread will take the result, representing the decoded linear PCM audio data,
- and resample it to the sample-rate of the AudioContext if it is different from the sample-rate
- of <dfn>audioData</dfn>. The final result (after possibly sample-rate converting) will be stored
- in an AudioBuffer.
- </li>
- <li>The <dfn>audioData</dfn> neutered state will be restored to normal
- </li>
- <li>
- The <dfn>successCallback</dfn> function will be scheduled to run on the main thread's event loop
- given the AudioBuffer from step (4) as an argument.
- </li>
- </ol>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-createBufferSource">The <code>createBufferSource</code>
- method</dt>
- <dd><p>Creates an <a
- href="#AudioBufferSourceNode-section"><code>AudioBufferSourceNode</code></a>.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-createMediaElementSource">The <code>createMediaElementSource</code>
- method</dt>
- <dd><p>Creates a <a
- href="#MediaElementAudioSourceNode-section"><code>MediaElementAudioSourceNode</code></a> given an HTMLMediaElement.
- As a consequence of calling this method, audio playback from the HTMLMediaElement will be re-routed
- into the processing graph of the AudioContext.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-createMediaStreamSource">The <code>createMediaStreamSource</code>
- method</dt>
- <dd><p>Creates a <a
- href="#MediaStreamAudioSourceNode-section"><code>MediaStreamAudioSourceNode</code></a> given a MediaStream.
- As a consequence of calling this method, audio playback from the MediaStream will be re-routed
- into the processing graph of the AudioContext.</p>
- </dd>
-</dl>
-
-<dl>
- <dt id="dfn-createMediaStreamDestination">The <code>createMediaStreamDestination</code>
- method</dt>
- <dd><p>Creates a <a
- href="#MediaStreamAudioDestinationNode-section"><code>MediaStreamAudioDestinationNode</code></a>.
- </p>
- </dd>
-</dl>
-
-<dl>
- <dt id="dfn-createScriptProcessor">The <code>createScriptProcessor</code>
- method</dt>
- <dd><p>Creates a <a
- href="#ScriptProcessorNode"><code>ScriptProcessorNode</code></a> for
- direct audio processing using JavaScript. An INDEX_SIZE_ERR exception MUST be thrown if <code>bufferSize</code> or <code>numberOfInputChannels</code> or <code>numberOfOutputChannels</code>
- are outside the valid range. </p>
- <p>The <dfn id="dfn-bufferSize">bufferSize</dfn> parameter determines the
- buffer size in units of sample-frames. If it's not passed in, or if the
- value is 0, then the implementation will choose the best buffer size for
- the given environment, which will be constant power of 2 throughout the lifetime
- of the node. Otherwise if the author explicitly specifies the bufferSize,
- it must be one of the following values: 256, 512, 1024, 2048, 4096, 8192,
- 16384. This value controls how
- frequently the <code>audioprocess</code> event is dispatched and
- how many sample-frames need to be processed each call. Lower values for
- <code>bufferSize</code> will result in a lower (better) <a
- href="#Latency-section">latency</a>. Higher values will be necessary to
- avoid audio breakup and <a href="#Glitching-section">glitches</a>.
- It is recommended for authors to not specify this buffer size and allow
- the implementation to pick a good buffer size to balance between latency
- and audio quality.
- </p>
- <p>The <dfn id="dfn-numberOfInputChannels">numberOfInputChannels</dfn> parameter (defaults to 2) and
- determines the number of channels for this node's input. Values of up to 32 must be supported. </p>
- <p>The <dfn id="dfn-numberOfOutputChannels">numberOfOutputChannels</dfn> parameter (defaults to 2) and
- determines the number of channels for this node's output. Values of up to 32 must be supported.</p>
- <p>It is invalid for both <code>numberOfInputChannels</code> and
- <code>numberOfOutputChannels</code> to be zero. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-createAnalyser">The <code>createAnalyser</code> method</dt>
- <dd><p>Creates a <a
- href="#AnalyserNode-section"><code>AnalyserNode</code></a>.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-createGain">The <code>createGain</code> method</dt>
- <dd><p>Creates a <a
- href="#GainNode-section"><code>GainNode</code></a>.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-createDelay">The <code>createDelay</code> method</dt>
- <dd><p>Creates a <a href="#DelayNode-section"><code>DelayNode</code></a>
- representing a variable delay line. The initial default delay time will
- be 0 seconds.</p>
- <p>The <dfn id="dfn-maxDelayTime">maxDelayTime</dfn> parameter is
- optional and specifies the maximum delay time in seconds allowed for the delay line. If specified, this value MUST be
- greater than zero and less than three minutes or a NOT_SUPPORTED_ERR exception will be thrown.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-createBiquadFilter">The <code>createBiquadFilter</code>
- method</dt>
- <dd><p>Creates a <a
- href="#BiquadFilterNode-section"><code>BiquadFilterNode</code></a>
- representing a second order filter which can be configured as one of
- several common filter types.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-createWaveShaper">The <code>createWaveShaper</code>
- method</dt>
- <dd><p>Creates a <a
- href="#WaveShaperNode-section"><code>WaveShaperNode</code></a>
- representing a non-linear distortion.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-createPanner">The <code>createPanner</code> method</dt>
- <dd><p>Creates an <a
- href="#PannerNode-section"><code>PannerNode</code></a>.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-createConvolver">The <code>createConvolver</code> method</dt>
- <dd><p>Creates a <a
- href="#ConvolverNode-section"><code>ConvolverNode</code></a>.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-createChannelSplitter">The <code>createChannelSplitter</code>
- method</dt>
- <dd><p>Creates an <a
- href="#ChannelSplitterNode-section"><code>ChannelSplitterNode</code></a>
- representing a channel splitter. An exception will be thrown for invalid parameter values.</p>
- <p>The <dfn id="dfn-numberOfOutputs">numberOfOutputs</dfn> parameter
- determines the number of outputs. Values of up to 32 must be supported. If not specified, then 6 will be used. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-createChannelMerger">The <code>createChannelMerger</code>
- method</dt>
- <dd><p>Creates an <a
- href="#ChannelMergerNode-section"><code>ChannelMergerNode</code></a>
- representing a channel merger. An exception will be thrown for invalid parameter values.</p>
- <p>The <dfn id="dfn-numberOfInputs">numberOfInputs</dfn> parameter
- determines the number of inputs. Values of up to 32 must be supported. If not specified, then 6 will be used. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-createDynamicsCompressor">The
- <code>createDynamicsCompressor</code> method</dt>
- <dd><p>Creates a <a
- href="#DynamicsCompressorNode-section"><code>DynamicsCompressorNode</code></a>.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-createOscillator">The
- <code>createOscillator</code> method</dt>
- <dd><p>Creates an <a
- href="#OscillatorNode-section"><code>OscillatorNode</code></a>.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-createPeriodicWave">The
- <code>createPeriodicWave</code> method</dt>
- <dd><p>Creates a <a
- href="#PeriodicWave-section"><code>PeriodicWave</code></a> representing a waveform containing arbitrary harmonic content.
- The <code>real</code> and <code>imag</code> parameters must be of type <code>Float32Array</code> of equal
- lengths greater than zero and less than or equal to 4096 or an exception will be thrown.
- These parameters specify the Fourier coefficients of a
- <a href="http://en.wikipedia.org/wiki/Fourier_series">Fourier series</a> representing the partials of a periodic waveform.
- The created PeriodicWave will be used with an <a href="#OscillatorNode-section"><code>OscillatorNode</code></a>
- and will represent a <em>normalized</em> time-domain waveform having maximum absolute peak value of 1.
- Another way of saying this is that the generated waveform of an <a href="#OscillatorNode-section"><code>OscillatorNode</code></a>
- will have maximum peak value at 0dBFS. Conveniently, this corresponds to the full-range of the signal values used by the Web Audio API.
- Because the PeriodicWave will be normalized on creation, the <code>real</code> and <code>imag</code> parameters
- represent <em>relative</em> values.
- </p>
- <p>The <dfn id="dfn-real">real</dfn> parameter represents an array of <code>cosine</code> terms (traditionally the A terms).
- In audio terminology, the first element (index 0) is the DC-offset of the periodic waveform and is usually set to zero.
- The second element (index 1) represents the fundamental frequency. The third element represents the first overtone, and so on.</p>
- <p>The <dfn id="dfn-imag">imag</dfn> parameter represents an array of <code>sine</code> terms (traditionally the B terms).
- The first element (index 0) should be set to zero (and will be ignored) since this term does not exist in the Fourier series.
- The second element (index 1) represents the fundamental frequency. The third element represents the first overtone, and so on.</p>
- </dd>
-</dl>
-</div>
-</div>
-
-<h3 id="lifetime-AudioContext">4.1.3. Lifetime</h3>
-<p class="norm">This section is informative.</p>
-
-<p>
-Once created, an <code>AudioContext</code> will continue to play sound until it has no more sound to play, or
-the page goes away.
-</p>
-
-<div id="OfflineAudioContext-section-section" class="section">
-<h2 id="OfflineAudioContext-section">4.1b. The OfflineAudioContext Interface</h2>
-<p>
-OfflineAudioContext is a particular type of AudioContext for rendering/mixing-down (potentially) faster than real-time.
-It does not render to the audio hardware, but instead renders as quickly as possible, calling a completion event handler
-with the result provided as an AudioBuffer.
-</p>
-
-
-<p>
-</p>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="offline-audio-context-idl">
-[Constructor(unsigned long numberOfChannels, unsigned long length, float sampleRate)]
-interface <dfn id="dfn-OfflineAudioContext">OfflineAudioContext</dfn> : AudioContext {
-
- void startRendering();
-
- attribute EventHandler oncomplete;
-
-};
-</code></pre>
-</div>
-</div>
-
-
-<div id="attributes-OfflineAudioContext-section" class="section">
-<h3 id="attributes-OfflineAudioContext">4.1b.1. Attributes</h3>
-<dl>
- <dt id="dfn-oncomplete"><code>oncomplete</code></dt>
- <dd><p>An EventHandler of type <a href="#OfflineAudioCompletionEvent-section">OfflineAudioCompletionEvent</a>.</p>
- </dd>
-</dl>
-</div>
-
-
-<div id="methodsandparams-OfflineAudioContext-section" class="section">
-<h3 id="methodsandparams-OfflineAudioContext">4.1b.2. Methods and Parameters</h3>
-<dl>
- <dt id="dfn-startRendering">The <code>startRendering</code>
- method</dt>
- <dd><p>Given the current connections and scheduled changes, starts rendering audio. The
- <code>oncomplete</code> handler will be called once the rendering has finished.
- This method must only be called one time or an exception will be thrown.</p>
- </dd>
-</dl>
-</div>
-
-
-<div id="OfflineAudioCompletionEvent-section" class="section">
-<h2 id="OfflineAudioCompletionEvent">4.1c. The OfflineAudioCompletionEvent Interface</h2>
-
-<p>This is an <code>Event</code> object which is dispatched to <a
-href="#OfflineAudioContext-section"><code>OfflineAudioContext</code></a>. </p>
-
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="offline-audio-completion-event-idl">
-
-interface <dfn id="dfn-OfflineAudioCompletionEvent">OfflineAudioCompletionEvent</dfn> : Event {
-
- readonly attribute AudioBuffer renderedBuffer;
-
-};
-</code></pre>
-</div>
-</div>
-
-<div id="attributes-OfflineAudioCompletionEvent-section" class="section">
-<h3 id="attributes-OfflineAudioCompletionEvent">4.1c.1. Attributes</h3>
-<dl>
- <dt id="dfn-renderedBuffer"><code>renderedBuffer</code></dt>
- <dd><p>An AudioBuffer containing the rendered audio data once an OfflineAudioContext has finished rendering.
- It will have a number of channels equal to the <code>numberOfChannels</code> parameter
- of the OfflineAudioContext constructor.</p>
- </dd>
-</dl>
-</div>
-</div>
-
-
-<div id="AudioNode-section-section" class="section">
-<h2 id="AudioNode-section">4.2. The AudioNode Interface</h2>
-
-<p>AudioNodes are the building blocks of an <a
-href="#AudioContext-section"><code>AudioContext</code></a>. This interface
-represents audio sources, the audio destination, and intermediate processing
-modules. These modules can be connected together to form <a
-href="#ModularRouting-section">processing graphs</a> for rendering audio to the
-audio hardware. Each node can have <dfn>inputs</dfn> and/or <dfn>outputs</dfn>.
-A <dfn>source node</dfn> has no inputs
-and a single output. An <a
-href="#AudioDestinationNode-section"><code>AudioDestinationNode</code></a> has
-one input and no outputs and represents the final destination to the audio
-hardware. Most processing nodes such as filters will have one input and one
-output. Each type of <code>AudioNode</code> differs in the details of how it processes or synthesizes audio. But, in general, <code>AudioNodes</code>
-will process its inputs (if it has any), and generate audio for its outputs (if it has any).
- </p>
-
-<p>
-Each <dfn>output</dfn> has one or more <dfn>channels</dfn>. The exact number of channels depends on the details of the specific AudioNode.
-</p>
-
-<p>
-An output may connect to one or more <code>AudioNode</code> inputs, thus <em>fan-out</em> is supported. An input initially has no connections,
-but may be connected from one
-or more <code>AudioNode</code> outputs, thus <em>fan-in</em> is supported. When the <code>connect()</code> method is called to connect
-an output of an AudioNode to an input of an AudioNode, we call that a <dfn>connection</dfn> to the input.
-</p>
-
-<p>
-Each AudioNode <dfn>input</dfn> has a specific number of channels at any given time. This number can change depending on the <dfn>connection(s)</dfn>
-made to the input. If the input has no connections then it has one channel which is silent.
-</p>
-
-<p>
-For each <dfn>input</dfn>, an <code>AudioNode</code> performs a mixing (usually an up-mixing) of all connections to that input.
-
-Please see <a href="#MixerGainStructure-section">Mixer Gain Structure</a> for more informative details, and the <a href="#UpMix-section">Channel up-mixing and down-mixing</a>
- section for normative requirements.
-
-</p>
-
-<p>
-For performance reasons, practical implementations will need to use block processing, with each <code>AudioNode</code> processing a
-fixed number of sample-frames of size <em>block-size</em>. In order to get uniform behavior across implementations, we will define this
-value explicitly. <em>block-size</em> is defined to be 128 sample-frames which corresponds to roughly 3ms at a sample-rate of 44.1KHz.
-</p>
-
-<p>
-AudioNodes are <em>EventTarget</em>s, as described in <cite><a href="http://dom.spec.whatwg.org/">DOM</a></cite>
-<a href="#DOM">[DOM]</a>. This means that it is possible to dispatch events to AudioNodes the same
-way that other EventTargets accept events.
-</p>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="audio-node-idl">
-
-enum <dfn>ChannelCountMode</dfn> {
- "max",
- "clamped-max",
- "explicit"
-};
-
-enum <dfn>ChannelInterpretation</dfn> {
- "speakers",
- "discrete"
-};
-
-interface <dfn id="dfn-AudioNode">AudioNode</dfn> : EventTarget {
-
- void connect(AudioNode destination, optional unsigned long output = 0, optional unsigned long input = 0);
- void connect(AudioParam destination, optional unsigned long output = 0);
- void disconnect(optional unsigned long output = 0);
-
- readonly attribute AudioContext context;
- readonly attribute unsigned long numberOfInputs;
- readonly attribute unsigned long numberOfOutputs;
-
- // Channel up-mixing and down-mixing rules for all inputs.
- attribute unsigned long channelCount;
- attribute ChannelCountMode channelCountMode;
- attribute ChannelInterpretation channelInterpretation;
-
-};
-</code></pre>
-</div>
-</div>
-
-<div id="attributes-AudioNode-section" class="section">
-<h3 id="attributes-AudioNode">4.2.1. Attributes</h3>
-<dl>
- <dt id="dfn-context"><code>context</code></dt>
- <dd><p>The AudioContext which owns this AudioNode.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-numberOfInputs_2"><code>numberOfInputs</code></dt>
- <dd><p>The number of inputs feeding into the AudioNode. For <dfn>source nodes</dfn>,
- this will be 0.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-numberOfOutputs_2"><code>numberOfOutputs</code></dt>
- <dd><p>The number of outputs coming out of the AudioNode. This will be 0
- for an AudioDestinationNode.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-channelCount"><code>channelCount</code><dt>
- <dd><p>The number of channels used when up-mixing and down-mixing connections to any inputs to the node. The default value is 2
- except for specific nodes where its value is specially determined.
- This attribute has no effect for nodes with no inputs.
- If this value is set to zero, the implementation MUST raise the
- NOT_SUPPORTED_ERR exception.</p>
- <p>See the <a href="#UpMix-section">Channel up-mixing and down-mixing</a>
- section for more information on this attribute.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-channelCountMode"><code>channelCountMode</code><dt>
- <dd><p>Determines how channels will be counted when up-mixing and down-mixing connections to any inputs to the node
- . This attribute has no effect for nodes with no inputs.</p>
- <p>See the <a href="#UpMix-section">Channel up-mixing and down-mixing</a>
- section for more information on this attribute.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-channelInterpretation"><code>channelInterpretation</code><dt>
- <dd><p>Determines how individual channels will be treated when up-mixing and down-mixing connections to any inputs to the node.
- This attribute has no effect for nodes with no inputs.</p>
- <p>See the <a href="#UpMix-section">Channel up-mixing and down-mixing</a>
- section for more information on this attribute.</p>
- </dd>
-</dl>
-</div>
-
-<div id="methodsandparams-AudioNode-section" class="section">
-<h3 id="methodsandparams-AudioNode">4.2.2. Methods and Parameters</h3>
-<dl>
- <dt id="dfn-connect-AudioNode">The <code>connect</code> to AudioNode method</dt>
- <dd><p>Connects the AudioNode to another AudioNode.</p>
- <p>The <dfn id="dfn-destination_2">destination</dfn> parameter is the
- AudioNode to connect to.</p>
- <p>The <dfn id="dfn-output_2">output</dfn> parameter is an index
- describing which output of the AudioNode from which to connect. An
- out-of-bound value throws an exception.</p>
- <p>The <dfn id="dfn-input_2">input</dfn> parameter is an index describing
- which input of the destination AudioNode to connect to. An out-of-bound
- value throws an exception. </p>
- <p>It is possible to connect an AudioNode output to more than one input
- with multiple calls to connect(). Thus, "fan-out" is supported. </p>
- <p>
- It is possible to connect an AudioNode to another AudioNode which creates a <em>cycle</em>.
- In other words, an AudioNode may connect to another AudioNode, which in turn connects back
- to the first AudioNode. This is allowed only if there is at least one
- <a class="dfnref" href="#DelayNode-section">DelayNode</a> in the <em>cycle</em> or an exception will
- be thrown.
- </p>
-
- <p>
- There can only be one connection between a given output of one specific node and a given input of another specific node.
- Multiple connections with the same termini are ignored. For example:
- </p>
-
- <pre>
- nodeA.connect(nodeB);
- nodeA.connect(nodeB);
-
- will have the same effect as
-
- nodeA.connect(nodeB);
- </pre>
-
- </dd>
-</dl>
-<dl>
- <dt id="dfn-connect-AudioParam">The <code>connect</code> to AudioParam method</dt>
- <dd><p>Connects the AudioNode to an AudioParam, controlling the parameter
- value with an audio-rate signal.
- </p>
-
- <p>The <dfn id="dfn-destination_3">destination</dfn> parameter is the
- AudioParam to connect to.</p>
- <p>The <dfn id="dfn-output_3-destination">output</dfn> parameter is an index
- describing which output of the AudioNode from which to connect. An
- out-of-bound value throws an exception.</p>
-
- <p>It is possible to connect an AudioNode output to more than one AudioParam
- with multiple calls to connect(). Thus, "fan-out" is supported. </p>
- <p>It is possible to connect more than one AudioNode output to a single AudioParam
- with multiple calls to connect(). Thus, "fan-in" is supported. </p>
- <p>An AudioParam will take the rendered audio data from any AudioNode output connected to it and <a href="#down-mix">convert it to mono</a> by down-mixing if it is not
- already mono, then mix it together with other such outputs and finally will mix with the <em>intrinsic</em>
- parameter value (the value the AudioParam would normally have without any audio connections), including any timeline changes
- scheduled for the parameter. </p>
-
- <p>
- There can only be one connection between a given output of one specific node and a specific AudioParam.
- Multiple connections with the same termini are ignored. For example:
- </p>
-
- <pre>
- nodeA.connect(param);
- nodeA.connect(param);
-
- will have the same effect as
-
- nodeA.connect(param);
- </pre>
-
- </dd>
-</dl>
-<dl>
- <dt id="dfn-disconnect">The <code>disconnect</code> method</dt>
- <dd><p>Disconnects an AudioNode's output.</p>
- <p>The <dfn id="dfn-output_3-disconnect">output</dfn> parameter is an index
- describing which output of the AudioNode to disconnect. An out-of-bound
- value throws an exception.</p>
- </dd>
-</dl>
-</div>
-</div>
-
-<h3 id="lifetime-AudioNode">4.2.3. Lifetime</h3>
-
-<p class="norm">This section is informative.</p>
-
-<p>An implementation may choose any method to avoid unnecessary resource usage and unbounded memory growth of unused/finished
-nodes. The following is a description to help guide the general expectation of how node lifetime would be managed.
-</p>
-
-<p>
-An <code>AudioNode</code> will live as long as there are any references to it. There are several types of references:
-</p>
-
-<ol>
-<li>A <em>normal</em> JavaScript reference obeying normal garbage collection rules. </li>
-<li>A <em>playing</em> reference for both <code>AudioBufferSourceNodes</code> and <code>OscillatorNodes</code>.
-These nodes maintain a <em>playing</em>
-reference to themselves while they are currently playing.</li>
-<li>A <em>connection</em> reference which occurs if another <code>AudioNode</code> is connected to it. </li>
-<li>A <em>tail-time</em> reference which an <code>AudioNode</code> maintains on itself as long as it has
-any internal processing state which has not yet been emitted. For example, a <code>ConvolverNode</code> has
-a tail which continues to play even after receiving silent input (think about clapping your hands in a large concert
- hall and continuing to hear the sound reverberate throughout the hall). Some <code>AudioNodes</code> have this
- property. Please see details for specific nodes.</li>
-</ol>
-
-<p>
-Any <code>AudioNodes</code> which are connected in a cycle <em>and</em> are directly or indirectly connected to the
-<code>AudioDestinationNode</code> of the <code>AudioContext</code> will stay alive as long as the <code>AudioContext</code> is alive.
-</p>
-
-<p>
-When an <code>AudioNode</code> has no references it will be deleted. But before it is deleted, it will disconnect itself
-from any other <code>AudioNodes</code> which it is connected to. In this way it releases all connection references (3) it has to other nodes.
-</p>
-
-<p>
-Regardless of any of the above references, it can be assumed that the <code>AudioNode</code> will be deleted when its <code>AudioContext</code> is deleted.
-</p>
-
-
-<div id="AudioDestinationNode-section" class="section">
-<h2 id="AudioDestinationNode">4.4. The AudioDestinationNode Interface</h2>
-
-<p>This is an <a href="#AudioNode-section"><code>AudioNode</code></a>
-representing the final audio destination and is what the user will ultimately
-hear. It can often be considered as an audio output device which is connected to
-speakers. All rendered audio to be heard will be routed to this node, a
-"terminal" node in the AudioContext's routing graph. There is only a single
-AudioDestinationNode per AudioContext, provided through the
-<code>destination</code> attribute of <a
-href="#AudioContext-section"><code>AudioContext</code></a>. </p>
-<pre>
- numberOfInputs : 1
- numberOfOutputs : 0
-
- channelCount = 2;
- channelCountMode = "explicit";
- channelInterpretation = "speakers";
-</pre>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="audio-destination-node-idl">
-
-interface <dfn id="dfn-AudioDestinationNode">AudioDestinationNode</dfn> : AudioNode {
-
- readonly attribute unsigned long maxChannelCount;
-
-};
-</code></pre>
-</div>
-</div>
-
-<div id="attributes-AudioDestinationNode-section" class="section">
-<h3 id="attributes-AudioDestinationNode">4.4.1. Attributes</h3>
-<dl>
- <dt id="dfn-maxChannelCount"><code>maxChannelCount</code></dt>
- <dd><p>The maximum number of channels that the <code>channelCount</code> attribute can be set to.
- An <code>AudioDestinationNode</code> representing the audio hardware end-point (the normal case) can potentially output more than
- 2 channels of audio if the audio hardware is multi-channel. <code>maxChannelCount</code> is the maximum number of channels that
- this hardware is capable of supporting. If this value is 0, then this indicates that <code>channelCount</code> may not be
- changed. This will be the case for an <code>AudioDestinationNode</code> in an <code>OfflineAudioContext</code> and also for
- basic implementations with hardware support for stereo output only.</p>
-
- <p><code>channelCount</code> defaults to 2 for a destination in a normal AudioContext, and may be set to any non-zero value less than or equal
- to <code>maxChannelCount</code>. An exception will be thrown if this value is not within the valid range. Giving a concrete example, if
- the audio hardware supports 8-channel output, then we may set <code>numberOfChannels</code> to 8, and render 8-channels of output.
- </p>
-
- <p>
- For an AudioDestinationNode in an OfflineAudioContext, the <code>channelCount</code> is determined when the offline context is created and this value
- may not be changed.
- </p>
-
- </dd>
-</dl>
-
-</div>
-</div>
-
-<div id="AudioParam-section" class="section">
-<h2 id="AudioParam">4.5. The AudioParam Interface</h2>
-
-<p>AudioParam controls an individual aspect of an <a
-href="#AudioNode-section"><code>AudioNode</code></a>'s functioning, such as
-volume. The parameter can be set immediately to a particular value using the
-"value" attribute. Or, value changes can be scheduled to happen at
-very precise times (in the coordinate system of AudioContext.currentTime), for envelopes, volume fades, LFOs, filter sweeps, grain
-windows, etc. In this way, arbitrary timeline-based automation curves can be
-set on any AudioParam. Additionally, audio signals from the outputs of <code>AudioNodes</code> can be connected
-to an <code>AudioParam</code>, summing with the <em>intrinsic</em> parameter value.
-</p>
-
-<p>
-Some synthesis and processing <code>AudioNodes</code> have <code>AudioParams</code> as attributes whose values must
- be taken into account on a per-audio-sample basis.
-For other <code>AudioParams</code>, sample-accuracy is not important and the value changes can be sampled more coarsely.
-Each individual <code>AudioParam</code> will specify that it is either an <em>a-rate</em> parameter
-which means that its values must be taken into account on a per-audio-sample basis, or it is a <em>k-rate</em> parameter.
-</p>
-
-<p>
-Implementations must use block processing, with each <code>AudioNode</code>
-processing 128 sample-frames in each block.
-</p>
-
-<p>
-For each 128 sample-frame block, the value of a <em>k-rate</em> parameter must
-be sampled at the time of the very first sample-frame, and that value must be
-used for the entire block. <em>a-rate</em> parameters must be sampled for each
-sample-frame of the block.
-</p>
-
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="audio-param-idl">
-
-interface <dfn id="dfn-AudioParam">AudioParam</dfn> {
-
- attribute float value;
- readonly attribute float defaultValue;
-
- <span class="comment">// Parameter automation. </span>
- void setValueAtTime(float value, double startTime);
- void linearRampToValueAtTime(float value, double endTime);
- void exponentialRampToValueAtTime(float value, double endTime);
-
- <span class="comment">// Exponentially approach the target value with a rate having the given time constant. </span>
- void setTargetAtTime(float target, double startTime, double timeConstant);
-
- <span class="comment">// Sets an array of arbitrary parameter values starting at time for the given duration. </span>
- <span class="comment">// The number of values will be scaled to fit into the desired duration. </span>
- void setValueCurveAtTime(Float32Array values, double startTime, double duration);
-
- <span class="comment">// Cancels all scheduled parameter changes with times greater than or equal to startTime. </span>
- void cancelScheduledValues(double startTime);
-
-};
-</code></pre>
-</div>
-</div>
-
-
-
-<div id="attributes-AudioParam-section" class="section">
-<h3 id="attributes-AudioParam">4.5.1. Attributes</h3>
-
-<dl>
- <dt id="dfn-value"><code>value</code></dt>
- <dd><p>The parameter's floating-point value. This attribute is initialized to the
- <code>defaultValue</code>. If a value is set during a time when there are any automation events scheduled then
- it will be ignored and no exception will be thrown.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-defaultValue"><code>defaultValue</code></dt>
- <dd><p>Initial value for the value attribute</p>
- </dd>
-</dl>
-</div>
-
-<div id="methodsandparams-AudioParam-section" class="section">
-<h3 id="methodsandparams-AudioParam">4.5.2. Methods and Parameters</h3>
-
-<p>
-An <code>AudioParam</code> maintains a time-ordered event list which is initially empty. The times are in
-the time coordinate system of AudioContext.currentTime. The events define a mapping from time to value. The following methods
-can change the event list by adding a new event into the list of a type specific to the method. Each event
-has a time associated with it, and the events will always be kept in time-order in the list. These
-methods will be called <em>automation</em> methods:</p>
-
-<ul>
-<li>setValueAtTime() - <em>SetValue</em></li>
-<li>linearRampToValueAtTime() - <em>LinearRampToValue</em></li>
-<li>exponentialRampToValueAtTime() - <em>ExponentialRampToValue</em></li>
-<li>setTargetAtTime() - <em>SetTarget</em></li>
-<li>setValueCurveAtTime() - <em>SetValueCurve</em></li>
-</ul>
-
-<p>
-The following rules will apply when calling these methods:
-</p>
-<ul>
-<li>If one of these events is added at a time where there is already an event of the exact same type, then the new event will replace the old
-one.</li>
-<li>If one of these events is added at a time where there is already one or more events of a different type, then it will be
-placed in the list after them, but before events whose times are after the event. </li>
-<li>If setValueCurveAtTime() is called for time T and duration D and there are any events having a time greater than T, but less than
-T + D, then an exception will be thrown. In other words, it's not ok to schedule a value curve during a time period containing other events.</li>
-<li>Similarly an exception will be thrown if any <em>automation</em> method is called at a time which is inside of the time interval
-of a <em>SetValueCurve</em> event at time T and duration D.</li>
-</ul>
-<p>
-</p>
-
-<dl>
- <dt id="dfn-setValueAtTime">The <code>setValueAtTime</code> method</dt>
- <dd><p>Schedules a parameter value change at the given time.</p>
- <p>The <dfn id="dfn-value_2">value</dfn> parameter is the value the
- parameter will change to at the given time.</p>
- <p>The <dfn id="dfn-startTime_2">startTime</dfn> parameter is the time in the same time coordinate system as AudioContext.currentTime.</p>
- <p>
- If there are no more events after this <em>SetValue</em> event, then for t >= startTime, v(t) = value. In other words, the value will remain constant.
