The Tor Browser: content/media/webaudio/test/blink/audio-testing.js@b8a032363ba2 (annotated)

content/media/webaudio/test/blink/audio-testing.js@b8a032363ba2 (annotated)

content/media/webaudio/test/blink/audio-testing.js

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 if (window.testRunner)
     testRunner.overridePreference("WebKitWebAudioEnabled", "1");
 function writeString(s, a, offset) {
     for (var i = 0; i < s.length; ++i) {
         a[offset + i] = s.charCodeAt(i);
     }
 }
 function writeInt16(n, a, offset) {
     n = Math.floor(n);
     var b1 = n & 255;
     var b2 = (n >> 8) & 255;
     a[offset + 0] = b1;
     a[offset + 1] = b2;
 }
 function writeInt32(n, a, offset) {
     n = Math.floor(n);
     var b1 = n & 255;
     var b2 = (n >> 8) & 255;
     var b3 = (n >> 16) & 255;
     var b4 = (n >> 24) & 255;
     a[offset + 0] = b1;
     a[offset + 1] = b2;
     a[offset + 2] = b3;
     a[offset + 3] = b4;
 }
 function writeAudioBuffer(audioBuffer, a, offset) {
     var n = audioBuffer.length;
     var channels = audioBuffer.numberOfChannels;
     for (var i = 0; i < n; ++i) {
         for (var k = 0; k < channels; ++k) {
             var buffer = audioBuffer.getChannelData(k);
             var sample = buffer[i] * 32768.0;
             // Clip samples to the limitations of 16-bit.
             // If we don't do this then we'll get nasty wrap-around distortion.
             if (sample < -32768)
                 sample = -32768;
             if (sample > 32767)
                 sample = 32767;
             writeInt16(sample, a, offset);
             offset += 2;
         }
     }
 }
 function createWaveFileData(audioBuffer) {
     var frameLength = audioBuffer.length;
     var numberOfChannels = audioBuffer.numberOfChannels;
     var sampleRate = audioBuffer.sampleRate;
     var bitsPerSample = 16;
     var byteRate = sampleRate * numberOfChannels * bitsPerSample/8;
     var blockAlign = numberOfChannels * bitsPerSample/8;
     var wavDataByteLength = frameLength * numberOfChannels * 2; // 16-bit audio
     var headerByteLength = 44;
     var totalLength = headerByteLength + wavDataByteLength;
     var waveFileData = new Uint8Array(totalLength);
     var subChunk1Size = 16; // for linear PCM
     var subChunk2Size = wavDataByteLength;
     var chunkSize = 4 + (8 + subChunk1Size) + (8 + subChunk2Size);
     writeString("RIFF", waveFileData, 0);
     writeInt32(chunkSize, waveFileData, 4);
     writeString("WAVE", waveFileData, 8);
     writeString("fmt ", waveFileData, 12);
     writeInt32(subChunk1Size, waveFileData, 16);      // SubChunk1Size (4)
     writeInt16(1, waveFileData, 20);                  // AudioFormat (2)
     writeInt16(numberOfChannels, waveFileData, 22);   // NumChannels (2)
     writeInt32(sampleRate, waveFileData, 24);         // SampleRate (4)
     writeInt32(byteRate, waveFileData, 28);           // ByteRate (4)
     writeInt16(blockAlign, waveFileData, 32);         // BlockAlign (2)
     writeInt32(bitsPerSample, waveFileData, 34);      // BitsPerSample (4)
     writeString("data", waveFileData, 36);
     writeInt32(subChunk2Size, waveFileData, 40);      // SubChunk2Size (4)
     // Write actual audio data starting at offset 44.
     writeAudioBuffer(audioBuffer, waveFileData, 44);
     return waveFileData;
 }
 function createAudioData(audioBuffer) {
     return createWaveFileData(audioBuffer);
 }
 function finishAudioTest(event) {
     var audioData = createAudioData(event.renderedBuffer);
     testRunner.setAudioData(audioData);
     testRunner.notifyDone();
 }
 // Create an impulse in a buffer of length sampleFrameLength
 function createImpulseBuffer(context, sampleFrameLength) {
     var audioBuffer = context.createBuffer(1, sampleFrameLength, context.sampleRate);
     var n = audioBuffer.length;
     var dataL = audioBuffer.getChannelData(0);
     for (var k = 0; k < n; ++k) {
         dataL[k] = 0;
     }
     dataL[0] = 1;
     return audioBuffer;
 }
 // Create a buffer of the given length with a linear ramp having values 0 <= x < 1.
 function createLinearRampBuffer(context, sampleFrameLength) {
     var audioBuffer = context.createBuffer(1, sampleFrameLength, context.sampleRate);
     var n = audioBuffer.length;
     var dataL = audioBuffer.getChannelData(0);
     for (var i = 0; i < n; ++i)
         dataL[i] = i / n;
     return audioBuffer;
 }
 // Create a buffer of the given length having a constant value.
 function createConstantBuffer(context, sampleFrameLength, constantValue) {
     var audioBuffer = context.createBuffer(1, sampleFrameLength, context.sampleRate);
     var n = audioBuffer.length;
     var dataL = audioBuffer.getChannelData(0);
     for (var i = 0; i < n; ++i)
         dataL[i] = constantValue;
     return audioBuffer;
 }
 // Create a stereo impulse in a buffer of length sampleFrameLength
 function createStereoImpulseBuffer(context, sampleFrameLength) {
     var audioBuffer = context.createBuffer(2, sampleFrameLength, context.sampleRate);
     var n = audioBuffer.length;
     var dataL = audioBuffer.getChannelData(0);
     var dataR = audioBuffer.getChannelData(1);
     for (var k = 0; k < n; ++k) {
         dataL[k] = 0;
         dataR[k] = 0;
     }
     dataL[0] = 1;
     dataR[0] = 1;
     return audioBuffer;
 }
 // Convert time (in seconds) to sample frames.
 function timeToSampleFrame(time, sampleRate) {
     return Math.floor(0.5 + time * sampleRate);
 }
 // Compute the number of sample frames consumed by start with
 // the specified |grainOffset|, |duration|, and |sampleRate|.
 function grainLengthInSampleFrames(grainOffset, duration, sampleRate) {
     var startFrame = timeToSampleFrame(grainOffset, sampleRate);
     var endFrame = timeToSampleFrame(grainOffset + duration, sampleRate);
     return endFrame - startFrame;
 }
 // True if the number is not an infinity or NaN
 function isValidNumber(x) {
     return !isNaN(x) && (x != Infinity) && (x != -Infinity);
 }
 function shouldThrowTypeError(func, text) {
     var ok = false;
     try {
         func();
     } catch (e) {
         if (e instanceof TypeError) {
             ok = true;
         }
     }
     if (ok) {
         testPassed(text + " threw TypeError.");
     } else {
         testFailed(text + " should throw TypeError.");
     }
 }