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diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffersourcenode-interface/sub-sample-scheduling.html b/testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffersourcenode-interface/sub-sample-scheduling.html new file mode 100644 index 0000000000..8c627f90f2 --- /dev/null +++ b/testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffersourcenode-interface/sub-sample-scheduling.html @@ -0,0 +1,423 @@ +<!doctype html> +<html> + <head> + <title> + Test Sub-Sample Accurate Scheduling for ABSN + </title> + <script src="/resources/testharness.js"></script> + <script src="/resources/testharnessreport.js"></script> + <script src="/webaudio/resources/audit-util.js"></script> + <script src="/webaudio/resources/audit.js"></script> + </head> + <body> + <script> + // Power of two so there's no roundoff converting from integer frames to + // time. + let sampleRate = 32768; + + let audit = Audit.createTaskRunner(); + + audit.define('sub-sample accurate start', (task, should) => { + // There are two channels, one for each source. Only need to render + // quanta for this test. + let context = new OfflineAudioContext( + {numberOfChannels: 2, length: 8192, sampleRate: sampleRate}); + let merger = new ChannelMergerNode( + context, {numberOfInputs: context.destination.channelCount}); + + merger.connect(context.destination); + + // Use a simple linear ramp for the sources with integer steps starting + // at 1 to make it easy to verify and test that have sub-sample accurate + // start. Ramp starts at 1 so we can easily tell when the source + // starts. + let rampBuffer = new AudioBuffer( + {length: context.length, sampleRate: context.sampleRate}); + let r = rampBuffer.getChannelData(0); + for (let k = 0; k < r.length; ++k) { + r[k] = k + 1; + } + + const src0 = new AudioBufferSourceNode(context, {buffer: rampBuffer}); + const src1 = new AudioBufferSourceNode(context, {buffer: rampBuffer}); + + // Frame where sources should start. This is pretty arbitrary, but one + // should be close to an integer and the other should be close to the + // next integer. We do this to catch the case where rounding of the + // start frame is being done. Rounding is incorrect. + const startFrame = 33; + const startFrame0 = startFrame + 0.1; + const startFrame1 = startFrame + 0.9; + + src0.connect(merger, 0, 0); + src1.connect(merger, 0, 1); + + src0.start(startFrame0 / context.sampleRate); + src1.start(startFrame1 / context.sampleRate); + + context.startRendering() + .then(audioBuffer => { + const output0 = audioBuffer.getChannelData(0); + const output1 = audioBuffer.getChannelData(1); + + // Compute the expected output by interpolating the ramp buffer of + // the sources if they started at the given frame. + const ramp = rampBuffer.getChannelData(0); + const expected0 = interpolateRamp(ramp, startFrame0); + const expected1 = interpolateRamp(ramp, startFrame1); + + // Verify output0 has the correct values + + // For information only + should(startFrame0, 'src0 start frame').beEqualTo(startFrame0); + + // Output must be zero before the source start frame, and it must + // be interpolated correctly after the start frame. The + // absoluteThreshold below is currently set for Chrome which does + // linear interpolation. This needs to be updated eventually if + // other browsers do not user interpolation. + should( + output0.slice(0, startFrame + 1), `output0[0:${startFrame}]`) + .beConstantValueOf(0); + should( + output0.slice(startFrame + 1, expected0.length), + `output0[${startFrame + 1}:${expected0.length - 1}]`) + .beCloseToArray( + expected0.slice(startFrame + 1), {absoluteThreshold: 0}); + + // Verify output1 has the correct values. Same approach as for + // output0. + should(startFrame1, 'src1 start frame').beEqualTo(startFrame1); + + should( + output1.slice(0, startFrame + 1), `output1[0:${startFrame}]`) + .beConstantValueOf(0); + should( + output1.slice(startFrame + 1, expected1.length), + `output1[${startFrame + 1}:${expected1.length - 1}]`) + .beCloseToArray( + expected1.slice(startFrame + 1), {absoluteThreshold: 0}); + }) + .then(() => task.done()); + }); + + audit.define('sub-sample accurate stop', (task, should) => { + // There are threes channesl, one for each source. Only need to render + // quanta for this test. + let context = new OfflineAudioContext( + {numberOfChannels: 3, length: 128, sampleRate: sampleRate}); + let merger = new ChannelMergerNode( + context, {numberOfInputs: context.destination.channelCount}); + + merger.connect(context.destination); + + // The source can be as simple constant for this test. + let buffer = new AudioBuffer( + {length: context.length, sampleRate: context.sampleRate}); + buffer.getChannelData(0).fill(1); + + const src0 = new AudioBufferSourceNode(context, {buffer: buffer}); + const src1 = new AudioBufferSourceNode(context, {buffer: buffer}); + const src2 = new AudioBufferSourceNode(context, {buffer: buffer}); + + // Frame where sources should start. This is pretty arbitrary, but one + // should be an integer, one should be close to an integer and the other + // should be close to the next integer. This is to catch the case where + // rounding is used for the end frame. Rounding is incorrect. + const endFrame = 33; + const endFrame1 = endFrame + 0.1; + const endFrame2 = endFrame + 0.9; + + src0.connect(merger, 0, 0); + src1.connect(merger, 0, 1); + src2.connect(merger, 0, 2); + + src0.start(0); + src1.start(0); + src2.start(0); + src0.stop(endFrame / context.sampleRate); + src1.stop(endFrame1 / context.sampleRate); + src2.stop(endFrame2 / context.sampleRate); + + context.startRendering() + .then(audioBuffer => { + let actual0 = audioBuffer.getChannelData(0); + let actual1 = audioBuffer.getChannelData(1); + let actual2 = audioBuffer.getChannelData(2); + + // Just verify that we stopped at the right time. + + // This is case where the end frame is an integer. Since the first + // output ends on an exact frame, the output must be zero at that + // frame number. We print the end frame for information only; it + // makes interpretation of the rest easier. + should(endFrame - 1, 'src0 end frame') + .beEqualTo(endFrame - 1); + should(actual0[endFrame - 1], `output0[${endFrame - 1}]`) + .notBeEqualTo(0); + should(actual0.slice(endFrame), + `output0[${endFrame}:]`) + .beConstantValueOf(0); + + // The case where the end frame is just a little above an integer. + // The output must not be zero just before the end and must be zero + // after. + should(endFrame1, 'src1 end frame') + .beEqualTo(endFrame1); + should(actual1[endFrame], `output1[${endFrame}]`) + .notBeEqualTo(0); + should(actual1.slice(endFrame + 1), + `output1[${endFrame + 1}:]`) + .beConstantValueOf(0); + + // The case where the end frame is just a little below an integer. + // The output must not be zero just before the end and must be zero + // after. + should(endFrame2, 'src2 end frame') + .beEqualTo(endFrame2); + should(actual2[endFrame], `output2[${endFrame}]`) + .notBeEqualTo(0); + should(actual2.slice(endFrame + 1), + `output2[${endFrame + 1}:]`) + .beConstantValueOf(0); + }) + .then(() => task.done()); + }); + + audit.define('sub-sample-grain', (task, should) => { + let context = new OfflineAudioContext( + {numberOfChannels: 2, length: 128, sampleRate: sampleRate}); + + let merger = new ChannelMergerNode( + context, {numberOfInputs: context.destination.channelCount}); + + merger.connect(context.destination); + + // The source can be as simple constant for this test. + let buffer = new AudioBuffer( + {length: context.length, sampleRate: context.sampleRate}); + buffer.getChannelData(0).fill(1); + + let src0 = new AudioBufferSourceNode(context, {buffer: buffer}); + let src1 = new AudioBufferSourceNode(context, {buffer: buffer}); + + src0.connect(merger, 0, 0); + src1.connect(merger, 0, 1); + + // Start a short grain. + const src0StartGrain = 3.1; + const src0EndGrain = 37.2; + src0.start( + src0StartGrain / context.sampleRate, 0, + (src0EndGrain - src0StartGrain) / context.sampleRate); + + const src1StartGrain = 5.8; + const src1EndGrain = 43.9; + src1.start( + src1StartGrain / context.sampleRate, 0, + (src1EndGrain - src1StartGrain) / context.sampleRate); + + context.startRendering() + .then(audioBuffer => { + let output0 = audioBuffer.getChannelData(0); + let output1 = audioBuffer.getChannelData(1); + + let expected = new Float32Array(context.length); + + // Compute the expected output for output0 and verify the actual + // output matches. + expected.fill(1); + for (let k = 0; k <= Math.floor(src0StartGrain); ++k) { + expected[k] = 0; + } + for (let k = Math.ceil(src0EndGrain); k < expected.length; ++k) { + expected[k] = 0; + } + + verifyGrain(should, output0, { + startGrain: src0StartGrain, + endGrain: src0EndGrain, + sourceName: 'src0', + outputName: 'output0' + }); + + verifyGrain(should, output1, { + startGrain: src1StartGrain, + endGrain: src1EndGrain, + sourceName: 'src1', + outputName: 'output1' + }); + }) + .then(() => task.done()); + }); + + audit.define( + 'sub-sample accurate start with playbackRate', (task, should) => { + // There are two channels, one for each source. Only need to render + // quanta for this test. + let context = new OfflineAudioContext( + {numberOfChannels: 2, length: 8192, sampleRate: sampleRate}); + let merger = new ChannelMergerNode( + context, {numberOfInputs: context.destination.channelCount}); + + merger.connect(context.destination); + + // Use a simple linear ramp for the sources with integer steps + // starting at 1 to make it easy to verify and test that have + // sub-sample accurate