- </p>
- <p>
- If the next event (having time T1) after this <em>SetValue</em> event is not of type <em>LinearRampToValue</em> or <em>ExponentialRampToValue</em>,
- then, for t: startTime &lt;= t &lt; T1, v(t) = value.
- In other words, the value will remain constant during this time interval, allowing the creation of "step" functions.
- </p>
- <p>
- If the next event after this <em>SetValue</em> event is of type <em>LinearRampToValue</em> or <em>ExponentialRampToValue</em> then please
- see details below.
- </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-linearRampToValueAtTime">The <code>linearRampToValueAtTime</code>
- method</dt>
- <dd><p>Schedules a linear continuous change in parameter value from the
- previous scheduled parameter value to the given value.</p>
- <p>The <dfn id="dfn-value_3">value</dfn> parameter is the value the
- parameter will linearly ramp to at the given time.</p>
- <p>The <dfn id="dfn-endTime_3">endTime</dfn> parameter is the time in the same time coordinate system as AudioContext.currentTime.</p>
-
- <p>
- The value during the time interval T0 &lt;= t &lt; T1 (where T0 is the time of the previous event and T1 is the endTime parameter passed into this method)
- will be calculated as:
- </p>
- <pre>
- v(t) = V0 + (V1 - V0) * ((t - T0) / (T1 - T0))
- </pre>
- <p>
- Where V0 is the value at the time T0 and V1 is the value parameter passed into this method.
- </p>
- <p>
- If there are no more events after this LinearRampToValue event then for t >= T1, v(t) = V1
- </p>
-
- </dd>
-</dl>
-<dl>
- <dt id="dfn-exponentialRampToValueAtTime">The
- <code>exponentialRampToValueAtTime</code> method</dt>
- <dd><p>Schedules an exponential continuous change in parameter value from
- the previous scheduled parameter value to the given value. Parameters
- representing filter frequencies and playback rate are best changed
- exponentially because of the way humans perceive sound. </p>
- <p>The <dfn id="dfn-value_4">value</dfn> parameter is the value the
- parameter will exponentially ramp to at the given time. An exception will be thrown if this value is less than
- or equal to 0, or if the value at the time of the previous event is less than or equal to 0.</p>
- <p>The <dfn id="dfn-endTime_4">endTime</dfn> parameter is the time in the same time coordinate system as AudioContext.currentTime.</p>
- <p>
- The value during the time interval T0 &lt;= t &lt; T1 (where T0 is the time of the previous event and T1 is the endTime parameter passed into this method)
- will be calculated as:
- </p>
- <pre>
- v(t) = V0 * (V1 / V0) ^ ((t - T0) / (T1 - T0))
- </pre>
- <p>
- Where V0 is the value at the time T0 and V1 is the value parameter passed into this method.
- </p>
- <p>
- If there are no more events after this ExponentialRampToValue event then for t >= T1, v(t) = V1
- </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-setTargetAtTime">The <code>setTargetAtTime</code>
- method</dt>
- <dd><p>Start exponentially approaching the target value at the given time
- with a rate having the given time constant. Among other uses, this is
- useful for implementing the "decay" and "release" portions of an ADSR
- envelope. Please note that the parameter value does not immediately
- change to the target value at the given time, but instead gradually
- changes to the target value.</p>
- <p>The <dfn id="dfn-target">target</dfn> parameter is the value
- the parameter will <em>start</em> changing to at the given time.</p>
- <p>The <dfn id="dfn-startTime">startTime</dfn> parameter is the time in the same time coordinate system as AudioContext.currentTime.</p>
- <p>The <dfn id="dfn-timeConstant">timeConstant</dfn> parameter is the
- time-constant value of first-order filter (exponential) approach to the
- target value. The larger this value is, the slower the transition will
- be.</p>
- <p>
- More precisely, <em>timeConstant</em> is the time it takes a first-order linear continuous time-invariant system
- to reach the value 1 - 1/e (around 63.2%) given a step input response (transition from 0 to 1 value).
- </p>
- <p>
- During the time interval: <em>T0</em> &lt;= t &lt; <em>T1</em>, where T0 is the <em>startTime</em> parameter and T1 represents the time of the event following this
- event (or <em>infinity</em> if there are no following events):
- </p>
- <pre>
- v(t) = V1 + (V0 - V1) * exp(-(t - T0) / <em>timeConstant</em>)
- </pre>
- <p>
- Where V0 is the initial value (the .value attribute) at T0 (the <em>startTime</em> parameter) and V1 is equal to the <em>target</em>
- parameter.
- </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-setValueCurveAtTime">The <code>setValueCurveAtTime</code>
- method</dt>
- <dd><p>Sets an array of arbitrary parameter values starting at the given
- time for the given duration. The number of values will be scaled to fit
- into the desired duration. </p>
- <p>The <dfn id="dfn-values">values</dfn> parameter is a Float32Array
- representing a parameter value curve. These values will apply starting at
- the given time and lasting for the given duration. </p>
- <p>The <dfn id="dfn-startTime_5">startTime</dfn> parameter is the time in the same time coordinate system as AudioContext.currentTime.</p>
- <p>The <dfn id="dfn-duration_5">duration</dfn> parameter is the
- amount of time in seconds (after the <em>time</em> parameter) where values will be calculated according to the <em>values</em> parameter..</p>
- <p>
- During the time interval: <em>startTime</em> &lt;= t &lt; <em>startTime</em> + <em>duration</em>, values will be calculated:
- </p>
- <pre>
- v(t) = values[N * (t - startTime) / duration], where <em>N</em> is the length of the <em>values</em> array.
- </pre>
- <p>
- After the end of the curve time interval (t >= <em>startTime</em> + <em>duration</em>), the value will remain constant at the final curve value,
- until there is another automation event (if any).
- </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-cancelScheduledValues">The <code>cancelScheduledValues</code>
- method</dt>
- <dd><p>Cancels all scheduled parameter changes with times greater than or
- equal to startTime.</p>
- <p>The <dfn>startTime</dfn> parameter is the starting
- time at and after which any previously scheduled parameter changes will
- be cancelled. It is a time in the same time coordinate system as AudioContext.currentTime.</p>
- </dd>
-</dl>
-</div>
-</div>
-
-
-
-<div id="computedValue-AudioParam-section" class="section">
-<h3>4.5.3. Computation of Value</h3>
-
-<p>
-<dfn>computedValue</dfn> is the final value controlling the audio DSP and is computed by the audio rendering thread during each rendering time quantum.
- It must be internally computed as follows:
-</p>
-
-<ol>
-<li>An <em>intrinsic</em> parameter value will be calculated at each time, which is either the value set directly to the .value attribute,
-or, if there are any scheduled parameter changes (automation events) with times before or at this time,
-the value as calculated from these events. If the .value attribute
-is set after any automation events have been scheduled, then these events will be removed. When read, the .value attribute
-always returns the <em>intrinsic</em> value for the current time. If automation events are removed from a given time range, then the
-<em>intrinsic</em> value will remain unchanged and stay at its previous value until either the .value attribute is directly set, or automation events are added
-for the time range.
-</li>
-
-<li>
-An AudioParam will take the rendered audio data from any AudioNode output connected to it and <a href="#down-mix">convert it to mono</a> by down-mixing if it is not
-already mono, then mix it together with other such outputs. If there are no AudioNodes connected to it, then this value is 0, having no
-effect on the <em>computedValue</em>.
-</li>
-
-<li>
-The <em>computedValue</em> is the sum of the <em>intrinsic</em> value and the value calculated from (2).
-</li>
-
-</ol>
-
-</div>
-
-
-<div id="example1-AudioParam-section" class="section">
-<h3 id="example1-AudioParam">4.5.4. AudioParam Automation Example</h3>
-
-
-
-<div class="example">
-
-<div class="exampleHeader">
-Example</div>
-<img alt="AudioParam automation" src="images/audioparam-automation1.png" />
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">ECMAScript</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="es-code">
-var t0 = 0;
-var t1 = 0.1;
-var t2 = 0.2;
-var t3 = 0.3;
-var t4 = 0.4;
-var t5 = 0.6;
-var t6 = 0.7;
-var t7 = 1.0;
-
-var curveLength = 44100;
-var curve = new Float32Array(curveLength);
-for (var i = 0; i &lt; curveLength; ++i)
- curve[i] = Math.sin(Math.PI * i / curveLength);
-
-param.setValueAtTime(0.2, t0);
-param.setValueAtTime(0.3, t1);
-param.setValueAtTime(0.4, t2);
-param.linearRampToValueAtTime(1, t3);
-param.linearRampToValueAtTime(0.15, t4);
-param.exponentialRampToValueAtTime(0.75, t5);
-param.exponentialRampToValueAtTime(0.05, t6);
-param.setValueCurveAtTime(curve, t6, t7 - t6);
-</code></pre>
-</div>
-</div>
-</div>
-</div>
-
-<div id="GainNode-section" class="section">
-<h2 id="GainNode">4.7. The GainNode Interface</h2>
-
-<p>Changing the gain of an audio signal is a fundamental operation in audio
-applications. The <code>GainNode</code> is one of the building blocks for creating <a
-href="#MixerGainStructure-section">mixers</a>.
-This interface is an AudioNode with a single input and single
-output: </p>
-<pre>
- numberOfInputs : 1
- numberOfOutputs : 1
-
- channelCountMode = "max";
- channelInterpretation = "speakers";
-</pre>
-
-<p>It multiplies the input audio signal by the (possibly time-varying) <code>gain</code> attribute, copying the result to the output.
- By default, it will take the input and pass it through to the output unchanged, which represents a constant gain change
- of 1.
-</p>
-
-<p>
-As with other <code>AudioParams</code>, the <code>gain</code> parameter represents a mapping from time
-(in the coordinate system of AudioContext.currentTime) to floating-point value.
-
-Every PCM audio sample in the input is multiplied by the <code>gain</code> parameter's value for the specific time
-corresponding to that audio sample. This multiplied value represents the PCM audio sample for the output.
-</p>
-
-<p>
-The number of channels of the output will always equal the number of channels of the input, with each channel
-of the input being multiplied by the <code>gain</code> values and being copied into the corresponding channel
-of the output.
-</p>
-
-<p>
- The implementation must make
-gain changes to the audio stream smoothly, without introducing noticeable
-clicks or glitches. This process is called "de-zippering". </p>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="gain-node-idl">
-
-interface <dfn id="dfn-GainNode">GainNode</dfn> : AudioNode {
-
- readonly attribute AudioParam gain;
-
-};
-</code></pre>
-</div>
-</div>
-
-<div id="attributes-GainNode-section" class="section">
-<h3 id="attributes-GainNode">4.7.1. Attributes</h3>
-<dl>
- <dt id="dfn-gain"><code>gain</code></dt>
- <dd><p>Represents the amount of gain to apply. Its
- default <code>value</code> is 1 (no gain change). The nominal <code>minValue</code> is 0, but may be
- set negative for phase inversion. The nominal <code>maxValue</code> is 1, but higher values are allowed (no
- exception thrown).This parameter is <em>a-rate</em> </p>
- </dd>
-</dl>
-</div>
-</div>
-
-<div id="DelayNode-section" class="section">
-<h2 id="DelayNode">4.8. The DelayNode Interface</h2>
-
-<p>A delay-line is a fundamental building block in audio applications. This
-interface is an AudioNode with a single input and single output: </p>
-<pre>
- numberOfInputs : 1
- numberOfOutputs : 1
-
- channelCountMode = "max";
- channelInterpretation = "speakers";
-</pre>
-
-<p>
-The number of channels of the output always equals the number of channels of the input.
-</p>
-
-<p>It delays the incoming audio signal by a certain amount. The default
-amount is 0 seconds (no delay). When the delay time is changed, the
-implementation must make the transition smoothly, without introducing
-noticeable clicks or glitches to the audio stream. </p>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="delay-node-idl">
-
-interface <dfn id="dfn-DelayNode">DelayNode</dfn> : AudioNode {
-
- readonly attribute AudioParam delayTime;
-
-};
-</code></pre>
-</div>
-</div>
-
-<div id="attributes-GainNode-section_2" class="section">
-<h3 id="attributes-GainNode_2">4.8.1. Attributes</h3>
-<dl>
- <dt id="dfn-delayTime_2"><code>delayTime</code></dt>
- <dd><p>An AudioParam object representing the amount of delay (in seconds)
- to apply. The default value (<code>delayTime.value</code>) is 0 (no
- delay). The minimum value is 0 and the maximum value is determined by the <em>maxDelayTime</em>
- argument to the <code>AudioContext</code> method <code>createDelay</code>. This parameter is <em>a-rate</em></p>
- </dd>
-</dl>
-</div>
-</div>
-
-<div id="AudioBuffer-section" class="section">
-<h2 id="AudioBuffer">4.9. The AudioBuffer Interface</h2>
-
-<p>This interface represents a memory-resident audio asset (for one-shot sounds
-and other short audio clips). Its format is non-interleaved IEEE 32-bit linear PCM with a
-nominal range of -1 -&gt; +1. It can contain one or more channels. Typically, it would be expected that the length
-of the PCM data would be fairly short (usually somewhat less than a minute).
-For longer sounds, such as music soundtracks, streaming should be used with the
-<code>audio</code> element and <code>MediaElementAudioSourceNode</code>. </p>
-
-<p>
-An AudioBuffer may be used by one or more AudioContexts.
-</p>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="audio-buffer-idl">
-
-interface <dfn id="dfn-AudioBuffer">AudioBuffer</dfn> {
-
- readonly attribute float sampleRate;
- readonly attribute long length;
-
- <span class="comment">// in seconds </span>
- readonly attribute double duration;
-
- readonly attribute long numberOfChannels;
-
- Float32Array getChannelData(unsigned long channel);
-
-};
-</code></pre>
-</div>
-</div>
-
-<div id="attributes-AudioBuffer-section" class="section">
-<h3 id="attributes-AudioBuffer">4.9.1. Attributes</h3>
-<dl>
- <dt id="dfn-sampleRate_AudioBuffer"><code>sampleRate</code></dt>
- <dd><p>The sample-rate for the PCM audio data in samples per second.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-length_AudioBuffer"><code>length</code></dt>
- <dd><p>Length of the PCM audio data in sample-frames.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-duration_AudioBuffer"><code>duration</code></dt>
- <dd><p>Duration of the PCM audio data in seconds.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-numberOfChannels_AudioBuffer"><code>numberOfChannels</code></dt>
- <dd><p>The number of discrete audio channels.</p>
- </dd>
-</dl>
-</div>
-
-<div id="methodsandparams-AudioBuffer-section" class="section">
-<h3 id="methodsandparams-AudioBuffer">4.9.2. Methods and Parameters</h3>
-<dl>
- <dt id="dfn-getChannelData">The <code>getChannelData</code> method</dt>
- <dd><p>Returns the <code>Float32Array</code> representing the PCM audio data for the specific channel.</p>
- <p>The <dfn id="dfn-channel">channel</dfn> parameter is an index
- representing the particular channel to get data for. An index value of 0 represents
- the first channel. This index value MUST be less than <code>numberOfChannels</code>
- or an exception will be thrown.</p>
- </dd>
-</dl>
-</div>
-</div>
-
-<div id="AudioBufferSourceNode-section" class="section">
-<h2 id="AudioBufferSourceNode">4.10. The AudioBufferSourceNode Interface</h2>
-
-<p>This interface represents an audio source from an in-memory audio asset in
-an <code>AudioBuffer</code>. It is useful for playing short audio assets
-which require a high degree of scheduling flexibility (can playback in
-rhythmically perfect ways). The start() method is used to schedule when
-sound playback will happen. The playback will stop automatically when
-the buffer's audio data has been completely
-played (if the <code>loop</code> attribute is false), or when the stop()
-method has been called and the specified time has been reached. Please see more
-details in the start() and stop() description. start() and stop() may not be issued
-multiple times for a given
-AudioBufferSourceNode. </p>
-<pre> numberOfInputs : 0
- numberOfOutputs : 1
- </pre>
-
-<p>
-The number of channels of the output always equals the number of channels of the AudioBuffer
-assigned to the .buffer attribute, or is one channel of silence if .buffer is NULL.
-</p>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="audio-buffer-source-node-idl">
-
-interface <dfn id="dfn-AudioBufferSourceNode">AudioBufferSourceNode</dfn> : AudioNode {
-
- attribute AudioBuffer? buffer;
-
- readonly attribute AudioParam playbackRate;
-
- attribute boolean loop;
- attribute double loopStart;
- attribute double loopEnd;
-
- void start(optional double when = 0, optional double offset = 0, optional double duration);
- void stop(optional double when = 0);
-
- attribute EventHandler onended;
-
-};
-</code></pre>
-</div>
-</div>
-
-<div id="attributes-AudioBufferSourceNode-section" class="section">
-<h3 id="attributes-AudioBufferSourceNode">4.10.1. Attributes</h3>
-<dl>
- <dt id="dfn-buffer_AudioBufferSourceNode"><code>buffer</code></dt>
- <dd><p>Represents the audio asset to be played. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-playbackRate_AudioBufferSourceNode"><code>playbackRate</code></dt>
- <dd><p>The speed at which to render the audio stream. The default
- playbackRate.value is 1. This parameter is <em>a-rate</em> </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-loop_AudioBufferSourceNode"><code>loop</code></dt>
- <dd><p>Indicates if the audio data should play in a loop. The default value is false. </p>
- </dd>
-</dl>
-
-<dl>
- <dt id="dfn-loopStart_AudioBufferSourceNode"><code>loopStart</code></dt>
- <dd><p>An optional value in seconds where looping should begin if the <code>loop</code> attribute is true.
- Its default value is 0, and it may usefully be set to any value between 0 and the duration of the buffer.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-loopEnd_AudioBufferSourceNode"><code>loopEnd</code></dt>
- <dd><p>An optional value in seconds where looping should end if the <code>loop</code> attribute is true.
- Its default value is 0, and it may usefully be set to any value between 0 and the duration of the buffer.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-onended_AudioBufferSourceNode"><code>onended</code></dt>
- <dd><p>A property used to set the <code>EventHandler</code> (described in <cite><a
- href="http://www.whatwg.org/specs/web-apps/current-work/#eventhandler">HTML</a></cite>)
- for the ended event that is dispatched to <a
- href="#AudioBufferSourceNode-section"><code>AudioBufferSourceNode</code></a>
- node types. When the playback of the buffer for an <code>AudioBufferSourceNode</code>
- is finished, an event of type <code>Event</code> (described in <cite><a
- href="http://www.whatwg.org/specs/web-apps/current-work/#event">HTML</a></cite>)
- will be dispatched to the event handler. </p>
- </dd>
-</dl>
-
-
-</div>
-</div>
-
-<div id="methodsandparams-AudioBufferSourceNode-section" class="section">
-<h3 id="methodsandparams-AudioBufferSourceNode">4.10.2. Methods and
-Parameters</h3>
-<dl>
- <dt id="dfn-start">The <code>start</code> method</dt>
- <dd><p>Schedules a sound to playback at an exact time.</p>
- <p>The <dfn id="dfn-when">when</dfn> parameter describes at what time (in
- seconds) the sound should start playing. It is in the same
- time coordinate system as AudioContext.currentTime. If 0 is passed in for
- this value or if the value is less than <b>currentTime</b>, then the
- sound will start playing immediately. <code>start</code> may only be called one time
- and must be called before <code>stop</code> is called or an exception will be thrown.</p>
- <p>The <dfn id="dfn-offset">offset</dfn> parameter describes
- the offset time in the buffer (in seconds) where playback will begin. If 0 is passed
- in for this value, then playback will start from the beginning of the buffer.</p>
- <p>The <dfn id="dfn-duration">duration</dfn> parameter
- describes the duration of the portion (in seconds) to be played. If this parameter is not passed,
- the duration will be equal to the total duration of the AudioBuffer minus the <code>offset</code> parameter.
- Thus if neither <code>offset</code> nor <code>duration</code> are specified then the implied duration is
- the total duration of the AudioBuffer.
- </p>
-
- </dd>
-</dl>
-<dl>
- <dt id="dfn-stop">The <code>stop</code> method</dt>
- <dd><p>Schedules a sound to stop playback at an exact time.</p>
- <p>The <dfn id="dfn-when_AudioBufferSourceNode_2">when</dfn> parameter
- describes at what time (in seconds) the sound should stop playing.
- It is in the same time coordinate system as AudioContext.currentTime.
- If 0 is passed in for this value or if the value is less than
- <b>currentTime</b>, then the sound will stop playing immediately.
- <code>stop</code> must only be called one time and only after a call to <code>start</code> or <code>stop</code>,
- or an exception will be thrown.</p>
- </dd>
-</dl>
-</div>
-
-<div id="looping-AudioBufferSourceNode-section" class="section">
-<h3 id="looping-AudioBufferSourceNode">4.10.3. Looping</h3>
-<p>
-If the <code>loop</code> attribute is true when <code>start()</code> is called, then playback will continue indefinitely
-until <code>stop()</code> is called and the stop time is reached. We'll call this "loop" mode. Playback always starts at the point in the buffer indicated
-by the <code>offset</code> argument of <code>start()</code>, and in <em>loop</em> mode will continue playing until it reaches the <em>actualLoopEnd</em> position
-in the buffer (or the end of the buffer), at which point it will wrap back around to the <em>actualLoopStart</em> position in the buffer, and continue
-playing according to this pattern.
-</p>
-
-<p>
-In <em>loop</em> mode then the <em>actual</em> loop points are calculated as follows from the <code>loopStart</code> and <code>loopEnd</code> attributes:
-</p>
-
-<blockquote>
-<pre>
- if ((loopStart || loopEnd) &amp;&amp; loopStart >= 0 &amp;&amp; loopEnd > 0 &amp;&amp; loopStart &lt; loopEnd) {
- actualLoopStart = loopStart;
- actualLoopEnd = min(loopEnd, buffer.length);
- } else {
- actualLoopStart = 0;
- actualLoopEnd = buffer.length;
- }
-</pre>
-</blockquote>
-
-<p>
-Note that the default values for <code>loopStart</code> and <code>loopEnd</code> are both 0, which indicates that looping should occur from the very start
-to the very end of the buffer.
-</p>
-
-<p>
-Please note that as a low-level implementation detail, the AudioBuffer is at a specific sample-rate (usually the same as the AudioContext sample-rate), and
-that the loop times (in seconds) must be converted to the appropriate sample-frame positions in the buffer according to this sample-rate.
-</p>
-
-</div>
-
-<div id="MediaElementAudioSourceNode-section" class="section">
-<h2 id="MediaElementAudioSourceNode">4.11. The MediaElementAudioSourceNode
-Interface</h2>
-
-<p>This interface represents an audio source from an <code>audio</code> or
-<code>video</code> element. </p>
-<pre> numberOfInputs : 0
- numberOfOutputs : 1
- </pre>
-
-<p>
-The number of channels of the output corresponds to the number of channels of the media referenced by the HTMLMediaElement.
-Thus, changes to the media element's .src attribute can change the number of channels output by this node.
-If the .src attribute is not set, then the number of channels output will be one silent channel.
-</p>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="media-element-audio-source-node-idl">
-
-interface <dfn id="dfn-MediaElementAudioSourceNode">MediaElementAudioSourceNode</dfn> : AudioNode {
-
-};
-</code></pre>
-</div>
-</div>
-</div>
-
-<p>A MediaElementAudioSourceNode
-is created given an HTMLMediaElement using the AudioContext <a href="#dfn-createMediaElementSource">createMediaElementSource()</a> method. </p>
-
-<p>
-The number of channels of the single output equals the number of channels of the audio referenced by
-the HTMLMediaElement passed in as the argument to createMediaElementSource(), or is 1 if the HTMLMediaElement
-has no audio.
-</p>
-
-<p>
-The HTMLMediaElement must behave in an identical fashion after the MediaElementAudioSourceNode has
-been created, <em>except</em> that the rendered audio will no longer be heard directly, but instead will be heard
-as a consequence of the MediaElementAudioSourceNode being connected through the routing graph. Thus pausing, seeking,
-volume, <code>.src</code> attribute changes, and other aspects of the HTMLMediaElement must behave as they normally would
-if <em>not</em> used with a MediaElementAudioSourceNode.
-</p>
-
-<div class="example">
-
-<div class="exampleHeader">
-Example</div>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">ECMAScript</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="es-code">
-var mediaElement = document.getElementById('mediaElementID');
-var sourceNode = context.createMediaElementSource(mediaElement);
-sourceNode.connect(filterNode);
- </code></pre>
-</div>
-</div>
-</div>
-</div>
-
-
-<div id="ScriptProcessorNode-section" class="section">
-<h2 id="ScriptProcessorNode">4.12. The ScriptProcessorNode Interface</h2>
-
-<p>This interface is an AudioNode which can generate, process, or analyse audio
-directly using JavaScript. </p>
-<pre>
- numberOfInputs : 1
- numberOfOutputs : 1
-
- channelCount = numberOfInputChannels;
- channelCountMode = "explicit";
- channelInterpretation = "speakers";
-</pre>
-
-<p>The ScriptProcessorNode is constructed with a <code>bufferSize</code> which
-must be one of the following values: 256, 512, 1024, 2048, 4096, 8192, 16384.
-This value controls how frequently the <code>audioprocess</code> event
-is dispatched and how many sample-frames need to be processed each call.
-Lower numbers for <code>bufferSize</code> will result in a lower (better) <a
-href="#Latency-section">latency</a>. Higher numbers will be necessary to avoid
-audio breakup and <a href="#Glitching-section">glitches</a>.
-This value will be picked by the implementation if the bufferSize argument
-to <code>createScriptProcessor</code> is not passed in, or is set to 0.</p>
-
-<p><code>numberOfInputChannels</code> and <code>numberOfOutputChannels</code>
-determine the number of input and output channels. It is invalid for both
-<code>numberOfInputChannels</code> and <code>numberOfOutputChannels</code> to
-be zero. </p>
-<pre> var node = context.createScriptProcessor(bufferSize, numberOfInputChannels, numberOfOutputChannels);
- </pre>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="script-processor-node-idl">
-
-interface <dfn id="dfn-ScriptProcessorNode">ScriptProcessorNode</dfn> : AudioNode {
-
- attribute EventHandler onaudioprocess;
-
- readonly attribute long bufferSize;
-
-};
-</code></pre>
-</div>
-</div>
-
-<div id="attributes-ScriptProcessorNode-section" class="section">
-<h3 id="attributes-ScriptProcessorNode">4.12.1. Attributes</h3>
-<dl>
- <dt id="dfn-onaudioprocess"><code>onaudioprocess</code></dt>
- <dd><p>A property used to set the <code>EventHandler</code> (described in <cite><a
- href="http://www.whatwg.org/specs/web-apps/current-work/#eventhandler">HTML</a></cite>)
- for the audioprocess event that is dispatched to <a
- href="#ScriptProcessorNode-section"><code>ScriptProcessorNode</code></a>
- node types. An event of type <a
- href="#AudioProcessingEvent-section"><code>AudioProcessingEvent</code></a>
- will be dispatched to the event handler. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-bufferSize_ScriptProcessorNode"><code>bufferSize</code></dt>
- <dd><p>The size of the buffer (in sample-frames) which needs to be
- processed each time <code>onprocessaudio</code> is called. Legal values
- are (256, 512, 1024, 2048, 4096, 8192, 16384). </p>
- </dd>
-</dl>
-</div>
-</div>
-
-<div id="AudioProcessingEvent-section" class="section">
-<h2 id="AudioProcessingEvent">4.13. The AudioProcessingEvent Interface</h2>
-
-<p>This is an <code>Event</code> object which is dispatched to <a
-href="#ScriptProcessorNode-section"><code>ScriptProcessorNode</code></a> nodes. </p>
-
-<p>The event handler processes audio from the input (if any) by accessing the
-audio data from the <code>inputBuffer</code> attribute. The audio data which is
-the result of the processing (or the synthesized data if there are no inputs)
-is then placed into the <code>outputBuffer</code>. </p>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="audio-processing-event-idl">
-
-interface <dfn id="dfn-AudioProcessingEvent">AudioProcessingEvent</dfn> : Event {
-
- readonly attribute double playbackTime;
- readonly attribute AudioBuffer inputBuffer;
- readonly attribute AudioBuffer outputBuffer;
-
-};
-</code></pre>
-</div>
-</div>
-
-<div id="attributes-AudioProcessingEvent-section" class="section">
-<h3 id="attributes-AudioProcessingEvent">4.13.1. Attributes</h3>
-<dl>
- <dt id="dfn-playbackTime"><code>playbackTime</code></dt>
- <dd><p>The time when the audio will be played in the same time coordinate system as AudioContext.currentTime.
- <code>playbackTime</code> allows for very tight synchronization between
- processing directly in JavaScript with the other events in the context's
- rendering graph. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-inputBuffer"><code>inputBuffer</code></dt>
- <dd><p>An AudioBuffer containing the input audio data. It will have a number of channels equal to the <code>numberOfInputChannels</code> parameter
- of the createScriptProcessor() method. This AudioBuffer is only valid while in the scope of the <code>onaudioprocess</code>
- function. Its values will be meaningless outside of this scope.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-outputBuffer"><code>outputBuffer</code></dt>
- <dd><p>An AudioBuffer where the output audio data should be written. It will have a number of channels equal to the
- <code>numberOfOutputChannels</code> parameter of the createScriptProcessor() method.
- Script code within the scope of the <code>onaudioprocess</code> function is expected to modify the
- <code>Float32Array</code> arrays representing channel data in this AudioBuffer.
