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