gecko-dev/content/media/webaudio/blink/ReverbAccumulationBuffer.h

70 строки
3.1 KiB
C++

/*
* 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
* 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
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef ReverbAccumulationBuffer_h
#define ReverbAccumulationBuffer_h
#include "nsTArray.h"
namespace WebCore {
typedef nsTArray<float> AudioFloatArray;
// ReverbAccumulationBuffer is a circular delay buffer with one client reading from it and multiple clients
// writing/accumulating to it at different delay offsets from the read position. The read operation will zero the memory
// just read from the buffer, so it will be ready for accumulation the next time around.
class ReverbAccumulationBuffer {
public:
ReverbAccumulationBuffer(size_t length);
// This will read from, then clear-out numberOfFrames
void readAndClear(float* destination, size_t numberOfFrames);
// Each ReverbConvolverStage will accumulate its output at the appropriate delay from the read position.
// We need to pass in and update readIndex here, since each ReverbConvolverStage may be running in
// a different thread than the realtime thread calling ReadAndClear() and maintaining m_readIndex
// Returns the writeIndex where the accumulation took place
int accumulate(float* source, size_t numberOfFrames, int* readIndex, size_t delayFrames);
size_t readIndex() const { return m_readIndex; }
void updateReadIndex(int* readIndex, size_t numberOfFrames) const;
size_t readTimeFrame() const { return m_readTimeFrame; }
void reset();
private:
AudioFloatArray m_buffer;
size_t m_readIndex;
size_t m_readTimeFrame; // for debugging (frame on continuous timeline)
};
} // namespace WebCore
#endif // ReverbAccumulationBuffer_h