- Any script modifications to this AudioBuffer outside of this scope will not produce any audible effects.</p>
- </dd>
-</dl>
-</div>
-</div>
-
-<div id="PannerNode-section" class="section">
-<h2 id="PannerNode">4.14. The PannerNode Interface</h2>
-
-<p>This interface represents a processing node which <a
-href="#Spatialization-section">positions / spatializes</a> an incoming audio
-stream in three-dimensional space. The spatialization is in relation to the <a
-href="#AudioContext-section"><code>AudioContext</code></a>'s <a
-href="#AudioListener-section"><code>AudioListener</code></a>
-(<code>listener</code> attribute). </p>
-
-<pre>
- numberOfInputs : 1
- numberOfOutputs : 1
-
- channelCount = 2;
- channelCountMode = "clamped-max";
- channelInterpretation = "speakers";
-</pre>
-
-<p>
-The audio stream from the input will be either mono or stereo, depending on the connection(s) to the input.
-</p>
-
-<p>
-The output of this node is hard-coded to stereo (2 channels) and <em>currently</em> cannot be configured.
-</p>
-
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="panner-node-idl">
-
-enum <dfn>PanningModelType</dfn> {
- "equalpower",
- "HRTF"
-};
-
-enum <dfn>DistanceModelType</dfn> {
- "linear",
- "inverse",
- "exponential"
-};
-
-interface <dfn id="dfn-PannerNode">PannerNode</dfn> : AudioNode {
-
- <span class="comment">// Default for stereo is HRTF </span>
- attribute PanningModelType panningModel;
-
- <span class="comment">// Uses a 3D cartesian coordinate system </span>
- void setPosition(double x, double y, double z);
- void setOrientation(double x, double y, double z);
- void setVelocity(double x, double y, double z);
-
- <span class="comment">// Distance model and attributes </span>
- attribute DistanceModelType distanceModel;
- attribute double refDistance;
- attribute double maxDistance;
- attribute double rolloffFactor;
-
- <span class="comment">// Directional sound cone </span>
- attribute double coneInnerAngle;
- attribute double coneOuterAngle;
- attribute double coneOuterGain;
-
-};
-</code></pre>
-</div>
-</div>
-</div>
-
-<div id="attributes-PannerNode_attributes-section" class="section">
-<h3 id="attributes-PannerNode_attributes">4.14.2. Attributes</h3>
-<dl>
- <dt id="dfn-panningModel"><code>panningModel</code></dt>
- <dd><p>Determines which spatialization algorithm will be used to position
- the audio in 3D space. The default is "HRTF". </p>
-
- <dl>
- <dt id="dfn-EQUALPOWER"><code>"equalpower"</code></dt>
- <dd><p>A simple and efficient spatialization algorithm using equal-power
- panning. </p>
- </dd>
- </dl>
- <dl>
- <dt id="dfn-HRTF"><code>"HRTF"</code></dt>
- <dd><p>A higher quality spatialization algorithm using a convolution with
- measured impulse responses from human subjects. This panning method
- renders stereo output. </p>
- </dd>
- </dl>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-distanceModel"><code>distanceModel</code></dt>
- <dd><p>Determines which algorithm will be used to reduce the volume of an
- audio source as it moves away from the listener. The default is "inverse".
-</p>
-
-<dl>
- <dt id="dfn-LINEAR_DISTANCE"><code>"linear"</code></dt>
- <dd><p>A linear distance model which calculates <em>distanceGain</em> according to: </p>
- <pre>
-1 - rolloffFactor * (distance - refDistance) / (maxDistance - refDistance)
- </pre>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-INVERSE_DISTANCE"><code>"inverse"</code></dt>
- <dd><p>An inverse distance model which calculates <em>distanceGain</em> according to: </p>
- <pre>
-refDistance / (refDistance + rolloffFactor * (distance - refDistance))
- </pre>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-EXPONENTIAL_DISTANCE"><code>"exponential"</code></dt>
- <dd><p>An exponential distance model which calculates <em>distanceGain</em> according to: </p>
- <pre>
-pow(distance / refDistance, -rolloffFactor)
- </pre>
- </dd>
-</dl>
-
-
- </dd>
-</dl>
-<dl>
- <dt id="dfn-refDistance"><code>refDistance</code></dt>
- <dd><p>A reference distance for reducing volume as source move further from
- the listener. The default value is 1. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-maxDistance"><code>maxDistance</code></dt>
- <dd><p>The maximum distance between source and listener, after which the
- volume will not be reduced any further. The default value is 10000. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-rolloffFactor"><code>rolloffFactor</code></dt>
- <dd><p>Describes how quickly the volume is reduced as source moves away
- from listener. The default value is 1. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-coneInnerAngle"><code>coneInnerAngle</code></dt>
- <dd><p>A parameter for directional audio sources, this is an angle, inside
- of which there will be no volume reduction. The default value is 360. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-coneOuterAngle"><code>coneOuterAngle</code></dt>
- <dd><p>A parameter for directional audio sources, this is an angle, outside
- of which the volume will be reduced to a constant value of
- <b>coneOuterGain</b>. The default value is 360. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-coneOuterGain"><code>coneOuterGain</code></dt>
- <dd><p>A parameter for directional audio sources, this is the amount of
- volume reduction outside of the <b>coneOuterAngle</b>. The default value is 0. </p>
- </dd>
-</dl>
-</div>
-
-<h3 id="Methods_and_Parameters">4.14.3. Methods and Parameters</h3>
-<dl>
- <dt id="dfn-setPosition">The <code>setPosition</code> method</dt>
- <dd><p>Sets the position of the audio source relative to the
- <b>listener</b> attribute. A 3D cartesian coordinate system is used.</p>
- <p>The <dfn id="dfn-x">x, y, z</dfn> parameters represent the coordinates
- in 3D space. </p>
- <p>The default value is (0,0,0)
- </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-setOrientation">The <code>setOrientation</code> method</dt>
- <dd><p>Describes which direction the audio source is pointing in the 3D
- cartesian coordinate space. Depending on how directional the sound is
- (controlled by the <b>cone</b> attributes), a sound pointing away from
- the listener can be very quiet or completely silent.</p>
- <p>The <dfn id="dfn-x_2">x, y, z</dfn> parameters represent a direction
- vector in 3D space. </p>
- <p>The default value is (1,0,0)
- </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-setVelocity">The <code>setVelocity</code> method</dt>
- <dd><p>Sets the velocity vector of the audio source. This vector controls
- both the direction of travel and the speed in 3D space. This velocity
- relative to the listener's velocity is used to determine how much doppler
- shift (pitch change) to apply. The units used for this vector is <em>meters / second</em>
- and is independent of the units used for position and orientation vectors.</p>
- <p>The <dfn id="dfn-x_3">x, y, z</dfn> parameters describe a direction
- vector indicating direction of travel and intensity. </p>
- <p>The default value is (0,0,0)
- </p>
- </dd>
-</dl>
-
-<div id="AudioListener-section" class="section">
-<h2 id="AudioListener">4.15. The AudioListener Interface</h2>
-
-<p>This interface represents the position and orientation of the person
-listening to the audio scene. All <a
-href="#PannerNode-section"><code>PannerNode</code></a> objects
-spatialize in relation to the AudioContext's <code>listener</code>. See <a
-href="#Spatialization-section">this</a> section for more details about
-spatialization. </p>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="audio-listener-idl">
-
-interface <dfn id="dfn-AudioListener">AudioListener</dfn> {
-
- attribute double dopplerFactor;
- attribute double speedOfSound;
-
- <span class="comment">// Uses a 3D cartesian coordinate system </span>
- void setPosition(double x, double y, double z);
- void setOrientation(double x, double y, double z, double xUp, double yUp, double zUp);
- void setVelocity(double x, double y, double z);
-
-};
-</code></pre>
-</div>
-</div>
-</div>
-
-<div id="attributes-AudioListener-section" class="section">
-<h3 id="attributes-AudioListener">4.15.1. Attributes</h3>
-<dl>
- <dt id="dfn-dopplerFactor"><code>dopplerFactor</code></dt>
- <dd><p>A constant used to determine the amount of pitch shift to use when
- rendering a doppler effect. The default value is 1. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-speedOfSound"><code>speedOfSound</code></dt>
- <dd><p>The speed of sound used for calculating doppler shift. The default
- value is 343.3. </p>
- </dd>
-</dl>
-</div>
-
-<h3 id="L15842">4.15.2. Methods and Parameters</h3>
-<dl>
- <dt id="dfn-setPosition_2">The <code>setPosition</code> method</dt>
- <dd><p>Sets the position of the listener in a 3D cartesian coordinate
- space. <code>PannerNode</code> objects use this position relative to
- individual audio sources for spatialization.</p>
- <p>The <dfn id="dfn-x_AudioListener">x, y, z</dfn> parameters represent
- the coordinates in 3D space. </p>
- <p>The default value is (0,0,0)
- </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-setOrientation_2">The <code>setOrientation</code> method</dt>
- <dd><p>Describes which direction the listener is pointing in the 3D
- cartesian coordinate space. Both a <b>front</b> vector and an <b>up</b>
- vector are provided. In simple human terms, the <b>front</b> vector represents which
- direction the person's nose is pointing. The <b>up</b> vector represents the
- direction the top of a person's head is pointing. These values are expected to
- be linearly independent (at right angles to each other). For normative requirements
- of how these values are to be interpreted, see the
- <a href="#Spatialization-section">spatialization section</a>.
- </p>
- <p>The <dfn id="dfn-x_setOrientation">x, y, z</dfn> parameters represent
- a <b>front</b> direction vector in 3D space, with the default value being (0,0,-1) </p>
- <p>The <dfn id="dfn-x_setOrientation_2">xUp, yUp, zUp</dfn> parameters
- represent an <b>up</b> direction vector in 3D space, with the default value being (0,1,0) </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-setVelocity_4">The <code>setVelocity</code> method</dt>
- <dd><p>Sets the velocity vector of the listener. This vector controls both
- the direction of travel and the speed in 3D space. This velocity relative to
- an audio source's velocity is used to determine how much doppler shift
- (pitch change) to apply. The units used for this vector is <em>meters / second</em>
- and is independent of the units used for position and orientation vectors.</p>
- <p>The <dfn id="dfn-x_setVelocity_5">x, y, z</dfn> parameters describe a
- direction vector indicating direction of travel and intensity. </p>
- <p>The default value is (0,0,0)
- </p>
- </dd>
-</dl>
-
-<div id="ConvolverNode-section" class="section">
-<h2 id="ConvolverNode">4.16. The ConvolverNode Interface</h2>
-
-<p>This interface represents a processing node which applies a <a
-href="#Convolution-section">linear convolution effect</a> given an impulse
-response. Normative requirements for multi-channel convolution matrixing are described
-<a href="#Convolution-reverb-effect">here</a>. </p>
-<pre>
- numberOfInputs : 1
- numberOfOutputs : 1
-
- channelCount = 2;
- channelCountMode = "clamped-max";
- channelInterpretation = "speakers";
-</pre>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="convolver-node-idl">
-
-interface <dfn id="dfn-ConvolverNode">ConvolverNode</dfn> : AudioNode {
-
- attribute AudioBuffer? buffer;
- attribute boolean normalize;
-
-};
-</code></pre>
-</div>
-</div>
-</div>
-
-<div id="attributes-ConvolverNode-section" class="section">
-<h3 id="attributes-ConvolverNode">4.16.1. Attributes</h3>
-<dl>
- <dt id="dfn-buffer_ConvolverNode"><code>buffer</code></dt>
- <dd><p>A mono, stereo, or 4-channel <code>AudioBuffer</code> containing the (possibly multi-channel) impulse response
- used by the ConvolverNode. This <code>AudioBuffer</code> must be of the same sample-rate as the AudioContext or an exception will
- be thrown. At the time when this attribute is set, the <em>buffer</em> and the state of the <em>normalize</em>
- attribute will be used to configure the ConvolverNode with this impulse response having the given normalization.
- The initial value of this attribute is null.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-normalize"><code>normalize</code></dt>
- <dd><p>Controls whether the impulse response from the buffer will be scaled
- by an equal-power normalization when the <code>buffer</code> atttribute
- is set. Its default value is <code>true</code> in order to achieve a more
- uniform output level from the convolver when loaded with diverse impulse
- responses. If <code>normalize</code> is set to <code>false</code>, then
- the convolution will be rendered with no pre-processing/scaling of the
- impulse response. Changes to this value do not take effect until the next time
- the <em>buffer</em> attribute is set. </p>
-
- </dd>
-</dl>
-
- <p>
- If the <em>normalize</em> attribute is false when the <em>buffer</em> attribute is set then the
- ConvolverNode will perform a linear convolution given the exact impulse response contained within the <em>buffer</em>.
- </p>
- <p>
- Otherwise, if the <em>normalize</em> attribute is true when the <em>buffer</em> attribute is set then the
- ConvolverNode will first perform a scaled RMS-power analysis of the audio data contained within <em>buffer</em> to calculate a
- <em>normalizationScale</em> given this algorithm:
- </p>
-
-
- <div class="block">
-
- <div class="blockTitleDiv">
-
- <div class="blockContent">
- <pre class="code"><code class="es-code">
-
-float calculateNormalizationScale(buffer)
-{
- const float GainCalibration = 0.00125;
- const float GainCalibrationSampleRate = 44100;
- const float MinPower = 0.000125;
-
- // Normalize by RMS power.
- size_t numberOfChannels = buffer->numberOfChannels();
- size_t length = buffer->length();
-
- float power = 0;
-
- for (size_t i = 0; i &lt; numberOfChannels; ++i) {
- float* sourceP = buffer->channel(i)->data();
- float channelPower = 0;
-
- int n = length;
- while (n--) {
- float sample = *sourceP++;
- channelPower += sample * sample;
- }
-
- power += channelPower;
- }
-
- power = sqrt(power / (numberOfChannels * length));
-
- // Protect against accidental overload.
- if (isinf(power) || isnan(power) || power &lt; MinPower)
- power = MinPower;
-
- float scale = 1 / power;
-
- // Calibrate to make perceived volume same as unprocessed.
- scale *= GainCalibration;
-
- // Scale depends on sample-rate.
- if (buffer->sampleRate())
- scale *= GainCalibrationSampleRate / buffer->sampleRate();
-
- // True-stereo compensation.
- if (buffer->numberOfChannels() == 4)
- scale *= 0.5;
-
- return scale;
-}
- </code></pre>
-
- </div>
- </div>
- </div>
-
-<p>
-During processing, the ConvolverNode will then take this calculated <em>normalizationScale</em> value and multiply it by the result of the linear convolution
-resulting from processing the input with the impulse response (represented by the <em>buffer</em>) to produce the
-final output. Or any mathematically equivalent operation may be used, such as pre-multiplying the
-input by <em>normalizationScale</em>, or pre-multiplying a version of the impulse-response by <em>normalizationScale</em>.
-</p>
-
-</div>
-
-<div id="AnalyserNode-section" class="section">
-<h2 id="AnalyserNode">4.17. The AnalyserNode Interface</h2>
-
-<p>This interface represents a node which is able to provide real-time
-frequency and time-domain <a href="#AnalyserNode">analysis</a>
-information. The audio stream will be passed un-processed from input to output.
-</p>
-<pre>
- numberOfInputs : 1
- numberOfOutputs : 1 <em>Note that this output may be left unconnected.</em>
-
- channelCount = 1;
- channelCountMode = "explicit";
- channelInterpretation = "speakers";
-</pre>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="analyser-node-idl">
-
-interface <dfn id="dfn-AnalyserNode">AnalyserNode</dfn> : AudioNode {
-
- <span class="comment">// Real-time frequency-domain data </span>
- void getFloatFrequencyData(Float32Array array);
- void getByteFrequencyData(Uint8Array array);
-
- <span class="comment">// Real-time waveform data </span>
- void getByteTimeDomainData(Uint8Array array);
-
- attribute unsigned long fftSize;
- readonly attribute unsigned long frequencyBinCount;
-
- attribute double minDecibels;
- attribute double maxDecibels;
-
- attribute double smoothingTimeConstant;
-
-};
-</code></pre>
-</div>
-</div>
-</div>
-
-<div id="attributes-ConvolverNode-section_2" class="section">
-<h3 id="attributes-ConvolverNode_2">4.17.1. Attributes</h3>
-<dl>
- <dt id="dfn-fftSize"><code>fftSize</code></dt>
- <dd><p>The size of the FFT used for frequency-domain analysis. This must be
- a non-zero power of two in the range 32 to 2048, otherwise an INDEX_SIZE_ERR exception MUST be thrown.
- The default value is 2048.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-frequencyBinCount"><code>frequencyBinCount</code></dt>
- <dd><p>Half the FFT size. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-minDecibels"><code>minDecibels</code></dt>
- <dd><p>The minimum power value in the scaling range for the FFT analysis
- data for conversion to unsigned byte values.
- The default value is -100.
- If the value of this attribute is set to a value more than or equal to <code>maxDecibels</code>,
- an INDEX_SIZE_ERR exception MUST be thrown.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-maxDecibels"><code>maxDecibels</code></dt>
- <dd><p>The maximum power value in the scaling range for the FFT analysis
- data for conversion to unsigned byte values.
- The default value is -30.
- If the value of this attribute is set to a value less than or equal to <code>minDecibels</code>,
- an INDEX_SIZE_ERR exception MUST be thrown.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-smoothingTimeConstant"><code>smoothingTimeConstant</code></dt>
- <dd><p>A value from 0 -&gt; 1 where 0 represents no time averaging
- with the last analysis frame.
- The default value is 0.8.
- If the value of this attribute is set to a value less than 0 or more than 1,
- an INDEX_SIZE_ERR exception MUST be thrown.</p>
- </dd>
-</dl>
-</div>
-
-<h3 id="methods-and-parameters">4.17.2. Methods and Parameters</h3>
-<dl>
- <dt id="dfn-getFloatFrequencyData">The <code>getFloatFrequencyData</code>
- method</dt>
- <dd><p>Copies the current frequency data into the passed floating-point
- array. If the array has fewer elements than the frequencyBinCount, the
- excess elements will be dropped. If the array has more elements than
- the frequencyBinCount, the excess elements will be ignored.</p>
- <p>The <dfn id="dfn-array">array</dfn> parameter is where
- frequency-domain analysis data will be copied. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-getByteFrequencyData">The <code>getByteFrequencyData</code>
- method</dt>
- <dd><p>Copies the current frequency data into the passed unsigned byte
- array. If the array has fewer elements than the frequencyBinCount, the
- excess elements will be dropped. If the array has more elements than
- the frequencyBinCount, the excess elements will be ignored.</p>
- <p>The <dfn id="dfn-array_2">array</dfn> parameter is where
- frequency-domain analysis data will be copied. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-getByteTimeDomainData">The <code>getByteTimeDomainData</code>
- method</dt>
- <dd><p>Copies the current time-domain (waveform) data into the passed
- unsigned byte array. If the array has fewer elements than the
- fftSize, the excess elements will be dropped. If the array has more
- elements than fftSize, the excess elements will be ignored.</p>
- <p>The <dfn id="dfn-array_3">array</dfn> parameter is where time-domain
- analysis data will be copied. </p>
- </dd>
-</dl>
-
-<div id="ChannelSplitterNode-section" class="section">
-<h2 id="ChannelSplitterNode">4.18. The ChannelSplitterNode Interface</h2>
-
-<p>The <code>ChannelSplitterNode</code> is for use in more advanced
-applications and would often be used in conjunction with <a
-href="#ChannelMergerNode-section"><code>ChannelMergerNode</code></a>. </p>
-<pre>
- numberOfInputs : 1
- numberOfOutputs : Variable N (defaults to 6) // number of "active" (non-silent) outputs is determined by number of channels in the input
-
- channelCountMode = "max";
- channelInterpretation = "speakers";
-</pre>
-
-<p>This interface represents an AudioNode for accessing the individual channels
-of an audio stream in the routing graph. It has a single input, and a number of
-"active" outputs which equals the number of channels in the input audio stream.
-For example, if a stereo input is connected to an
-<code>ChannelSplitterNode</code> then the number of active outputs will be two
-(one from the left channel and one from the right). There are always a total
-number of N outputs (determined by the <code>numberOfOutputs</code> parameter to the AudioContext method <code>createChannelSplitter()</code>),
- The default number is 6 if this value is not provided. Any outputs
-which are not "active" will output silence and would typically not be connected
-to anything. </p>
-
-<h3 id="example-1">Example:</h3>
-<img alt="channel splitter" src="images/channel-splitter.png" />
-
-<p>Please note that in this example, the splitter does <b>not</b> interpret the channel identities (such as left, right, etc.), but
-simply splits out channels in the order that they are input.</p>
-
-<p>One application for <code>ChannelSplitterNode</code> is for doing "matrix
-mixing" where individual gain control of each channel is desired. </p>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="channel-splitter-node-idl">
-
-interface <dfn id="dfn-ChannelSplitterNode">ChannelSplitterNode</dfn> : AudioNode {
-
-};
-</code></pre>
-</div>
-</div>
-</div>
-
-<div id="ChannelMergerNode-section" class="section">
-<h2 id="ChannelMergerNode">4.19. The ChannelMergerNode Interface</h2>
-
-<p>The <code>ChannelMergerNode</code> is for use in more advanced applications
-and would often be used in conjunction with <a
-href="#ChannelSplitterNode-section"><code>ChannelSplitterNode</code></a>. </p>
-<pre>
- numberOfInputs : Variable N (default to 6) // number of connected inputs may be less than this
- numberOfOutputs : 1
-
- channelCountMode = "max";
- channelInterpretation = "speakers";
-</pre>
-
-<p>This interface represents an AudioNode for combining channels from multiple
-audio streams into a single audio stream. It has a variable number of inputs (defaulting to 6), but not all of them
-need be connected. There is a single output whose audio stream has a number of
-channels equal to the sum of the numbers of channels of all the connected
-inputs. For example, if an <code>ChannelMergerNode</code> has two connected
-inputs (both stereo), then the output will be four channels, the first two from
-the first input and the second two from the second input. In another example
-with two connected inputs (both mono), the output will be two channels
-(stereo), with the left channel coming from the first input and the right
-channel coming from the second input. </p>
-
-<h3 id="example-2">Example:</h3>
-<img alt="channel merger" src="images/channel-merger.png" />
-
-<p>Please note that in this example, the merger does <b>not</b> interpret the channel identities (such as left, right, etc.), but
-simply combines channels in the order that they are input.</p>
-
-
-<p>Be aware that it is possible to connect an <code>ChannelMergerNode</code>
-in such a way that it outputs an audio stream with a large number of channels
-greater than the maximum supported by the audio hardware. In this case where such an output is connected
-to the AudioContext .destination (the audio hardware), then the extra channels will be ignored.
-Thus, the <code>ChannelMergerNode</code> should be used in situations where the number
-of channels is well understood. </p>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="channel-merger-node-idl">
-
-interface <dfn id="dfn-ChannelMergerNode">ChannelMergerNode</dfn> : AudioNode {
-
-};
-</code></pre>
-</div>
-</div>
-</div>
-
-<div id="DynamicsCompressorNode-section" class="section">
-<h2 id="DynamicsCompressorNode">4.20. The DynamicsCompressorNode Interface</h2>
-
-<p>DynamicsCompressorNode is an AudioNode processor implementing a dynamics
-compression effect. </p>
-
-<p>Dynamics compression is very commonly used in musical production and game
-audio. It lowers the volume of the loudest parts of the signal and raises the
-volume of the softest parts. Overall, a louder, richer, and fuller sound can be
-achieved. It is especially important in games and musical applications where
-large numbers of individual sounds are played simultaneous to control the
-overall signal level and help avoid clipping (distorting) the audio output to
-the speakers. </p>
-<pre>
- numberOfInputs : 1
- numberOfOutputs : 1
-
- channelCount = 2;
- channelCountMode = "explicit";
- channelInterpretation = "speakers";
-</pre>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="dynamics-compressor-node-idl">
-
-interface <dfn id="dfn-DynamicsCompressorNode">DynamicsCompressorNode</dfn> : AudioNode {
-
- readonly attribute AudioParam threshold; // in Decibels
- readonly attribute AudioParam knee; // in Decibels
- readonly attribute AudioParam ratio; // unit-less
- readonly attribute AudioParam reduction; // in Decibels
- readonly attribute AudioParam attack; // in Seconds
- readonly attribute AudioParam release; // in Seconds
-
-};
-</code>
-</pre>
-</div>
-</div>
-
-<div id="attributes-DynamicsCompressorNode-section" class="section">
-<h3 id="attributes-DynamicsCompressorNode">4.20.1. Attributes</h3>
-<p>
-All parameters are <em>k-rate</em>
-</p>
-
-<dl>
- <dt id="dfn-threshold"><code>threshold</code></dt>
- <dd><p>The decibel value above which the compression will start taking
- effect. Its default value is -24, with a nominal range of -100 to 0. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-knee"><code>knee</code></dt>
- <dd><p>A decibel value representing the range above the threshold where the
- curve smoothly transitions to the "ratio" portion. Its default value is 30, with a nominal range of 0 to 40. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-ratio"><code>ratio</code></dt>
- <dd><p>The amount of dB change in input for a 1 dB change in output. Its default value is 12, with a nominal range of 1 to 20. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-reduction"><code>reduction</code></dt>
- <dd><p>A read-only decibel value for metering purposes, representing the
- current amount of gain reduction that the compressor is applying to the
- signal. If fed no signal the value will be 0 (no gain reduction). The nominal range is -20 to 0. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-attack"><code>attack</code></dt>
- <dd><p>The amount of time (in seconds) to reduce the gain by 10dB. Its default value is 0.003, with a nominal range of 0 to 1. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-release"><code>release</code></dt>
- <dd><p>The amount of time (in seconds) to increase the gain by 10dB. Its default value is 0.250, with a nominal range of 0 to 1. </p>
- </dd>
-</dl>
-</div>
-</div>
-
-<div id="BiquadFilterNode-section" class="section">
-<h2 id="BiquadFilterNode">4.21. The BiquadFilterNode Interface</h2>
-
-<p>BiquadFilterNode is an AudioNode processor implementing very common
-low-order filters. </p>
-
-<p>Low-order filters are the building blocks of basic tone controls (bass, mid,
-treble), graphic equalizers, and more advanced filters. Multiple
-BiquadFilterNode filters can be combined to form more complex filters. The
-filter parameters such as "frequency" can be changed over time for filter
-sweeps, etc. Each BiquadFilterNode can be configured as one of a number of
-common filter types as shown in the IDL below. The default filter type
-is "lowpass".</p>
-<pre>
- numberOfInputs : 1
- numberOfOutputs : 1
-
- channelCountMode = "max";
- channelInterpretation = "speakers";
-</pre>
-<p>
-The number of channels of the output always equals the number of channels of the input.
-</p>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="biquad-filter-node-idl">
-
-enum <dfn>BiquadFilterType</dfn> {
- "lowpass",
- "highpass",
- "bandpass",
- "lowshelf",
- "highshelf",
- "peaking",
- "notch",
- "allpass"
-};
-
-interface <dfn id="dfn-BiquadFilterNode">BiquadFilterNode</dfn> : AudioNode {
-
- attribute BiquadFilterType type;
- readonly attribute AudioParam frequency; // in Hertz
- readonly attribute AudioParam detune; // in Cents
- readonly attribute AudioParam Q; // Quality factor
- readonly attribute AudioParam gain; // in Decibels
-
- void getFrequencyResponse(Float32Array frequencyHz,
- Float32Array magResponse,
- Float32Array phaseResponse);
-
-};
-</code></pre>
-</div>
-</div>
-</div>
-
-<p>The filter types are briefly described below. We note that all of these
-filters are very commonly used in audio processing. In terms of implementation,
-they have all been derived from standard analog filter prototypes. For more
-technical details, we refer the reader to the excellent <a
-href="http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt">reference</a> by
-Robert Bristow-Johnson.</p>
-
-<p>
-All parameters are <em>k-rate</em> with the following default parameter values:
-</p>
-
-<blockquote>
-<dl>
- <dt>frequency</dt>
- <dd>350Hz, with a nominal range of 10 to the Nyquist frequency (half the sample-rate).
- </dd>
- <dt><a href="http://en.wikipedia.org/wiki/Q_factor">Q</a></dt>
- <dd>1, with a nominal range of 0.0001 to 1000.</dd>
- <dt>gain</dt>
- <dd>0, with a nominal range of -40 to 40.</dd>
-</dl>
-</blockquote>
-
-
-
-<div id="BiquadFilterNode-description-section" class="section">
-<h3 id="BiquadFilterNode-description">4.21.1 "lowpass"</h3>
-
-<p>A <a href="http://en.wikipedia.org/wiki/Low-pass_filter">lowpass filter</a>
-allows frequencies below the cutoff frequency to pass through and attenuates
-frequencies above the cutoff. It implements a standard second-order
-resonant lowpass filter with 12dB/octave rolloff.</p>
-
-<blockquote>
- <dl>
- <dt>frequency</dt>
- <dd>The cutoff frequency</dd>
- <dt>Q</dt>
- <dd>Controls how peaked the response will be at the cutoff frequency. A
- large value makes the response more peaked. Please note that for this filter type, this
- value is not a traditional Q, but is a resonance value in decibels.</dd>
- <dt>gain</dt>
- <dd>Not used in this filter type</dd>
- </dl>
-</blockquote>
-
-<h3 id="HIGHPASS">4.21.2 "highpass"</h3>
-
-<p>A <a href="http://en.wikipedia.org/wiki/High-pass_filter">highpass
-filter</a> is the opposite of a lowpass filter. Frequencies above the cutoff
-frequency are passed through, but frequencies below the cutoff are attenuated.
