| <!DOCTYPE html> |
| |
| <html> |
| <head> |
| <script src="../resources/js-test.js"></script> |
| <script type="text/javascript" src="resources/audio-testing.js"></script> |
| </head> |
| |
| <body> |
| <div id="description"></div> |
| <div id="console"></div> |
| |
| <script> |
| description("Channel mixing rules for AudioNodes."); |
| |
| var context = 0; |
| var sampleRate = 44100; |
| 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 = ["1", "2", "3", "4", "5", "6", "7", "8", "11", "12", "14", "18", "111", "122", "123", "124", "128"]; |
| |
| // A list of mixing rules, each of which will be tested against all of the connections in connectionsList. |
| var mixingRulesList = [ |
| {channelCount: 2, channelCountMode: "max", channelInterpretation: "speakers"}, |
| {channelCount: 4, channelCountMode: "clamped-max", channelInterpretation: "speakers"}, |
| |
| // Test up-down-mix to some explicit speaker layouts. |
| {channelCount: 1, channelCountMode: "explicit", channelInterpretation: "speakers"}, |
| {channelCount: 2, channelCountMode: "explicit", channelInterpretation: "speakers"}, |
| {channelCount: 4, channelCountMode: "explicit", channelInterpretation: "speakers"}, |
| {channelCount: 6, channelCountMode: "explicit", channelInterpretation: "speakers"}, |
| |
| {channelCount: 2, channelCountMode: "max", channelInterpretation: "discrete"}, |
| {channelCount: 4, channelCountMode: "clamped-max", channelInterpretation: "discrete"}, |
| {channelCount: 4, 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) { |
| alert("discreteSum(): invalid AudioBuffer!"); |
| return; |
| } |
| |
| var numberOfChannels = sourceBuffer.numberOfChannels < destBuffer.numberOfChannels ? sourceBuffer.numberOfChannels : destBuffer.numberOfChannels; |
| var length = numberOfChannels; |
| |
| 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) { |
| // Handle mono -> stereo 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 == 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 == 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 { |
| // 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(context.destination); |
| |
| 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 / 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 s = "connections: " + connections + ", " + channelCountMode; |
| |
| // channelCount is ignored in "max" mode. |
| if (channelCountMode == "clamped-max" || channelCountMode == "explicit") { |
| s += "(" + channelCount + ")"; |
| } |
| |
| s += ", " + channelInterpretation; |
| |
| var computedNumberOfChannels = computeNumberOfChannels(connections, channelCount, channelCountMode); |
| |
| // Show rendered output for this test: |
| // |
| // console.log(s); |
| // var sampleFrameOffset = testNumber * singleTestFrameLength; |
| // for (var c = 0; c < renderNumberOfChannels; ++c) { |
| // var data = renderedBuffer.getChannelData(c); |
| // var s = ""; |
| // for (var sampleFrame = 0; sampleFrame < singleTestFrameLength; ++sampleFrame) { |
| // s += data[sampleFrame + sampleFrameOffset] + " "; |
| // } |
| // s += "\n"; |
| // console.log(s); |
| // } |
| // return; |
| |
| // 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 { |
| alert("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]; |
| } |
| |
| // We may need to add an epsilon in the comparison if we add more test vectors. |
| if (renderedValue != expectedValue) { |
| var message = s + "rendered: " + renderedValue + " expected: " + expectedValue + " channel: " + c + " frame: " + frame; |
| testFailed(s); |
| return; |
| } |
| } |
| } |
| |
| testPassed(s); |
| } |
| |
| function checkResult(event) { |
| var buffer = event.renderedBuffer; |
| |
| // Sanity check result. |
| if (buffer.length != numberOfTests * singleTestFrameLength || buffer.numberOfChannels != renderNumberOfChannels) { |
| testFailed("OfflineAudioContext result not of expected size!"); |
| finishJSTest(); |
| return; |
| } |
| |
| // 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); |
| } |
| } |
| |
| finishJSTest(); |
| } |
| |
| function runTest() { |
| window.jsTestIsAsync = true; |
| |
| // 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 webkitOfflineAudioContext(renderNumberOfChannels, totalFrameLength, sampleRate); |
| |
| // Set destination to discrete mixing. |
| context.destination.channelCount = renderNumberOfChannels; |
| context.destination.channelCountMode = "explicit"; |
| context.destination.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. |
| context.oncomplete = checkResult; |
| context.startRendering(); |
| } |
| |
| runTest(); |
| |
| </script> |
| </body> |
| </html> |