The Tor Browser: content/media/webaudio/blink/HRTFPanner.cpp@6474c204b198 (annotated)

content/media/webaudio/blink/HRTFPanner.cpp@6474c204b198 (annotated)

content/media/webaudio/blink/HRTFPanner.cpp

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /*
  * Copyright (C) 2010, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 #include "HRTFPanner.h"
 #include "HRTFDatabaseLoader.h"
 #include "FFTConvolver.h"
 #include "HRTFDatabase.h"
 using namespace std;
 using namespace mozilla;
 using dom::ChannelInterpretation;
 namespace WebCore {
 // The value of 2 milliseconds is larger than the largest delay which exists in any HRTFKernel from the default HRTFDatabase (0.0136 seconds).
 // We ASSERT the delay values used in process() with this value.
 const double MaxDelayTimeSeconds = 0.002;
 const int UninitializedAzimuth = -1;
 const unsigned RenderingQuantum = WEBAUDIO_BLOCK_SIZE;
 HRTFPanner::HRTFPanner(float sampleRate, mozilla::TemporaryRef<HRTFDatabaseLoader> databaseLoader)
     : m_databaseLoader(databaseLoader)
     , m_sampleRate(sampleRate)
     , m_crossfadeSelection(CrossfadeSelection1)
     , m_azimuthIndex1(UninitializedAzimuth)
     , m_azimuthIndex2(UninitializedAzimuth)
     // m_elevation1 and m_elevation2 are initialized in pan()
     , m_crossfadeX(0)
     , m_crossfadeIncr(0)
     , m_convolverL1(HRTFElevation::fftSizeForSampleRate(sampleRate))
     , m_convolverR1(m_convolverL1.fftSize())
     , m_convolverL2(m_convolverL1.fftSize())
     , m_convolverR2(m_convolverL1.fftSize())
     , m_delayLine(MaxDelayTimeSeconds * sampleRate, 1.0)
 {
     MOZ_ASSERT(m_databaseLoader);
     MOZ_COUNT_CTOR(HRTFPanner);
     m_tempL1.SetLength(RenderingQuantum);
     m_tempR1.SetLength(RenderingQuantum);
     m_tempL2.SetLength(RenderingQuantum);
     m_tempR2.SetLength(RenderingQuantum);
 }
 HRTFPanner::~HRTFPanner()
 {
     MOZ_COUNT_DTOR(HRTFPanner);
 }
 size_t HRTFPanner::sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
 {
     size_t amount = aMallocSizeOf(this);
     if (m_databaseLoader) {
         m_databaseLoader->sizeOfIncludingThis(aMallocSizeOf);
     }
     amount += m_convolverL1.sizeOfExcludingThis(aMallocSizeOf);
     amount += m_convolverR1.sizeOfExcludingThis(aMallocSizeOf);
     amount += m_convolverL2.sizeOfExcludingThis(aMallocSizeOf);
     amount += m_convolverR2.sizeOfExcludingThis(aMallocSizeOf);
     amount += m_delayLine.SizeOfExcludingThis(aMallocSizeOf);
     amount += m_tempL1.SizeOfExcludingThis(aMallocSizeOf);
     amount += m_tempL2.SizeOfExcludingThis(aMallocSizeOf);
     amount += m_tempR1.SizeOfExcludingThis(aMallocSizeOf);
     amount += m_tempR2.SizeOfExcludingThis(aMallocSizeOf);
     return amount;
 }
 void HRTFPanner::reset()
 {
     m_azimuthIndex1 = UninitializedAzimuth;
     m_azimuthIndex2 = UninitializedAzimuth;
     // m_elevation1 and m_elevation2 are initialized in pan()
     m_crossfadeSelection = CrossfadeSelection1;
     m_crossfadeX = 0.0f;
     m_crossfadeIncr = 0.0f;
     m_convolverL1.reset();
     m_convolverR1.reset();
     m_convolverL2.reset();
     m_convolverR2.reset();
     m_delayLine.Reset();
 }
 int HRTFPanner::calculateDesiredAzimuthIndexAndBlend(double azimuth, double& azimuthBlend)
 {
     // Convert the azimuth angle from the range -180 -> +180 into the range 0 -> 360.
     // The azimuth index may then be calculated from this positive value.
     if (azimuth < 0)
         azimuth += 360.0;
     HRTFDatabase* database = m_databaseLoader->database();
     MOZ_ASSERT(database);
     int numberOfAzimuths = database->numberOfAzimuths();
     const double angleBetweenAzimuths = 360.0 / numberOfAzimuths;
     // Calculate the azimuth index and the blend (0 -> 1) for interpolation.
     double desiredAzimuthIndexFloat = azimuth / angleBetweenAzimuths;
     int desiredAzimuthIndex = static_cast<int>(desiredAzimuthIndexFloat);
     azimuthBlend = desiredAzimuthIndexFloat - static_cast<double>(desiredAzimuthIndex);
     // We don't immediately start using this azimuth index, but instead approach this index from the last index we rendered at.
     // This minimizes the clicks and graininess for moving sources which occur otherwise.