-It implements a standard second-order resonant highpass filter with
-12dB/octave rolloff.</p>
-
-<blockquote>
- <dl>
- <dt>frequency</dt>
- <dd>The cutoff frequency below which the frequencies are attenuated</dd>
- <dt>Q</dt>
- <dd>Controls how peaked the response will be at the cutoff frequency. A
- large value makes the response more peaked. Please note that for this filter type, this
- value is not a traditional Q, but is a resonance value in decibels.</dd>
- <dt>gain</dt>
- <dd>Not used in this filter type</dd>
- </dl>
-</blockquote>
-
-<h3 id="BANDPASS">4.21.3 "bandpass"</h3>
-
-<p>A <a href="http://en.wikipedia.org/wiki/Band-pass_filter">bandpass
-filter</a> allows a range of frequencies to pass through and attenuates the
-frequencies below and above this frequency range. It implements a
-second-order bandpass filter.</p>
-
-<blockquote>
- <dl>
- <dt>frequency</dt>
- <dd>The center of the frequency band</dd>
- <dt><a href="http://en.wikipedia.org/wiki/Q_factor">Q</a></dt>
- <dd>Controls the width of the band. The width becomes narrower as the Q
- value increases.</dd>
- <dt>gain</dt>
- <dd>Not used in this filter type</dd>
- </dl>
-</blockquote>
-
-<h3 id="LOWSHELF">4.21.4 "lowshelf"</h3>
-
-<p>The lowshelf filter allows all frequencies through, but adds a boost (or
-attenuation) to the lower frequencies. It implements a second-order
-lowshelf filter.</p>
-
-<blockquote>
- <dl>
- <dt>frequency</dt>
- <dd>The upper limit of the frequences where the boost (or attenuation) is
- applied.</dd>
- <dt><a href="http://en.wikipedia.org/wiki/Q_factor">Q</a></dt>
- <dd>Not used in this filter type.</dd>
- <dt>gain</dt>
- <dd>The boost, in dB, to be applied. If the value is negative, the
- frequencies are attenuated.</dd>
- </dl>
-</blockquote>
-
-<h3 id="L16352">4.21.5 "highshelf"</h3>
-
-<p>The highshelf filter is the opposite of the lowshelf filter and allows all
-frequencies through, but adds a boost to the higher frequencies. It
-implements a second-order highshelf filter</p>
-
-<blockquote>
- <dl>
- <dt>frequency</dt>
- <dd>The lower limit of the frequences where the boost (or attenuation) is
- applied.</dd>
- <dt><a href="http://en.wikipedia.org/wiki/Q_factor">Q</a></dt>
- <dd>Not used in this filter type.</dd>
- <dt>gain</dt>
- <dd>The boost, in dB, to be applied. If the value is negative, the
- frequencies are attenuated.</dd>
- </dl>
-</blockquote>
-
-<h3 id="PEAKING">4.21.6 "peaking"</h3>
-
-<p>The peaking filter allows all frequencies through, but adds a boost (or
-attenuation) to a range of frequencies. </p>
-
-<blockquote>
- <dl>
- <dt>frequency</dt>
- <dd>The center frequency of where the boost is applied.</dd>
- <dt><a href="http://en.wikipedia.org/wiki/Q_factor">Q</a></dt>
- <dd>Controls the width of the band of frequencies that are boosted. A
- large value implies a narrow width.</dd>
- <dt>gain</dt>
- <dd>The boost, in dB, to be applied. If the value is negative, the
- frequencies are attenuated.</dd>
- </dl>
-</blockquote>
-
-<h3 id="NOTCH">4.21.7 "notch"</h3>
-
-<p>The notch filter (also known as a <a
-href="http://en.wikipedia.org/wiki/Band-stop_filter">band-stop or
-band-rejection filter</a>) is the opposite of a bandpass filter. It allows all
-frequencies through, except for a set of frequencies.</p>
-
-<blockquote>
- <dl>
- <dt>frequency</dt>
- <dd>The center frequency of where the notch is applied.</dd>
- <dt><a href="http://en.wikipedia.org/wiki/Q_factor">Q</a></dt>
- <dd>Controls the width of the band of frequencies that are attenuated. A
- large value implies a narrow width.</dd>
- <dt>gain</dt>
- <dd>Not used in this filter type.</dd>
- </dl>
-</blockquote>
-
-<h3 id="ALLPASS">4.21.8 "allpass"</h3>
-
-<p>An <a
-href="http://en.wikipedia.org/wiki/All-pass_filter#Digital_Implementation">allpass
-filter</a> allows all frequencies through, but changes the phase relationship
-between the various frequencies. It implements a second-order allpass
-filter</p>
-
-<blockquote>
- <dl>
- <dt>frequency</dt>
- <dd>The frequency where the center of the phase transition occurs. Viewed
- another way, this is the frequency with maximal <a
- href="http://en.wikipedia.org/wiki/Group_delay">group delay</a>.</dd>
- <dt><a href="http://en.wikipedia.org/wiki/Q_factor">Q</a></dt>
- <dd>Controls how sharp the phase transition is at the center frequency. A
- larger value implies a sharper transition and a larger group delay.</dd>
- <dt>gain</dt>
- <dd>Not used in this filter type.</dd>
- </dl>
-</blockquote>
-
-<h3 id="Methods">4.21.9. Methods</h3>
-<dl>
- <dt id="dfn-getFrequencyResponse">The <code>getFrequencyResponse</code>
- method</dt>
- <dd><p>Given the current filter parameter settings, calculates the
- frequency response for the specified frequencies. </p>
- <p>The <dfn id="dfn-frequencyHz">frequencyHz</dfn> parameter specifies an
- array of frequencies at which the response values will be calculated.</p>
- <p>The <dfn id="dfn-magResponse">magResponse</dfn> parameter specifies an
- output array receiving the linear magnitude response values.</p>
- <p>The <dfn id="dfn-phaseResponse">phaseResponse</dfn> parameter
- specifies an output array receiving the phase response values in
- radians.</p>
- </dd>
-</dl>
-</div>
-
-<div id="WaveShaperNode-section" class="section">
-<h2 id="WaveShaperNode">4.22. The WaveShaperNode Interface</h2>
-
-<p>WaveShaperNode is an AudioNode processor implementing non-linear distortion
-effects. </p>
-
-<p>Non-linear waveshaping distortion is commonly used for both subtle
-non-linear warming, or more obvious distortion effects. Arbitrary non-linear
-shaping curves may be specified.</p>
-<pre>
- numberOfInputs : 1
- numberOfOutputs : 1
-
- channelCountMode = "max";
- channelInterpretation = "speakers";
-</pre>
-
-<p>
-The number of channels of the output always equals the number of channels of the input.
-</p>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="wave-shaper-node-idl">
-
-enum <dfn>OverSampleType</dfn> {
- "none",
- "2x",
- "4x"
-};
-
-interface <dfn id="dfn-WaveShaperNode">WaveShaperNode</dfn> : AudioNode {
-
- attribute Float32Array? curve;
- attribute OverSampleType oversample;
-
-};
-</code></pre>
-</div>
-</div>
-
-<div id="attributes-WaveShaperNode-section" class="section">
-<h3 id="attributes-WaveShaperNode">4.22.1. Attributes</h3>
-<dl>
- <dt id="dfn-curve"><code>curve</code></dt>
- <dd><p>The shaping curve used for the waveshaping effect. The input signal
- is nominally within the range -1 -&gt; +1. Each input sample within this
- range will index into the shaping curve with a signal level of zero
- corresponding to the center value of the curve array. Any sample value
- less than -1 will correspond to the first value in the curve array. Any
- sample value greater than +1 will correspond to the last value in
- the curve array. The implementation must perform linear interpolation between
- adjacent points in the curve. Initially the curve attribute is null, which means that
- the WaveShaperNode will pass its input to its output without modification.</p>
- </dd>
-</dl>
-
-<dl>
- <dt id="dfn-oversample"><code>oversample</code></dt>
- <dd><p>Specifies what type of oversampling (if any) should be used when applying the shaping curve.
- The default value is "none", meaning the curve will be applied directly to the input samples.
- A value of "2x" or "4x" can improve the quality of the processing by avoiding some aliasing, with
- the "4x" value yielding the highest quality. For some applications, it's better to use no oversampling
- in order to get a very precise shaping curve.
- </p>
- <p>
- A value of "2x" or "4x" means that the following steps must be performed:
- <ol>
- <li>Up-sample the input samples to 2x or 4x the sample-rate of the AudioContext. Thus for each
- processing block of 128 samples, generate 256 (for 2x) or 512 (for 4x) samples.</li>
- <li>Apply the shaping curve.</li>
- <li>Down-sample the result back to the sample-rate of the AudioContext. Thus taking the 256 (or 512) processed samples, generating 128 as
- the final result.
- </ol>
- The exact up-sampling and down-sampling filters are not specified, and can be tuned for sound quality (low aliasing, etc.), low latency, and performance.
- </p>
- </dd>
-</dl>
-</div>
-</div>
-
-<div id="OscillatorNode-section" class="section">
-<h2 id="OscillatorNode">4.23. The OscillatorNode Interface</h2>
-
-<p>OscillatorNode represents an audio source generating a periodic waveform. It can be set to
-a few commonly used waveforms. Additionally, it can be set to an arbitrary periodic
-waveform through the use of a <a href="#PeriodicWave-section"><code>PeriodicWave</code></a> object. </p>
-
-<p>Oscillators are common foundational building blocks in audio synthesis. An OscillatorNode will start emitting sound at the time
-specified by the <code>start()</code> method. </p>
-
-<p>
-Mathematically speaking, a <em>continuous-time</em> periodic waveform can have very high (or infinitely high) frequency information when considered
-in the frequency domain. When this waveform is sampled as a discrete-time digital audio signal at a particular sample-rate,
-then care must be taken to discard (filter out) the high-frequency information higher than the <em>Nyquist</em> frequency (half the sample-rate)
-before converting the waveform to a digital form. If this is not done, then <em>aliasing</em> of higher frequencies (than the Nyquist frequency) will fold
-back as mirror images into frequencies lower than the Nyquist frequency. In many cases this will cause audibly objectionable artifacts.
-This is a basic and well understood principle of audio DSP.
-</p>
-
-<p>
-There are several practical approaches that an implementation may take to avoid this aliasing.
-But regardless of approach, the <em>idealized</em> discrete-time digital audio signal is well defined mathematically.
-The trade-off for the implementation is a matter of implementation cost (in terms of CPU usage) versus fidelity to
-achieving this ideal.
-</p>
-
-<p>
-It is expected that an implementation will take some care in achieving this ideal, but it is reasonable to consider lower-quality,
-less-costly approaches on lower-end hardware.
-</p>
-
-<p>
-Both .frequency and .detune are <em>a-rate</em> parameters and are used together to determine a <em>computedFrequency</em> value:
-</p>
-
-<pre>
-computedFrequency(t) = frequency(t) * pow(2, detune(t) / 1200)
-</pre>
-
-<p>
-The OscillatorNode's instantaneous phase at each time is the time integral of <em>computedFrequency</em>.
-</p>
-
-<pre> numberOfInputs : 0
- numberOfOutputs : 1 (mono output)
- </pre>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="oscillator-node-idl">
-
-enum <dfn>OscillatorType</dfn> {
- "sine",
- "square",
- "sawtooth",
- "triangle",
- "custom"
-};
-
-interface <dfn id="dfn-OscillatorNode">OscillatorNode</dfn> : AudioNode {
-
- attribute OscillatorType type;
-
- readonly attribute AudioParam frequency; // in Hertz
- readonly attribute AudioParam detune; // in Cents
-
- void start(double when);
- void stop(double when);
- void setPeriodicWave(PeriodicWave periodicWave);
-
- attribute EventHandler onended;
-
-};
-</code></pre>
-</div>
-</div>
-
-<div id="attributes-OscillatorNode-section" class="section">
-<h3 id="attributes-OscillatorNode">4.23.1. Attributes</h3>
-<dl>
- <dt id="dfn-type"><code>type</code></dt>
- <dd><p>The shape of the periodic waveform. It may directly be set to any of the type constant values except for "custom".
- The <a href="#dfn-setPeriodicWave"><code>setPeriodicWave()</code></a> method can be used to set a custom waveform, which results in this attribute
- being set to "custom". The default value is "sine". </p>
- </dd>
-</dl>
-
-<dl>
- <dt id="dfn-frequency"><code>frequency</code></dt>
- <dd><p>The frequency (in Hertz) of the periodic waveform. This parameter is <em>a-rate</em> </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-detune"><code>detune</code></dt>
- <dd><p>A detuning value (in Cents) which will offset the <code>frequency</code> by the given amount.
- This parameter is <em>a-rate</em> </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-onended"><code>onended</code></dt>
- <dd><p>A property used to set the <code>EventHandler</code> (described in <cite><a
- href="http://www.whatwg.org/specs/web-apps/current-work/#eventhandler">HTML</a></cite>)
- for the ended event that is dispatched to <a
- href="#OscillatorNode-section"><code>OscillatorNode</code></a>
- node types. When the playback of the buffer for an <code>OscillatorNode</code>
- is finished, an event of type <code>Event</code> (described in <cite><a
- href="http://www.whatwg.org/specs/web-apps/current-work/#event">HTML</a></cite>)
- will be dispatched to the event handler. </p>
- </dd>
-</dl>
-</div>
-</div>
-
-<div id="methodsandparams-OscillatorNode-section" class="section">
-<h3 id="methodsandparams-OscillatorNode">4.23.2. Methods and Parameters</h3>
-<dl>
- <dt id="dfn-setPeriodicWave">The <code>setPeriodicWave</code>
- method</dt>
- <dd><p>Sets an arbitrary custom periodic waveform given a <a href="#PeriodicWave-section"><code>PeriodicWave</code></a>.</p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-start-AudioBufferSourceNode">The <code>start</code>
- method</dt>
- <dd><p>defined as in <a href="#AudioBufferSourceNode-section"><code>AudioBufferSourceNode</code></a>. </p>
- </dd>
-</dl>
-<dl>
- <dt id="dfn-stop-AudioBufferSourceNode">The <code>stop</code>
- method</dt>
- <dd><p>defined as in <a href="#AudioBufferSourceNode-section"><code>AudioBufferSourceNode</code></a>. </p>
- </dd>
-</dl>
-</div>
-
-
-<div id="PeriodicWave-section" class="section">
-<h2 id="PeriodicWave">4.24. The PeriodicWave Interface</h2>
-
-<p>PeriodicWave represents an arbitrary periodic waveform to be used with an <a href="#OscillatorNode-section"><code>OscillatorNode</code></a>.
-Please see <a href="#dfn-createPeriodicWave">createPeriodicWave()</a> and <a href="#dfn-setPeriodicWave">setPeriodicWave()</a> and for more details. </p>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="wavetable-idl">
-
-interface <dfn id="dfn-PeriodicWave">PeriodicWave</dfn> {
-
-};
-</code></pre>
-</div>
-</div>
-</div>
-
-<div id="MediaStreamAudioSourceNode-section" class="section">
-<h2 id="MediaStreamAudioSourceNode">4.25. The MediaStreamAudioSourceNode
-Interface</h2>
-
-<p>This interface represents an audio source from a <code>MediaStream</code>.
-The first <code>AudioMediaStreamTrack</code> from the <code>MediaStream</code> will be
-used as a source of audio.</p>
-<pre> numberOfInputs : 0
- numberOfOutputs : 1
-</pre>
-
- <p>
- The number of channels of the output corresponds to the number of channels of the <code>AudioMediaStreamTrack</code>.
- If there is no valid audio track, then the number of channels output will be one silent channel.
- </p>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="media-stream-audio-source-node-idl">
-
-interface <dfn id="dfn-MediaStreamAudioSourceNode">MediaStreamAudioSourceNode</dfn> : AudioNode {
-
-};
-</code></pre>
-</div>
-</div>
-</div>
-
-<div id="MediaStreamAudioDestinationNode-section" class="section">
-<h2 id="MediaStreamAudioDestinationNode">4.26. The MediaStreamAudioDestinationNode
-Interface</h2>
-
-<p>This interface is an audio destination representing a <code>MediaStream</code> with a single <code>AudioMediaStreamTrack</code>.
-This MediaStream is created when the node is created and is accessible via the <dfn>stream</dfn> attribute.
-This stream can be used in a similar way as a MediaStream obtained via getUserMedia(), and
-can, for example, be sent to a remote peer using the RTCPeerConnection addStream() method.
-</p>
-<pre>
- numberOfInputs : 1
- numberOfOutputs : 0
-
- channelCount = 2;
- channelCountMode = "explicit";
- channelInterpretation = "speakers";
-</pre>
-
-<p>
-The number of channels of the input is by default 2 (stereo). Any connections to the input
-are up-mixed/down-mixed to the number of channels of the input.
-</p>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">Web IDL</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="idl-code" id="media-stream-audio-destination-node-idl">
-
-interface <dfn id="dfn-MediaStreamAudioDestinationNode">MediaStreamAudioDestinationNode</dfn> : AudioNode {
-
- readonly attribute MediaStream stream;
-
-};
-</code></pre>
-</div>
-</div>
-
-<div id="attributes-MediaStreamAudioDestinationNode-section" class="section">
-<h3 id="attributes-MediaStreamAudioDestinationNode">4.26.1. Attributes</h3>
-<dl>
- <dt id="dfn-stream"><code>stream</code></dt>
- <dd><p>A MediaStream containing a single AudioMediaStreamTrack with the same number of channels
- as the node itself.</p>
- </dd>
-</dl>
-</div>
-
-</div>
-
-<div id="MixerGainStructure-section" class="section">
-<h2 id="MixerGainStructure">6. Mixer Gain Structure</h2>
-
-<p class="norm">This section is informative.</p>
-
-<h3 id="background">Background</h3>
-
-<p>One of the most important considerations when dealing with audio processing
-graphs is how to adjust the gain (volume) at various points. For example, in a
-standard mixing board model, each input bus has pre-gain, post-gain, and
-send-gains. Submix and master out busses also have gain control. The gain
-control described here can be used to implement standard mixing boards as well
-as other architectures. </p>
-
-<div id="SummingJunction-section" class="section">
-<h3 id="SummingJunction">Summing Inputs</h3>
-</div>
-
-<p>The inputs to <a href="#AudioNode-section"><code>AudioNodes</code></a> have
-the ability to accept connections from multiple outputs. The input then acts as
-a unity gain summing junction with each output signal being added with the
-others: </p>
-<img alt="unity gain summing junction"
-src="images/unity-gain-summing-junction.png" />
-
-<p>In cases where the channel layouts of the outputs do not match, a mix (usually up-mix) will occur according to the <a
-href="#UpMix-section">mixing rules</a>.
-</p>
-
-<h3 id="gain-Control">Gain Control</h3>
-
-<p>But many times, it's important to be able to control the gain for each of
-the output signals. The <a
-href="#GainNode-section"><code>GainNode</code></a> gives this
-control: </p>
-<img alt="mixer architecture new" src="images/mixer-architecture-new.png" />
-
-<p>Using these two concepts of unity gain summing junctions and GainNodes,
-it's possible to construct simple or complex mixing scenarios. </p>
-
-<h3 id="Example-mixer-with-send-busses">Example: Mixer with Send Busses</h3>
-
-<p>In a routing scenario involving multiple sends and submixes, explicit
-control is needed over the volume or "gain" of each connection to a mixer. Such
-routing topologies are very common and exist in even the simplest of electronic
-gear sitting around in a basic recording studio. </p>
-
-<p>Here's an example with two send mixers and a main mixer. Although possible,
-for simplicity's sake, pre-gain control and insert effects are not illustrated:
-</p>
-<img alt="mixer gain structure" src="images/mixer-gain-structure.png" />
-
-<p>This diagram is using a shorthand notation where "send 1", "send 2", and
-"main bus" are actually inputs to AudioNodes, but here are represented as
-summing busses, where the intersections g2_1, g3_1, etc. represent the "gain"
-or volume for the given source on the given mixer. In order to expose this
-gain, an <a href="#dfn-GainNode"><code>GainNode</code></a> is used:
-</p>
-
-<p>Here's how the above diagram could be constructed in JavaScript: </p>
-
-<div class="example">
-
-<div class="exampleHeader">
-Example</div>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">ECMAScript</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="es-code">
-
-var context = 0;
-var compressor = 0;
-var reverb = 0;
-var delay = 0;
-var s1 = 0;
-var s2 = 0;
-
-var source1 = 0;
-var source2 = 0;
-var g1_1 = 0;
-var g2_1 = 0;
-var g3_1 = 0;
-var g1_2 = 0;
-var g2_2 = 0;
-var g3_2 = 0;
-
-<span class="comment">// Setup routing graph </span>
-function setupRoutingGraph() {
- context = new AudioContext();
-
- compressor = context.createDynamicsCompressor();
-
- <span class="comment">// Send1 effect </span>
- reverb = context.createConvolver();
- <span class="comment">// Convolver impulse response may be set here or later </span>
-
- <span class="comment">// Send2 effect </span>
- delay = context.createDelay();
-
- <span class="comment">// Connect final compressor to final destination </span>
- compressor.connect(context.destination);
-
- <span class="comment">// Connect sends 1 &amp; 2 through effects to main mixer </span>
- s1 = context.createGain();
- reverb.connect(s1);
- s1.connect(compressor);
-
- s2 = context.createGain();
- delay.connect(s2);
- s2.connect(compressor);
-
- <span class="comment">// Create a couple of sources </span>
- source1 = context.createBufferSource();
- source2 = context.createBufferSource();
- source1.buffer = manTalkingBuffer;
- source2.buffer = footstepsBuffer;
-
- <span class="comment">// Connect source1 </span>
- g1_1 = context.createGain();
- g2_1 = context.createGain();
- g3_1 = context.createGain();
- source1.connect(g1_1);
- source1.connect(g2_1);
- source1.connect(g3_1);
- g1_1.connect(compressor);
- g2_1.connect(reverb);
- g3_1.connect(delay);
-
- <span class="comment">// Connect source2 </span>
- g1_2 = context.createGain();
- g2_2 = context.createGain();
- g3_2 = context.createGain();
- source2.connect(g1_2);
- source2.connect(g2_2);
- source2.connect(g3_2);
- g1_2.connect(compressor);
- g2_2.connect(reverb);
- g3_2.connect(delay);
-
- <span class="comment">// We now have explicit control over all the volumes g1_1, g2_1, ..., s1, s2 </span>
- g2_1.gain.value = 0.2; <span class="comment"> // For example, set source1 reverb gain </span>
-
- <span class="comment"> // Because g2_1.gain is an "AudioParam", </span>
- <span class="comment"> // an automation curve could also be attached to it. </span>
- <span class="comment"> // A "mixing board" UI could be created in canvas or WebGL controlling these gains. </span>
-}
-
- </code></pre>
-</div>
-</div>
-</div>
-</div>
-<br />
-
-
-<div id="DynamicLifetime-section">
-<h2 id="DynamicLifetime">7. Dynamic Lifetime</h2>
-
-<h3 id="DynamicLifetime-background">Background</h3>
-
-<p class="norm">This section is informative. Please see <a href="#lifetime-AudioContext">AudioContext lifetime</a>
-and <a href="#lifetime-AudioNode">AudioNode lifetime</a> for normative requirements
-</p>
-
-<p>In addition to allowing the creation of static routing configurations, it
-should also be possible to do custom effect routing on dynamically allocated
-voices which have a limited lifetime. For the purposes of this discussion,
-let's call these short-lived voices "notes". Many audio applications
-incorporate the ideas of notes, examples being drum machines, sequencers, and
-3D games with many one-shot sounds being triggered according to game play. </p>
-
-<p>In a traditional software synthesizer, notes are dynamically allocated and
-released from a pool of available resources. The note is allocated when a MIDI
-note-on message is received. It is released when the note has finished playing
-either due to it having reached the end of its sample-data (if non-looping), it
-having reached a sustain phase of its envelope which is zero, or due to a MIDI
-note-off message putting it into the release phase of its envelope. In the MIDI
-note-off case, the note is not released immediately, but only when the release
-envelope phase has finished. At any given time, there can be a large number of
-notes playing but the set of notes is constantly changing as new notes are
-added into the routing graph, and old ones are released. </p>
-
-<p>The audio system automatically deals with tearing-down the part of the
-routing graph for individual "note" events. A "note" is represented by an
-<code>AudioBufferSourceNode</code>, which can be directly connected to other
-processing nodes. When the note has finished playing, the context will
-automatically release the reference to the <code>AudioBufferSourceNode</code>,
-which in turn will release references to any nodes it is connected to, and so
-on. The nodes will automatically get disconnected from the graph and will be
-deleted when they have no more references. Nodes in the graph which are
-long-lived and shared between dynamic voices can be managed explicitly.
-Although it sounds complicated, this all happens automatically with no extra
-JavaScript handling required. </p>
-
-<h3 id="Example-DynamicLifetime">Example</h3>
-
-<div class="example">
-
-<div class="exampleHeader">
-Example</div>
-<img alt="dynamic allocation" src="images/dynamic-allocation.png" />
-
-<p>The low-pass filter, panner, and second gain nodes are directly connected
-from the one-shot sound. So when it has finished playing the context will
-automatically release them (everything within the dotted line). If there are no
-longer any JavaScript references to the one-shot sound and connected nodes,
-then they will be immediately removed from the graph and deleted. The streaming
-source, has a global reference and will remain connected until it is explicitly
-disconnected. Here's how it might look in JavaScript: </p>
-
-<div class="block">
-
-<div class="blockTitleDiv">
-<span class="blockTitle">ECMAScript</span></div>
-
-<div class="blockContent">
-<pre class="code"><code class="es-code">
-
-var context = 0;
-var compressor = 0;
-var gainNode1 = 0;
-var streamingAudioSource = 0;
-
-<span class="comment">// Initial setup of the "long-lived" part of the routing graph </span>
-function setupAudioContext() {
- context = new AudioContext();
-
- compressor = context.createDynamicsCompressor();
- gainNode1 = context.createGain();
-
- // Create a streaming audio source.
- var audioElement = document.getElementById('audioTagID');
- streamingAudioSource = context.createMediaElementSource(audioElement);
- streamingAudioSource.connect(gainNode1);
-
- gainNode1.connect(compressor);
- compressor.connect(context.destination);
-}
-
-<span class="comment">// Later in response to some user action (typically mouse or key event) </span>
-<span class="comment">// a one-shot sound can be played. </span>
-function playSound() {
- var oneShotSound = context.createBufferSource();
- oneShotSound.buffer = dogBarkingBuffer;
-
- <span class="comment">// Create a filter, panner, and gain node. </span>
- var lowpass = context.createBiquadFilter();
- var panner = context.createPanner();
- var gainNode2 = context.createGain();
-
- <span class="comment">// Make connections </span>
- oneShotSound.connect(lowpass);
- lowpass.connect(panner);
- panner.connect(gainNode2);
- gainNode2.connect(compressor);
-
- <span class="comment">// Play 0.75 seconds from now (to play immediately pass in 0)</span>
- oneShotSound.start(context.currentTime + 0.75);
-}
-</code></pre>
-</div>
-</div>
-</div>
-</div>
-
-
-
-<div id="UpMix-section" class="section">
-<h2 id="UpMix">9. Channel up-mixing and down-mixing</h2>
-
-<p class="norm">This section is normative.</p>
-
-<img src="images/unity-gain-summing-junction.png">
-
-<p>
-<a href="#MixerGainStructure-section">Mixer Gain Structure</a>
-describes how an <dfn>input</dfn> to an AudioNode can be connected from one or more <dfn>outputs</dfn>
-of an AudioNode. Each of these connections from an output represents a stream with
-a specific non-zero number of channels. An input has <em>mixing rules</em> for combining the channels
-from all of the connections to it. As a simple example, if an input is connected from a mono output and
-a stereo output, then the mono connection will usually be up-mixed to stereo and summed with
-the stereo connection. But, of course, it's important to define the exact <em>mixing rules</em> for
-every input to every AudioNode. The default mixing rules for all of the inputs have been chosen so that
-things "just work" without worrying too much about the details, especially in the very common
-case of mono and stereo streams. But the rules can be changed for advanced use cases, especially
-multi-channel.
-</p>
-
-<p>
-To define some terms, <em>up-mixing</em> refers to the process of taking a stream with a smaller
-number of channels and converting it to a stream with a larger number of channels. <em>down-mixing</em>
-refers to the process of taking a stream with a larger number of channels and converting it to a stream
-with a smaller number of channels.
-</p>
-
-<p>
-An AudioNode input use three basic pieces of information to determine how to mix all the outputs
-connected to it. As part of this process it computes an internal value <dfn>computedNumberOfChannels</dfn>
- representing the actual number of channels of the input at any given time:
-</p>
-
-<p>
-The AudioNode attributes involved in channel up-mixing and down-mixing rules are defined
-<a href="#attributes-AudioNode-section">above</a>. The following is a more precise specification
-on what each of them mean.
-</p>
-
-<ul>
-<li><dfn>channelCount</dfn> is used to help compute <dfn>computedNumberOfChannels</dfn>.</li>
-
-<li><dfn>channelCountMode</dfn> determines how <dfn>computedNumberOfChannels</dfn> will be computed.
-Once this number is computed, all of the connections will be up or down-mixed to that many channels. For most nodes,
-the default value is "max".
-<ul>
-<li>“max”: <dfn>computedNumberOfChannels</dfn> is computed as the maximum of the number of channels of all connections.
-In this mode <dfn>channelCount</dfn> is ignored.</li>
-<li>“clamped-max”: same as “max” up to a limit of the <dfn>channelCount</dfn></li>
-<li>“explicit”: <dfn>computedNumberOfChannels</dfn> is the exact value as specified in <dfn>channelCount</dfn></li>
-</ul>
-
-</li>
-
-<li><dfn>channelInterpretation</dfn> determines how the individual channels will be treated.
-For example, will they be treated as speakers having a specific layout, or will they
-be treated as simple discrete channels? This value influences exactly how the up and down mixing is
-performed. The default value is "speakers".
-
-<ul>
-<li>“speakers”: use <a href="#ChannelLayouts">up-down-mix equations for mono/stereo/quad/5.1</a>.
-In cases where the number of channels do not match any of these basic speaker layouts, revert
-to "discrete".
-</li>
-<li>“discrete”: up-mix by filling channels until they run out then zero out remaining channels.
- down-mix by filling as many channels as possible, then dropping remaining channels</li>
-</ul>
-
-</li>
-
-</ul>
-
-<p>
-For each input of an AudioNode, an implementation must:
-</p>
-
-<ol>
-<li>Compute <dfn>computedNumberOfChannels</dfn>.</li>
-<li>For each connection to the input:
-<ul>
-<li> up-mix or down-mix the connection to <dfn>computedNumberOfChannels</dfn> according to <dfn>channelInterpretation</dfn>.</li>
-<li> Mix it together with all of the other mixed streams (from other connections). This is a straight-forward mixing together of each of the corresponding channels from each
-connection.</li>
-</ul>
-</li>
-</ol>
-
-
-
-
-<div id="ChannelLayouts-section" class="section">
-<h3 id="ChannelLayouts">9.1. Speaker Channel Layouts</h3>
-
-<p class="norm">This section is normative.</p>
-
-<p>
-When <dfn>channelInterpretation</dfn> is "speakers" then the up-mixing and down-mixing
-is defined for specific channel layouts.
