| <!doctype html> |
| <html> |
| <head> |
| <title>Test ConstantSourceNode Output</title> |
| <script src="../resources/testharness.js"></script> |
| <script src="../resources/testharnessreport.js"></script> |
| <script src="resources/audio-testing.js"></script> |
| <script src="resources/audioparam-testing.js"></script> |
| </head> |
| |
| <body> |
| <script> |
| var sampleRate = 48000; |
| var renderDuration = 0.125; |
| var renderFrames = sampleRate * renderDuration; |
| |
| var audit = Audit.createTaskRunner(); |
| |
| audit.defineTask("constant source", function (taskDone) { |
| // Verify a constant source outputs the correct (fixed) constant. |
| var context = new OfflineAudioContext(1, renderFrames, sampleRate); |
| var node = new ConstantSourceNode(context, { |
| offset: 0.5 |
| }); |
| node.connect(context.destination); |
| node.start(); |
| |
| context.startRendering().then(function (buffer) { |
| var actual = buffer.getChannelData(0); |
| var expected = new Float32Array(actual.length); |
| expected.fill(node.offset.value); |
| |
| Should("ConstantSourceNode({offset: 0.5})", actual) |
| .beEqualToArray(expected); |
| }).then(taskDone); |
| }); |
| |
| audit.defineTask("start/stop", function (taskDone) { |
| // Verify a constant source starts and stops at the correct time and has |
| // the correct (fixed) value. |
| var context = new OfflineAudioContext(1, renderFrames, sampleRate); |
| var node = new ConstantSourceNode(context, { |
| offset: 1 |
| }); |
| node.connect(context.destination); |
| |
| var startFrame = 10; |
| var stopFrame = 300; |
| |
| node.start(startFrame / context.sampleRate); |
| node.stop(stopFrame / context.sampleRate); |
| |
| context.startRendering().then(function (buffer) { |
| var actual = buffer.getChannelData(0); |
| var expected = new Float32Array(actual.length); |
| // The expected output is all 1s from start to stop time. |
| expected.fill(0); |
| |
| for (var k = startFrame; k < stopFrame; ++k) { |
| expected[k] = node.offset.value; |
| } |
| |
| var success = Should("ConstantSourceNode frames [0, " + |
| startFrame + ")", |
| actual.slice(0, startFrame)) |
| .beConstantValueOf(0); |
| |
| success = Should("ConstantSourceNode frames [" + startFrame + |
| ", " + |
| stopFrame + ")", |
| actual.slice(startFrame, stopFrame)) |
| .beConstantValueOf(1) && success; |
| |
| success = Should("ConstantSourceNode frames [" + stopFrame + ", " + |
| renderFrames + ")", |
| actual.slice(stopFrame)) |
| .beConstantValueOf(0) && success; |
| |
| Should("ConstantSourceNode started and stopped", success) |
| .summarize( |
| "at the correct times with the correct values", |
| "with the incorrect times or values"); |
| }).then(taskDone); |
| |
| }); |
| |
| audit.defineTask("basic automation", function (taskDone) { |
| // Verify that automation works as expected. |
| var context = new OfflineAudioContext(1, renderFrames, sampleRate); |
| var source = context.createConstantSource(); |
| source.connect(context.destination); |
| |
| var rampEndTime = renderDuration / 2; |
| source.offset.setValueAtTime(0.5, 0); |
| source.offset.linearRampToValueAtTime(1, rampEndTime); |
| |
| source.start(); |
| |
| context.startRendering() |
| .then(function (buffer) { |
| var actual = buffer.getChannelData(0); |
| var expected = createLinearRampArray(0, rampEndTime, 0.5, 1, |
| context.sampleRate); |
| |
| var rampEndFrame = Math.ceil(rampEndTime * context.sampleRate); |
| var success = Should("ConstantSourceNode.linearRamp(1, 0.5)", |
| actual.slice(0, rampEndFrame)) |
| .beCloseToArray(expected, { |
| // Experimentally determined threshold.. |
| relativeThreshold: 7.1610e-7 |
| }); |
| |
| success = Should("ConstantSourceNode after ramp", |
| actual.slice(rampEndFrame)) |
| .beConstantValueOf(1) && success; |
| |
| Should("ConstantSourceNode automation", success) |
| .summarize( |
| "produced the correct values", |
| "did not produce the correct values"); |
| }) |
| .then(taskDone); |
| }); |
| |
| audit.defineTask("connected audioparam", function (taskDone) { |
| // Verify the constant source output with connected AudioParam produces |
| // the correct output. |
| var context = new OfflineAudioContext(2, renderFrames, sampleRate) |
| context.destination.channelInterpretation = "discrete"; |
| var source = new ConstantSourceNode(context, { |
| offset: 1 |
| }); |
| var osc = context.createOscillator(); |
| var merger = context.createChannelMerger(2); |
| merger.connect(context.destination); |
| |
| source.connect(merger, 0, 0); |
| osc.connect(merger, 0, 1); |
| osc.connect(source.offset); |
| |
| osc.start(); |
| var sourceStartFrame = 10; |
| source.start(sourceStartFrame / context.sampleRate); |
| |
| context.startRendering() |
| .then(function (buffer) { |
| // Channel 0 and 1 should be identical, except channel 0 (the |
| // source) is silent at the beginning. |
| var actual = buffer.getChannelData(0); |
| var expected = buffer.getChannelData(1); |
| // The expected output should be oscillator + 1 because offset |
| // is 1. |
| expected = expected.map(x => 1 + x); |
| var success = true; |
| |
| // The initial part of the output should be silent because the |
| // source node hasn't started yet. |
| success = Should("ConstantSourceNode frames [0, " + |
| sourceStartFrame + ")", actual.slice(0, sourceStartFrame) |
| ) |
| .beConstantValueOf(0); |
| // The rest of the output should be the same as the oscillator (in |
| // channel 1) |
| success = Should("ConstantSourceNode frames [" + |
| sourceStartFrame + ", " + renderFrames + ")", |
| actual.slice(sourceStartFrame)) |
| .beCloseToArray(expected.slice(sourceStartFrame), 0); |
| |
| Should("ConstantSourceNode with connected AudioParam", |
| success) |
| .summarize( |
| "had the expected output", |
| "did not have the expected output"); |
| }) |
| .then(taskDone); |
| }); |
| |
| audit.runTasks(); |
| </script> |
| </body> |
| </html> |
