The Tor Browser: content/media/webaudio/blink/DynamicsCompressor.cpp@44a2da4a2ab2

Replace accessor implementation with direct member state manipulation, by
request https://trac.torproject.org/projects/tor/ticket/9701#comment:32

     1 /*

     2  * Copyright (C) 2011 Google Inc. All rights reserved.

     3  *

     4  * Redistribution and use in source and binary forms, with or without

     5  * modification, are permitted provided that the following conditions

     6  * are met:

     7  *

     8  * 1.  Redistributions of source code must retain the above copyright

     9  *     notice, this list of conditions and the following disclaimer.

    10  * 2.  Redistributions in binary form must reproduce the above copyright

    11  *     notice, this list of conditions and the following disclaimer in the

    12  *     documentation and/or other materials provided with the distribution.

    13  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of

    14  *     its contributors may be used to endorse or promote products derived

    15  *     from this software without specific prior written permission.

    16  *

    17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY

    18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

    19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

    20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY

    21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

    22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

    23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND

    24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

    25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

    26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

    27  */

    29 #include "DynamicsCompressor.h"

    30 #include "AudioSegment.h"

    32 #include <cmath>

    33 #include "AudioNodeEngine.h"

    34 #include "nsDebug.h"

    36 using mozilla::WEBAUDIO_BLOCK_SIZE;

    37 using mozilla::AudioBlockCopyChannelWithScale;

    39 namespace WebCore {

    41 DynamicsCompressor::DynamicsCompressor(float sampleRate, unsigned numberOfChannels)

    42     : m_numberOfChannels(numberOfChannels)

    43     , m_sampleRate(sampleRate)

    44     , m_compressor(sampleRate, numberOfChannels)

    45 {

    46     // Uninitialized state - for parameter recalculation.

    47     m_lastFilterStageRatio = -1;

    48     m_lastAnchor = -1;

    49     m_lastFilterStageGain = -1;

    51     setNumberOfChannels(numberOfChannels);

    52     initializeParameters();

    53 }

    55 size_t DynamicsCompressor::sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const

    56 {

    57     size_t amount = aMallocSizeOf(this);

    58     amount += m_preFilterPacks.SizeOfExcludingThis(aMallocSizeOf);

    59     for (size_t i = 0; i < m_preFilterPacks.Length(); i++) {

    60         if (m_preFilterPacks[i]) {

    61             amount += m_preFilterPacks[i]->sizeOfIncludingThis(aMallocSizeOf);

    62         }

    63     }

    65     amount += m_postFilterPacks.SizeOfExcludingThis(aMallocSizeOf);

    66     for (size_t i = 0; i < m_postFilterPacks.Length(); i++) {

    67         if (m_postFilterPacks[i]) {

    68             amount += m_postFilterPacks[i]->sizeOfIncludingThis(aMallocSizeOf);

    69         }

    70     }

    72     amount += m_sourceChannels.SizeOfExcludingThis(aMallocSizeOf);

    73     amount += m_destinationChannels.SizeOfExcludingThis(aMallocSizeOf);

    74     amount += m_compressor.sizeOfExcludingThis(aMallocSizeOf);

    75     return amount;

    76 }

    78 void DynamicsCompressor::setParameterValue(unsigned parameterID, float value)

    79 {

    80     MOZ_ASSERT(parameterID < ParamLast);

    81     if (parameterID < ParamLast)

    82         m_parameters[parameterID] = value;

    83 }

    85 void DynamicsCompressor::initializeParameters()

    86 {

    87     // Initializes compressor to default values.

    89     m_parameters[ParamThreshold] = -24; // dB

    90     m_parameters[ParamKnee] = 30; // dB

    91     m_parameters[ParamRatio] = 12; // unit-less

    92     m_parameters[ParamAttack] = 0.003f; // seconds

    93     m_parameters[ParamRelease] = 0.250f; // seconds

    94     m_parameters[ParamPreDelay] = 0.006f; // seconds

    96     // Release zone values 0 -> 1.

    97     m_parameters[ParamReleaseZone1] = 0.09f;

    98     m_parameters[ParamReleaseZone2] = 0.16f;

    99     m_parameters[ParamReleaseZone3] = 0.42f;

   100     m_parameters[ParamReleaseZone4] = 0.98f;

   102     m_parameters[ParamFilterStageGain] = 4.4f; // dB

   103     m_parameters[ParamFilterStageRatio] = 2;

   104     m_parameters[ParamFilterAnchor] = 15000 / nyquist();

   106     m_parameters[ParamPostGain] = 0; // dB

   107     m_parameters[ParamReduction] = 0; // dB

   109     // Linear crossfade (0 -> 1).