-</p>
-
-<p>It's important to define the channel ordering (and define some
-abbreviations) for these speaker layouts.</p>
-
-<p>
-For now, only considers cases for mono, stereo, quad, 5.1. Later other channel
-layouts can be defined.
-</p>
-
-<h4 id ="ChannelOrdering">9.1.1. Channel ordering</h4>
-
-<pre> Mono
- 0: M: mono
-
- Stereo
- 0: L: left
- 1: R: right
- </pre>
-
-<pre> Quad
- 0: L: left
- 1: R: right
- 2: SL: surround left
- 3: SR: surround right
-
- 5.1
- 0: L: left
- 1: R: right
- 2: C: center
- 3: LFE: subwoofer
- 4: SL: surround left
- 5: SR: surround right
- </pre>
-</div>
-
-<h4 id="UpMix-sub">9.1.2. Up Mixing speaker layouts</h4>
-
-<pre>Mono up-mix:
-
- 1 -&gt; 2 : up-mix from mono to stereo
- output.L = input;
- output.R = input;
-
- 1 -&gt; 4 : up-mix from mono to quad
- output.L = input;
- output.R = input;
- output.SL = 0;
- output.SR = 0;
-
- 1 -&gt; 5.1 : up-mix from mono to 5.1
- output.L = 0;
- output.R = 0;
- output.C = input; // put in center channel
- output.LFE = 0;
- output.SL = 0;
- output.SR = 0;
-
-Stereo up-mix:
-
- 2 -&gt; 4 : up-mix from stereo to quad
- output.L = input.L;
- output.R = input.R;
- output.SL = 0;
- output.SR = 0;
-
- 2 -&gt; 5.1 : up-mix from stereo to 5.1
- output.L = input.L;
- output.R = input.R;
- output.C = 0;
- output.LFE = 0;
- output.SL = 0;
- output.SR = 0;
-
-Quad up-mix:
-
- 4 -&gt; 5.1 : up-mix from stereo to 5.1
- output.L = input.L;
- output.R = input.R;
- output.C = 0;
- output.LFE = 0;
- output.SL = input.SL;
- output.SR = input.SR;</pre>
-
-<h4 id="down-mix">9.1.3. Down Mixing speaker layouts</h4>
-
-<p>A down-mix will be necessary, for example, if processing 5.1 source
-material, but playing back stereo. </p>
-<pre>
-Mono down-mix:
-
- 2 -&gt; 1 : stereo to mono
- output = 0.5 * (input.L + input.R);
-
- 4 -&gt; 1 : quad to mono
- output = 0.25 * (input.L + input.R + input.SL + input.SR);
-
- 5.1 -&gt; 1 : 5.1 to mono
- output = 0.7071 * (input.L + input.R) + input.C + 0.5 * (input.SL + input.SR)
-
-
-Stereo down-mix:
-
- 4 -&gt; 2 : quad to stereo
- output.L = 0.5 * (input.L + input.SL);
- output.R = 0.5 * (input.R + input.SR);
-
- 5.1 -&gt; 2 : 5.1 to stereo
- output.L = L + 0.7071 * (input.C + input.SL)
- output.R = R + 0.7071 * (input.C + input.SR)
-
-Quad down-mix:
-
- 5.1 -&gt; 4 : 5.1 to quad
- output.L = L + 0.7071 * input.C
- output.R = R + 0.7071 * input.C
- output.SL = input.SL
- output.SR = input.SR
-
-</pre>
-</div>
-
-<h3 id="ChannelRules-section">9.2. Channel Rules Examples</h3>
-
-<p class="norm">This section is informative.</p>
-
-<div class="block">
-<div class="blockTitleDiv">
-<div class="blockContent">
-<pre class="code"><code class="idl-code">
-// Set gain node to explicit 2-channels (stereo).
-gain.channelCount = 2;
-gain.channelCountMode = "explicit";
-gain.channelInterpretation = "speakers";
-
-// Set "hardware output" to 4-channels for DJ-app with two stereo output busses.
-context.destination.channelCount = 4;
-context.destination.channelCountMode = "explicit";
-context.destination.channelInterpretation = "discrete";
-
-// Set "hardware output" to 8-channels for custom multi-channel speaker array
-// with custom matrix mixing.
-context.destination.channelCount = 8;
-context.destination.channelCountMode = "explicit";
-context.destination.channelInterpretation = "discrete";
-
-// Set "hardware output" to 5.1 to play an HTMLAudioElement.
-context.destination.channelCount = 6;
-context.destination.channelCountMode = "explicit";
-context.destination.channelInterpretation = "speakers";
-
-// Explicitly down-mix to mono.
-gain.channelCount = 1;
-gain.channelCountMode = "explicit";
-gain.channelInterpretation = "speakers";
-</code></pre>
-</div>
-</div>
-</div>
-
-
-<div id="Spatialization-section" class="section">
-<h2 id="Spatialization">11. Spatialization / Panning </h2>
-
-<h3 id="Spatialization-background">Background</h3>
-
-<p>A common feature requirement for modern 3D games is the ability to
-dynamically spatialize and move multiple audio sources in 3D space. Game audio
-engines such as OpenAL, FMOD, Creative's EAX, Microsoft's XACT Audio, etc. have
-this ability. </p>
-
-<p>Using an <code>PannerNode</code>, an audio stream can be spatialized or
-positioned in space relative to an <code>AudioListener</code>. An <a
-href="#AudioContext-section"><code>AudioContext</code></a> will contain a
-single <code>AudioListener</code>. Both panners and listeners have a position
-in 3D space using a right-handed cartesian coordinate system.
-The units used in the coordinate system are not defined, and do not need to be
-because the effects calculated with these coordinates are independent/invariant
-of any particular units such as meters or feet. <code>PannerNode</code>
-objects (representing the source stream) have an <code>orientation</code>
-vector representing in which direction the sound is projecting. Additionally,
-they have a <code>sound cone</code> representing how directional the sound is.
-For example, the sound could be omnidirectional, in which case it would be
-heard anywhere regardless of its orientation, or it can be more directional and
-heard only if it is facing the listener. <code>AudioListener</code> objects
-(representing a person's ears) have an <code>orientation</code> and
-<code>up</code> vector representing in which direction the person is facing.
-Because both the source stream and the listener can be moving, they both have a
-<code>velocity</code> vector representing both the speed and direction of
-movement. Taken together, these two velocities can be used to generate a
-doppler shift effect which changes the pitch. </p>
-
-<p>
-During rendering, the <code>PannerNode</code> calculates an <em>azimuth</em>
-and <em>elevation</em>. These values are used internally by the implementation in
-order to render the spatialization effect. See the <a href="#Spatialization-panning-algorithm">Panning Algorithm</a> section
-for details of how these values are used.
-</p>
-
-<p>
-The following algorithm must be used to calculate the <em>azimuth</em>
-and <em>elevation</em>:
-</p>
-
-<div class="block">
-<div class="blockTitleDiv">
-<div class="blockContent">
-<pre class="code"><code class="es-code">
-// Calculate the source-listener vector.
-vec3 sourceListener = source.position - listener.position;
-
-if (sourceListener.isZero()) {
- // Handle degenerate case if source and listener are at the same point.
- azimuth = 0;
- elevation = 0;
- return;
-}
-
-sourceListener.normalize();
-
-// Align axes.
-vec3 listenerFront = listener.orientation;
-vec3 listenerUp = listener.up;
-vec3 listenerRight = listenerFront.cross(listenerUp);
-listenerRight.normalize();
-
-vec3 listenerFrontNorm = listenerFront;
-listenerFrontNorm.normalize();
-
-vec3 up = listenerRight.cross(listenerFrontNorm);
-
-float upProjection = sourceListener.dot(up);
-
-vec3 projectedSource = sourceListener - upProjection * up;
-projectedSource.normalize();
-
-azimuth = 180 * acos(projectedSource.dot(listenerRight)) / PI;
-
-// Source in front or behind the listener.
-double frontBack = projectedSource.dot(listenerFrontNorm);
-if (frontBack &lt; 0)
- azimuth = 360 - azimuth;
-
-// Make azimuth relative to "front" and not "right" listener vector.
-if ((azimuth >= 0) &amp;&amp; (azimuth &lt;= 270))
- azimuth = 90 - azimuth;
-else
- azimuth = 450 - azimuth;
-
-elevation = 90 - 180 * acos(sourceListener.dot(up)) / PI;
-
-if (elevation > 90)
- elevation = 180 - elevation;
-else if (elevation &lt; -90)
- elevation = -180 - elevation;
-</code></pre>
-</div>
-</div>
-</div>
-
-<h3 id="Spatialization-panning-algorithm">Panning Algorithm</h3>
-
-<p>
-<em>mono->stereo</em> and <em>stereo->stereo</em> panning must be supported.
-<em>mono->stereo</em> processing is used when all connections to the input are mono.
-Otherwise <em>stereo->stereo</em> processing is used.</p>
-
-<p>The following algorithms must be implemented: </p>
-<ul>
- <li>Equal-power (Vector-based) panning
- <p>This is a simple and relatively inexpensive algorithm which provides
- basic, but reasonable results. It is commonly used when panning musical sources.
- </p>
- The <em>elevation</em> value is ignored in this panning algorithm.
-
- <p>
- The following steps are used for processing:
- </p>
-
- <ol>
-
- <li>
- <p>
- The <em>azimuth</em> value is first contained to be within the range -90 &lt;= <em>azimuth</em> &lt;= +90 according to:
- </p>
- <pre>
- // Clamp azimuth to allowed range of -180 -> +180.
- azimuth = max(-180, azimuth);
- azimuth = min(180, azimuth);
-
- // Now wrap to range -90 -> +90.
- if (azimuth &lt; -90)
- azimuth = -180 - azimuth;
- else if (azimuth > 90)
- azimuth = 180 - azimuth;
- </pre>
- </li>
-
- <li>
- <p>
- A 0 -> 1 normalized value <em>x</em> is calculated from <em>azimuth</em> for <em>mono->stereo</em> as:
- </p>
- <pre>
- x = (azimuth + 90) / 180
- </pre>
-
- <p>
- Or for <em>stereo->stereo</em> as:
- </p>
- <pre>
- if (azimuth &lt;= 0) { // from -90 -> 0
- // inputL -> outputL and "equal-power pan" inputR as in mono case
- // by transforming the "azimuth" value from -90 -> 0 degrees into the range -90 -> +90.
- x = (azimuth + 90) / 90;
- } else { // from 0 -> +90
- // inputR -> outputR and "equal-power pan" inputL as in mono case
- // by transforming the "azimuth" value from 0 -> +90 degrees into the range -90 -> +90.
- x = azimuth / 90;
- }
- </pre>
- </li>
-
- <li>
- <p>
- Left and right gain values are then calculated:
- </p>
- <pre>
- gainL = cos(0.5 * PI * x);
- gainR = sin(0.5 * PI * x);
- </pre>
- </li>
-
- <li>
- <p>For <em>mono->stereo</em>, the output is calculated as:</p>
- <pre>
- outputL = input * gainL
- outputR = input * gainR
- </pre>
- <p>Else for <em>stereo->stereo</em>, the output is calculated as:</p>
- <pre>
- if (azimuth &lt;= 0) { // from -90 -> 0
- outputL = inputL + inputR * gainL;
- outputR = inputR * gainR;
- } else { // from 0 -> +90
- outputL = inputL * gainL;
- outputR = inputR + inputL * gainR;
- }
- </pre>
- </li>
-
- </ol>
-
-
-
- </li>
- <li><a
- href="http://en.wikipedia.org/wiki/Head-related_transfer_function">HRTF</a>
- panning (stereo only)
- <p>This requires a set of HRTF impulse responses recorded at a variety of
- azimuths and elevations. There are a small number of open/free impulse
- responses available. The implementation requires a highly optimized
- convolution function. It is somewhat more costly than "equal-power", but
- provides a more spatialized sound. </p>
- <img alt="HRTF panner" src="images/HRTF_panner.png" /></li>
-</ul>
-
-<h3 id="Spatialization-distance-effects">Distance Effects</h3>
-<p>
-Sounds which are closer are louder, while sounds further away are quieter.
-Exactly <em>how</em> a sound's volume changes according to distance from the listener
-depends on the <em>distanceModel</em> attribute.
-</p>
-
-
-<p>
-During audio rendering, a <em>distance</em> value will be calculated based on the panner and listener positions according to:
-</p>
-<pre>
-v = panner.position - listener.position
-</pre>
-<pre>
-distance = sqrt(dot(v, v))
-</pre>
-
-<p>
-<em>distance</em> will then be used to calculate <em>distanceGain</em> which depends
-on the <em>distanceModel</em> attribute. See the <a href="#dfn-distanceModel">distanceModel</a> section for details of
-how this is calculated for each distance model.
-</p>
-<p>As part of its processing, the <code>PannerNode</code> scales/multiplies the input audio signal by <em>distanceGain</em>
-to make distant sounds quieter and nearer ones louder.
-</p>
-
-
-
-
-<h3 id="Spatialization-sound-cones">Sound Cones</h3>
-
-<p>The listener and each sound source have an orientation vector describing
-which way they are facing. Each sound source's sound projection characteristics
-are described by an inner and outer "cone" describing the sound intensity as a
-function of the source/listener angle from the source's orientation vector.
-Thus, a sound source pointing directly at the listener will be louder than if
-it is pointed off-axis. Sound sources can also be omni-directional. </p>
-
-<p>
-The following algorithm must be used to calculate the gain contribution due
-to the cone effect, given the source (the <code>PannerNode</code>) and the listener:
-</p>
-
-<div class="block">
-<div class="blockTitleDiv">
-<div class="blockContent">
-<pre class="code"><code class="idl-code">
-if (source.orientation.isZero() || ((source.coneInnerAngle == 360) &amp;&amp; (source.coneOuterAngle == 360)))
- return 1; // no cone specified - unity gain
-
-// Normalized source-listener vector
-vec3 sourceToListener = listener.position - source.position;
-sourceToListener.normalize();
-
-vec3 normalizedSourceOrientation = source.orientation;
-normalizedSourceOrientation.normalize();
-
-// Angle between the source orientation vector and the source-listener vector
-double dotProduct = sourceToListener.dot(normalizedSourceOrientation);
-double angle = 180 * acos(dotProduct) / PI;
-double absAngle = fabs(angle);
-
-// Divide by 2 here since API is entire angle (not half-angle)
-double absInnerAngle = fabs(source.coneInnerAngle) / 2;
-double absOuterAngle = fabs(source.coneOuterAngle) / 2;
-double gain = 1;
-
-if (absAngle &lt;= absInnerAngle)
- // No attenuation
- gain = 1;
-else if (absAngle &gt;= absOuterAngle)
- // Max attenuation
- gain = source.coneOuterGain;
-else {
- // Between inner and outer cones
- // inner -> outer, x goes from 0 -> 1
- double x = (absAngle - absInnerAngle) / (absOuterAngle - absInnerAngle);
- gain = (1 - x) + source.coneOuterGain * x;
-}
-
-return gain;
-</code></pre>
-</div>
-</div>
-</div>
-
-<h3 id="Spatialization-doppler-shift">Doppler Shift</h3>
-<ul>
- <li>Introduces a pitch shift which can realistically simulate moving
- sources.</li>
- <li>Depends on: source / listener velocity vectors, speed of sound, doppler
- factor.</li>
-</ul>
-
-<p>
-The following algorithm must be used to calculate the doppler shift value which is used
-as an additional playback rate scalar for all AudioBufferSourceNodes connecting directly or
-indirectly to the AudioPannerNode:
-</p>
-
-<div class="block">
-<div class="blockTitleDiv">
-<div class="blockContent">
-<pre class="code"><code class="idl-code">
-double dopplerShift = 1; // Initialize to default value
-double dopplerFactor = listener.dopplerFactor;
-
-if (dopplerFactor > 0) {
- double speedOfSound = listener.speedOfSound;
-
- // Don't bother if both source and listener have no velocity.
- if (!source.velocity.isZero() || !listener.velocity.isZero()) {
- // Calculate the source to listener vector.
- vec3 sourceToListener = source.position - listener.position;
-
- double sourceListenerMagnitude = sourceToListener.length();
-
- double listenerProjection = sourceToListener.dot(listener.velocity) / sourceListenerMagnitude;
- double sourceProjection = sourceToListener.dot(source.velocity) / sourceListenerMagnitude;
-
- listenerProjection = -listenerProjection;
- sourceProjection = -sourceProjection;
-
- double scaledSpeedOfSound = speedOfSound / dopplerFactor;
- listenerProjection = min(listenerProjection, scaledSpeedOfSound);
- sourceProjection = min(sourceProjection, scaledSpeedOfSound);
-
- dopplerShift = ((speedOfSound - dopplerFactor * listenerProjection) / (speedOfSound - dopplerFactor * sourceProjection));
- fixNANs(dopplerShift); // Avoid illegal values
-
- // Limit the pitch shifting to 4 octaves up and 3 octaves down.
- dopplerShift = min(dopplerShift, 16);
- dopplerShift = max(dopplerShift, 0.125);
- }
-}
-</code></pre>
-</div>
-</div>
-</div>
-
-
-
-
-</div>
-
-<div id="Convolution-section" class="section">
-<h2 id="Convolution">12. Linear Effects using Convolution</h2>
-
-<h3 id="Convolution-background">Background</h3>
-
-<p><a href="http://en.wikipedia.org/wiki/Convolution">Convolution</a> is a
-mathematical process which can be applied to an audio signal to achieve many
-interesting high-quality linear effects. Very often, the effect is used to
-simulate an acoustic space such as a concert hall, cathedral, or outdoor
-amphitheater. It can also be used for complex filter effects, like a muffled
-sound coming from inside a closet, sound underwater, sound coming through a
-telephone, or playing through a vintage speaker cabinet. This technique is very
-commonly used in major motion picture and music production and is considered to
-be extremely versatile and of high quality. </p>
-
-<p>Each unique effect is defined by an <code>impulse response</code>. An
-impulse response can be represented as an audio file and <a
-href="#recording-impulse-responses">can be recorded</a> from a real acoustic
-space such as a cave, or can be synthetically generated through a great variety
-of techniques. </p>
-
-<h3 id="Convolution-motivation">Motivation for use as a Standard</h3>
-
-<p>A key feature of many game audio engines (OpenAL, FMOD, Creative's EAX,
-Microsoft's XACT Audio, etc.) is a reverberation effect for simulating the
-sound of being in an acoustic space. But the code used to generate the effect
-has generally been custom and algorithmic (generally using a hand-tweaked set
-of delay lines and allpass filters which feedback into each other). In nearly
-all cases, not only is the implementation custom, but the code is proprietary
-and closed-source, each company adding its own "black magic" to achieve its
-unique quality. Each implementation being custom with a different set of
-parameters makes it impossible to achieve a uniform desired effect. And the
-code being proprietary makes it impossible to adopt a single one of the
-implementations as a standard. Additionally, algorithmic reverberation effects
-are limited to a relatively narrow range of different effects, regardless of
-how the parameters are tweaked. </p>
-
-<p>A convolution effect solves these problems by using a very precisely defined
-mathematical algorithm as the basis of its processing. An impulse response
-represents an exact sound effect to be applied to an audio stream and is easily
-represented by an audio file which can be referenced by URL. The range of
-possible effects is enormous. </p>
-
-<h3 id="Convolution-implementation-guide">Implementation Guide</h3>
-<p>
-Linear convolution can be implemented efficiently.
-Here are some <a href="https://dvcs.w3.org/hg/audio/raw-file/tip/webaudio/convolution.html">notes</a>
-describing how it can be practically implemented.
-</p>
-
-<h3 id="Convolution-reverb-effect">Reverb Effect (with matrixing)</h3>
-
-<p class="norm">This section is normative.</p>
-
-<p>
-In the general case the source
-has N input channels, the impulse response has K channels, and the playback
-system has M output channels. Thus it's a matter of how to matrix these
-channels to achieve the final result.
-</p>
-
-<p>
-The subset of N, M, K below must be implemented (note that the first image in the diagram is just illustrating
-the general case and is not normative, while the following images are normative).
-Without loss of generality, developers desiring more complex and arbitrary matrixing can use multiple <code>ConvolverNode</code>
-objects in conjunction with an <code>ChannelMergerNode</code>.
-</p>
-
-
-<p>Single channel convolution operates on a mono audio input, using a mono
-impulse response, and generating a mono output. But to achieve a more spacious sound, 2 channel audio
-inputs and 1, 2, or 4 channel impulse responses will be considered. The following diagram, illustrates the
-common cases for stereo playback where N and M are 1 or 2 and K is 1, 2, or 4.
-</p>
-<img alt="reverb matrixing" src="images/reverb-matrixing.png" />
-
-<h3 id="recording-impulse-responses">Recording Impulse Responses</h3>
-
-<p class="norm">This section is informative.</p>
-<img alt="impulse response" src="images/impulse-response.png" /> <br />
-<br />
-
-
-<p>The most <a
-href="http://pcfarina.eng.unipr.it/Public/Papers/226-AES122.pdf">modern</a> and
-accurate way to record the impulse response of a real acoustic space is to use
-a long exponential sine sweep. The test-tone can be as long as 20 or 30
-seconds, or longer. <br />
-Several recordings of the test tone played through a speaker can be made with
-microphones placed and oriented at various positions in the room. It's
-important to document speaker placement/orientation, the types of microphones,
-their settings, placement, and orientations for each recording taken. </p>
-
-<p>Post-processing is required for each of these recordings by performing an
-inverse-convolution with the test tone, yielding the impulse response of the
-room with the corresponding microphone placement. These impulse responses are
-then ready to be loaded into the convolution reverb engine to re-create the
-sound of being in the room. </p>
-
-<h3 id="tools">Tools</h3>
-
-<p>Two command-line tools have been written: <br />
-<code>generate_testtones</code> generates an exponential sine-sweep test-tone
-and its inverse. Another tool <code>convolve</code> was written for
-post-processing. With these tools, anybody with recording equipment can record
-their own impulse responses. To test the tools in practice, several recordings
-were made in a warehouse space with interesting acoustics. These were later
-post-processed with the command-line tools. </p>
-<pre>% generate_testtones -h
-Usage: generate_testtone
- [-o /Path/To/File/To/Create] Two files will be created: .tone and .inverse
- [-rate &lt;sample rate&gt;] sample rate of the generated test tones
- [-duration &lt;duration&gt;] The duration, in seconds, of the generated files
- [-min_freq &lt;min_freq&gt;] The minimum frequency, in hertz, for the sine sweep
-
-% convolve -h
-Usage: convolve input_file impulse_response_file output_file</pre>
-<br />
-
-
-<h3 id="recording-setup">Recording Setup</h3>
-<img alt="recording setup" src="images/recording-setup.png" /> <br />
-<br />
-Audio Interface: Metric Halo Mobile I/O 2882 <br />
-<br />
-<br />
-<br />
-<img alt="microphones speaker" src="images/microphones-speaker.png" /> <br />
-<br />
-<img alt="microphone" src="images/microphone.png" /> <img alt="speaker"
-src="images/speaker.png" /> <br />
-<br />
-Microphones: AKG 414s, Speaker: Mackie HR824 <br />
-<br />
-<br />
-
-
-<h3 id="warehouse">The Warehouse Space</h3>
-<img alt="warehouse" src="images/warehouse.png" /> <br />
-<br />
-</div>
-
-<div id="JavaScriptProcessing-section" class="section">
-<h2 id="JavaScriptProcessing">13. JavaScript Synthesis and Processing</h2>
-
-<p class="norm">This section is informative.</p>
-
-<p>The Mozilla project has conducted <a
-href="https://wiki.mozilla.org/Audio_Data_API">Experiments</a> to synthesize
-and process audio directly in JavaScript. This approach is interesting for a
-certain class of audio processing and they have produced a number of impressive
-demos. This specification includes a means of synthesizing and processing
-directly using JavaScript by using a special subtype of <a
-href="#AudioNode-section"><code>AudioNode</code></a> called <a
-href="#ScriptProcessorNode-section"><code>ScriptProcessorNode</code></a>. </p>
-
-<p>Here are some interesting examples where direct JavaScript processing can be
-useful: </p>
-
-<h3 id="custom-DSP-effects">Custom DSP Effects</h3>
-
-<p>Unusual and interesting custom audio processing can be done directly in JS.
-It's also a good test-bed for prototyping new algorithms. This is an extremely
-rich area. </p>
-
-<h3 id="educational-applications">Educational Applications</h3>
-
-<p>JS processing is ideal for illustrating concepts in computer music synthesis
-and processing, such as showing the de-composition of a square wave into its
-harmonic components, FM synthesis techniques, etc. </p>
-
-<h3 id="javaScript-performance">JavaScript Performance</h3>
-
-<p>JavaScript has a variety of <a
-href="#JavaScriptPerformance-section">performance issues</a> so it is not
-suitable for all types of audio processing. The approach proposed in this
-document includes the ability to perform computationally intensive aspects of
-the audio processing (too expensive for JavaScript to compute in real-time)
-such as multi-source 3D spatialization and convolution in optimized C++ code.
-Both direct JavaScript processing and C++ optimized code can be combined due to
-the APIs <a href="#ModularRouting-section">modular approach</a>. </p>
-
-<div id="Performance-section" class="section">
-<h2 id="Performance">15. Performance Considerations</h2>
-
-<div id="Latency-section" class="section">
-<h3 id="Latency">15.1. Latency: What it is and Why it's Important</h3>
-</div>
-<img alt="latency" src="images/latency.png" />
-
-<p>For web applications, the time delay between mouse and keyboard events
-(keydown, mousedown, etc.) and a sound being heard is important. </p>
-
-<p>This time delay is called latency and is caused by several factors (input
-device latency, internal buffering latency, DSP processing latency, output
-device latency, distance of user's ears from speakers, etc.), and is
-cummulative. The larger this latency is, the less satisfying the user's
-experience is going to be. In the extreme, it can make musical production or
-game-play impossible. At moderate levels it can affect timing and give the
-impression of sounds lagging behind or the game being non-responsive. For
-musical applications the timing problems affect rhythm. For gaming, the timing
-problems affect precision of gameplay. For interactive applications, it
-generally cheapens the users experience much in the same way that very low
-animation frame-rates do. Depending on the application, a reasonable latency
-can be from as low as 3-6 milliseconds to 25-50 milliseconds. </p>
-
-<div id="Glitching-section" class="section">
-<h3 id="audio-glitching">15.2. Audio Glitching</h3>
-</div>
-
-<p>Audio glitches are caused by an interruption of the normal continuous audio
-stream, resulting in loud clicks and pops. It is considered to be a
-catastrophic failure of a multi-media system and must be avoided. It can be
-caused by problems with the threads responsible for delivering the audio stream
-to the hardware, such as scheduling latencies caused by threads not having the
-proper priority and time-constraints. It can also be caused by the audio DSP
-trying to do more work than is possible in real-time given the CPU's speed. </p>
-
-<h3 id="hardware-scalability">15.3. Hardware Scalability</h3>
-
-<p>The system should gracefully degrade to allow audio processing under
-resource constrained conditions without dropping audio frames. </p>
-
-<p>First of all, it should be clear that regardless of the platform, the audio
-processing load should never be enough to completely lock up the machine.
-Second, the audio rendering needs to produce a clean, un-interrupted audio
-stream without audible <a href="#Glitching-section">glitches</a>. </p>
-
-<p>The system should be able to run on a range of hardware, from mobile phones
-and tablet devices to laptop and desktop computers. But the more limited
-compute resources on a phone device make it necessary to consider techniques to
-scale back and reduce the complexity of the audio rendering. For example,
-voice-dropping algorithms can be implemented to reduce the total number of
-notes playing at any given time. </p>
-
-<p>Here's a list of some techniques which can be used to limit CPU usage: </p>
-
-<h4 id="CPU-monitoring">15.3.1. CPU monitoring</h4>
-
-<p>In order to avoid audio breakup, CPU usage must remain below 100%. </p>
-
-<p>The relative CPU usage can be dynamically measured for each AudioNode (and
-chains of connected nodes) as a percentage of the rendering time quantum. In a
-single-threaded implementation, overall CPU usage must remain below 100%. The
-measured usage may be used internally in the implementation for dynamic
-adjustments to the rendering. It may also be exposed through a
-<code>cpuUsage</code> attribute of <code>AudioNode</code> for use by
-JavaScript. </p>
-
-<p>In cases where the measured CPU usage is near 100% (or whatever threshold is
-considered too high), then an attempt to add additional <code>AudioNodes</code>
-into the rendering graph can trigger voice-dropping. </p>
-
-<h4 id="Voice-dropping">15.3.2. Voice Dropping</h4>
-
-<p>Voice-dropping is a technique which limits the number of voices (notes)
-playing at the same time to keep CPU usage within a reasonable range. There can
-either be an upper threshold on the total number of voices allowed at any given
-time, or CPU usage can be dynamically monitored and voices dropped when CPU
-usage exceeds a threshold. Or a combination of these two techniques can be
-applied. When CPU usage is monitored for each voice, it can be measured all the
-way from a source node through any effect processing nodes which apply
-uniquely to that voice. </p>
-
-<p>When a voice is "dropped", it needs to happen in such a way that it doesn't
-introduce audible clicks or pops into the rendered audio stream. One way to
-achieve this is to quickly fade-out the rendered audio for that voice before
-completely removing it from the rendering graph. </p>
-
-<p>When it is determined that one or more voices must be dropped, there are
-various strategies for picking which voice(s) to drop out of the total ensemble
-of voices currently playing. Here are some of the factors which can be used in
-combination to help with this decision: </p>
-<ul>
- <li>Older voices, which have been playing the longest can be dropped instead
- of more recent voices. </li>
- <li>Quieter voices, which are contributing less to the overall mix may be
- dropped instead of louder ones. </li>
- <li>Voices which are consuming relatively more CPU resources may be dropped
- instead of less "expensive" voices.</li>
- <li>An AudioNode can have a <code>priority</code> attribute to help determine
- the relative importance of the voices.</li>
-</ul>
-
-<h4 id="Simplification-of-Effects-Processing">15.3.3. Simplification of Effects
-Processing</h4>
-
-<p>Most of the effects described in this document are relatively inexpensive
-and will likely be able to run even on the slower mobile devices. However, the
-<a href="#ConvolverNode-section">convolution effect</a> can be configured with
-a variety of impulse responses, some of which will likely be too heavy for
-mobile devices. Generally speaking, CPU usage scales with the length of the
-impulse response and the number of channels it has. Thus, it is reasonable to
-consider that impulse responses which exceed a certain length will not be
-allowed to run. The exact limit can be determined based on the speed of the
-device. Instead of outright rejecting convolution with these long responses, it
-may be interesting to consider truncating the impulse responses to the maximum
-allowed length and/or reducing the number of channels of the impulse response.
