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/*
* Copyright (C) 2011 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.
* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE 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 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.
*/
#ifndef DynamicsCompressor_h
#define DynamicsCompressor_h
#include "DynamicsCompressorKernel.h"
#include "ZeroPole.h"
#include "nsTArray.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/UniquePtr.h"
namespace mozilla {
class AudioBlock;
} // namespace mozilla
namespace WebCore {
using mozilla::AudioBlock;
using mozilla::UniquePtr;
// DynamicsCompressor implements a flexible audio dynamics compression effect
// such as is commonly used in musical production and game audio. It lowers the
// volume of the loudest parts of the signal and raises the volume of the
// softest parts, making the sound richer, fuller, and more controlled.
class DynamicsCompressor {
public:
enum {
ParamThreshold,
ParamKnee,
ParamRatio,
ParamAttack,
ParamRelease,
ParamPreDelay,
ParamReleaseZone1,
ParamReleaseZone2,
ParamReleaseZone3,
ParamReleaseZone4,
ParamPostGain,
ParamFilterStageGain,
ParamFilterStageRatio,
ParamFilterAnchor,
ParamEffectBlend,
ParamReduction,
ParamLast
};
DynamicsCompressor(float sampleRate, unsigned numberOfChannels);
void process(const AudioBlock* sourceChunk, AudioBlock* destinationChunk,
unsigned framesToProcess);
void reset();
void setNumberOfChannels(unsigned);
unsigned numberOfChannels() const { return m_numberOfChannels; }
void setParameterValue(unsigned parameterID, float value);
float parameterValue(unsigned parameterID);
float sampleRate() const { return m_sampleRate; }
float nyquist() const { return m_sampleRate / 2; }
double tailTime() const { return 0; }
double latencyTime() const {
return m_compressor.latencyFrames() / static_cast<double>(sampleRate());
}
size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
protected:
unsigned m_numberOfChannels;
// m_parameters holds the tweakable compressor parameters.
float m_parameters[ParamLast];
void initializeParameters();
float m_sampleRate;
// Emphasis filter controls.
float m_lastFilterStageRatio;
float m_lastAnchor;
float m_lastFilterStageGain;
struct ZeroPoleFilterPack4 {
ZeroPole filters[4];
size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const {
return aMallocSizeOf(this);
}
};
// Per-channel emphasis filters.
nsTArray<UniquePtr<ZeroPoleFilterPack4> > m_preFilterPacks;
nsTArray<UniquePtr<ZeroPoleFilterPack4> > m_postFilterPacks;
mozilla::UniquePtr<const float*[]> m_sourceChannels;
mozilla::UniquePtr<float*[]> m_destinationChannels;
void setEmphasisStageParameters(unsigned stageIndex, float gain,
float normalizedFrequency /* 0 -> 1 */);
void setEmphasisParameters(float gain, float anchorFreq,
float filterStageRatio);
// The core compressor.
DynamicsCompressorKernel m_compressor;
};
} // namespace WebCore
#endif // DynamicsCompressor_h