| <!DOCTYPE html> |
| |
| <!-- |
| Tests that we are able to schedule a series of notes to playback with sample-accuracy. |
| We use an impulse so we can tell exactly where the rendering is happening. |
| --> |
| |
| <html> |
| <head> |
| <script src="../resources/js-test.js"></script> |
| <script type="text/javascript" src="resources/audio-testing.js"></script> |
| <script type="text/javascript" src="resources/buffer-loader.js"></script> |
| </head> |
| |
| <body> |
| |
| <div id="description"></div> |
| <div id="console"></div> |
| |
| <script> |
| description("Tests sample-accurate scheduling."); |
| |
| var sampleRate = 44100.0; |
| var lengthInSeconds = 4; |
| |
| var context = 0; |
| var bufferLoader = 0; |
| var impulse; |
| |
| // See if we can render at exactly these sample offsets. |
| var sampleOffsets = [0, 3, 512, 517, 1000, 1005, 20000, 21234, 37590]; |
| |
| function createImpulse() { |
| // An impulse has a value of 1 at time 0, and is otherwise 0. |
| impulse = context.createBuffer(2, 512, sampleRate); |
| var sampleDataL = impulse.getChannelData(0); |
| var sampleDataR = impulse.getChannelData(1); |
| sampleDataL[0] = 1.0; |
| sampleDataR[0] = 1.0; |
| } |
| |
| function playNote(time) { |
| var bufferSource = context.createBufferSource(); |
| bufferSource.buffer = impulse; |
| bufferSource.connect(context.destination); |
| bufferSource.start(time); |
| } |
| |
| function checkSampleAccuracy(event) { |
| var buffer = event.renderedBuffer; |
| |
| var bufferDataL = buffer.getChannelData(0); |
| var bufferDataR = buffer.getChannelData(1); |
| |
| var success = true; |
| var impulseCount = 0; |
| var badOffsetCount = false; |
| |
| // Go through every sample and make sure it's 0, except at positions in sampleOffsets. |
| for (var i = 0; i < buffer.length; ++i) { |
| // Make sure left == right |
| if (bufferDataL[i] != bufferDataR[i]) { |
| testFailed("Rendered buffer left and right channels are not identical."); |
| success = false; |
| break; |
| } |
| |
| if (bufferDataL[i] != 0) { |
| // Make sure this index is in sampleOffsets |
| var found = false; |
| for (var j = 0; j < sampleOffsets.length; ++j) { |
| if (sampleOffsets[j] == i) { |
| found = true; |
| break; |
| } |
| } |
| ++impulseCount; |
| if (!found) { |
| testFailed("Non-zero sample found at sample offset " + i); |
| success = false; |
| ++badOffsetCount; |
| } |
| } |
| } |
| |
| if (impulseCount == sampleOffsets.length) { |
| if (badOffsetCount == 0) { |
| testPassed("Expected number of events found."); |
| } else { |
| testFailed("Expected number of events found, but " + badOffsetCount + " are at incorrect offsets."); |
| success = false; |
| } |
| } else { |
| testFailed("Expected " + sampleOffsets.length + " impulses but only found " + impulseCount); |
| success = false; |
| } |
| |
| if (success) { |
| testPassed("All events rendered with sample-accuracy."); |
| } else { |
| testFailed("Events NOT rendered with sample-accuracy."); |
| } |
| |
| finishJSTest(); |
| } |
| |
| function runTest() { |
| window.jsTestIsAsync = true; |
| |
| // Create offline audio context. |
| context = new webkitOfflineAudioContext(2, sampleRate * lengthInSeconds, sampleRate); |
| createImpulse(); |
| |
| for (var i = 0; i < sampleOffsets.length; ++i) { |
| var timeInSeconds = sampleOffsets[i] / sampleRate; |
| playNote(timeInSeconds); |
| } |
| |
| context.oncomplete = checkSampleAccuracy; |
| context.startRendering(); |
| } |
| |
| runTest(); |
| |
| </script> |
| </body> |
| </html> |