-</p>
-
-<p>In addition to the convolution effect. The <a
-href="#PannerNode-section"><code>PannerNode</code></a> may also be
-expensive if using the HRTF panning model. For slower devices, a cheaper
-algorithm such as EQUALPOWER can be used to conserve compute resources. </p>
-
-<h4 id="Sample-rate">15.3.4. Sample Rate</h4>
-
-<p>For very slow devices, it may be worth considering running the rendering at
-a lower sample-rate than normal. For example, the sample-rate can be reduced
-from 44.1KHz to 22.05KHz. This decision must be made when the
-<code>AudioContext</code> is created, because changing the sample-rate
-on-the-fly can be difficult to implement and will result in audible glitching
-when the transition is made. </p>
-
-<h4 id="pre-flighting">15.3.5. Pre-flighting</h4>
-
-<p>It should be possible to invoke some kind of "pre-flighting" code (through
-JavaScript) to roughly determine the power of the machine. The JavaScript code
-can then use this information to scale back any more intensive processing it
-may normally run on a more powerful machine. Also, the underlying
-implementation may be able to factor in this information in the voice-dropping
-algorithm. </p>
-
-<p><span class="ednote">TODO: add specification and more detail here </span></p>
-
-<h4 id="Authoring-for-different-user-agents">15.3.6. Authoring for different
-user agents</h4>
-JavaScript code can use information about user-agent to scale back any more
-intensive processing it may normally run on a more powerful machine.
-
-<h4 id="Scalability-of-Direct-JavaScript-Synthesis">15.3.7. Scalability of
-Direct JavaScript Synthesis / Processing</h4>
-
-<p>Any audio DSP / processing code done directly in JavaScript should also be
-concerned about scalability. To the extent possible, the JavaScript code itself
-needs to monitor CPU usage and scale back any more ambitious processing when
-run on less powerful devices. If it's an "all or nothing" type of processing,
-then user-agent check or pre-flighting should be done to avoid generating an
-audio stream with audio breakup. </p>
-
-<div id="JavaScriptPerformance-section" class="section">
-<h3 id="JavaScriptPerformance">15.4. JavaScript Issues with real-time
-Processing and Synthesis: </h3>
-</div>
-While processing audio in JavaScript, it is extremely challenging to get
-reliable, glitch-free audio while achieving a reasonably low-latency,
-especially under heavy processor load.
-<ul>
- <li>JavaScript is very much slower than heavily optimized C++ code and is not
- able to take advantage of SSE optimizations and multi-threading which is
- critical for getting good performance on today's processors. Optimized
- native code can be on the order of twenty times faster for processing FFTs
- as compared with JavaScript. It is not efficient enough for heavy-duty
- processing of audio such as convolution and 3D spatialization of large
- numbers of audio sources. </li>
- <li>setInterval() and XHR handling will steal time from the audio processing.
- In a reasonably complex game, some JavaScript resources will be needed for
- game physics and graphics. This creates challenges because audio rendering
- is deadline driven (to avoid glitches and get low enough latency).</li>
- <li>JavaScript does not run in a real-time processing thread and thus can be
- pre-empted by many other threads running on the system.</li>
- <li>Garbage Collection (and autorelease pools on Mac OS X) can cause
- unpredictable delay on a JavaScript thread. </li>
- <li>Multiple JavaScript contexts can be running on the main thread, stealing
- time from the context doing the processing. </li>
- <li>Other code (other than JavaScript) such as page rendering runs on the
- main thread. </li>
- <li>Locks can be taken and memory is allocated on the JavaScript thread. This
- can cause additional thread preemption. </li>
-</ul>
-The problems are even more difficult with today's generation of mobile devices
-which have processors with relatively poor performance and power consumption /
-battery-life issues. <br />
-<br />
-
-
-<div id="ExampleApplications-section" class="section">
-<h2 id="ExampleApplications">16. Example Applications</h2>
-
-<p class="norm">This section is informative.</p>
-
-<p>Please see the <a
-href="http://chromium.googlecode.com/svn/trunk/samples/audio/index.html">demo</a>
-page for working examples. </p>
-
-<p>Here are some of the types of applications a web audio system should be able
-to support: </p>
-
-<h3 id="basic-sound-playback">Basic Sound Playback</h3>
-
-<p>Simple and <a href="#Latency-section"><strong>low-latency</strong></a>
-playback of sound effects in response to simple user actions such as mouse
-click, roll-over, key press. </p>
-<br />
-
-
-<h3 id="threeD-environmentse-and-games">3D Environments and Games</h3>
-<img alt="quake" src="http://payload48.cargocollective.com/1/2/66805/3278334/redteam_680.jpg" />
-<br />
-<br />
-
-
-<p>Electronic Arts has produced an impressive immersive game called
- <a href="http://sophie-lu.com/Strike-Fortress-EA">Strike Fortress</a>,
-taking advantage of 3D spatialization and convolution for room simulation.</p>
-
-<img alt="beach demo" src="images/beach-demo.png" />
-
-<p>3D environments with audio are common in games made for desktop applications
-and game consoles. Imagine a 3D island environment with spatialized audio,
-seagulls flying overhead, the waves crashing against the shore, the crackling
-of the fire, the creaking of the bridge, and the rustling of the trees in the
-wind. The sounds can be positioned naturally as one moves through the scene.
-Even going underwater, low-pass filters can be tweaked for just the right
-underwater sound. </p>
-<br />
-<br />
-<img alt="box2d" src="images/box2d.png" /> <img alt="8-ball"
-src="images/8-ball.png" /> <br />
-<br />
-
-
-<p><a href="http://box2d.org/">Box2D</a> is an interesting open-source
-library for 2D game physics. It has various implementations, including one
-based on Canvas 2D. A demo has been created with dynamic sound effects for each
-of the object collisions, taking into account the velocities vectors and
-positions to spatialize the sound events, and modulate audio effect parameters
-such as filter cutoff. </p>
-
-<p>A virtual pool game with multi-sampled sound effects has also been created.
-</p>
-<br />
-
-
-<h3 id="musical-applications">Musical Applications</h3>
-<img alt="garageband" src="images/garage-band.png" /> <img
-alt="shiny drum machine" src="images/shiny-drum-machine.png" /> <img
-alt="tonecraft" src="images/tonecraft.png" /> <br />
-<br />
-Many music composition and production applications are possible. Applications
-requiring tight scheduling of audio events can be implemented and can be both
-educational and entertaining. Drum machines, digital DJ applications, and even
-timeline-based digital music production software with some of the features of
-<a href="http://en.wikipedia.org/wiki/GarageBand">GarageBand</a> can be
-written. <br />
-<br />
-
-
-<h3 id="music-visualizers">Music Visualizers</h3>
-<img alt="music visualizer" src="images/music-visualizer.png" /> <br />
-<br />
-When combined with WebGL GLSL shaders, realtime analysis data can be presented
-in entertaining ways. These can be as advanced as any found in iTunes. <br />
-<br />
-
-
-<h3 id="educational-applications_2">Educational Applications</h3>
-<img alt="javascript processing" src="images/javascript-processing.png" />
-
-<p>A variety of educational applications can be written, illustrating concepts
-in music theory and computer music synthesis and processing. </p>
-<br />
-
-
-<h3 id="artistic-audio-exploration">Artistic Audio Exploration</h3>
-
-<p>There are many creative possibilites for artistic sonic environments for
-installation pieces. </p>
-<br />
-</div>
-
-<div id="SecurityConsiderations-section" class="section">
-<h2 id="SecurityConsiderations">17. Security Considerations</h2>
-
-<p>This section is <em>informative.</em> </p>
-</div>
-
-<div id="PrivacyConsiderations-section" class="section">
-<h2 id="PrivacyConsiderations">18. Privacy Considerations</h2>
-
-<p>This section is <em>informative</em>. When giving various information on
-available AudioNodes, the Web Audio API potentially exposes information on
-characteristic features of the client (such as audio hardware sample-rate) to
-any page that makes use of the AudioNode interface. Additionally, timing
-information can be collected through the RealtimeAnalyzerNode or
-ScriptProcessorNode interface. The information could subsequently be used to
-create a fingerprint of the client. </p>
-
-<p>Currently audio input is not specified in this document, but it will involve
-gaining access to the client machine's audio input or microphone. This will
-require asking the user for permission in an appropriate way, probably via the
-<a href="http://developers.whatwg.org/">getUserMedia()
-API</a>. </p>
-</div>
-
-<div id="requirements-section" class="section">
-<h2 id="requirements">19. Requirements and Use Cases</h2>
-
-<p>Please see <a href="#ExampleApplications-section">Example Applications</a>
-</p>
-</div>
-
-<div id="oldnames-section" class="section">
-<h2 id="OldNames">20. Old Names</h2>
-
-<p class="norm">This section is informative.</p>
-
-<p>Some method and attribute names have been improved during API review.
-The new names are described in the main body of this specification in the
-description for each node type, etc. Here's a description of the older names
-to help content authors migrate to the latest spec. Note that the partial
-interfaces are not normative and are only descriptive:
-</p>
-<blockquote>
-<pre>
-
-partial interface <dfn>AudioBufferSourceNode</dfn> {
- // Same as start()
- void noteOn(double when);
- void noteGrainOn(double when, double grainOffset, double grainDuration);
-
- // Same as stop()
- void noteOff(double when);
-};
-
-partial interface <dfn>AudioContext</dfn> {
- // Same as createGain()
- GainNode createGainNode();
-
- // Same as createDelay()
- DelayNode createDelayNode(optional double maxDelayTime = 1.0);
-
- // Same as createScriptProcessor()
- ScriptProcessorNode createJavaScriptNode(optional unsigned long bufferSize = 0,
- optional unsigned long numberOfInputChannels = 2,
- optional unsigned long numberOfOutputChannels = 2);
-};
-
-partial interface <dfn>OscillatorNode</dfn> {
- // Same as start()
- void noteOn(double when);
-
- // Same as stop()
- void noteOff(double when);
-};
-
-partial interface <dfn>AudioParam</dfn> {
- // Same as setTargetAtTime()
- void setTargetValueAtTime(float target, double startTime, double timeConstant);
-};
-
-</pre>
-</blockquote>
-
-<p>Some attributes taking constant values have changed during API review.
-The old way used integer values, while the new way uses Web IDL string values.
-</p>
-
-<blockquote>
-<pre>
-// PannerNode constants for the .panningModel attribute
-
-// Old way
-const unsigned short EQUALPOWER = 0;
-const unsigned short HRTF = 1;
-
-// New way
-enum <dfn>PanningModelType</dfn> {
- "equalpower",
- "HRTF"
-};
-</pre>
-</blockquote>
-
-<blockquote>
-<pre>
-// PannerNode constants for the .distanceModel attribute
-
-// Old way
-const unsigned short LINEAR_DISTANCE = 0;
-const unsigned short INVERSE_DISTANCE = 1;
-const unsigned short EXPONENTIAL_DISTANCE = 2;
-
-// New way
-enum <dfn>DistanceModelType</dfn> {
- "linear",
- "inverse",
- "exponential"
-};
-</pre>
-</blockquote>
-
-
-
-<blockquote>
-<pre>
-// BiquadFilterNode constants for the .type attribute
-
-// Old way
-const unsigned short LOWPASS = 0;
-const unsigned short HIGHPASS = 1;
-const unsigned short BANDPASS = 2;
-const unsigned short LOWSHELF = 3;
-const unsigned short HIGHSHELF = 4;
-const unsigned short PEAKING = 5;
-const unsigned short NOTCH = 6;
-const unsigned short ALLPASS = 7;
-
-// New way
-enum <dfn>BiquadFilterType</dfn> {
- "lowpass",
- "highpass",
- "bandpass",
- "lowshelf",
- "highshelf",
- "peaking",
- "notch",
- "allpass"
-};
-</pre>
-</blockquote>
-
-<blockquote>
-<pre>
-// OscillatorNode constants for the .type attribute
-
-// Old way
-const unsigned short SINE = 0;
-const unsigned short SQUARE = 1;
-const unsigned short SAWTOOTH = 2;
-const unsigned short TRIANGLE = 3;
-const unsigned short CUSTOM = 4;
-
-// New way
-enum <dfn>OscillatorType</dfn> {
- "sine",
- "square",
- "sawtooth",
- "triangle",
- "custom"
-};
-</pre>
-</blockquote>
-
-
-
-</div>
-
-</div>
-</div>
-
-<div class="appendix section" id="references">
-<h2 id="L17310">A.References</h2>
-
-<div class="section" id="normative-references">
-<h3 id="Normative-references">A.1 Normative references</h3>
-<dl>
- <dt id="DOM">[DOM] </dt>
- <dd><a href="http://dom.spec.whatwg.org/">DOM</a>,
- A. van Kesteren, A. Gregor, Ms2ger. WHATWG.</dd>
- <dt id="HTML">[HTML] </dt>
- <dd><a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/">HTML</a>,
- I. Hickson. WHATWG.</dd>
- <dt id="RFC2119">[RFC2119] </dt>
- <dd>S. Bradner. <a
- href="http://www.ietf.org/rfc/rfc2119.txt"><cite><span>Key words for use
- in RFCs to Indicate Requirement Levels.</span></cite></a> Internet RFC
- 2119. URL: <a
- href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a>
- </dd>
-</dl>
-</div>
-
-<div class="section" id="informative-references">
-<h3 id="Informative-references">A.2 Informative references</h3>
-
-<p>No informative references.</p>
-</div>
-</div>
-
-<div class="section" id="acknowledgements">
-<h2 id="L17335">B.Acknowledgements</h2>
-
-<p>Special thanks to the W3C <a href="http://www.w3.org/2011/audio/">Audio
-Working Group</a>. Members of the Working Group are (at the time of writing,
-and by alphabetical order): <br />
-Berkovitz, Joe (public Invited expert);Cardoso, Gabriel (INRIA);Carlson, Eric
-(Apple, Inc.);Gregan, Matthew (Mozilla Foundation);Jägenstedt, Philip (Opera
-Software);Kalliokoski, Jussi (public Invited expert);Lowis, Chris (British
-Broadcasting Corporation);MacDonald, Alistair (W3C Invited Experts);Michel,
-Thierry (W3C/ERCIM);Noble, Jer (Apple, Inc.);O'Callahan, Robert(Mozilla
-Foundation);Paradis, Matthew (British Broadcasting Corporation);Raman, T.V.
-(Google, Inc.);Rogers, Chris (Google, Inc.);Schepers, Doug (W3C/MIT);Shires,
-Glen (Google, Inc.);Smith, Michael (W3C/Keio);Thereaux, Olivier (British
-Broadcasting Corporation);Wei, James (Intel Corporation);Wilson, Chris (Google,
-Inc.); </p>
-</div>
-
-<div class="section" id="ChangeLog-section">
-<h2 id="ChangeLog">C. Web Audio API Change Log</h2>
-<pre>
-user: crogers
-date: Sun Dec 09 17:13:56 2012 -0800
-summary: Basic description of OfflineAudioContext
-
-user: crogers
-date: Tue Dec 04 15:59:30 2012 -0800
-summary: minor correction to wording for minValue and maxValue
-
-user: crogers
-date: Tue Dec 04 15:49:29 2012 -0800
-summary: Bug 20161: Make decodeAudioData neuter its array buffer argument when it begins decoding a buffer, and bring it back to normal when the decoding is finished
-
-user: crogers
-date: Tue Dec 04 15:35:17 2012 -0800
-summary: Bug 20039: Refine description of audio decoding
-
-user: crogers
-date: Tue Dec 04 15:23:07 2012 -0800
-summary: elaborate on decoding steps for AudioContext createBuffer() and decodeAudioData()
-
-user: crogers
-date: Tue Dec 04 14:56:19 2012 -0800
-summary: Bug 19770: Note that if the last event for an AudioParam is a setCurveValue event, the computed value after that event will be equal to the latest curve value
-
-user: crogers
-date: Tue Dec 04 14:48:04 2012 -0800
-summary: Bug 19769: Note that before the first automation event, the computed AudioParam value will be AudioParam.value
-
-user: crogers
-date: Tue Dec 04 14:40:51 2012 -0800
-summary: Bug 19768: Explicitly mention that the initial value of AudioParam.value will be defaultValue
-
-user: crogers
-date: Tue Dec 04 14:35:59 2012 -0800
-summary: Bug 19767: Explicitly mention that the 2nd component of AudioParam.computedValue will be 0 if there are no AudioNodes connected to it
-
-user: crogers
-date: Tue Dec 04 14:30:08 2012 -0800
-summary: Bug 19764: Note in the spec that AudioParam.minValue/maxValue are merely informational
-
-user: crogers
-date: Mon Dec 03 18:03:13 2012 -0800
-summary: Convert integer constants to Web IDL enum string constants
-
-user: crogers
-date: Mon Dec 03 15:19:22 2012 -0800
-summary: Bug 17411: (AudioPannerNodeUnits): AudioPannerNode units are underspecified
-
-user: Ehsan Akhgari (Mozilla)
-date: Thu Nov 29 15:59:38 2012 -0500
-summary: Change the Web IDL description of decodeAudioData arguments
-
-user: crogers
-date: Wed Nov 14 13:24:01 2012 -0800
-summary: Bug 17393: (UseDoubles): float/double inconsistency
-
-user: crogers
-date: Wed Nov 14 13:16:57 2012 -0800
-summary: Bug 17356: (AudioListenerOrientation): AudioListener.setOrientation vectors
-
-user: crogers
-date: Wed Nov 14 12:56:06 2012 -0800
-summary: Bug 19957: PannerNode.coneGain is unused
-
-user: crogers
-date: Wed Nov 14 12:40:46 2012 -0800
-summary: Bug 17412: AudioPannerNodeVectorNormalization): AudioPannerNode orientation normalization unspecified
-
-user: crogers
-date: Wed Nov 14 12:16:41 2012 -0800
-summary: Bug 17411: (AudioPannerNodeUnits): AudioPannerNode units are underspecified
-
-user: crogers
-date: Tue Nov 13 16:14:22 2012 -0800
-summary: be more explicit about maxDelayTime units
-
-user: crogers
-date: Tue Nov 13 16:02:50 2012 -0800
-summary: Bug 19766: Clarify that reading AudioParam.computedValue will return the latest computed value for the latest audio quantum
-
-user: crogers
-date: Tue Nov 13 15:47:25 2012 -0800
-summary: Bug 19872: Should specify the defaults for PannerNode's position, ...
-
-user: crogers
-date: Tue Nov 13 15:27:53 2012 -0800
-summary: Bug 17390: (Joe Berkovitz): Loop start/stop points
-
-user: croger
-date: Tue Nov 13 14:49:20 2012 -0800
-summary: Bug 19765: Note that setting AudioParam.value will be ignored when any automation events have been set on the object
-
-user: crogers
-date: Tue Nov 13 14:39:07 2012 -0800
-summary: Bug 19873: Clarify PannerNode.listener
-
-user: crogers
-date: Tue Nov 13 13:35:21 2012 -0800
-summary: Bug 19900: Clarify the default values for the AudioParam attributes of BiquadFilterNode
-
-user: crogers
-date: Tue Nov 13 13:06:38 2012 -0800
-summary: Bug 19884: Specify the default value and ranges for the DynamicsCompressorNode AudioParam members
-
-user: crogers
-date: Tue Nov 13 12:57:02 2012 -0800
-summary: Bug 19910: Disallow AudioContext.createDelay(max) where max &lt;= 0
-
-user: crogers
-date: Mon Nov 12 12:02:18 2012 -0800
-summary: Add example code for more complex example
-
-user: Ehsan Akhgari (Mozilla)
-date: Thu Nov 01 11:32:39 2012 -0400
-summary: Specify the default value for the AudioContext.createDelay() optional argument in Web IDL
-
-user: Ehsan Akhgari (Mozilla)
-date: Tue Oct 30 20:29:48 2012 -0400
-summary: Mark the AudioParam members as readonly
-
-user: Ehsan Akhgari (Mozilla)
-date: Tue Oct 30 20:24:52 2012 -0400
-summary: Make GainNode and DelayNode valid Web IDL
-
-user: crogers
-date: Mon Oct 29 14:29:23 2012 -0700
-summary: consolidate AudioBufferSourceNode start() method
-
-user: crogers
-date: Fri Oct 19 15:15:28 2012 -0700
-summary: Bug 18332: Node creation method naming inconsistencies
-
-user: crogers
-date: Mon Oct 15 17:22:54 2012 -0700
-summary: Bug 17407: Interface naming inconsistency
-
-user: crogers
-date: Tue Oct 09 17:21:19 2012 -0700
-summary: Bug 17369: Oscillator.detune attribute not defined
-
-user: crogers
-date: Tue Oct 09 16:08:50 2012 -0700
-summary: Bug 17346: HTMLMediaElement integration
-
-user: crogers
-date: Tue Oct 09 15:20:50 2012 -0700
-summary: Bug 17354: AudioListener default position, orientation and velocity
-
-user: crogers
-date: Tue Oct 09 15:02:04 2012 -0700
-summary: Bug 17795: Behavior of multiple connections to same node needs to be explicitly defined
-
-user: crogers
-date: Mon Oct 08 13:18:45 2012 -0700
-summary: Add missing AudioContext.createWaveShaper() method
-
-user: crogers
-date: Fri Oct 05 18:13:44 2012 -0700
-summary: Bug 17399: AudioParam sampling is undefined
-
-user: crogers
-date: Fri Oct 05 17:41:52 2012 -0700
-summary: Bug 17386: Realtime Analysis empty section
-
-user: crogers
-date: Fri Oct 05 17:38:14 2012 -0700
-summary: minor tweak to down-mix section
-
-user: crogers
-date: Fri Oct 05 17:35:05 2012 -0700
-summary: Bug 17380: Channel down mixing incomplete
-
-user: crogers
-date: Fri Oct 05 15:40:57 2012 -0700
-summary: Bug 17375: MixerGainStructure should be marked as informative
-
-user: crogers
-date: Fri Oct 05 14:29:20 2012 -0700
-summary: Bug 17381: (EventScheduling): Event Scheduling ('Need more detail here')
-
-user: crogers
-date: Fri Oct 05 13:12:46 2012 -0700
-summary: Fix 18663: Need a method to get a readonly reading of the combined value when using AudioParam automation curve
-
-user: crogers
-date: Fri Oct 05 12:48:36 2012 -0700
-summary: Fix 18662: Setting audioparam value while there is an automation curve will cancel that automation curve and set value immediately
-
-user: crogers
-date: Fri Oct 05 12:26:28 2012 -0700
-summary: Fix 18661: Use startTime / endTime parameter names for AudioParam automation methods
-
-user: crogers
-date: Wed Oct 03 12:26:39 2012 -0700
-summary: Specify default value for .distanceModel
-
-user: crogers
-date: Tue Oct 02 12:33:36 2012 -0700
-summary: Fix Issues 17338 and 17337: AudioGain interface is not needed (Part 2)
-
-user: crogers
-date: Tue Oct 02 12:28:55 2012 -0700
-summary: Fix Issues 17338 and 17337: AudioGain interface is not needed
-
-user: Ehsan Akhgari (Mozilla)
-date: Wed Sep 26 18:22:36 2012 -0400
-summary: Make AudioBufferSourceNode.buffer nullable
-
-user: crogers
-date: Tue Sep 25 12:56:14 2012 -0700
-summary: noteOn/noteOff changed to start/stop -- added deprecation notes
-
-user: Ehsan Akhgari (Mozilla)
-date: Fri Aug 24 18:27:29 2012 -0400
-summary: Make the AudioContext object have a constructor
-
-user: Ehsan Akhgari (Mozilla)
-date: Fri Aug 24 15:54:10 2012 -0400
-summary: Denote IDL definitions as Web IDL
-
-user: Ehsan Akhgari (Mozilla)
-date: Fri Aug 24 15:04:37 2012 -0400
-summary: Use `long` instead of `int`, since the int type doesn't exist in Web IDL
-
-user: Ehsan Akhgari (Mozilla)
-date: Fri Aug 24 15:02:43 2012 -0400
-summary: Add a missing attribute keyword in AudioProcessingEvent
-
-user: Ehsan Akhgari (Mozilla)
-date: Tue Aug 21 15:36:48 2012 -0400
-summary: Remove the 'raises' notation from the IDLs
-
-user: crogers
-date: Thu Aug 16 16:30:55 2012 -0700
-summary: Issue 17398: Add more detailed information about how AudioParam value is calculated
-
-user: crogers
-date: Thu Aug 16 15:21:38 2012 -0700
-summary: another try with the style sheet
-
-user: crogers
-date: Thu Aug 16 14:53:54 2012 -0700
-summary: use local style sheet to avoid https errors
-
-user: Ehsan Akhgari (Mozilla)
-date: Wed Aug 15 23:05:49 2012 -0400
-summary: Replace the white-space based indentation of Web IDL code with a CSS-based one
-
-user: Ehsan Akhgari (Mozilla)
-date: Wed Aug 15 22:56:03 2012 -0400
-summary: Remove more useless trailing whitespaces
-
-user: Ehsan Akhgari (Mozilla)
-date: Wed Aug 15 22:47:21 2012 -0400
-summary: Remove the optional 'in' keyword from the Web IDL method declarations
-
-user: Ehsan Akhgari (Mozilla)
-date: Wed Aug 15 22:42:03 2012 -0400
-summary: Add trailing semicolons for Web IDL interface declarations
-
-user: Ehsan Akhgari (Mozilla)
-date: Wed Aug 15 22:37:32 2012 -0400
-summary: Remove useless trailing spaces
-
-user: Ehsan Akhgari (Mozilla)
-date: Wed Aug 15 22:35:33 2012 -0400
-summary: Use the correct Web IDL notation for the AudioBufferCallback callback type
-
-user: Ehsan Akhgari (Mozilla)
-date: Wed Aug 15 22:28:37 2012 -0400
-summary: Remove the extra semicolon in the IDL file for AudioContext
-
-user: Ehsan Akhgari (Mozilla)
-date: Wed Aug 15 22:24:02 2012 -0400
-summary: Replace the old [Optional] IDL tag with the Web IDL optional keyword
-
-user: Ehsan Akhgari (Mozilla)
-date: Tue Aug 14 10:18:19 2012 -0400
-summary: Empty changeset to test my commit access
-
-date: Mon Aug 13 13:26:52 2012 -0700
-* Integrate Thierry Michel's 3rd public working draft edits
-
-date: Tue Jun 26 15:56:31 2012 -0700
-* add MediaStreamAudioSourceNode
-
-date: Mon Jun 18 13:26:21 2012 -0700
-* minor formatting fix
-
-date: Mon Jun 18 13:19:34 2012 -0700
-* Add details for azimuth/elevation calculation
-
-date: Fri Jun 15 17:35:27 2012 -0700
-* Add equal-power-panning details
-
-date: Thu Jun 14 17:31:16 2012 -0700
-* Add equations for distance models
-
-date: Wed Jun 13 17:40:49 2012 -0700
-* Bug 17334: Add precise equations for AudioParam.setTargetValueAtTime()
-
-date: Fri Jun 08 17:44:26 2012 -0700
-* fix small typo
-
-date: Fri Jun 08 16:54:04 2012 -0700
-* Bug 17413: AudioBuffers' relationship to AudioContext
-
-date: Fri Jun 08 16:05:45 2012 -0700
-* Bug 17359: Add much more detail about ConvolverNode
-
-date: Fri Jun 08 12:59:29 2012 -0700
-* minor formatting fix
-
-date: Fri Jun 08 12:57:11 2012 -0700
-* Bug 17335: Add much more technical detail to setValueCurveAtTime()
-
-date: Wed Jun 06 16:34:43 2012 -0700
-*Add much more detail about parameter automation, including an example
-
-date: Mon Jun 04 17:25:08 2012 -0700
-* ISSUE-85: OscillatorNode folding considerations
-
-date: Mon Jun 04 17:02:20 2012 -0700
-* ISSUE-45: AudioGain scale underdefined
-
-date: Mon Jun 04 16:40:43 2012 -0700
-* ISSUE-41: AudioNode as input to AudioParam underdefined
-
-date: Mon Jun 04 16:14:48 2012 -0700
-* ISSUE-20: Relationship to currentTime
-
-date: Mon Jun 04 15:48:49 2012 -0700
-* ISSUE-94: Dynamic Lifetime
-
-date: Mon Jun 04 13:59:31 2012 -0700
-* ISSUE-42: add more detail about AudioParam sampling and block processing
-
-date: Mon Jun 04 12:28:48 2012 -0700
-* fix typo - minor edits
-
-date: Thu May 24 18:01:20 2012 -0700
-* ISSUE-69: add implementors guide for linear convolution
-
-date: Thu May 24 17:35:45 2012 -0700
-* ISSUE-49: better define AudioBuffer audio data access
-
-date: Thu May 24 17:15:29 2012 -0700
-* fix small typo
-
-date: Thu May 24 17:13:34 2012 -0700
-* ISSUE-24: define circular routing behavior
-
-date: Thu May 24 16:35:24 2012 -0700
-* ISSUE-42: specify a-rate or k-rate for each AudioParam
-
-date: Fri May 18 17:01:36 2012 -0700
-* ISSUE-53: noteOn and noteOff interaction
-
-date: Fri May 18 16:33:29 2012 -0700
-* ISSUE-34: Remove .name attribute from AudioParam
-
-date: Fri May 18 16:27:19 2012 -0700
-* ISSUE-33: Add maxNumberOfChannels attribute to AudioDestinationNode
-
-date: Fri May 18 15:50:08 2012 -0700
-* ISSUE-19: added more info about AudioBuffer - IEEE 32-bit
-
-date: Fri May 18 15:37:27 2012 -0700
-* ISSUE-29: remove reference to webkitAudioContext
-
-date: Fri Apr 27 12:36:54 2012 -0700
-* fix two small typos reported by James Wei
-
-date: Tue Apr 24 12:27:11 2012 -0700
-* small cleanup to ChannelSplitterNode and ChannelMergerNode
-
-date: Tue Apr 17 11:35:56 2012 -0700
-* small fix to createWaveTable()
-
-date: Tue Apr 13 2012
-* Cleanup AudioNode connect() and disconnect() method descriptions.
