content/media/webaudio/blink/FFTConvolver.cpp@44a2da4a2ab2 (annotated)
content/media/webaudio/blink/FFTConvolver.cpp
Fri, 16 Jan 2015 04:50:19 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Fri, 16 Jan 2015 04:50:19 +0100
- branch
- TOR_BUG_9701
- changeset 13
- 44a2da4a2ab2
- permissions
- -rw-r--r--
Replace accessor implementation with direct member state manipulation, by
request https://trac.torproject.org/projects/tor/ticket/9701#comment:32
| michael@0 | 1 | /* |
| michael@0 | 2 | * Copyright (C) 2010 Google Inc. All rights reserved. |
| michael@0 | 3 | * |
| michael@0 | 4 | * Redistribution and use in source and binary forms, with or without |
| michael@0 | 5 | * modification, are permitted provided that the following conditions |
| michael@0 | 6 | * are met: |
| michael@0 | 7 | * |
| michael@0 | 8 | * 1. Redistributions of source code must retain the above copyright |
| michael@0 | 9 | * notice, this list of conditions and the following disclaimer. |
| michael@0 | 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| michael@0 | 11 | * notice, this list of conditions and the following disclaimer in the |
| michael@0 | 12 | * documentation and/or other materials provided with the distribution. |
| michael@0 | 13 | * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of |
| michael@0 | 14 | * its contributors may be used to endorse or promote products derived |
| michael@0 | 15 | * from this software without specific prior written permission. |
| michael@0 | 16 | * |
| michael@0 | 17 | * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY |
| michael@0 | 18 | * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| michael@0 | 19 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| michael@0 | 20 | * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY |
| michael@0 | 21 | * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| michael@0 | 22 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| michael@0 | 23 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| michael@0 | 24 | * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| michael@0 | 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| michael@0 | 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| michael@0 | 27 | */ |
| michael@0 | 28 | |
| michael@0 | 29 | #include "FFTConvolver.h" |
| michael@0 | 30 | #include "mozilla/PodOperations.h" |
| michael@0 | 31 | |
| michael@0 | 32 | using namespace mozilla; |
| michael@0 | 33 | |
| michael@0 | 34 | namespace WebCore { |
| michael@0 | 35 | |
| michael@0 | 36 | FFTConvolver::FFTConvolver(size_t fftSize) |
| michael@0 | 37 | : m_frame(fftSize) |
| michael@0 | 38 | , m_readWriteIndex(0) |
| michael@0 | 39 | { |
| michael@0 | 40 | m_inputBuffer.SetLength(fftSize); |
| michael@0 | 41 | PodZero(m_inputBuffer.Elements(), fftSize); |
| michael@0 | 42 | m_outputBuffer.SetLength(fftSize); |
| michael@0 | 43 | PodZero(m_outputBuffer.Elements(), fftSize); |
| michael@0 | 44 | m_lastOverlapBuffer.SetLength(fftSize / 2); |
| michael@0 | 45 | PodZero(m_lastOverlapBuffer.Elements(), fftSize / 2); |
| michael@0 | 46 | } |
| michael@0 | 47 | |
| michael@0 | 48 | size_t FFTConvolver::sizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const |
| michael@0 | 49 | { |
| michael@0 | 50 | size_t amount = 0; |
| michael@0 | 51 | amount += m_frame.SizeOfExcludingThis(aMallocSizeOf); |
| michael@0 | 52 | amount += m_inputBuffer.SizeOfExcludingThis(aMallocSizeOf); |
| michael@0 | 53 | amount += m_outputBuffer.SizeOfExcludingThis(aMallocSizeOf); |
| michael@0 | 54 | amount += m_lastOverlapBuffer.SizeOfExcludingThis(aMallocSizeOf); |
| michael@0 | 55 | return amount; |
| michael@0 | 56 | } |
| michael@0 | 57 | |
| michael@0 | 58 | size_t FFTConvolver::sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const |
| michael@0 | 59 | { |
| michael@0 | 60 | return aMallocSizeOf(this) + sizeOfExcludingThis(aMallocSizeOf); |
