diff options
Diffstat (limited to 'testing/web-platform/tests/webaudio')
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 = { - '&': '&', - '<': '<', - '>': '>', - '"': '"', - "'": ''' - }; - - /** 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 & 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><script></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 - * `&`, `<`, `>`, `"`, and `'` 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 & 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 Binary files differdeleted file mode 100644 index f660c3c4b..000000000 --- a/testing/web-platform/tests/webaudio/resources/sin_440Hz_-6dBFS_1s.wav +++ /dev/null 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 <crogers@google.com></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 <<a -href="mailto:public-audio@w3.org">public-audio@w3.org</a>> (<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 <= t < 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 <= t < 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 <= t < 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> <= t < <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> <= t < <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 < 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 -> +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) && loopStart >= 0 && loopEnd > 0 && loopStart < 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 < 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 < 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 -> 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 -> +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 & 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 -> 2 : up-mix from mono to stereo - output.L = input; - output.R = input; - - 1 -> 4 : up-mix from mono to quad - output.L = input; - output.R = input; - output.SL = 0; - output.SR = 0; - - 1 -> 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 -> 4 : up-mix from stereo to quad - output.L = input.L; - output.R = input.R; - output.SL = 0; - output.SR = 0; - - 2 -> 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 -> 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 -> 1 : stereo to mono - output = 0.5 * (input.L + input.R); - - 4 -> 1 : quad to mono - output = 0.25 * (input.L + input.R + input.SL + input.SR); - - 5.1 -> 1 : 5.1 to mono - output = 0.7071 * (input.L + input.R) + input.C + 0.5 * (input.SL + input.SR) - - -Stereo down-mix: - - 4 -> 2 : quad to stereo - output.L = 0.5 * (input.L + input.SL); - output.R = 0.5 * (input.R + input.SR); - - 5.1 -> 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 -> 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 < 0) - azimuth = 360 - azimuth; - -// Make azimuth relative to "front" and not "right" listener vector. -if ((azimuth >= 0) && (azimuth <= 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 < -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 <= <em>azimuth</em> <= +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 < -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 <= 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 <= 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) && (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 <= absInnerAngle) - // No attenuation - gain = 1; -else if (absAngle >= 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 <sample rate>] sample rate of the generated test tones - [-duration <duration>] The duration, in seconds, of the generated files - [-min_freq <min_freq>] 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 <= 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 deleted file mode 100644 index e69de29bb..000000000 --- a/testing/web-platform/tests/webaudio/the-audio-api/the-analysernode-interface/.gitkeep +++ /dev/null diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffer-interface/.gitkeep b/testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffer-interface/.gitkeep deleted file mode 100644 index e69de29bb..000000000 --- a/testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffer-interface/.gitkeep +++ /dev/null diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffer-interface/idl-test.html b/testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffer-interface/idl-test.html deleted file mode 100644 index 72ed88d3c..000000000 --- a/testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffer-interface/idl-test.html +++ /dev/null @@ -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 Binary files differdeleted file mode 100644 index b445bd8a6..000000000 --- a/testing/web-platform/tests/webaudio/the-audio-api/the-gainnode-interface/gain-expected.wav +++ /dev/null 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> |