-* Add AudioNode connect() to AudioParam method.
-
-date: Tue Apr 13 2012
-* Add OscillatorNode and WaveTable
-* Define default values for optional arguments in createJavaScriptNode(), createChannelSplitter(), createChannelMerger()
-* Define default filter type for BiquadFilterNode as LOWPASS
-
-date: Tue Apr 11 2012
-* add AudioContext .activeSourceCount attribute
-* createBuffer() methods can throw exceptions
-* add AudioContext method createMediaElementSource()
-* update AudioContext methods createJavaScriptNode() (clean up description of parameters)
-* update AudioContext method createChannelSplitter() (add numberOfOutputs parameter)
-* update AudioContext method createChannelMerger() (add numberOfInputs parameter)
-* update description of out-of-bounds AudioParam values (exception will not be thrown)
-* remove AudioBuffer .gain attribute
-* remove AudioBufferSourceNode .gain attribute
-* remove AudioListener .gain attribute
-* add AudioBufferSourceNode .playbackState attribute and state constants
-* AnalyserNode no longer requires its output be connected to anything
-* update ChannelMergerNode section describing numberOfOutputs (defaults to 6 but settable in constructor)
-* update ChannelSplitterNode section describing numberOfInputs (defaults to 6 but settable in constructor)
-* add note in Spatialization sections about potential to get arbitrary convolution matrixing
-
-date: Tue Apr 10 2012
-* Rebased editor's draft document based on edits from Thierry Michel (from 2nd public working draft).
-
-date: Tue Mar 13 12:13:41 2012 -0100
-* fixed all the HTML errors
-* added ids to all Headings
-* added alt attribute to all img
-* fix broken anchors
-* added a new status of this document section
-* added mandatory spec headers
-* generated a new table of content
-* added a Reference section
-* added an Acknowledgments section
-* added a Web Audio API Change Log
-
-date: Fri Mar 09 15:12:42 2012 -0800
-* add optional maxDelayTime argument to createDelay()
-* add more detail about playback state to AudioBufferSourceNode
-* upgrade noteOn(), noteGrainOn(), noteOff() times to double from float
-
-date: Mon Feb 06 16:52:39 2012 -0800
-* Cleanup ScriptProcessorNode section
-* Add distance model constants for PannerNode according to the OpenAL spec
-* Add .normalize attribute to ConvolverNode
-* Add getFrequencyResponse() method to BiquadFilterNode
-* Tighten up the up-mix equations
-
-date: Fri Nov 04 15:40:58 2011 -0700
-summary: Add more technical detail to BiquadFilterNode description (contributed by Raymond Toy)
-
-date: Sat Oct 15 19:08:15 2011 -0700
-summary: small edits to the introduction
-
-date: Sat Oct 15 19:00:15 2011 -0700
-summary: initial commit
-
-date: Tue Sep 13 12:49:11 2011 -0700
-summary: add convolution reverb design document
-
-date: Mon Aug 29 17:05:58 2011 -0700
-summary: document the decodeAudioData() method
-
-date: Mon Aug 22 14:36:33 2011 -0700
-summary: fix broken MediaElementAudioSourceNode link
-
-date: Mon Aug 22 14:33:57 2011 -0700
-summary: refine section describing integration with HTMLMediaElement
-
-date: Mon Aug 01 12:05:53 2011 -0700
-summary: add Privacy section
-
-date: Mon Jul 18 17:53:50 2011 -0700
-summary: small update - tweak musical applications thumbnail images
-
-date: Mon Jul 18 17:23:00 2011 -0700
-summary: initial commit of Web Audio API specification</pre>
-</div>
-</body>
-</html>
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-analysernode-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-analysernode-interface/.gitkeep
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deleted file mode 100644
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deleted file mode 100644
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@@ -1,107 +0,0 @@
-<!DOCTYPE html>
-<html class="a">
-<head>
-<title>AudioBuffer IDL Test</title>
-<script src="/resources/testharness.js"></script><script src="/resources/testharnessreport.js"></script><script src="/resources/idlharness.js"></script><script src="/resources/WebIDLParser.js"></script><script src="/webaudio/js/lodash.js"></script><script src="/webaudio/js/vendor-prefixes.js"></script><script src="/webaudio/js/helpers.js"></script><style type="text/css">
- #event-target-idl,
- #audio-context-idl
- { visibility:hidden; height: 0px;}
- </style>
-</head>
-<body class="a">
-
- <pre id="event-target-idl">interface EventTarget {
- void addEventListener(DOMString type, EventListener? callback, optional boolean capture = false);
- void removeEventListener(DOMString type, EventListener? callback, optional boolean capture = false);
- boolean dispatchEvent(Event event);
-};
-
-/*
-callback interface EventListener {
- void handleEvent(Event event);
-};
-*/
-// Callback interfaces are not supported yet, but that's ok
-interface EventListener {};
-</pre>
-
- <pre id="audio-context-idl">callback DecodeSuccessCallback = void (AudioBuffer decodedData);
-callback DecodeErrorCallback = void ();
-
-[Constructor]
-interface AudioContext : EventTarget {
-
- readonly attribute AudioDestinationNode destination;
- readonly attribute float sampleRate;
- readonly attribute double currentTime;
- readonly attribute AudioListener listener;
-
- AudioBuffer createBuffer(unsigned long numberOfChannels, unsigned long length, float sampleRate);
-
- void decodeAudioData(ArrayBuffer audioData,
- DecodeSuccessCallback successCallback,
- optional DecodeErrorCallback errorCallback);
-
-
- // AudioNode creation
- AudioBufferSourceNode createBufferSource();
-
- MediaElementAudioSourceNode createMediaElementSource(HTMLMediaElement mediaElement);
-
- MediaStreamAudioSourceNode createMediaStreamSource(MediaStream mediaStream);
- MediaStreamAudioDestinationNode createMediaStreamDestination();
-
- ScriptProcessorNode createScriptProcessor(optional unsigned long bufferSize = 0,
- optional unsigned long numberOfInputChannels = 2,
- optional unsigned long numberOfOutputChannels = 2);
-
- AnalyserNode createAnalyser();
- GainNode createGain();
- DelayNode createDelay(optional double maxDelayTime = 1.0);
- BiquadFilterNode createBiquadFilter();
- WaveShaperNode createWaveShaper();
- PannerNode createPanner();
- ConvolverNode createConvolver();
-
- ChannelSplitterNode createChannelSplitter(optional unsigned long numberOfOutputs = 6);
- ChannelMergerNode createChannelMerger(optional unsigned long numberOfInputs = 6);
-
- DynamicsCompressorNode createDynamicsCompressor();
-
- OscillatorNode createOscillator();
- PeriodicWave createPeriodicWave(Float32Array real, Float32Array imag);
-
-};</pre>
-
- <pre id="audio-buffer-idl">interface AudioBuffer {
-
- readonly attribute float sampleRate;
- readonly attribute long length;
-
- // in seconds
- readonly attribute double duration;
-
- readonly attribute long numberOfChannels;
-
- Float32Array getChannelData(unsigned long channel);
-
-};</pre>
-
- <div id="log"></div>
-
- <script>
-(function() {
- var idl_array = new IdlArray();
- idl_array.add_untested_idls(document.getElementById("event-target-idl").textContent);
- idl_array.add_untested_idls(document.getElementById("audio-context-idl").textContent);
- idl_array.add_idls(document.getElementById("audio-buffer-idl").textContent);
-
- // For these tests the value of the arguments is unimportant.
- audio_buffer = (new AudioContext).createBuffer(numberOfChannels = 1, length = 256, sampleRate = 44100);
-
- idl_array.add_objects({AudioBuffer: ["audio_buffer"]});
- idl_array.test();
-})();
- </script>
-</body>
-</html>
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffersourcenode-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffersourcenode-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffersourcenode-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-audiocontext-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-audiocontext-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-audiocontext-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-audiodestinationnode-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-audiodestinationnode-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-audiodestinationnode-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-audiodestinationnode-interface/idl-test.html b/testing/web-platform/tests/webaudio/the-audio-api/the-audiodestinationnode-interface/idl-test.html
deleted file mode 100644
index 257b18df5..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-audiodestinationnode-interface/idl-test.html
+++ /dev/null
@@ -1,128 +0,0 @@
-<!DOCTYPE html>
-<html class="a">
-<head>
-<title>AudioDestinationNode IDL Test</title>
-<script src="/resources/testharness.js"></script><script src="/resources/testharnessreport.js"></script><script src="/resources/idlharness.js"></script><script src="/resources/WebIDLParser.js"></script><script src="/webaudio/js/lodash.js"></script><script src="/webaudio/js/vendor-prefixes.js"></script><script src="/webaudio/js/helpers.js"></script><style type="text/css">
- #event-target-idl,
- #audio-context-idl,
- #audio-node-idl
- { visibility:hidden; height: 0px;}
- </style>
-</head>
-<body class="a">
-
- <pre id="event-target-idl">interface EventTarget {
- void addEventListener(DOMString type, EventListener? callback, optional boolean capture = false);
- void removeEventListener(DOMString type, EventListener? callback, optional boolean capture = false);
- boolean dispatchEvent(Event event);
-};
-
-/*
-callback interface EventListener {
- void handleEvent(Event event);
-};
-*/
-// Callback interfaces are not supported yet, but that's ok
-interface EventListener {};
-</pre>
-
- <pre id="audio-context-idl">callback DecodeSuccessCallback = void (AudioBuffer decodedData);
-callback DecodeErrorCallback = void ();
-
-[Constructor]
-interface AudioContext : EventTarget {
-
- readonly attribute AudioDestinationNode destination;
- readonly attribute float sampleRate;
- readonly attribute double currentTime;
- readonly attribute AudioListener listener;
-
- AudioBuffer createBuffer(unsigned long numberOfChannels, unsigned long length, float sampleRate);
-
- void decodeAudioData(ArrayBuffer audioData,
- DecodeSuccessCallback successCallback,
- optional DecodeErrorCallback errorCallback);
-
-
- // AudioNode creation
- AudioBufferSourceNode createBufferSource();
-
- MediaElementAudioSourceNode createMediaElementSource(HTMLMediaElement mediaElement);
-
- MediaStreamAudioSourceNode createMediaStreamSource(MediaStream mediaStream);
- MediaStreamAudioDestinationNode createMediaStreamDestination();
-
- ScriptProcessorNode createScriptProcessor(optional unsigned long bufferSize = 0,
- optional unsigned long numberOfInputChannels = 2,
- optional unsigned long numberOfOutputChannels = 2);
-
- AnalyserNode createAnalyser();
- GainNode createGain();
- DelayNode createDelay(optional double maxDelayTime = 1.0);
- BiquadFilterNode createBiquadFilter();
- WaveShaperNode createWaveShaper();
- PannerNode createPanner();
- ConvolverNode createConvolver();
-
- ChannelSplitterNode createChannelSplitter(optional unsigned long numberOfOutputs = 6);
- ChannelMergerNode createChannelMerger(optional unsigned long numberOfInputs = 6);
-
- DynamicsCompressorNode createDynamicsCompressor();
-
- OscillatorNode createOscillator();
- PeriodicWave createPeriodicWave(Float32Array real, Float32Array imag);
-
-};</pre>
-
- <pre id="audio-node-idl">enum ChannelCountMode {
- "max",
- "clamped-max",
- "explicit"
-};
-
-enum ChannelInterpretation {
- "speakers",
- "discrete"
-};
-
-interface AudioNode : EventTarget {
-
- void connect(AudioNode destination, optional unsigned long output = 0, optional unsigned long input = 0);
- void connect(AudioParam destination, optional unsigned long output = 0);
- void disconnect(optional unsigned long output = 0);
-
- readonly attribute AudioContext context;
- readonly attribute unsigned long numberOfInputs;
- readonly attribute unsigned long numberOfOutputs;
-
- // Channel up-mixing and down-mixing rules for all inputs.
- attribute unsigned long channelCount;
- attribute ChannelCountMode channelCountMode;
- attribute ChannelInterpretation channelInterpretation;
-
-};</pre>
-
- <pre id="audio-destination-node-idl">interface AudioDestinationNode : AudioNode {
-
- readonly attribute unsigned long maxChannelCount;
-
-};</pre>
-
- <div id="log"></div>
-
- <script>
-(function() {
- var idl_array = new IdlArray();
- idl_array.add_untested_idls(document.getElementById("event-target-idl").textContent);
- idl_array.add_untested_idls(document.getElementById("audio-context-idl").textContent);
- idl_array.add_untested_idls(document.getElementById("audio-node-idl").textContent);
- idl_array.add_idls(document.getElementById("audio-destination-node-idl").textContent);
-
- audio_destination_node = (new AudioContext).destination;
-
- idl_array.add_objects({AudioDestinationNode: ["audio_destination_node"]});
- idl_array.test();
-})();
- </script>
-</body>
-</html>
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-audiolistener-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-audiolistener-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-audiolistener-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-audionode-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-audionode-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-audionode-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-audionode-interface/audionode-connect-return-value.html b/testing/web-platform/tests/webaudio/the-audio-api/the-audionode-interface/audionode-connect-return-value.html
deleted file mode 100644
index 3af44fb7a..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-audionode-interface/audionode-connect-return-value.html
+++ /dev/null
@@ -1,15 +0,0 @@
-<!DOCTYPE html>
-<title>Test the return value of connect when connecting two AudioNodes</title>
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<script>
-test(function(t) {
- var context = new OfflineAudioContext(1, 1, 44100);
- var g1 = context.createGain();
- var g2 = context.createGain();
- var rv = g1.connect(g2);
- assert_equals(rv, g2);
- var rv = g1.connect(g2);
- assert_equals(rv, g2);
-}, "connect should return the node connected to.");
-</script>
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-audioparam-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-audioparam-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-audioparam-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-audioparam-interface/retrospective-setValueAtTime.html b/testing/web-platform/tests/webaudio/the-audio-api/the-audioparam-interface/retrospective-setValueAtTime.html
deleted file mode 100644
index dde8c27b9..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-audioparam-interface/retrospective-setValueAtTime.html
+++ /dev/null
@@ -1,71 +0,0 @@
-<!DOCTYPE html>
-<title>Test setValueAtTime with startTime in the past</title>
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<script>
-function do_test(t, context) {
- var source = context.createBufferSource();
- source.buffer =
- function() {
- var buffer = context.createBuffer(1, 1, context.sampleRate);
- buffer.getChannelData(0)[0] = 1.0;
- return buffer;
- }();
- source.loop = true;
- source.start();
-
- // Use a ramp of slope 1/sample to measure time.
- // The end value is the extent of exact precision in single precision float.
- const rampEnd = Math.pow(2, 24);
- const rampEndSeconds = rampEnd / context.sampleRate;
- var test = context.createGain();
- test.gain.setValueAtTime(0.0, 0.0);
- test.gain.linearRampToValueAtTime(rampEnd, rampEndSeconds);
-
- // With a different starting point on the same line, the result should be
- // the same. |currentTime| may include double precision floating point
- // rounding errors, so round to nearest integer sample to ignore these.
- var scheduledSample = Math.round(context.currentTime * context.sampleRate);
- assert_equals(scheduledSample % 128, 0,
- "currentTime advances in blocks of 128 samples");
- var reference = context.createGain();
- reference.gain.setValueAtTime(scheduledSample, context.currentTime);
- reference.gain.linearRampToValueAtTime(rampEnd, rampEndSeconds);
-
- source.connect(test);
- source.connect(reference);
-
- var merger = context.createChannelMerger();
- test.connect(merger, 0, 0);
- reference.connect(merger, 0, 1);
-
- var processor = context.createScriptProcessor(0, 2, 0);
- merger.connect(processor);
- processor.onaudioprocess =
- t.step_func_done((e) => {
- source.stop();
- processor.onaudioprocess = null;
-
- var testValue = e.inputBuffer.getChannelData(0)[0];
- var referenceValue = e.inputBuffer.getChannelData(1)[0];
-
- assert_equals(testValue, referenceValue,
- "ramp value matches expected");
- assert_greater_than_equal(testValue, scheduledSample,
- "time does not retreat");
- assert_equals(testValue % 128, 0,
- "ScriptProcessor blocks align on 128-sample blocks");
- });
-}
-
-async_test(function(t) {
- var context = new AudioContext;
- (function waitForTimeAdvance() {
- if (context.currentTime == 0) {
- t.step_timeout(waitForTimeAdvance, 0);
- } else {
- do_test(t, context);
- }
- })();
-});
-</script>
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-audioparam-interface/setTargetAtTime-after-event-within-block.html b/testing/web-platform/tests/webaudio/the-audio-api/the-audioparam-interface/setTargetAtTime-after-event-within-block.html
deleted file mode 100644
index 827aeeabd..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-audioparam-interface/setTargetAtTime-after-event-within-block.html
+++ /dev/null
@@ -1,54 +0,0 @@
-<!DOCTYPE html>
-<title>Test setTargetAtTime after an event in the same processing block</title>
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<script>
-promise_test(function() {
- const bufferSize = 179;
- const valueStartOffset = 42;
- const targetStartOffset = 53;
- const sampleRate = 48000;
- const scheduledValue = -0.5;
-
- var context = new OfflineAudioContext(1, bufferSize, sampleRate);
-
- var gain = context.createGain();
- gain.gain.setValueAtTime(scheduledValue, valueStartOffset/sampleRate);
- gain.gain.setTargetAtTime(scheduledValue, targetStartOffset/sampleRate,
- 128/sampleRate);
- gain.connect(context.destination);
-
- // Apply unit DC signal to gain node.
- var source = context.createBufferSource();
- source.buffer =
- function() {
- var buffer = context.createBuffer(1, 1, context.sampleRate);
- buffer.getChannelData(0)[0] = 1.0;
- return buffer;
- }();
- source.loop = true;
- source.start();
- source.connect(gain);
-
- return context.startRendering().
- then(function(buffer) {
- assert_equals(buffer.length, bufferSize, "output buffer length");
- var output = buffer.getChannelData(0);
- var i = 0;
- for (; i < valueStartOffset; ++i) {
- // "Its default value is 1."
- assert_equals(output[i], 1.0, "default gain at sample " + i);
- }
- for (; i < buffer.length; ++i) {
- // "If the next event (having time T1) after this SetValue event is
- // not of type LinearRampToValue or ExponentialRampToValue, then, for
- // T0≤t<T1: v(t)=V".
- // "Start exponentially approaching the target value at the given time
- // with a rate having the given time constant."
- // The target is the same value, and so the SetValue value continues.
- assert_equals(output[i], scheduledValue,
- "scheduled value at sample " + i);
- }
- });
-});
-</script>
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-audioparam-interface/setValueAtTime-within-block.html b/testing/web-platform/tests/webaudio/the-audio-api/the-audioparam-interface/setValueAtTime-within-block.html
deleted file mode 100644
index 36fde2b99..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-audioparam-interface/setValueAtTime-within-block.html
+++ /dev/null
@@ -1,48 +0,0 @@
-<!DOCTYPE html>
-<title>Test setValueAtTime with start time not on a block boundary</title>
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<script>
-promise_test(function() {
- const bufferSize = 200;
- const offset = 65;
- const sampleRate = 48000;
- const scheduledValue = -2.0;
-
- var context = new OfflineAudioContext(1, bufferSize, sampleRate);
-
- var gain = context.createGain();
- gain.gain.setValueAtTime(scheduledValue, offset/sampleRate);
- gain.connect(context.destination);
-
- // Apply unit DC signal to gain node.
- var source = context.createBufferSource();
- source.buffer =
- function() {
- var buffer = context.createBuffer(1, 1, context.sampleRate);
- buffer.getChannelData(0)[0] = 1.0;
- return buffer;
- }();
- source.loop = true;
- source.start();
- source.connect(gain);
-
- return context.startRendering().
- then(function(buffer) {
- assert_equals(buffer.length, bufferSize, "output buffer length");
- var output = buffer.getChannelData(0);
- var i = 0;
- for (; i < offset; ++i) {
- // "Its default value is 1."
- assert_equals(output[i], 1.0, "default gain at sample " + i);
- }
- for (; i < buffer.length; ++i) {
- // "If there are no more events after this SetValue event, then for
- // t≥T0, v(t)=V, where T0 is the startTime parameter and V is the
- // value parameter."
- assert_equals(output[i], scheduledValue,
- "scheduled value at sample " + i);
- }
- });
-});
-</script>
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-audioprocessingevent-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-audioprocessingevent-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-audioprocessingevent-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-biquadfilternode-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-biquadfilternode-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-biquadfilternode-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-channelmergernode-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-channelmergernode-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-channelmergernode-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-channelsplitternode-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-channelsplitternode-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-channelsplitternode-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-constantsourcenode-interface/test-constantsourcenode.html b/testing/web-platform/tests/webaudio/the-audio-api/the-constantsourcenode-interface/test-constantsourcenode.html
deleted file mode 100644
index a49ae875b..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-constantsourcenode-interface/test-constantsourcenode.html
+++ /dev/null
@@ -1,135 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<title>Test the ConstantSourceNode Interface</title>
-<script src=/resources/testharness.js></script>
-<script src=/resources/testharnessreport.js></script>
-<script>
-test(function(t) {
- var ac = new AudioContext();
-
- var csn = ac.createConstantSource();
- assert_true(csn.offset.value == 1.0, "Default offset is 1.0");
-
- csn = new ConstantSourceNode(ac);
- assert_true(csn.offset.value == 1.0, "Default offset is 1.0");
-
- csn = new ConstantSourceNode(ac, {offset: -0.25});
- assert_true(csn.offset.value == -0.25, "Offset can be set during construction");
-}, "ConstantSourceNode can be constructed");
-
-test(function(t) {
- var ac = new AudioContext();
-
- var csn = ac.createConstantSource();
-
- assert_throws("InvalidStateError", function() {
- csn.stop(1);
- }, "Start must be called before stop");
-
- assert_throws("NotSupportedError", function() {
- csn.start(-1);
- }, "When can not be negative");
-
- csn.start(0);
- assert_throws("NotSupportedError", function() {
- csn.stop(-1);
- }, "When can not be negative");
-}, "ConstantSourceNode stop and start");
-
-async_test(function(t) {
- var ac = new OfflineAudioContext(1, 2048, 44100);
- var csn = ac.createConstantSource();
- csn.connect(ac.destination);
- csn.start()
- csn.stop(1024/44100)
- csn.onended = function(e) {
- t.step(function() {
- assert_true(e.type == "ended", "Event type should be 'ended', received: " + e.type);
- });
- t.done();
- }
- ac.startRendering();
-}, "ConstantSourceNode onended event");
-
-async_test(function(t) {
- var ac = new OfflineAudioContext(1, 2048, 44100);
- var csn = ac.createConstantSource();
- csn.connect(ac.destination);
- csn.start(512/44100)
- csn.stop(1024/44100)
-
- ac.oncomplete = function(e) {
- t.step(function() {
- var result = e.renderedBuffer.getChannelData(0);
- for (var i = 0; i < 2048; ++i) {
- if (i >= 512 && i < 1024) {
- assert_true(result[i] == 1.0, "sample " + i + " should equal 1.0");
- } else {
- assert_true(result[i] == 0.0, "sample " + i + " should equal 0.0");
- }
- }
- });
- t.done();
- }
-
- ac.startRendering();
-}, "ConstantSourceNode start and stop when work");
-
-async_test(function(t) {
- var ac = new OfflineAudioContext(1, 2048, 44100);
- var csn = ac.createConstantSource();
- csn.offset.value = 0.25;
- csn.connect(ac.destination);
- csn.start()
-
- ac.oncomplete = function(e) {
- t.step(function() {
- var result = e.renderedBuffer.getChannelData(0);
- for (var i = 0; i < 2048; ++i) {
- assert_true(result[i] == 0.25, "sample " + i + " should equal 0.25");
- }
- });
- t.done();
- }
-
- ac.startRendering();
-}, "ConstantSourceNode with no automation");
-
-async_test(function(t) {
- var ac = new OfflineAudioContext(1, 2048, 44100);
-
- var timeConstant = 2.0;
- var offsetStart = 0.25;
- var offsetEnd = 0.1;
-
- var csn = ac.createConstantSource();
- csn.offset.value = offsetStart;
- csn.offset.setTargetAtTime(offsetEnd, 1024/ac.sampleRate, timeConstant);
- csn.connect(ac.destination);
- csn.start()
-
- ac.oncomplete = function(e) {
- t.step(function() {
- // create buffer with expected values
- var buffer = ac.createBuffer(1, 2048, ac.sampleRate);
- for (var i = 0; i < 2048; ++i) {
- if (i < 1024) {
- buffer.getChannelData(0)[i] = offsetStart;
- } else {
- time = (i-1024)/ac.sampleRate;
- buffer.getChannelData(0)[i] = offsetEnd + (offsetStart - offsetEnd)*Math.exp(-time/timeConstant);
- }
- }
-
- var result = e.renderedBuffer.getChannelData(0);
- var expected = buffer.getChannelData(0);
- for (var i = 0; i < 2048; ++i) {
- assert_true(Math.abs(result[i] - expected[i]) < 1e-6, "sample " + i + " should equal " + expected[i]);
- }
- });
- t.done();
- }
-
- ac.startRendering();
-}, "ConstantSourceNode with automation");
-</script>
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-convolvernode-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-convolvernode-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-convolvernode-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-delaynode-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-delaynode-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-delaynode-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-delaynode-interface/idl-test.html b/testing/web-platform/tests/webaudio/the-audio-api/the-delaynode-interface/idl-test.html
deleted file mode 100644
index 4587e39c0..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-delaynode-interface/idl-test.html
+++ /dev/null
@@ -1,152 +0,0 @@
-<!DOCTYPE html>
-<html class="a">
-<head>
-<title>DelayNode IDL Test</title>
-<script src="/resources/testharness.js"></script><script src="/resources/testharnessreport.js"></script><script src="/resources/idlharness.js"></script><script src="/resources/WebIDLParser.js"></script><script src="/webaudio/js/lodash.js"></script><script src="/webaudio/js/vendor-prefixes.js"></script><script src="/webaudio/js/helpers.js"></script><style type="text/css">
- #event-target-idl,
- #audio-context-idl,
- #audio-node-idl,
- #audio-param-idl
- { visibility:hidden; height: 0px;}
- </style>
-</head>
-<body class="a">
-
- <pre id="event-target-idl">interface EventTarget {
- void addEventListener(DOMString type, EventListener? callback, optional boolean capture = false);
- void removeEventListener(DOMString type, EventListener? callback, optional boolean capture = false);
- boolean dispatchEvent(Event event);
-};
-
-/*
-callback interface EventListener {
- void handleEvent(Event event);
-};
-*/
-// Callback interfaces are not supported yet, but that's ok
-interface EventListener {};
-</pre>
-
- <pre id="audio-context-idl">callback DecodeSuccessCallback = void (AudioBuffer decodedData);
-callback DecodeErrorCallback = void ();
-
-[Constructor]
-interface AudioContext : EventTarget {
-
- readonly attribute AudioDestinationNode destination;
- readonly attribute float sampleRate;
- readonly attribute double currentTime;
- readonly attribute AudioListener listener;
-
- AudioBuffer createBuffer(unsigned long numberOfChannels, unsigned long length, float sampleRate);
-
- void decodeAudioData(ArrayBuffer audioData,
- DecodeSuccessCallback successCallback,
- optional DecodeErrorCallback errorCallback);
-
-
- // AudioNode creation
- AudioBufferSourceNode createBufferSource();
-
- MediaElementAudioSourceNode createMediaElementSource(HTMLMediaElement mediaElement);
-
- MediaStreamAudioSourceNode createMediaStreamSource(MediaStream mediaStream);
- MediaStreamAudioDestinationNode createMediaStreamDestination();
-
- ScriptProcessorNode createScriptProcessor(optional unsigned long bufferSize = 0,
- optional unsigned long numberOfInputChannels = 2,
- optional unsigned long numberOfOutputChannels = 2);
-
- AnalyserNode createAnalyser();
- GainNode createGain();
- DelayNode createDelay(optional double maxDelayTime = 1.0);
- BiquadFilterNode createBiquadFilter();
- WaveShaperNode createWaveShaper();
- PannerNode createPanner();
- ConvolverNode createConvolver();
-
- ChannelSplitterNode createChannelSplitter(optional unsigned long numberOfOutputs = 6);
- ChannelMergerNode createChannelMerger(optional unsigned long numberOfInputs = 6);
-
- DynamicsCompressorNode createDynamicsCompressor();
-
- OscillatorNode createOscillator();
- PeriodicWave createPeriodicWave(Float32Array real, Float32Array imag);
-
-};</pre>
-
- <pre id="audio-node-idl">enum ChannelCountMode {
- "max",
- "clamped-max",
- "explicit"
-};
-
-enum ChannelInterpretation {
- "speakers",
- "discrete"
-};
-
-interface AudioNode : EventTarget {
-
- void connect(AudioNode destination, optional unsigned long output = 0, optional unsigned long input = 0);
- void connect(AudioParam destination, optional unsigned long output = 0);
- void disconnect(optional unsigned long output = 0);
-
- readonly attribute AudioContext context;
- readonly attribute unsigned long numberOfInputs;
- readonly attribute unsigned long numberOfOutputs;
-
- // Channel up-mixing and down-mixing rules for all inputs.
- attribute unsigned long channelCount;
- attribute ChannelCountMode channelCountMode;
- attribute ChannelInterpretation channelInterpretation;
-
-};</pre>
-
- <pre id="audio-param-idl">interface AudioParam {
-
- attribute float value;
- readonly attribute float defaultValue;
-
- // Parameter automation.
- void setValueAtTime(float value, double startTime);
- void linearRampToValueAtTime(float value, double endTime);
- void exponentialRampToValueAtTime(float value, double endTime);
-
- // Exponentially approach the target value with a rate having the given time constant.
- void setTargetAtTime(float target, double startTime, double timeConstant);
-
- // Sets an array of arbitrary parameter values starting at time for the given duration.
