content/media/webaudio/blink/Reverb.h
author Ehsan Akhgari <ehsan@mozilla.com>
Mon, 10 Jun 2013 16:08:38 -0400
changeset 134587 6bed30223d8f63012b88f9ae9faaf44dd88d0911
child 134588 b7efc129d2b1a487e5aa79eede28cc9c4dfb92a9
permissions -rw-r--r--
Bug 815643 - Part 3: Import the Convolution processing implementation from Blink; r=roc The original code was copied from Blink SVN revision 150518.

/*
 * Copyright (C) 2010 Google Inc. All rights reserved.
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 *     from this software without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
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#ifndef Reverb_h
#define Reverb_h

#include "core/platform/audio/ReverbConvolver.h"
#include <wtf/Vector.h>

namespace WebCore {

class AudioBus;
    
// Multi-channel convolution reverb with channel matrixing - one or more ReverbConvolver objects are used internally.

class Reverb {
public:
    enum { MaxFrameSize = 256 };

    // renderSliceSize is a rendering hint, so the FFTs can be optimized to not all occur at the same time (very bad when rendering on a real-time thread).
    Reverb(AudioBus* impulseResponseBuffer, size_t renderSliceSize, size_t maxFFTSize, size_t numberOfChannels, bool useBackgroundThreads, bool normalize);

    void process(const AudioBus* sourceBus, AudioBus* destinationBus, size_t framesToProcess);
    void reset();

    size_t impulseResponseLength() const { return m_impulseResponseLength; }
    size_t latencyFrames() const;

private:
    void initialize(AudioBus* impulseResponseBuffer, size_t renderSliceSize, size_t maxFFTSize, size_t numberOfChannels, bool useBackgroundThreads);

    size_t m_impulseResponseLength;

    Vector<OwnPtr<ReverbConvolver> > m_convolvers;

    // For "True" stereo processing
    RefPtr<AudioBus> m_tempBuffer;
};

} // namespace WebCore

#endif // Reverb_h