1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/content/media/webaudio/blink/FFTConvolver.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,132 @@
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 "FFTConvolver.h"
1.33 +#include "mozilla/PodOperations.h"
1.34 +
1.35 +using namespace mozilla;
1.36 +
1.37 +namespace WebCore {
1.38 +
1.39 +FFTConvolver::FFTConvolver(size_t fftSize)
1.40 + : m_frame(fftSize)
1.41 + , m_readWriteIndex(0)
1.42 +{
1.43 + m_inputBuffer.SetLength(fftSize);
1.44 + PodZero(m_inputBuffer.Elements(), fftSize);
1.45 + m_outputBuffer.SetLength(fftSize);
1.46 + PodZero(m_outputBuffer.Elements(), fftSize);
1.47 + m_lastOverlapBuffer.SetLength(fftSize / 2);
1.48 + PodZero(m_lastOverlapBuffer.Elements(), fftSize / 2);
1.49 +}
1.50 +
1.51 +size_t FFTConvolver::sizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
1.52 +{
1.53 + size_t amount = 0;
1.54 + amount += m_frame.SizeOfExcludingThis(aMallocSizeOf);
1.55 + amount += m_inputBuffer.SizeOfExcludingThis(aMallocSizeOf);
1.56 + amount += m_outputBuffer.SizeOfExcludingThis(aMallocSizeOf);
1.57 + amount += m_lastOverlapBuffer.SizeOfExcludingThis(aMallocSizeOf);
1.58 + return amount;
1.59 +}
1.60 +
1.61 +size_t FFTConvolver::sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
1.62 +{
1.63 + return aMallocSizeOf(this) + sizeOfExcludingThis(aMallocSizeOf);
1.64 +}
1.65 +
1.66 +void FFTConvolver::process(FFTBlock* fftKernel, const float* sourceP, float* destP, size_t framesToProcess)
1.67 +{
1.68 + size_t halfSize = fftSize() / 2;
1.69 +
1.70 + // framesToProcess must be an exact multiple of halfSize,
1.71 + // or halfSize is a multiple of framesToProcess when halfSize > framesToProcess.
1.72 + bool isGood = !(halfSize % framesToProcess && framesToProcess % halfSize);
1.73 + MOZ_ASSERT(isGood);
1.74 + if (!isGood)
1.75 + return;
1.76 +
1.77 + size_t numberOfDivisions = halfSize <= framesToProcess ? (framesToProcess / halfSize) : 1;
1.78 + size_t divisionSize = numberOfDivisions == 1 ? framesToProcess : halfSize;
1.79 +
1.80 + for (size_t i = 0; i < numberOfDivisions; ++i, sourceP += divisionSize, destP += divisionSize) {
1.81 + // Copy samples to input buffer (note contraint above!)
1.82 + float* inputP = m_inputBuffer.Elements();
1.83 +
1.84 + // Sanity check
1.85 + bool isCopyGood1 = sourceP && inputP && m_readWriteIndex + divisionSize <= m_inputBuffer.Length();
1.86 + MOZ_ASSERT(isCopyGood1);
1.87 + if (!isCopyGood1)
1.88 + return;
1.89 +
1.90 + memcpy(inputP + m_readWriteIndex, sourceP, sizeof(float) * divisionSize);
1.91 +
1.92 + // Copy samples from output buffer
1.93 + float* outputP = m_outputBuffer.Elements();
1.94 +
1.95 + // Sanity check
1.96 + bool isCopyGood2 = destP && outputP && m_readWriteIndex + divisionSize <= m_outputBuffer.Length();
1.97 + MOZ_ASSERT(isCopyGood2);
1.98 + if (!isCopyGood2)
1.99 + return;
1.100 +
1.101 + memcpy(destP, outputP + m_readWriteIndex, sizeof(float) * divisionSize);
1.102 + m_readWriteIndex += divisionSize;
1.103 +
1.104 + // Check if it's time to perform the next FFT
1.105 + if (m_readWriteIndex == halfSize) {
1.106 + // The input buffer is now filled (get frequency-domain version)
1.107 + m_frame.PerformFFT(m_inputBuffer.Elements());
1.108 + m_frame.Multiply(*fftKernel);
1.109 + m_frame.GetInverseWithoutScaling(m_outputBuffer.Elements());
1.110 +
1.111 + // Overlap-add 1st half from previous time
1.112 + AudioBufferAddWithScale(m_lastOverlapBuffer.Elements(), 1.0f,
1.113 + m_outputBuffer.Elements(), halfSize);
1.114 +
1.115 + // Finally, save 2nd half of result
1.116 + bool isCopyGood3 = m_outputBuffer.Length() == 2 * halfSize && m_lastOverlapBuffer.Length() == halfSize;
1.117 + MOZ_ASSERT(isCopyGood3);
1.118 + if (!isCopyGood3)
1.119 + return;
1.120 +
1.121 + memcpy(m_lastOverlapBuffer.Elements(), m_outputBuffer.Elements() + halfSize, sizeof(float) * halfSize);
1.122 +
1.123 + // Reset index back to start for next time
1.124 + m_readWriteIndex = 0;
1.125 + }
1.126 + }
1.127 +}
1.128 +
1.129 +void FFTConvolver::reset()
1.130 +{
1.131 + PodZero(m_lastOverlapBuffer.Elements(), m_lastOverlapBuffer.Length());
1.132 + m_readWriteIndex = 0;
1.133 +}
1.134 +
1.135 +} // namespace WebCore