     desiredAzimuthIndex = max(0, desiredAzimuthIndex);
     desiredAzimuthIndex = min(numberOfAzimuths - 1, desiredAzimuthIndex);
     return desiredAzimuthIndex;
 }
 void HRTFPanner::pan(double desiredAzimuth, double elevation, const AudioChunk* inputBus, AudioChunk* outputBus)
 {
 #ifdef DEBUG
     unsigned numInputChannels =
         inputBus->IsNull() ? 0 : inputBus->mChannelData.Length();
     MOZ_ASSERT(numInputChannels <= 2);
     MOZ_ASSERT(inputBus->mDuration == WEBAUDIO_BLOCK_SIZE);
 #endif
     bool isOutputGood = outputBus && outputBus->mChannelData.Length() == 2 && outputBus->mDuration == WEBAUDIO_BLOCK_SIZE;
     MOZ_ASSERT(isOutputGood);
     if (!isOutputGood) {
         if (outputBus)
             outputBus->SetNull(outputBus->mDuration);
         return;
     }
     HRTFDatabase* database = m_databaseLoader->database();
     if (!database) { // not yet loaded
         outputBus->SetNull(outputBus->mDuration);
         return;
     }
     // IRCAM HRTF azimuths values from the loaded database is reversed from the panner's notion of azimuth.
     double azimuth = -desiredAzimuth;
     bool isAzimuthGood = azimuth >= -180.0 && azimuth <= 180.0;
     MOZ_ASSERT(isAzimuthGood);
     if (!isAzimuthGood) {
         outputBus->SetNull(outputBus->mDuration);
         return;
     }
     // Normally, we'll just be dealing with mono sources.
     // If we have a stereo input, implement stereo panning with left source processed by left HRTF, and right source by right HRTF.
     // Get destination pointers.
     float* destinationL =
         static_cast<float*>(const_cast<void*>(outputBus->mChannelData[0]));
     float* destinationR =
         static_cast<float*>(const_cast<void*>(outputBus->mChannelData[1]));
     double azimuthBlend;
     int desiredAzimuthIndex = calculateDesiredAzimuthIndexAndBlend(azimuth, azimuthBlend);
     // Initially snap azimuth and elevation values to first values encountered.
     if (m_azimuthIndex1 == UninitializedAzimuth) {
         m_azimuthIndex1 = desiredAzimuthIndex;
         m_elevation1 = elevation;
     }
     if (m_azimuthIndex2 == UninitializedAzimuth) {
         m_azimuthIndex2 = desiredAzimuthIndex;
         m_elevation2 = elevation;
     }
     // Cross-fade / transition over a period of around 45 milliseconds.
     // This is an empirical value tuned to be a reasonable trade-off between
     // smoothness and speed.
     const double fadeFrames = sampleRate() <= 48000 ? 2048 : 4096;
     // Check for azimuth and elevation changes, initiating a cross-fade if needed.
     if (!m_crossfadeX && m_crossfadeSelection == CrossfadeSelection1) {
         if (desiredAzimuthIndex != m_azimuthIndex1 || elevation != m_elevation1) {
             // Cross-fade from 1 -> 2
             m_crossfadeIncr = 1 / fadeFrames;
             m_azimuthIndex2 = desiredAzimuthIndex;
             m_elevation2 = elevation;
         }
     }
     if (m_crossfadeX == 1 && m_crossfadeSelection == CrossfadeSelection2) {
         if (desiredAzimuthIndex != m_azimuthIndex2 || elevation != m_elevation2) {
             // Cross-fade from 2 -> 1
             m_crossfadeIncr = -1 / fadeFrames;
             m_azimuthIndex1 = desiredAzimuthIndex;
             m_elevation1 = elevation;
         }
     }
     // Get the HRTFKernels and interpolated delays.
     HRTFKernel* kernelL1;
     HRTFKernel* kernelR1;
     HRTFKernel* kernelL2;
     HRTFKernel* kernelR2;
     double frameDelayL1;
     double frameDelayR1;
     double frameDelayL2;
     double frameDelayR2;
     database->getKernelsFromAzimuthElevation(azimuthBlend, m_azimuthIndex1, m_elevation1, kernelL1, kernelR1, frameDelayL1, frameDelayR1);
     database->getKernelsFromAzimuthElevation(azimuthBlend, m_azimuthIndex2, m_elevation2, kernelL2, kernelR2, frameDelayL2, frameDelayR2);
     bool areKernelsGood = kernelL1 && kernelR1 && kernelL2 && kernelR2;
     MOZ_ASSERT(areKernelsGood);
     if (!areKernelsGood) {
         outputBus->SetNull(outputBus->mDuration);
         return;
     }
     MOZ_ASSERT(frameDelayL1 / sampleRate() < MaxDelayTimeSeconds && frameDelayR1 / sampleRate() < MaxDelayTimeSeconds);
