Source/platform/audio/AudioDelayDSPKernel.h

/*
 * Copyright (C) 2010, Google Inc. All rights reserved.
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#ifndef AudioDelayDSPKernel_h
#define AudioDelayDSPKernel_h

#include "platform/audio/AudioArray.h"
#include "platform/audio/AudioDSPKernel.h"

namespace blink {

class PLATFORM_EXPORT AudioDelayDSPKernel : public AudioDSPKernel {
public:
    AudioDelayDSPKernel(double maxDelayTime, float sampleRate);

    virtual void process(const float* source, float* destination, size_t framesToProcess) override;
    virtual void reset() override;

    double maxDelayTime() const { return m_maxDelayTime; }

    void setDelayFrames(double numberOfFrames) { m_desiredDelayFrames = numberOfFrames; }

    virtual double tailTime() const override;
    virtual double latencyTime() const override;

protected:
    AudioDelayDSPKernel(AudioDSPKernelProcessor*, size_t processingSizeInFrames);

    virtual bool hasSampleAccurateValues();
    virtual void calculateSampleAccurateValues(float* delayTimes, size_t framesToProcess);
    virtual double delayTime(float sampleRate);

    AudioFloatArray m_buffer;
    double m_maxDelayTime;
    int m_writeIndex;
    double m_currentDelayTime;
    double m_smoothingRate;
    bool m_firstTime;
    double m_desiredDelayFrames;

    AudioFloatArray m_delayTimes;

    size_t bufferLengthForDelay(double delayTime, double sampleRate) const;
};

} // namespace blink

#endif // AudioDelayDSPKernel_h