   110     m_parameters[ParamEffectBlend] = 1;

   111 }

   113 float DynamicsCompressor::parameterValue(unsigned parameterID)

   114 {

   115     MOZ_ASSERT(parameterID < ParamLast);

   116     return m_parameters[parameterID];

   117 }

   119 void DynamicsCompressor::setEmphasisStageParameters(unsigned stageIndex, float gain, float normalizedFrequency /* 0 -> 1 */)

   120 {

   121     float gk = 1 - gain / 20;

   122     float f1 = normalizedFrequency * gk;

   123     float f2 = normalizedFrequency / gk;

   124     float r1 = expf(-f1 * M_PI);

   125     float r2 = expf(-f2 * M_PI);

   127     MOZ_ASSERT(m_numberOfChannels == m_preFilterPacks.Length());

   129     for (unsigned i = 0; i < m_numberOfChannels; ++i) {

   130         // Set pre-filter zero and pole to create an emphasis filter.

   131         ZeroPole& preFilter = m_preFilterPacks[i]->filters[stageIndex];

   132         preFilter.setZero(r1);

   133         preFilter.setPole(r2);

   135         // Set post-filter with zero and pole reversed to create the de-emphasis filter.

   136         // If there were no compressor kernel in between, they would cancel each other out (allpass filter).

   137         ZeroPole& postFilter = m_postFilterPacks[i]->filters[stageIndex];

   138         postFilter.setZero(r2);

   139         postFilter.setPole(r1);

   140     }

   141 }

   143 void DynamicsCompressor::setEmphasisParameters(float gain, float anchorFreq, float filterStageRatio)

   144 {

   145     setEmphasisStageParameters(0, gain, anchorFreq);

   146     setEmphasisStageParameters(1, gain, anchorFreq / filterStageRatio);

   147     setEmphasisStageParameters(2, gain, anchorFreq / (filterStageRatio * filterStageRatio));

   148     setEmphasisStageParameters(3, gain, anchorFreq / (filterStageRatio * filterStageRatio * filterStageRatio));

   149 }

   151 void DynamicsCompressor::process(const AudioChunk* sourceChunk, AudioChunk* destinationChunk, unsigned framesToProcess)

   152 {

   153     // Though numberOfChannels is retrived from destinationBus, we still name it numberOfChannels instead of numberOfDestinationChannels.

   154     // It's because we internally match sourceChannels's size to destinationBus by channel up/down mix. Thus we need numberOfChannels

   155     // to do the loop work for both m_sourceChannels and m_destinationChannels.

   157     unsigned numberOfChannels = destinationChunk->mChannelData.Length();

   158     unsigned numberOfSourceChannels = sourceChunk->mChannelData.Length();

   160     MOZ_ASSERT(numberOfChannels == m_numberOfChannels && numberOfSourceChannels);

   162     if (numberOfChannels != m_numberOfChannels || !numberOfSourceChannels) {

   163         destinationChunk->SetNull(WEBAUDIO_BLOCK_SIZE);

   164         return;

   165     }

   167     switch (numberOfChannels) {

   168     case 2: // stereo

   169         m_sourceChannels[0] = static_cast<const float*>(sourceChunk->mChannelData[0]);

   171         if (numberOfSourceChannels > 1)

   172             m_sourceChannels[1] = static_cast<const float*>(sourceChunk->mChannelData[1]);

   173         else

   174             // Simply duplicate mono channel input data to right channel for stereo processing.

   175             m_sourceChannels[1] = m_sourceChannels[0];

   177         break;

   178     default:

   179         // FIXME : support other number of channels.

   180         NS_WARNING("Support other number of channels");

   181         destinationChunk->SetNull(WEBAUDIO_BLOCK_SIZE);

   182         return;

   183     }

   185     for (unsigned i = 0; i < numberOfChannels; ++i)

   186         m_destinationChannels[i] = const_cast<float*>(static_cast<const float*>(

   187             destinationChunk->mChannelData[i]));

   189     float filterStageGain = parameterValue(ParamFilterStageGain);

   190     float filterStageRatio = parameterValue(ParamFilterStageRatio);

   191     float anchor = parameterValue(ParamFilterAnchor);

   193     if (filterStageGain != m_lastFilterStageGain || filterStageRatio != m_lastFilterStageRatio || anchor != m_lastAnchor) {

   194         m_lastFilterStageGain = filterStageGain;

   195         m_lastFilterStageRatio = filterStageRatio;

   196         m_lastAnchor = anchor;

   198         setEmphasisParameters(filterStageGain, anchor, filterStageRatio);

   199     }

   201     float sourceWithVolume[WEBAUDIO_BLOCK_SIZE];

   203     // Apply pre-emphasis filter.

   204     // Note that the final three stages are computed in-place in the destination buffer.