     MOZ_ASSERT(frameDelayL2 / sampleRate() < MaxDelayTimeSeconds && frameDelayR2 / sampleRate() < MaxDelayTimeSeconds);
     // Crossfade inter-aural delays based on transitions.
     double frameDelaysL[WEBAUDIO_BLOCK_SIZE];
     double frameDelaysR[WEBAUDIO_BLOCK_SIZE];
     {
       float x = m_crossfadeX;
       float incr = m_crossfadeIncr;
       for (unsigned i = 0; i < WEBAUDIO_BLOCK_SIZE; ++i) {
         frameDelaysL[i] = (1 - x) * frameDelayL1 + x * frameDelayL2;
         frameDelaysR[i] = (1 - x) * frameDelayR1 + x * frameDelayR2;
         x += incr;
       }
     }
     // First run through delay lines for inter-aural time difference.
     m_delayLine.Write(*inputBus);
     // "Speakers" means a mono input is read into both outputs (with possibly
     // different delays).
     m_delayLine.ReadChannel(frameDelaysL, outputBus, 0,
                             ChannelInterpretation::Speakers);
     m_delayLine.ReadChannel(frameDelaysR, outputBus, 1,
                             ChannelInterpretation::Speakers);
     m_delayLine.NextBlock();
     bool needsCrossfading = m_crossfadeIncr;
     // Have the convolvers render directly to the final destination if we're not cross-fading.
     float* convolutionDestinationL1 = needsCrossfading ? m_tempL1.Elements() : destinationL;
     float* convolutionDestinationR1 = needsCrossfading ? m_tempR1.Elements() : destinationR;
     float* convolutionDestinationL2 = needsCrossfading ? m_tempL2.Elements() : destinationL;
     float* convolutionDestinationR2 = needsCrossfading ? m_tempR2.Elements() : destinationR;
     // Now do the convolutions.
     // Note that we avoid doing convolutions on both sets of convolvers if we're not currently cross-fading.
     if (m_crossfadeSelection == CrossfadeSelection1 || needsCrossfading) {
         m_convolverL1.process(kernelL1->fftFrame(), destinationL, convolutionDestinationL1, WEBAUDIO_BLOCK_SIZE);
         m_convolverR1.process(kernelR1->fftFrame(), destinationR, convolutionDestinationR1, WEBAUDIO_BLOCK_SIZE);
     }
     if (m_crossfadeSelection == CrossfadeSelection2 || needsCrossfading) {
         m_convolverL2.process(kernelL2->fftFrame(), destinationL, convolutionDestinationL2, WEBAUDIO_BLOCK_SIZE);
         m_convolverR2.process(kernelR2->fftFrame(), destinationR, convolutionDestinationR2, WEBAUDIO_BLOCK_SIZE);
     }
     if (needsCrossfading) {
         // Apply linear cross-fade.
         float x = m_crossfadeX;
         float incr = m_crossfadeIncr;
         for (unsigned i = 0; i < WEBAUDIO_BLOCK_SIZE; ++i) {
             destinationL[i] = (1 - x) * convolutionDestinationL1[i] + x * convolutionDestinationL2[i];
             destinationR[i] = (1 - x) * convolutionDestinationR1[i] + x * convolutionDestinationR2[i];
             x += incr;
         }
         // Update cross-fade value from local.
         m_crossfadeX = x;
         if (m_crossfadeIncr > 0 && fabs(m_crossfadeX - 1) < m_crossfadeIncr) {
             // We've fully made the crossfade transition from 1 -> 2.
             m_crossfadeSelection = CrossfadeSelection2;
             m_crossfadeX = 1;
             m_crossfadeIncr = 0;
         } else if (m_crossfadeIncr < 0 && fabs(m_crossfadeX) < -m_crossfadeIncr) {
             // We've fully made the crossfade transition from 2 -> 1.
             m_crossfadeSelection = CrossfadeSelection1;
             m_crossfadeX = 0;
             m_crossfadeIncr = 0;
         }
     }
 }
 int HRTFPanner::maxTailFrames() const
 {
     // Although the ideal tail time would be the length of the impulse
     // response, there is additional tail time from the approximations in the
     // implementation.  Because HRTFPanner is implemented with a DelayKernel
     // and a FFTConvolver, the tailTime of the HRTFPanner is the sum of the
     // tailTime of the DelayKernel and the tailTime of the FFTConvolver.
     // The FFTConvolver has a tail time of fftSize(), including latency of
     // fftSize()/2.
     return m_delayLine.MaxDelayTicks() + fftSize();
 }
 } // namespace WebCore

The Tor Browser / annotate

content/media/webaudio/blink/HRTFPanner.cpp@6474c204b198 (annotated)

content/media/webaudio/blink/HRTFPanner.cpp