- // The number of values will be scaled to fit into the desired duration.
- void setValueCurveAtTime(Float32Array values, double startTime, double duration);
-
- // Cancels all scheduled parameter changes with times greater than or equal to startTime.
- void cancelScheduledValues(double startTime);
-
-};</pre>
-
-<pre id="delay-node-idl">interface DelayNode : AudioNode {
-
- readonly attribute AudioParam delayTime;
-
-};</pre>
-
- <div id="log"></div>
-
- <script>
-(function() {
- var idl_array = new IdlArray();
- idl_array.add_untested_idls(document.getElementById("event-target-idl").textContent);
- idl_array.add_untested_idls(document.getElementById("audio-context-idl").textContent);
- idl_array.add_untested_idls(document.getElementById("audio-node-idl").textContent);
- idl_array.add_untested_idls(document.getElementById("audio-param-idl").textContent);
- idl_array.add_idls(document.getElementById("delay-node-idl").textContent);
-
- delay_node = (new AudioContext).createDelay();
-
- idl_array.add_objects({DelayNode: ["delay_node"]});
- idl_array.test();
-})();
- </script>
-</body>
-</html>
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-dynamicscompressornode-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-dynamicscompressornode-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-dynamicscompressornode-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-gainnode-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-gainnode-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-gainnode-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-gainnode-interface/gain-expected.wav b/testing/web-platform/tests/webaudio/the-audio-api/the-gainnode-interface/gain-expected.wav
deleted file mode 100644
index b445bd8a6..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-gainnode-interface/gain-expected.wav
+++ /dev/null
Binary files differ
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-gainnode-interface/idl-test.html b/testing/web-platform/tests/webaudio/the-audio-api/the-gainnode-interface/idl-test.html
deleted file mode 100644
index dea13b179..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-gainnode-interface/idl-test.html
+++ /dev/null
@@ -1,152 +0,0 @@
-<!DOCTYPE html>
-<html class="a">
-<head>
-<title>GainNode IDL Test</title>
-<script src="/resources/testharness.js"></script><script src="/resources/testharnessreport.js"></script><script src="/resources/idlharness.js"></script><script src="/resources/WebIDLParser.js"></script><script src="/webaudio/js/lodash.js"></script><script src="/webaudio/js/vendor-prefixes.js"></script><script src="/webaudio/js/helpers.js"></script><style type="text/css">
- #event-target-idl,
- #audio-context-idl,
- #audio-node-idl,
- #audio-param-idl
- { visibility:hidden; height: 0px;}
- </style>
-</head>
-<body class="a">
-
- <pre id="event-target-idl">interface EventTarget {
- void addEventListener(DOMString type, EventListener? callback, optional boolean capture = false);
- void removeEventListener(DOMString type, EventListener? callback, optional boolean capture = false);
- boolean dispatchEvent(Event event);
-};
-
-/*
-callback interface EventListener {
- void handleEvent(Event event);
-};
-*/
-// Callback interfaces are not supported yet, but that's ok
-interface EventListener {};
-</pre>
-
- <pre id="audio-context-idl">callback DecodeSuccessCallback = void (AudioBuffer decodedData);
-callback DecodeErrorCallback = void ();
-
-[Constructor]
-interface AudioContext : EventTarget {
-
- readonly attribute AudioDestinationNode destination;
- readonly attribute float sampleRate;
- readonly attribute double currentTime;
- readonly attribute AudioListener listener;
-
- AudioBuffer createBuffer(unsigned long numberOfChannels, unsigned long length, float sampleRate);
-
- void decodeAudioData(ArrayBuffer audioData,
- DecodeSuccessCallback successCallback,
- optional DecodeErrorCallback errorCallback);
-
-
- // AudioNode creation
- AudioBufferSourceNode createBufferSource();
-
- MediaElementAudioSourceNode createMediaElementSource(HTMLMediaElement mediaElement);
-
- MediaStreamAudioSourceNode createMediaStreamSource(MediaStream mediaStream);
- MediaStreamAudioDestinationNode createMediaStreamDestination();
-
- ScriptProcessorNode createScriptProcessor(optional unsigned long bufferSize = 0,
- optional unsigned long numberOfInputChannels = 2,
- optional unsigned long numberOfOutputChannels = 2);
-
- AnalyserNode createAnalyser();
- GainNode createGain();
- DelayNode createDelay(optional double maxDelayTime = 1.0);
- BiquadFilterNode createBiquadFilter();
- WaveShaperNode createWaveShaper();
- PannerNode createPanner();
- ConvolverNode createConvolver();
-
- ChannelSplitterNode createChannelSplitter(optional unsigned long numberOfOutputs = 6);
- ChannelMergerNode createChannelMerger(optional unsigned long numberOfInputs = 6);
-
- DynamicsCompressorNode createDynamicsCompressor();
-
- OscillatorNode createOscillator();
- PeriodicWave createPeriodicWave(Float32Array real, Float32Array imag);
-
-};</pre>
-
- <pre id="audio-node-idl">enum ChannelCountMode {
- "max",
- "clamped-max",
- "explicit"
-};
-
-enum ChannelInterpretation {
- "speakers",
- "discrete"
-};
-
-interface AudioNode : EventTarget {
-
- void connect(AudioNode destination, optional unsigned long output = 0, optional unsigned long input = 0);
- void connect(AudioParam destination, optional unsigned long output = 0);
- void disconnect(optional unsigned long output = 0);
-
- readonly attribute AudioContext context;
- readonly attribute unsigned long numberOfInputs;
- readonly attribute unsigned long numberOfOutputs;
-
- // Channel up-mixing and down-mixing rules for all inputs.
- attribute unsigned long channelCount;
- attribute ChannelCountMode channelCountMode;
- attribute ChannelInterpretation channelInterpretation;
-
-};</pre>
-
- <pre id="audio-param-idl">interface AudioParam {
-
- attribute float value;
- readonly attribute float defaultValue;
-
- // Parameter automation.
- void setValueAtTime(float value, double startTime);
- void linearRampToValueAtTime(float value, double endTime);
- void exponentialRampToValueAtTime(float value, double endTime);
-
- // Exponentially approach the target value with a rate having the given time constant.
- void setTargetAtTime(float target, double startTime, double timeConstant);
-
- // Sets an array of arbitrary parameter values starting at time for the given duration.
- // The number of values will be scaled to fit into the desired duration.
- void setValueCurveAtTime(Float32Array values, double startTime, double duration);
-
- // Cancels all scheduled parameter changes with times greater than or equal to startTime.
- void cancelScheduledValues(double startTime);
-
-};</pre>
-
-<pre id="gain-node-idl">interface GainNode : AudioNode {
-
- readonly attribute AudioParam gain;
-
-};</pre>
-
- <div id="log"></div>
-
- <script>
-(function() {
- var idl_array = new IdlArray();
- idl_array.add_untested_idls(document.getElementById("event-target-idl").textContent);
- idl_array.add_untested_idls(document.getElementById("audio-context-idl").textContent);
- idl_array.add_untested_idls(document.getElementById("audio-node-idl").textContent);
- idl_array.add_untested_idls(document.getElementById("audio-param-idl").textContent);
- idl_array.add_idls(document.getElementById("gain-node-idl").textContent);
-
- gain_node = (new AudioContext).createGain();
-
- idl_array.add_objects({GainNode: ["gain_node"]});
- idl_array.test();
-})();
- </script>
-</body>
-</html>
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-gainnode-interface/test-gainnode.html b/testing/web-platform/tests/webaudio/the-audio-api/the-gainnode-interface/test-gainnode.html
deleted file mode 100644
index 4f92fbbe5..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-gainnode-interface/test-gainnode.html
+++ /dev/null
@@ -1,121 +0,0 @@
-<!doctype html>
-
-<!--
-Tests that GainNode is properly scaling the gain.
-We'll render 11 notes, starting at a gain of 1.0, decreasing in gain by 0.1.
-The 11th note will be of gain 0.0, so it should be silent (at the end in the rendered output).
-
-Based on a test from the WebKit test suite
-(https://github.com/WebKit/webkit/blob/master/LayoutTests/webaudio/gain.html)
--->
-
-<html class="a">
- <head>
- <title>GainNode interface</title>
- <script src="/resources/testharness.js"></script>
- <script src="/resources/testharnessreport.js"></script>
- <script src="/webaudio/js/lodash.js"></script>
- <script src="/webaudio/js/vendor-prefixes.js"></script>
- <script src="/webaudio/js/helpers.js"></script>
- <script src="/webaudio/js/buffer-loader.js"></script>
- </head>
- <body class="a">
- <div id="log"></div>
- <script>
-var gainNodeTest = async_test("GainNode");
-
-var sampleRate = 44100.0;
-var bufferDurationSeconds = 0.125;
-var numberOfNotes = 11;
-var noteSpacing = bufferDurationSeconds + 0.020; // leave 20ms of silence between each "note"
-var lengthInSeconds = numberOfNotes * noteSpacing;
-
-var context = 0;
-var expectedBuffer = 0;
-var actualBuffer = 0;
-var sinWaveBuffer = 0;
-
-function createSinWaveBuffer(lengthInSeconds, frequency) {
- var audioBuffer = context.createBuffer(2, lengthInSeconds * sampleRate, sampleRate);
-
- var n = audioBuffer.length;
- var channelL = audioBuffer.getChannelData(0);
- var channelR = audioBuffer.getChannelData(1);
-
- for (var i = 0; i < n; ++i) {
- channelL[i] = Math.sin(frequency * 2.0*Math.PI * i / sampleRate);
- channelR[i] = channelL[i];
- }
-
- return audioBuffer;
-}
-
-function playNote(time, gain) {
- var source = context.createBufferSource();
- source.buffer = sinWaveBuffer;
-
- var gainNode = context.createGain();
- gainNode.gain.value = gain;
-
- source.connect(gainNode);
- gainNode.connect(context.destination);
-
- source.start(time);
-}
-
-function loadExpectedBuffer(event) {
- actualBuffer = event.renderedBuffer;
-
- bufferLoader = new BufferLoader(
- context,
- ['/webaudio/the-audio-api/the-gainnode-interface/gain-expected.wav'],
- bufferLoadCompleted
- );
- bufferLoader.load();
-};
-
-function bufferLoadCompleted(buffer) {
- compareExpectedWithActualBuffer(buffer);
-};
-
-setup( function() {
- // Create offline audio context.
- context = new OfflineAudioContext(2, sampleRate * lengthInSeconds, sampleRate);
-
- // Create a buffer for a short "note".
- sinWaveBuffer = createSinWaveBuffer(bufferDurationSeconds, 880.0);
-
- // Render 11 notes, starting at a gain of 1.0, decreasing in gain by 0.1.
- // The last note will be of gain 0.0, so shouldn't be perceptible in the rendered output.
- for (var i = 0; i < numberOfNotes; ++i) {
- var time = i * noteSpacing;
- var gain = 1.0 - i / (numberOfNotes - 1);
- playNote(time, gain);
- }
-
- context.oncomplete = loadExpectedBuffer;
- context.startRendering();
-}, {timeout: 10000});
-
-function compareExpectedWithActualBuffer(expected) {
- var expectedBuffer = expected[0];
-
- gainNodeTest.step(function() {
- assert_array_approx_equals(expectedBuffer.getChannelData(0),
- actualBuffer.getChannelData(0),
- 1e-4,
- "comparing expected and rendered buffers (channel 0)");
- });
-
- gainNodeTest.step(function() {
- assert_array_approx_equals(expectedBuffer.getChannelData(1),
- actualBuffer.getChannelData(1),
- 1e-4,
- "comparing expected and rendered buffers (channel 1)");
- });
-
- gainNodeTest.done();
-};
- </script>
- </body>
-</html>
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-iirfilternode-interface/test-iirfilternode.html b/testing/web-platform/tests/webaudio/the-audio-api/the-iirfilternode-interface/test-iirfilternode.html
deleted file mode 100644
index 61c11ffc5..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-iirfilternode-interface/test-iirfilternode.html
+++ /dev/null
@@ -1,59 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<title>Test the IIRFilterNode Interface</title>
-<script src=/resources/testharness.js></script>
-<script src=/resources/testharnessreport.js></script>
-<script>
-test(function(t) {
- var ac = new AudioContext();
-
- function check_args(arg1, arg2, err, desc) {
- test(function() {
- assert_throws(err, function() {
- ac.createIIRFilter(arg1, arg2)
- })
- }, desc)
- }
-
- check_args([], [1.0], 'NotSupportedError',
- 'feedforward coefficients can not be empty');
-
- check_args([1.0], [], 'NotSupportedError',
- 'feedback coefficients can not be empty');
-
- var coeff = new Float32Array(21)
- coeff[0] = 1.0;
-
- check_args(coeff, [1.0], 'NotSupportedError',
- 'more than 20 feedforward coefficients can not be used');
-
- check_args([1.0], coeff, 'NotSupportedError',
- 'more than 20 feedback coefficients can not be used');
-
- check_args([0.0, 0.0], [1.0], 'InvalidStateError',
- 'at least one feedforward coefficient must be non-zero');
-
- check_args([0.5, 0.5], [0.0], 'InvalidStateError',
- 'the first feedback coefficient must be non-zero');
-
-}, "IIRFilterNode coefficients are checked properly");
-
-test(function(t) {
- var ac = new AudioContext();
-
- var frequencies = new Float32Array([-1.0, ac.sampleRate*0.5 - 1.0, ac.sampleRate]);
- var magResults = new Float32Array(3);
- var phaseResults = new Float32Array(3);
-
- var filter = ac.createIIRFilter([0.5, 0.5], [1.0]);
- filter.getFrequencyResponse(frequencies, magResults, phaseResults);
-
- assert_true(isNaN(magResults[0]), "Invalid input frequency should give NaN magnitude response");
- assert_true(!isNaN(magResults[1]), "Valid input frequency should not give NaN magnitude response");
- assert_true(isNaN(magResults[2]), "Invalid input frequency should give NaN magnitude response");
- assert_true(isNaN(phaseResults[0]), "Invalid input frequency should give NaN phase response");
- assert_true(!isNaN(phaseResults[1]), "Valid input frequency should not give NaN phase response");
- assert_true(isNaN(phaseResults[2]), "Invalid input frequency should give NaN phase response");
-
-}, "IIRFilterNode getFrequencyResponse handles invalid frequencies properly");
-</script>
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-mediaelementaudiosourcenode-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-mediaelementaudiosourcenode-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-mediaelementaudiosourcenode-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-mediaelementaudiosourcenode-interface/mediaElementAudioSourceToScriptProcessorTest.html b/testing/web-platform/tests/webaudio/the-audio-api/the-mediaelementaudiosourcenode-interface/mediaElementAudioSourceToScriptProcessorTest.html
deleted file mode 100644
index ba6eec668..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-mediaelementaudiosourcenode-interface/mediaElementAudioSourceToScriptProcessorTest.html
+++ /dev/null
@@ -1,124 +0,0 @@
-<!doctype html>
-
-<!--
-Tests that a create MediaElementSourceNode that is passed through
-a script processor passes the stream data.
-The the script processor saves the input buffers it gets to a temporary
-array, and after the playback has stopped, the contents are compared
-to those of a loaded AudioBuffer with the same source.
-
-Somewhat similiar to a test from Mozilla:
-(http://dxr.mozilla.org/mozilla-central/source/content/media/webaudio/test/test_mediaElementAudioSourceNode.html?force=1)
--->
-
-<html class="a">
- <head>
- <title>MediaElementAudioSource interface test (to scriptProcessor)</title>
- <script src="/resources/testharness.js"></script>
- <script src="/resources/testharnessreport.js"></script>
- <script src="/webaudio/js/lodash.js"></script>
- <script src="/webaudio/js/vendor-prefixes.js"></script>
- <script src="/webaudio/js/helpers.js"></script>
- <script src="/webaudio/js/buffer-loader.js"></script>
- </head>
- <body class="a">
- <div id="log"></div>
- <script>
- var elementSourceTest = async_test("Element Source tests completed");
-
- var src = '/webaudio/resources/sin_440Hz_-6dBFS_1s.wav';
- var BUFFER_SIZE = 2048;
- var context = null;
- var actualBufferArrayC0 = new Float32Array(0);
- var actualBufferArrayC1 = new Float32Array(0);
- var audio = null, source = null, processor = null
-
- function loadExpectedBuffer(event) {
- bufferLoader = new BufferLoader(
- context,
- [src],
- bufferLoadCompleted
- );
- bufferLoader.load();
- };
-
- function bufferLoadCompleted(buffer) {
- runTests(buffer);
- };
-
- function concatTypedArray(arr1, arr2) {
- var result = new Float32Array(arr1.length + arr2.length);
- result.set(arr1);
- result.set(arr2, arr1.length);
- return result;
- }
-
- // Create Audio context
- context = new AudioContext();
-
- // Create an audio element, and a media element source
- audio = document.createElement('audio');
- audio.src = src;
- source = context.createMediaElementSource(audio);
-
-function processListener (e) {
- actualBufferArrayC0 = concatTypedArray(actualBufferArrayC0, e.inputBuffer.getChannelData(0));
- actualBufferArrayC1 = concatTypedArray(actualBufferArrayC1, e.inputBuffer.getChannelData(1));
-}
-
- // Create a processor node to copy the input to the actual buffer
- processor = context.createScriptProcessor(BUFFER_SIZE);
- source.connect(processor);
- processor.connect(context.destination);
- processor.addEventListener('audioprocess', processListener);
-
- // When media playback ended, save the begin to compare with expected buffer
- audio.addEventListener("ended", function(e) {
- // Setting a timeout since we need audioProcess event to run for all samples
- window.setTimeout(loadExpectedBuffer, 50);
- });
-
- audio.play();
-
- function runTests(expected) {
- source.disconnect();
- processor.disconnect();
-
- // firefox seems to process events after disconnect
- processor.removeEventListener('audioprocess', processListener)
-
- var expectedBuffer = expected[0];
-
- // Trim the actual elements because we don't have a fine-grained
- // control over the start and end time of recording the data.
- var actualTrimmedC0 = trimEmptyElements(actualBufferArrayC0);
- var actualTrimmedC1 = trimEmptyElements(actualBufferArrayC1);
- var expectedLength = trimEmptyElements(expectedBuffer.getChannelData(0)).length;
-
- // Test that there is some data.
- test(function() {
- assert_greater_than(actualTrimmedC0.length, 0,
- "processed data array (C0) length greater than 0");
- assert_greater_than(actualTrimmedC1.length, 0,
- "processed data array (C1) length greater than 0");
- }, "Channel 0 processed some data");
-
- // Test the actual contents of the 1st and second channel.
- test(function() {
- assert_array_approx_equals(
- actualTrimmedC0,
- trimEmptyElements(expectedBuffer.getChannelData(0)),
- 1e-4,
- "comparing expected and rendered buffers (channel 0)");
- assert_array_approx_equals(
- actualTrimmedC1,
- trimEmptyElements(expectedBuffer.getChannelData(1)),
- 1e-4,
- "comparing expected and rendered buffers (channel 1)");
- }, "All data processed correctly");
-
- elementSourceTest.done();
- };
- </script>
- </body>
-</html>
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-mediastreamaudiodestinationnode-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-mediastreamaudiodestinationnode-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-mediastreamaudiodestinationnode-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-mediastreamaudiosourcenode-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-mediastreamaudiosourcenode-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-mediastreamaudiosourcenode-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-offlineaudiocontext-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-offlineaudiocontext-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-offlineaudiocontext-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-offlineaudiocontext-interface/current-time-block-size.html b/testing/web-platform/tests/webaudio/the-audio-api/the-offlineaudiocontext-interface/current-time-block-size.html
deleted file mode 100644
index ee976f7f7..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-offlineaudiocontext-interface/current-time-block-size.html
+++ /dev/null
@@ -1,17 +0,0 @@
-<!DOCTYPE html>
-<title>Test currentTime at completion of OfflineAudioContext rendering</title>
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<script>
-promise_test(function() {
- // sampleRate is a power of two so that time can be represented exactly
- // in double currentTime.
- var context = new OfflineAudioContext(1, 1, 65536);
- return context.startRendering().
- then(function(buffer) {
- assert_equals(buffer.length, 1, "buffer length");
- assert_equals(context.currentTime, 128 / context.sampleRate,
- "currentTime at completion");
- });
-});
-</script>
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-oscillatornode-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-oscillatornode-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-oscillatornode-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-pannernode-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-pannernode-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-pannernode-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-pannernode-interface/test-pannernode-automation.html b/testing/web-platform/tests/webaudio/the-audio-api/the-pannernode-interface/test-pannernode-automation.html
deleted file mode 100644
index 74bbdc6fe..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-pannernode-interface/test-pannernode-automation.html
+++ /dev/null
@@ -1,31 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<title></title>
-<script src=/resources/testharness.js></script>
-<script src=/resources/testharnessreport.js></script>
-<script>
-promise_test(function(t) {
- var ac = new OfflineAudioContext(2, 2048, 44100);
- var panner = ac.createPanner();
- panner.positionX.value = -1;
- panner.positionY.value = -1;
- panner.positionZ.value = 1;
- panner.positionX.setValueAtTime(1, 1024/ac.sampleRate);
- var osc = ac.createOscillator();
- osc.connect(panner);
- panner.connect(ac.destination);
- osc.start()
- return ac.startRendering().then(function(buffer) {
- var left = buffer.getChannelData(0);
- var right = buffer.getChannelData(1);
- for (var i = 0; i < 2048; ++i) {
- if (i < 1024) {
- assert_true(Math.abs(left[i]) >= Math.abs(right[i]), "index " + i + " should be on the left");
- } else {
- assert_true(Math.abs(left[i]) < Math.abs(right[i]), "index " + i + " should be on the right");
- }
- }
- });
-}, "PannerNode AudioParam automation works properly");
-
-</script>
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-periodicwave-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-periodicwave-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-periodicwave-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-scriptprocessornode-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-scriptprocessornode-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-scriptprocessornode-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-waveshapernode-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-waveshapernode-interface/.gitkeep
deleted file mode 100644
index e69de29bb..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-waveshapernode-interface/.gitkeep
+++ /dev/null
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-waveshapernode-interface/curve-tests.html b/testing/web-platform/tests/webaudio/the-audio-api/the-waveshapernode-interface/curve-tests.html
deleted file mode 100644
index 791b74a6c..000000000
--- a/testing/web-platform/tests/webaudio/the-audio-api/the-waveshapernode-interface/curve-tests.html
+++ /dev/null
@@ -1,212 +0,0 @@
-<!doctype html>
-<html>
-<head>
- <title>WaveShaperNode interface - Curve tests | WebAudio</title>
-
- <script type="text/javascript" src="/resources/testharness.js"></script>
- <script type="text/javascript" src="/resources/testharnessreport.js"></script>
- <script type="text/javascript" src="../../js/vendor-prefixes.js"></script>
-</head>
-<body>
- <div id="log">
- </div>
-
- <script type="text/javascript">
- var sampleRate=44100.0;
- var tolerance=0.01;
-
- /*
- Testing that -1, 0 and +1 map correctly to curve (with 1:1 correlation)
- =======================================================================
- From the specification:
- The input signal is nominally within the range -1 -> +1.
- Each input sample within this range will index into the shaping curve with a signal level of zero corresponding
- to the center value of the curve array.
- */
- (function() {
- var threeElementCurve=[2.0, -3.0, 4.0];
- var inputData=[-1.0, 0, 1.0];
- var expectedData=[2.0, -3.0, 4.0];
- executeTest(threeElementCurve, inputData, expectedData, "Testing that -1, 0 and +1 map correctly to curve (with 1:1 correlation)");
- })();
-
- /*
- Testing interpolation (where inputs don't correlate directly to curve elements)
- ===============================================================================
- From the specification:
- The implementation must perform linear interpolation between adjacent points in the curve.
- */
- (function() {
- var threeElementCurve=[2.0, -3.0, 4.0];
- var inputData=[-0.5, +0.5, +0.75];
- var expectedData=[-0.5, +0.5, +2.25];
- executeTest(threeElementCurve, inputData, expectedData, "Testing interpolation (where inputs don't correlate directly to curve elements)");
- })();
-
- /*
- Testing out-of-range inputs (should be mapped to the first/last elements of the curve)
- ======================================================================================
- From the specification:
- Any sample value less than -1 will correspond to the first value in the curve array.
- Any sample value greater than +1 will correspond to the last value in the curve array.
- */
- (function() {
- var threeElementCurve=[2.0, -3.0, 4.0];
- var inputData=[-1.5, +1.5];
- var expectedData=[2.0, 4.0];
- executeTest(threeElementCurve, inputData, expectedData, "Testing out-of-range inputs (should be mapped to the first/last elements of the curve)");
- })();
-
- /*
- Testing a 2-element curve (does not have a middle element)
- ==========================================================
- From the specification:
- Each input sample within this range will index into the shaping curve with a signal level of zero corresponding
- to the center value of the curve array.
- The implementation must perform linear interpolation between adjacent points in the curve.
- */
- (function() {
- var twoElementCurve=[2.0, -2.0];
- var inputData=[-1.0, 0, 1.0];
- var expectedData=[2.0, 0.0, -2.0];
- executeTest(twoElementCurve, inputData, expectedData, "Testing a 2-element curve (does not have a middle element)");
- })();
-
- /*
- Testing a 4-element curve (does not have a middle element)
- ==========================================================
- From the specification:
- Each input sample within this range will index into the shaping curve with a signal level of zero corresponding
- to the center value of the curve array.
- The implementation must perform linear interpolation between adjacent points in the curve.
- */
- (function() {
- var fourElementCurve=[1.0, 2.0, 4.0, 7.0];
- var inputData=[-1.0, 0, 1.0];
- var expectedData=[1.0, 3.0, 7.0];
- executeTest(fourElementCurve, inputData, expectedData, "Testing a 4-element curve (does not have a middle element)");
- })();
-
- /*
- Testing a huge curve
- ====================
- From the specification:
- Each input sample within this range will index into the shaping curve with a signal level of zero corresponding
- to the center value of the curve array.
- */
- (function() {
- var bigCurve=[];
- for(var i=0;i<=60000;i++) { bigCurve.push(i/3.5435); }
- var inputData=[-1.0, 0, 1.0];
- var expectedData=[bigCurve[0], bigCurve[30000], bigCurve[60000]];
- executeTest(bigCurve, inputData, expectedData, "Testing a huge curve");
- })();
-
- /*
- Testing single-element curve (boundary condition)
- =================================================
- From the specification:
- Each input sample within this range will index into the shaping curve with a signal level of zero corresponding
- to the center value of the curve array.
- Any sample value less than -1 will correspond to the first value in the curve array.
- Any sample value greater than +1 will correspond to the last value in the curve array.
- The implementation must perform linear interpolation between adjacent points in the curve.
- Note:
- I found a post on the W3C audio mailing list (from one of the Chris's) that suggested it would be feasible
- to use the WaveShaperNode to create constant values.
- */
- (function() {
- var oneElementCurve=[1.0];
- var inputData=[-1.0, 0, 1.0, -2.0, 2.0];
- var expectedData=[1.0, 1.0, 1.0, 1.0, 1.0];
- executeTest(oneElementCurve, inputData, expectedData, "Testing single-element curve (boundary condition)");
- })();
-
- /*
- Testing null curve (should return input values)
- ===============================================
- From the specification:
- Initially the curve attribute is null, which means that the WaveShaperNode will pass its input to its output
- without modification.
- */
- (function() {
- var inputData=[-1.0, 0, 1.0, 2.0];
- var expectedData=[-1.0, 0.0, 1.0, 2.0];
- executeTest(null, inputData, expectedData, "Testing null curve (should return input values)");
- })();
-
- /*
- Testing zero-element curve (unspecified result)
- ===============================================
- From the specification:
- Unspecified result (I assume it will be treated in the same way as a null curve).
- Note:
- Mozilla test_waveShaperNoCurve.html indicates they expect same results as a null curve.
- */
- (function() {
- var zeroElementCurve=[];
- var inputData=[-1.0, 0, 1.0, 2.0];
- var expectedData=[-1.0, 0.0, 1.0, 2.0];
- executeTest(zeroElementCurve, inputData, expectedData, "Testing zero-element curve (unspecified result)");
- })();
-
-
- /**
- * Function that does the actual testing (using an asynchronous test).
- * @param {?Array.<number>} curveData - Array containing values for the WaveShaper curve.
- * @param {!Array.<number>} inputData - Array containing values for the input stream.
- * @param {!Array.<number>} expectedData - Array containing expected results for each of the corresponding inputs.
- * @param {!string} testName - Name of the test case.
- */
- function executeTest(curveData, inputData, expectedData, testName) {
- var stTest=async_test("WaveShaperNode - "+testName);
-
- // Create offline audio context.
- var ac=new OfflineAudioContext(1, inputData.length, sampleRate);
-
- // Create the WaveShaper and its curve.
- var waveShaper=ac.createWaveShaper();
- if(curveData!=null) {
- var curve=new Float32Array(curveData.length);
- for(var i=0;i<curveData.length;i++) { curve[i]=curveData[i]; }
- waveShaper.curve=curve;
- }
- waveShaper.connect(ac.destination);
-
- // Create buffer containing the input values.
- var inputBuffer=ac.createBuffer(1, Math.max(inputData.length, 2), sampleRate);
- var d=inputBuffer.getChannelData(0);
- for(var i=0;i<inputData.length;i++) { d[i]=inputData[i]; }
-
- // Play the input buffer through the WaveShaper.
- var src=ac.createBufferSource();
- src.buffer=inputBuffer;
- src.connect(waveShaper);
- src.start();
-
- // Test the outputs match the expected values.
- ac.oncomplete=function(ev) {
- var d=ev.renderedBuffer.getChannelData(0);
-
- stTest.step(function() {
- for(var i=0;i<expectedData.length;i++) {
- var curveText="null";
- if(curve!=null) {
- if(curveData.length<20) {
- curveText=curveData.join(",");
- } else {
- curveText="TooBigToDisplay ("+(curveData.length-1)+" elements)";
- }
- }
- var comment="Input="+inputData[i]+", Curve=["+curveText+"] >>> ";
- assert_approx_equals(d[i], expectedData[i], tolerance, comment);
- }
- });
-
- stTest.done();
- };
- ac.startRendering();
- }
- </script>
-</body>
-</html>