   205     for (unsigned i = 0; i < numberOfChannels; ++i) {

   206         const float* sourceData;

   207         if (sourceChunk->mVolume == 1.0f) {

   208           // Fast path, the volume scale doesn't need to get taken into account

   209           sourceData = m_sourceChannels[i];

   210         } else {

   211           AudioBlockCopyChannelWithScale(m_sourceChannels[i],

   212                                          sourceChunk->mVolume,

   213                                          sourceWithVolume);

   214           sourceData = sourceWithVolume;

   215         }

   217         float* destinationData = m_destinationChannels[i];

   218         ZeroPole* preFilters = m_preFilterPacks[i]->filters;

   220         preFilters[0].process(sourceData, destinationData, framesToProcess);

   221         preFilters[1].process(destinationData, destinationData, framesToProcess);

   222         preFilters[2].process(destinationData, destinationData, framesToProcess);

   223         preFilters[3].process(destinationData, destinationData, framesToProcess);

   224     }

   226     float dbThreshold = parameterValue(ParamThreshold);

   227     float dbKnee = parameterValue(ParamKnee);

   228     float ratio = parameterValue(ParamRatio);

   229     float attackTime = parameterValue(ParamAttack);

   230     float releaseTime = parameterValue(ParamRelease);

   231     float preDelayTime = parameterValue(ParamPreDelay);

   233     // This is effectively a master volume on the compressed signal (pre-blending).

   234     float dbPostGain = parameterValue(ParamPostGain);

   236     // Linear blending value from dry to completely processed (0 -> 1)

   237     // 0 means the signal is completely unprocessed.

   238     // 1 mixes in only the compressed signal.

   239     float effectBlend = parameterValue(ParamEffectBlend);

   241     float releaseZone1 = parameterValue(ParamReleaseZone1);

   242     float releaseZone2 = parameterValue(ParamReleaseZone2);

   243     float releaseZone3 = parameterValue(ParamReleaseZone3);

   244     float releaseZone4 = parameterValue(ParamReleaseZone4);

   246     // Apply compression to the pre-filtered signal.

   247     // The processing is performed in place.

   248     m_compressor.process(m_destinationChannels.get(),

   249                          m_destinationChannels.get(),

   250                          numberOfChannels,

   251                          framesToProcess,

   253                          dbThreshold,

   254                          dbKnee,

   255                          ratio,

   256                          attackTime,

   257                          releaseTime,

   258                          preDelayTime,

   259                          dbPostGain,

   260                          effectBlend,

   262                          releaseZone1,

   263                          releaseZone2,

   264                          releaseZone3,

   265                          releaseZone4

   266                          );

   268     // Update the compression amount.

   269     setParameterValue(ParamReduction, m_compressor.meteringGain());

   271     // Apply de-emphasis filter.

   272     for (unsigned i = 0; i < numberOfChannels; ++i) {

   273         float* destinationData = m_destinationChannels[i];

   274         ZeroPole* postFilters = m_postFilterPacks[i]->filters;

   276         postFilters[0].process(destinationData, destinationData, framesToProcess);

   277         postFilters[1].process(destinationData, destinationData, framesToProcess);

   278         postFilters[2].process(destinationData, destinationData, framesToProcess);

   279         postFilters[3].process(destinationData, destinationData, framesToProcess);

   280     }

   281 }

   283 void DynamicsCompressor::reset()

   284 {

   285     m_lastFilterStageRatio = -1; // for recalc

   286     m_lastAnchor = -1;

   287     m_lastFilterStageGain = -1;

   289     for (unsigned channel = 0; channel < m_numberOfChannels; ++channel) {

   290         for (unsigned stageIndex = 0; stageIndex < 4; ++stageIndex) {

   291             m_preFilterPacks[channel]->filters[stageIndex].reset();

   292             m_postFilterPacks[channel]->filters[stageIndex].reset();

   293         }

   294     }

   296     m_compressor.reset();

   297 }

   299 void DynamicsCompressor::setNumberOfChannels(unsigned numberOfChannels)

   300 {

   301     if (m_preFilterPacks.Length() == numberOfChannels)

   302         return;

   304     m_preFilterPacks.Clear();

   305     m_postFilterPacks.Clear();

   306     for (unsigned i = 0; i < numberOfChannels; ++i) {

   307         m_preFilterPacks.AppendElement(new ZeroPoleFilterPack4());

   308         m_postFilterPacks.AppendElement(new ZeroPoleFilterPack4());

   309     }

   311     m_sourceChannels = new const float* [numberOfChannels];

   312     m_destinationChannels = new float* [numberOfChannels];

   314     m_compressor.setNumberOfChannels(numberOfChannels);

   315     m_numberOfChannels = numberOfChannels;

   316 }

   318 } // namespace WebCore

The Tor Browser / file revision

content/media/webaudio/blink/DynamicsCompressor.cpp@44a2da4a2ab2

content/media/webaudio/blink/DynamicsCompressor.cpp