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/*
* 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.
*/
#include "ReverbAccumulationBuffer.h"
#include "AudioNodeEngine.h"
#include "mozilla/PodOperations.h"
#include <algorithm>
using namespace mozilla;
namespace WebCore {
ReverbAccumulationBuffer::ReverbAccumulationBuffer(size_t length)
: m_readIndex(0), m_readTimeFrame(0) {
m_buffer.SetLength(length);
PodZero(m_buffer.Elements(), length);
}
void ReverbAccumulationBuffer::readAndClear(float* destination,
size_t numberOfFrames) {
size_t bufferLength = m_buffer.Length();
bool isCopySafe =
m_readIndex <= bufferLength && numberOfFrames <= bufferLength;
MOZ_ASSERT(isCopySafe);
if (!isCopySafe) return;
size_t framesAvailable = bufferLength - m_readIndex;
size_t numberOfFrames1 = std::min(numberOfFrames, framesAvailable);
size_t numberOfFrames2 = numberOfFrames - numberOfFrames1;
float* source = m_buffer.Elements();
memcpy(destination, source + m_readIndex, sizeof(float) * numberOfFrames1);
memset(source + m_readIndex, 0, sizeof(float) * numberOfFrames1);
// Handle wrap-around if necessary
if (numberOfFrames2 > 0) {
memcpy(destination + numberOfFrames1, source,
sizeof(float) * numberOfFrames2);
memset(source, 0, sizeof(float) * numberOfFrames2);
}
m_readIndex = (m_readIndex + numberOfFrames) % bufferLength;
m_readTimeFrame += numberOfFrames;
}
void ReverbAccumulationBuffer::updateReadIndex(int* readIndex,
size_t numberOfFrames) const {
// Update caller's readIndex
*readIndex = (*readIndex + numberOfFrames) % m_buffer.Length();
}
int ReverbAccumulationBuffer::accumulate(const float* source,
size_t numberOfFrames, int* readIndex,
size_t delayFrames) {
size_t bufferLength = m_buffer.Length();
size_t writeIndex = (*readIndex + delayFrames) % bufferLength;
// Update caller's readIndex
*readIndex = (*readIndex + numberOfFrames) % bufferLength;
size_t framesAvailable = bufferLength - writeIndex;
size_t numberOfFrames1 = std::min(numberOfFrames, framesAvailable);
size_t numberOfFrames2 = numberOfFrames - numberOfFrames1;
float* destination = m_buffer.Elements();
bool isSafe = writeIndex <= bufferLength &&
numberOfFrames1 + writeIndex <= bufferLength &&
numberOfFrames2 <= bufferLength;
MOZ_ASSERT(isSafe);
if (!isSafe) return 0;
AudioBufferAddWithScale(source, 1.0f, destination + writeIndex,
numberOfFrames1);
if (numberOfFrames2 > 0) {
AudioBufferAddWithScale(source + numberOfFrames1, 1.0f, destination,
numberOfFrames2);
}
return writeIndex;
}
void ReverbAccumulationBuffer::reset() {
PodZero(m_buffer.Elements(), m_buffer.Length());
m_readIndex = 0;
m_readTimeFrame = 0;
}
} // namespace WebCore
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