Source/WebCore/Modules/webaudio/DynamicsCompressorNode.h

/*
 * 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
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 *    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
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#pragma once

#include "AudioNode.h"
#include "AudioParam.h"
#include <memory>

namespace WebCore {

class DynamicsCompressor;

class DynamicsCompressorNode final : public AudioNode {
    WTF_MAKE_ISO_ALLOCATED(DynamicsCompressorNode);
public:
    static Ref<DynamicsCompressorNode> create(BaseAudioContext& context, float sampleRate)
    {
        return adoptRef(*new DynamicsCompressorNode(context, sampleRate));
    }

    virtual ~DynamicsCompressorNode();

    // AudioNode
    void process(size_t framesToProcess) override;
    void reset() override;
    void initialize() override;
    void uninitialize() override;

    // Static compression curve parameters.
    AudioParam* threshold() { return m_threshold.get(); }
    AudioParam* knee() { return m_knee.get(); }
    AudioParam* ratio() { return m_ratio.get(); }
    AudioParam* attack() { return m_attack.get(); }
    AudioParam* release() { return m_release.get(); }

    // Amount by which the compressor is currently compressing the signal in decibels.
    AudioParam* reduction() { return m_reduction.get(); }

private:
    double tailTime() const override;
    double latencyTime() const override;

    DynamicsCompressorNode(BaseAudioContext&, float sampleRate);

    std::unique_ptr<DynamicsCompressor> m_dynamicsCompressor;
    RefPtr<AudioParam> m_threshold;
    RefPtr<AudioParam> m_knee;
    RefPtr<AudioParam> m_ratio;
    RefPtr<AudioParam> m_reduction;
    RefPtr<AudioParam> m_attack;
    RefPtr<AudioParam> m_release;
};

} // namespace WebCore