| michael@0 | 61 | } |
| michael@0 | 62 | |
| michael@0 | 63 | void FFTConvolver::process(FFTBlock* fftKernel, const float* sourceP, float* destP, size_t framesToProcess) |
| michael@0 | 64 | { |
| michael@0 | 65 | size_t halfSize = fftSize() / 2; |
| michael@0 | 66 | |
| michael@0 | 67 | // framesToProcess must be an exact multiple of halfSize, |
| michael@0 | 68 | // or halfSize is a multiple of framesToProcess when halfSize > framesToProcess. |
| michael@0 | 69 | bool isGood = !(halfSize % framesToProcess && framesToProcess % halfSize); |
| michael@0 | 70 | MOZ_ASSERT(isGood); |
| michael@0 | 71 | if (!isGood) |
| michael@0 | 72 | return; |
| michael@0 | 73 | |
| michael@0 | 74 | size_t numberOfDivisions = halfSize <= framesToProcess ? (framesToProcess / halfSize) : 1; |
| michael@0 | 75 | size_t divisionSize = numberOfDivisions == 1 ? framesToProcess : halfSize; |
| michael@0 | 76 | |
| michael@0 | 77 | for (size_t i = 0; i < numberOfDivisions; ++i, sourceP += divisionSize, destP += divisionSize) { |
| michael@0 | 78 | // Copy samples to input buffer (note contraint above!) |
| michael@0 | 79 | float* inputP = m_inputBuffer.Elements(); |
| michael@0 | 80 | |
| michael@0 | 81 | // Sanity check |
| michael@0 | 82 | bool isCopyGood1 = sourceP && inputP && m_readWriteIndex + divisionSize <= m_inputBuffer.Length(); |
| michael@0 | 83 | MOZ_ASSERT(isCopyGood1); |
| michael@0 | 84 | if (!isCopyGood1) |
| michael@0 | 85 | return; |
| michael@0 | 86 | |
| michael@0 | 87 | memcpy(inputP + m_readWriteIndex, sourceP, sizeof(float) * divisionSize); |
| michael@0 | 88 | |
| michael@0 | 89 | // Copy samples from output buffer |
| michael@0 | 90 | float* outputP = m_outputBuffer.Elements(); |
| michael@0 | 91 | |
| michael@0 | 92 | // Sanity check |
| michael@0 | 93 | bool isCopyGood2 = destP && outputP && m_readWriteIndex + divisionSize <= m_outputBuffer.Length(); |
| michael@0 | 94 | MOZ_ASSERT(isCopyGood2); |
| michael@0 | 95 | if (!isCopyGood2) |
| michael@0 | 96 | return; |
| michael@0 | 97 | |
| michael@0 | 98 | memcpy(destP, outputP + m_readWriteIndex, sizeof(float) * divisionSize); |
| michael@0 | 99 | m_readWriteIndex += divisionSize; |
| michael@0 | 100 | |
| michael@0 | 101 | // Check if it's time to perform the next FFT |
| michael@0 | 102 | if (m_readWriteIndex == halfSize) { |
| michael@0 | 103 | // The input buffer is now filled (get frequency-domain version) |
| michael@0 | 104 | m_frame.PerformFFT(m_inputBuffer.Elements()); |
| michael@0 | 105 | m_frame.Multiply(*fftKernel); |
| michael@0 | 106 | m_frame.GetInverseWithoutScaling(m_outputBuffer.Elements()); |
| michael@0 | 107 | |
| michael@0 | 108 | // Overlap-add 1st half from previous time |
| michael@0 | 109 | AudioBufferAddWithScale(m_lastOverlapBuffer.Elements(), 1.0f, |
| michael@0 | 110 | m_outputBuffer.Elements(), halfSize); |
| michael@0 | 111 | |
| michael@0 | 112 | // Finally, save 2nd half of result |
| michael@0 | 113 | bool isCopyGood3 = m_outputBuffer.Length() == 2 * halfSize && m_lastOverlapBuffer.Length() == halfSize; |
| michael@0 | 114 | MOZ_ASSERT(isCopyGood3); |
| michael@0 | 115 | if (!isCopyGood3) |
| michael@0 | 116 | return; |
| michael@0 | 117 | |
| michael@0 | 118 | memcpy(m_lastOverlapBuffer.Elements(), m_outputBuffer.Elements() + halfSize, sizeof(float) * halfSize); |
| michael@0 | 119 | |
| michael@0 | 120 | // Reset index back to start for next time |
| michael@0 | 121 | m_readWriteIndex = 0; |
| michael@0 | 122 | } |
| michael@0 | 123 | } |
| michael@0 | 124 | } |
| michael@0 | 125 | |
| michael@0 | 126 | void FFTConvolver::reset() |
| michael@0 | 127 | { |
| michael@0 | 128 | PodZero(m_lastOverlapBuffer.Elements(), m_lastOverlapBuffer.Length()); |
| michael@0 | 129 | m_readWriteIndex = 0; |
| michael@0 | 130 | } |
| michael@0 | 131 | |
| michael@0 | 132 | } // namespace WebCore |
