/*

 * 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

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 */

#ifndef DynamicsCompressor_h

#define DynamicsCompressor_h

#include "DynamicsCompressorKernel.h"

#include "ZeroPole.h"

#include "nsTArray.h"

#include "nsAutoPtr.h"

#include "mozilla/MemoryReporting.h"

#include "mozilla/UniquePtr.h"

namespace mozilla {

class AudioBlock;

} // namespace mozilla

namespace WebCore {

using mozilla::AudioBlock;

// 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;

    typedef struct {

        ZeroPole filters[4];

        size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const

        {

            return aMallocSizeOf(this);

        }

    } ZeroPoleFilterPack4;

    // Per-channel emphasis filters.

    nsTArray<nsAutoPtr<ZeroPoleFilterPack4> > m_preFilterPacks;

    nsTArray<nsAutoPtr<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