BiquadProcessor.h   [plain text]


/*
 * 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
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 *    notice, this list of conditions and the following disclaimer.
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 *    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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#ifndef BiquadProcessor_h
#define BiquadProcessor_h

#include "AudioDSPKernel.h"
#include "AudioDSPKernelProcessor.h"
#include "AudioNode.h"
#include "AudioParam.h"
#include "Biquad.h"
#include <wtf/RefPtr.h>

namespace WebCore {

// BiquadProcessor is an AudioDSPKernelProcessor which uses Biquad objects to implement several common filters.

class BiquadProcessor : public AudioDSPKernelProcessor {
public:
    enum FilterType {
        LowPass2,
        HighPass2,
        Peaking,
        Allpass,
        LowShelf,
        HighShelf
    };
    
    BiquadProcessor(FilterType, double sampleRate, size_t numberOfChannels, bool autoInitialize = true);
    virtual ~BiquadProcessor();
    
    virtual PassOwnPtr<AudioDSPKernel> createKernel();
        
    virtual void process(AudioBus* source, AudioBus* destination, size_t framesToProcess);

    bool filterCoefficientsDirty() const { return m_filterCoefficientsDirty; }

    AudioParam* parameter1() { return m_parameter1.get(); }
    AudioParam* parameter2() { return m_parameter2.get(); }
    AudioParam* parameter3() { return m_parameter3.get(); }

    FilterType type() const { return m_type; }

private:
    FilterType m_type;

    RefPtr<AudioParam> m_parameter1;
    RefPtr<AudioParam> m_parameter2;
    RefPtr<AudioParam> m_parameter3;

    // so DSP kernels know when to re-compute coefficients
    bool m_filterCoefficientsDirty;
};

} // namespace WebCore

#endif // BiquadProcessor_h