The Tor Browser / file comparison
comparison: content/media/webaudio/blink/FFTConvolver.cpp
content/media/webaudio/blink/FFTConvolver.cpp
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| 1 /* | |
| 2 * Copyright (C) 2010 Google Inc. All rights reserved. | |
| 3 * | |
| 4 * Redistribution and use in source and binary forms, with or without | |
| 5 * modification, are permitted provided that the following conditions | |
| 6 * are met: | |
| 7 * | |
| 8 * 1. Redistributions of source code must retain the above copyright | |
| 9 * notice, this list of conditions and the following disclaimer. | |
| 10 * 2. Redistributions in binary form must reproduce the above copyright | |
| 11 * notice, this list of conditions and the following disclaimer in the | |
| 12 * documentation and/or other materials provided with the distribution. | |
| 13 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of | |
| 14 * its contributors may be used to endorse or promote products derived | |
| 15 * from this software without specific prior written permission. | |
| 16 * | |
| 17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY | |
| 18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED | |
| 19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |
| 20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY | |
| 21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES | |
| 22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | |
| 23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND | |
| 24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
| 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
| 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| 27 */ | |
| 28 | |
| 29 #include "FFTConvolver.h" | |
| 30 #include "mozilla/PodOperations.h" | |
| 31 | |
| 32 using namespace mozilla; | |
| 33 | |
| 34 namespace WebCore { | |
| 35 | |
| 36 FFTConvolver::FFTConvolver(size_t fftSize) | |
| 37 : m_frame(fftSize) | |
| 38 , m_readWriteIndex(0) | |
| 39 { | |
| 40 m_inputBuffer.SetLength(fftSize); | |
| 41 PodZero(m_inputBuffer.Elements(), fftSize); | |
| 42 m_outputBuffer.SetLength(fftSize); | |
| 43 PodZero(m_outputBuffer.Elements(), fftSize); | |
| 44 m_lastOverlapBuffer.SetLength(fftSize / 2); | |
| 45 PodZero(m_lastOverlapBuffer.Elements(), fftSize / 2); | |
| 46 } | |
| 47 | |
| 48 size_t FFTConvolver::sizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const | |
| 49 { | |
| 50 size_t amount = 0; | |
| 51 amount += m_frame.SizeOfExcludingThis(aMallocSizeOf); | |
| 52 amount += m_inputBuffer.SizeOfExcludingThis(aMallocSizeOf); | |
| 53 amount += m_outputBuffer.SizeOfExcludingThis(aMallocSizeOf); | |
| 54 amount += m_lastOverlapBuffer.SizeOfExcludingThis(aMallocSizeOf); | |
| 55 return amount; | |
| 56 } | |
| 57 | |
| 58 size_t FFTConvolver::sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const | |
| 59 { | |
| 60 return aMallocSizeOf(this) + sizeOfExcludingThis(aMallocSizeOf); | |
| 61 } | |
| 62 | |
| 63 void FFTConvolver::process(FFTBlock* fftKernel, const float* sourceP, float* destP, size_t framesToProcess) | |
| 64 { | |
| 65 size_t halfSize = fftSize() / 2; | |
| 66 | |
| 67 // framesToProcess must be an exact multiple of halfSize, | |
| 68 // or halfSize is a multiple of framesToProcess when halfSize > framesToProcess. | |
| 69 bool isGood = !(halfSize % framesToProcess && framesToProcess % halfSize); | |
| 70 MOZ_ASSERT(isGood); | |
| 71 if (!isGood) | |
| 72 return; | |
| 73 | |
| 74 size_t numberOfDivisions = halfSize <= framesToProcess ? (framesToProcess / halfSize) : 1; | |
| 75 size_t divisionSize = numberOfDivisions == 1 ? framesToProcess : halfSize; | |
| 76 | |
| 77 for (size_t i = 0; i < numberOfDivisions; ++i, sourceP += divisionSize, destP += divisionSize) { | |
| 78 // Copy samples to input buffer (note contraint above!) | |
| 79 float* inputP = m_inputBuffer.Elements(); | |
| 80 | |
| 81 // Sanity check | |
| 82 bool isCopyGood1 = sourceP && inputP && m_readWriteIndex + divisionSize <= m_inputBuffer.Length(); | |
| 83 MOZ_ASSERT(isCopyGood1); | |
| 84 if (!isCopyGood1) | |
| 85 return; | |
| 86 | |
| 87 memcpy(inputP + m_readWriteIndex, sourceP, sizeof(float) * divisionSize); | |
| 88 | |
| 89 // Copy samples from output buffer | |
| 90 float* outputP = m_outputBuffer.Elements(); | |
| 91 | |
| 92 // Sanity check | |
| 93 bool isCopyGood2 = destP && outputP && m_readWriteIndex + divisionSize <= m_outputBuffer.Length(); | |
| 94 MOZ_ASSERT(isCopyGood2); | |
| 95 if (!isCopyGood2) | |
| 96 return; | |
| 97 | |
| 98 memcpy(destP, outputP + m_readWriteIndex, sizeof(float) * divisionSize); | |
| 99 m_readWriteIndex += divisionSize; | |
| 100 | |
| 101 // Check if it's time to perform the next FFT | |
| 102 if (m_readWriteIndex == halfSize) { | |
| 103 // The input buffer is now filled (get frequency-domain version) | |
| 104 m_frame.PerformFFT(m_inputBuffer.Elements()); | |
| 105 m_frame.Multiply(*fftKernel); | |
| 106 m_frame.GetInverseWithoutScaling(m_outputBuffer.Elements()); | |
| 107 | |
| 108 // Overlap-add 1st half from previous time | |
| 109 AudioBufferAddWithScale(m_lastOverlapBuffer.Elements(), 1.0f, | |
| 110 m_outputBuffer.Elements(), halfSize); | |
| 111 | |
| 112 // Finally, save 2nd half of result | |
| 113 bool isCopyGood3 = m_outputBuffer.Length() == 2 * halfSize && m_lastOverlapBuffer.Length() == halfSize; | |
| 114 MOZ_ASSERT(isCopyGood3); | |
| 115 if (!isCopyGood3) | |
| 116 return; | |
| 117 | |
| 118 memcpy(m_lastOverlapBuffer.Elements(), m_outputBuffer.Elements() + halfSize, sizeof(float) * halfSize); | |
| 119 | |
| 120 // Reset index back to start for next time | |
| 121 m_readWriteIndex = 0; | |
| 122 } | |
| 123 } | |
| 124 } | |
| 125 | |
| 126 void FFTConvolver::reset() | |
| 127 { | |
| 128 PodZero(m_lastOverlapBuffer.Elements(), m_lastOverlapBuffer.Length()); | |
| 129 m_readWriteIndex = 0; | |
| 130 } | |
| 131 | |
| 132 } // namespace WebCore |