start. Ramp starts at 1 so we can easily + // tell when the source starts. + let buffer = new AudioBuffer( + {length: context.length, sampleRate: context.sampleRate}); + let r = buffer.getChannelData(0); + for (let k = 0; k < r.length; ++k) { + r[k] = k + 1; + } + + // Two sources with different playback rates + const src0 = new AudioBufferSourceNode( + context, {buffer: buffer, playbackRate: .25}); + const src1 = new AudioBufferSourceNode( + context, {buffer: buffer, playbackRate: 4}); + + // Frame where sources start. Pretty arbitrary but should not be an + // integer. + const startFrame = 17.8; + + src0.connect(merger, 0, 0); + src1.connect(merger, 0, 1); + + src0.start(startFrame / context.sampleRate); + src1.start(startFrame / context.sampleRate); + + context.startRendering() + .then(audioBuffer => { + const output0 = audioBuffer.getChannelData(0); + const output1 = audioBuffer.getChannelData(1); + + const frameBefore = Math.floor(startFrame); + const frameAfter = frameBefore + 1; + + // Informative message so we know what the following output + // indices really mean. + should(startFrame, 'Source start frame') + .beEqualTo(startFrame); + + // Verify the output + + // With a startFrame of 17.8, the first output is at frame 18, + // but the actual start is at 17.8. So we would interpolate + // the output 0.2 fraction of the way between 17.8 and 18, for + // an output of 1.2 for our ramp. But the playback rate is + // 0.25, so we're really only 1/4 as far along as we think so + // the output is .2*0.25 of the way between 1 and 2 or 1.05. + + const ramp0 = buffer.getChannelData(0)[0]; + const ramp1 = buffer.getChannelData(0)[1]; + + const src0Output = ramp0 + + (ramp1 - ramp0) * (frameAfter - startFrame) * + src0.playbackRate.value; + + let playbackMessage = + `With playbackRate ${src0.playbackRate.value}:`; + + should( + output0[frameBefore], + `${playbackMessage} output0[${frameBefore}]`) + .beEqualTo(0); + should( + output0[frameAfter], + `${playbackMessage} output0[${frameAfter}]`) + .beCloseTo(src0Output, {threshold: 4.542e-8}); + + const src1Output = ramp0 + + (ramp1 - ramp0) * (frameAfter - startFrame) * + src1.playbackRate.value; + + playbackMessage = + `With playbackRate ${src1.playbackRate.value}:`; + + should( + output1[frameBefore], + `${playbackMessage} output1[${frameBefore}]`) + .beEqualTo(0); + should( + output1[frameAfter], + `${playbackMessage} output1[${frameAfter}]`) + .beCloseTo(src1Output, {threshold: 4.542e-8}); + }) + .then(() => task.done()); + }); + + audit.run(); + + // Given an input ramp in |rampBuffer|, interpolate the signal assuming + // this ramp is used for an ABSN that starts at frame |startFrame|, which + // is not necessarily an integer. For simplicity we just use linear + // interpolation here. The interpolation is not part of the spec but + // this should be pretty close to whatever interpolation is being done. + function interpolateRamp(rampBuffer, startFrame) { + // |start| is the last zero sample before the ABSN actually starts. + const start = Math.floor(startFrame); + // One less than the rampBuffer because we can't linearly interpolate + // the last frame. + let result = new Float32Array(rampBuffer.length - 1); + + for (let k = 0; k <= start; ++k) { + result[k] = 0; + } + + // Now start linear interpolation. + let frame = startFrame; + let index = 1; + for (let k = start + 1; k < result.length; ++k) { + let s0 = rampBuffer[index]; + let s1 = rampBuffer[index - 1]; + let delta = frame - k; + let s = s1 - delta * (s0 - s1); + result[k] = s; + ++frame; + ++index; + } + + return result; + } + + function verifyGrain(should, output, options) { + let {startGrain, endGrain, sourceName, outputName} = options; + let expected = new Float32Array(output.length); + // Compute the expected output for output and verify the actual + // output matches. + expected.fill(1); + for (let k = 0; k <= Math.floor(startGrain); ++k) { + expected[k] = 0; + } + for (let k = Math.ceil(endGrain); k < expected.length; ++k) { + expected[k] = 0; + } + + should(startGrain, `${sourceName} grain start`).beEqualTo(startGrain); + should(endGrain - startGrain, `${sourceName} grain duration`) + .beEqualTo(endGrain - startGrain); + should(endGrain, `${sourceName} grain end`).beEqualTo(endGrain); + should(output, outputName).beEqualToArray(expected); + should( + output[Math.floor(startGrain)], + `${outputName}[${Math.floor(startGrain)}]`) + .beEqualTo(0); + should( + output[1 + Math.floor(startGrain)], + `${outputName}[${1 + Math.floor(startGrain)}]`) + .notBeEqualTo(0); + should( + output[Math.floor(endGrain)], + `${outputName}[${Math.floor(endGrain)}]`) + .notBeEqualTo(0); + should( + output[1 + Math.floor(endGrain)], + `${outputName}[${1 + Math.floor(endGrain)}]`) + .beEqualTo(0); + } + </script> + </body> +</html> |