1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/content/media/webaudio/blink/ReverbAccumulationBuffer.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,116 @@
1.4 +/*
1.5 + * Copyright (C) 2010 Google Inc. All rights reserved.
1.6 + *
1.7 + * Redistribution and use in source and binary forms, with or without
1.8 + * modification, are permitted provided that the following conditions
1.9 + * are met:
1.10 + *
1.11 + * 1. Redistributions of source code must retain the above copyright
1.12 + * notice, this list of conditions and the following disclaimer.
1.13 + * 2. Redistributions in binary form must reproduce the above copyright
1.14 + * notice, this list of conditions and the following disclaimer in the
1.15 + * documentation and/or other materials provided with the distribution.
1.16 + * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
1.17 + * its contributors may be used to endorse or promote products derived
1.18 + * from this software without specific prior written permission.
1.19 + *
1.20 + * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
1.21 + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
1.22 + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
1.23 + * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
1.24 + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
1.25 + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
1.26 + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
1.27 + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1.28 + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
1.29 + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.30 + */
1.31 +
1.32 +#include "ReverbAccumulationBuffer.h"
1.33 +#include "AudioNodeEngine.h"
1.34 +#include "mozilla/PodOperations.h"
1.35 +#include <algorithm>
1.36 +
1.37 +using namespace mozilla;
1.38 +
1.39 +namespace WebCore {
1.40 +
1.41 +ReverbAccumulationBuffer::ReverbAccumulationBuffer(size_t length)
1.42 + : m_readIndex(0)
1.43 + , m_readTimeFrame(0)
1.44 +{
1.45 + m_buffer.SetLength(length);
1.46 + PodZero(m_buffer.Elements(), length);
1.47 +}
1.48 +
1.49 +void ReverbAccumulationBuffer::readAndClear(float* destination, size_t numberOfFrames)
1.50 +{
1.51 + size_t bufferLength = m_buffer.Length();
1.52 + bool isCopySafe = m_readIndex <= bufferLength && numberOfFrames <= bufferLength;
1.53 +
1.54 + MOZ_ASSERT(isCopySafe);
1.55 + if (!isCopySafe)
1.56 + return;
1.57 +
1.58 + size_t framesAvailable = bufferLength - m_readIndex;
1.59 + size_t numberOfFrames1 = std::min(numberOfFrames, framesAvailable);
1.60 + size_t numberOfFrames2 = numberOfFrames - numberOfFrames1;
1.61 +
1.62 + float* source = m_buffer.Elements();
1.63 + memcpy(destination, source + m_readIndex, sizeof(float) * numberOfFrames1);
1.64 + memset(source + m_readIndex, 0, sizeof(float) * numberOfFrames1);
1.65 +
1.66 + // Handle wrap-around if necessary
1.67 + if (numberOfFrames2 > 0) {
1.68 + memcpy(destination + numberOfFrames1, source, sizeof(float) * numberOfFrames2);
1.69 + memset(source, 0, sizeof(float) * numberOfFrames2);
1.70 + }
1.71 +
1.72 + m_readIndex = (m_readIndex + numberOfFrames) % bufferLength;
1.73 + m_readTimeFrame += numberOfFrames;
1.74 +}
1.75 +
1.76 +void ReverbAccumulationBuffer::updateReadIndex(int* readIndex, size_t numberOfFrames) const
1.77 +{
1.78 + // Update caller's readIndex
1.79 + *readIndex = (*readIndex + numberOfFrames) % m_buffer.Length();
1.80 +}
1.81 +
1.82 +int ReverbAccumulationBuffer::accumulate(float* source, size_t numberOfFrames, int* readIndex, size_t delayFrames)
1.83 +{
1.84 + size_t bufferLength = m_buffer.Length();
1.85 +
1.86 + size_t writeIndex = (*readIndex + delayFrames) % bufferLength;
1.87 +
1.88 + // Update caller's readIndex
1.89 + *readIndex = (*readIndex + numberOfFrames) % bufferLength;
1.90 +
1.91 + size_t framesAvailable = bufferLength - writeIndex;
1.92 + size_t numberOfFrames1 = std::min(numberOfFrames, framesAvailable);
1.93 + size_t numberOfFrames2 = numberOfFrames - numberOfFrames1;
1.94 +
1.95 + float* destination = m_buffer.Elements();
1.96 +
1.97 + bool isSafe = writeIndex <= bufferLength && numberOfFrames1 + writeIndex <= bufferLength && numberOfFrames2 <= bufferLength;
1.98 + MOZ_ASSERT(isSafe);
1.99 + if (!isSafe)
1.100 + return 0;
1.101 +
1.102 + AudioBufferAddWithScale(source, 1.0f, destination + writeIndex, numberOfFrames1);
1.103 +
1.104 + // Handle wrap-around if necessary
1.105 + if (numberOfFrames2 > 0) {
1.106 + AudioBufferAddWithScale(source + numberOfFrames1, 1.0f, destination, numberOfFrames2);
1.107 + }
1.108 +
1.109 + return writeIndex;
1.110 +}
1.111 +
1.112 +void ReverbAccumulationBuffer::reset()
1.113 +{
1.114 + PodZero(m_buffer.Elements(), m_buffer.Length());
1.115 + m_readIndex = 0;
1.116 + m_readTimeFrame = 0;
1.117 +}
1.118 +
1.119 +} // namespace WebCore
