<!DOCTYPE html> <html> <head> <title>Testcase for AudioNode channel up-mix/down-mix rules</title> <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script> <script type="text/javascript" src="webaudio.js"></script> <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" /> </head> <body> <script> // This test is based on http://src.chromium.org/viewvc/blink/trunk/LayoutTests/webaudio/audionode-channel-rules.html var context = null; var sp = null; var renderNumberOfChannels = 8; var singleTestFrameLength = 8; var testBuffers; // A list of connections to an AudioNode input, each of which is to be used in one or more specific test cases. // Each element in the list is a string, with the number of connections corresponding to the length of the string, // and each character in the string is from '1' to '8' representing a 1 to 8 channel connection (from an AudioNode output). // For example, the string "128" means 3 connections, having 1, 2, and 8 channels respectively. var connectionsList = []; for (var i = 1; i <= 8; ++i) { connectionsList.push(i.toString()); for (var j = 1; j <= 8; ++j) { connectionsList.push(i.toString() + j.toString()); } } // A list of mixing rules, each of which will be tested against all of the connections in connectionsList. var mixingRulesList = [ {channelCount: 1, channelCountMode: "max", channelInterpretation: "speakers"}, {channelCount: 2, channelCountMode: "clamped-max", channelInterpretation: "speakers"}, {channelCount: 3, channelCountMode: "clamped-max", channelInterpretation: "speakers"}, {channelCount: 4, channelCountMode: "clamped-max", channelInterpretation: "speakers"}, {channelCount: 5, channelCountMode: "clamped-max", channelInterpretation: "speakers"}, {channelCount: 6, channelCountMode: "clamped-max", channelInterpretation: "speakers"}, {channelCount: 7, channelCountMode: "clamped-max", channelInterpretation: "speakers"}, {channelCount: 2, channelCountMode: "explicit", channelInterpretation: "speakers"}, {channelCount: 3, channelCountMode: "explicit", channelInterpretation: "speakers"}, {channelCount: 4, channelCountMode: "explicit", channelInterpretation: "speakers"}, {channelCount: 5, channelCountMode: "explicit", channelInterpretation: "speakers"}, {channelCount: 6, channelCountMode: "explicit", channelInterpretation: "speakers"}, {channelCount: 7, channelCountMode: "explicit", channelInterpretation: "speakers"}, {channelCount: 8, channelCountMode: "explicit", channelInterpretation: "speakers"}, {channelCount: 1, channelCountMode: "max", channelInterpretation: "discrete"}, {channelCount: 2, channelCountMode: "clamped-max", channelInterpretation: "discrete"}, {channelCount: 3, channelCountMode: "clamped-max", channelInterpretation: "discrete"}, {channelCount: 4, channelCountMode: "clamped-max", channelInterpretation: "discrete"}, {channelCount: 5, channelCountMode: "clamped-max", channelInterpretation: "discrete"}, {channelCount: 6, channelCountMode: "clamped-max", channelInterpretation: "discrete"}, {channelCount: 3, channelCountMode: "explicit", channelInterpretation: "discrete"}, {channelCount: 4, channelCountMode: "explicit", channelInterpretation: "discrete"}, {channelCount: 5, channelCountMode: "explicit", channelInterpretation: "discrete"}, {channelCount: 6, channelCountMode: "explicit", channelInterpretation: "discrete"}, {channelCount: 7, channelCountMode: "explicit", channelInterpretation: "discrete"}, {channelCount: 8, channelCountMode: "explicit", channelInterpretation: "discrete"}, ]; var numberOfTests = mixingRulesList.length * connectionsList.length; // Create an n-channel buffer, with all sample data zero except for a shifted impulse. // The impulse position depends on the channel index. // For example, for a 4-channel buffer: // channel0: 1 0 0 0 0 0 0 0 // channel1: 0 1 0 0 0 0 0 0 // channel2: 0 0 1 0 0 0 0 0 // channel3: 0 0 0 1 0 0 0 0 function createTestBuffer(numberOfChannels) { var buffer = context.createBuffer(numberOfChannels, singleTestFrameLength, context.sampleRate); for (var i = 0; i < numberOfChannels; ++i) { var data = buffer.getChannelData(i); data[i] = 1; } return buffer; } // Discrete channel interpretation mixing: // https://dvcs.w3.org/hg/audio/raw-file/tip/webaudio/specification.html#UpMix // up-mix by filling channels until they run out then ignore remaining dest channels. // down-mix by filling as many channels as possible, then dropping remaining source channels. function discreteSum(sourceBuffer, destBuffer) { if (sourceBuffer.length != destBuffer.length) { is(sourceBuffer.length, destBuffer.length, "source and destination buffers should have the same length"); } var numberOfChannels = Math.min(sourceBuffer.numberOfChannels, destBuffer.numberOfChannels); var length = sourceBuffer.length; for (var c = 0; c < numberOfChannels; ++c) { var source = sourceBuffer.getChannelData(c); var dest = destBuffer.getChannelData(c); for (var i = 0; i < length; ++i) { dest[i] += source[i]; } } } // Speaker channel interpretation mixing: // https://dvcs.w3.org/hg/audio/raw-file/tip/webaudio/specification.html#UpMix function speakersSum(sourceBuffer, destBuffer) { var numberOfSourceChannels = sourceBuffer.numberOfChannels; var numberOfDestinationChannels = destBuffer.numberOfChannels; var length = destBuffer.length; if ((numberOfDestinationChannels == 2 && numberOfSourceChannels == 1) || (numberOfDestinationChannels == 4 && numberOfSourceChannels == 1)) { // Handle mono -> stereo/Quad case (summing mono channel into both left and right). var source = sourceBuffer.getChannelData(0); var destL = destBuffer.getChannelData(0); var destR = destBuffer.getChannelData(1); for (var i = 0; i < length; ++i) { destL[i] += source[i]; destR[i] += source[i]; } } else if ((numberOfDestinationChannels == 4 && numberOfSourceChannels == 2) || (numberOfDestinationChannels == 6 && numberOfSourceChannels == 2)) { // Handle stereo -> Quad/5.1 case (summing left and right channels into the output's left and right). var sourceL = sourceBuffer.getChannelData(0); var sourceR = sourceBuffer.getChannelData(1); var destL = destBuffer.getChannelData(0); var destR = destBuffer.getChannelData(1); for (var i = 0; i < length; ++i) { destL[i] += sourceL[i]; destR[i] += sourceR[i]; } } else if (numberOfDestinationChannels == 1 && numberOfSourceChannels == 2) { // Handle stereo -> mono case. output += 0.5 * (input.L + input.R). var sourceL = sourceBuffer.getChannelData(0); var sourceR = sourceBuffer.getChannelData(1); var dest = destBuffer.getChannelData(0); for (var i = 0; i < length; ++i) { dest[i] += 0.5 * (sourceL[i] + sourceR[i]); } } else if (numberOfDestinationChannels == 1 && numberOfSourceChannels == 4) { // Handle Quad -> mono case. output += 0.25 * (input.L + input.R + input.SL + input.SR). var sourceL = sourceBuffer.getChannelData(0); var sourceR = sourceBuffer.getChannelData(1); var sourceSL = sourceBuffer.getChannelData(2); var sourceSR = sourceBuffer.getChannelData(3); var dest = destBuffer.getChannelData(0); for (var i = 0; i < length; ++i) { dest[i] += 0.25 * (sourceL[i] + sourceR[i] + sourceSL[i] + sourceSR[i]); } } else if (numberOfDestinationChannels == 2 && numberOfSourceChannels == 4) { // Handle Quad -> stereo case. outputLeft += 0.5 * (input.L + input.SL), // outputRight += 0.5 * (input.R + input.SR). var sourceL = sourceBuffer.getChannelData(0); var sourceR = sourceBuffer.getChannelData(1); var sourceSL = sourceBuffer.getChannelData(2); var sourceSR = sourceBuffer.getChannelData(3); var destL = destBuffer.getChannelData(0); var destR = destBuffer.getChannelData(1); for (var i = 0; i < length; ++i) { destL[i] += 0.5 * (sourceL[i] + sourceSL[i]); destR[i] += 0.5 * (sourceR[i] + sourceSR[i]); } } else if (numberOfDestinationChannels == 6 && numberOfSourceChannels == 4) { // Handle Quad -> 5.1 case. outputLeft += (inputL, inputR, 0, 0, inputSL, inputSR) var sourceL = sourceBuffer.getChannelData(0); var sourceR = sourceBuffer.getChannelData(1); var sourceSL = sourceBuffer.getChannelData(2); var sourceSR = sourceBuffer.getChannelData(3); var destL = destBuffer.getChannelData(0); var destR = destBuffer.getChannelData(1); var destSL = destBuffer.getChannelData(4); var destSR = destBuffer.getChannelData(5); for (var i = 0; i < length; ++i) { destL[i] += sourceL[i]; destR[i] += sourceR[i]; destSL[i] += sourceSL[i]; destSR[i] += sourceSR[i]; } } else if (numberOfDestinationChannels == 6 && numberOfSourceChannels == 1) { // Handle mono -> 5.1 case, sum mono channel into center. var source = sourceBuffer.getChannelData(0); var dest = destBuffer.getChannelData(2); for (var i = 0; i < length; ++i) { dest[i] += source[i]; } } else if (numberOfDestinationChannels == 1 && numberOfSourceChannels == 6) { // Handle 5.1 -> mono. var sourceL = sourceBuffer.getChannelData(0); var sourceR = sourceBuffer.getChannelData(1); var sourceC = sourceBuffer.getChannelData(2); // skip LFE for now, according to current spec. var sourceSL = sourceBuffer.getChannelData(4); var sourceSR = sourceBuffer.getChannelData(5); var dest = destBuffer.getChannelData(0); for (var i = 0; i < length; ++i) { dest[i] += 0.7071 * (sourceL[i] + sourceR[i]) + sourceC[i] + 0.5 * (sourceSL[i] + sourceSR[i]); } } else if (numberOfDestinationChannels == 2 && numberOfSourceChannels == 6) { // Handle 5.1 -> stereo. var sourceL = sourceBuffer.getChannelData(0); var sourceR = sourceBuffer.getChannelData(1); var sourceC = sourceBuffer.getChannelData(2); // skip LFE for now, according to current spec. var sourceSL = sourceBuffer.getChannelData(4); var sourceSR = sourceBuffer.getChannelData(5); var destL = destBuffer.getChannelData(0); var destR = destBuffer.getChannelData(1); for (var i = 0; i < length; ++i) { destL[i] += sourceL[i] + 0.7071 * (sourceC[i] + sourceSL[i]); destR[i] += sourceR[i] + 0.7071 * (sourceC[i] + sourceSR[i]); } } else if (numberOfDestinationChannels == 4 && numberOfSourceChannels == 6) { // Handle 5.1 -> Quad. var sourceL = sourceBuffer.getChannelData(0); var sourceR = sourceBuffer.getChannelData(1); var sourceC = sourceBuffer.getChannelData(2); // skip LFE for now, according to current spec. var sourceSL = sourceBuffer.getChannelData(4); var sourceSR = sourceBuffer.getChannelData(5); var destL = destBuffer.getChannelData(0); var destR = destBuffer.getChannelData(1); var destSL = destBuffer.getChannelData(2); var destSR = destBuffer.getChannelData(3); for (var i = 0; i < length; ++i) { destL[i] += sourceL[i] + 0.7071 * sourceC[i]; destR[i] += sourceR[i] + 0.7071 * sourceC[i]; destSL[i] += sourceSL[i]; destSR[i] += sourceSR[i]; } } else { // Fallback for unknown combinations. discreteSum(sourceBuffer, destBuffer); } } function scheduleTest(testNumber, connections, channelCount, channelCountMode, channelInterpretation) { var mixNode = context.createGain(); mixNode.channelCount = channelCount; mixNode.channelCountMode = channelCountMode; mixNode.channelInterpretation = channelInterpretation; mixNode.connect(sp); for (var i = 0; i < connections.length; ++i) { var connectionNumberOfChannels = connections.charCodeAt(i) - "0".charCodeAt(0); var source = context.createBufferSource(); // Get a buffer with the right number of channels, converting from 1-based to 0-based index. var buffer = testBuffers[connectionNumberOfChannels - 1]; source.buffer = buffer; source.connect(mixNode); // Start at the right offset. var sampleFrameOffset = testNumber * singleTestFrameLength; var time = sampleFrameOffset / context.sampleRate; source.start(time); } } function computeNumberOfChannels(connections, channelCount, channelCountMode) { if (channelCountMode == "explicit") return channelCount; var computedNumberOfChannels = 1; // Must have at least one channel. // Compute "computedNumberOfChannels" based on all the connections. for (var i = 0; i < connections.length; ++i) { var connectionNumberOfChannels = connections.charCodeAt(i) - "0".charCodeAt(0); computedNumberOfChannels = Math.max(computedNumberOfChannels, connectionNumberOfChannels); } if (channelCountMode == "clamped-max") computedNumberOfChannels = Math.min(computedNumberOfChannels, channelCount); return computedNumberOfChannels; } function checkTestResult(renderedBuffer, testNumber, connections, channelCount, channelCountMode, channelInterpretation) { var computedNumberOfChannels = computeNumberOfChannels(connections, channelCount, channelCountMode); // Create a zero-initialized silent AudioBuffer with computedNumberOfChannels. var destBuffer = context.createBuffer(computedNumberOfChannels, singleTestFrameLength, context.sampleRate); // Mix all of the connections into the destination buffer. for (var i = 0; i < connections.length; ++i) { var connectionNumberOfChannels = connections.charCodeAt(i) - "0".charCodeAt(0); var sourceBuffer = testBuffers[connectionNumberOfChannels - 1]; // convert from 1-based to 0-based index if (channelInterpretation == "speakers") { speakersSum(sourceBuffer, destBuffer); } else if (channelInterpretation == "discrete") { discreteSum(sourceBuffer, destBuffer); } else { ok(false, "Invalid channel interpretation!"); } } // Validate that destBuffer matches the rendered output. // We need to check the rendered output at a specific sample-frame-offset corresponding // to the specific test case we're checking for based on testNumber. var sampleFrameOffset = testNumber * singleTestFrameLength; for (var c = 0; c < renderNumberOfChannels; ++c) { var renderedData = renderedBuffer.getChannelData(c); for (var frame = 0; frame < singleTestFrameLength; ++frame) { var renderedValue = renderedData[frame + sampleFrameOffset]; var expectedValue = 0; if (c < destBuffer.numberOfChannels) { var expectedData = destBuffer.getChannelData(c); expectedValue = expectedData[frame]; } if (Math.abs(renderedValue - expectedValue) > 1e-4) { var s = "connections: " + connections + ", " + channelCountMode; // channelCount is ignored in "max" mode. if (channelCountMode == "clamped-max" || channelCountMode == "explicit") { s += "(" + channelCount + ")"; } s += ", " + channelInterpretation + ". "; var message = s + "rendered: " + renderedValue + " expected: " + expectedValue + " channel: " + c + " frame: " + frame; is(renderedValue, expectedValue, message); } } } } function checkResult(event) { var buffer = event.inputBuffer; // Sanity check result. ok(buffer.length != numberOfTests * singleTestFrameLength || buffer.numberOfChannels != renderNumberOfChannels, "Sanity check"); // Check all the tests. var testNumber = 0; for (var m = 0; m < mixingRulesList.length; ++m) { var mixingRules = mixingRulesList[m]; for (var i = 0; i < connectionsList.length; ++i, ++testNumber) { checkTestResult(buffer, testNumber, connectionsList[i], mixingRules.channelCount, mixingRules.channelCountMode, mixingRules.channelInterpretation); } } sp.onaudioprocess = null; SimpleTest.finish(); } SimpleTest.waitForExplicitFinish(); function runTest() { // Create 8-channel offline audio context. // Each test will render 8 sample-frames starting at sample-frame position testNumber * 8. var totalFrameLength = numberOfTests * singleTestFrameLength; context = new AudioContext(); var nextPowerOfTwo = 256; while (nextPowerOfTwo < totalFrameLength) { nextPowerOfTwo *= 2; } sp = context.createScriptProcessor(nextPowerOfTwo, renderNumberOfChannels); // Set destination to discrete mixing. sp.channelCount = renderNumberOfChannels; sp.channelCountMode = "explicit"; sp.channelInterpretation = "discrete"; // Create test buffers from 1 to 8 channels. testBuffers = new Array(); for (var i = 0; i < renderNumberOfChannels; ++i) { testBuffers[i] = createTestBuffer(i + 1); } // Schedule all the tests. var testNumber = 0; for (var m = 0; m < mixingRulesList.length; ++m) { var mixingRules = mixingRulesList[m]; for (var i = 0; i < connectionsList.length; ++i, ++testNumber) { scheduleTest(testNumber, connectionsList[i], mixingRules.channelCount, mixingRules.channelCountMode, mixingRules.channelInterpretation); } } // Render then check results. sp.onaudioprocess = checkResult; } runTest(); </script> </body> </html>