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| 1 /* |
| 2 * Copyright (C) 2012 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 "platform/audio/AudioFIFO.h" |
| 30 |
| 31 namespace blink { |
| 32 |
| 33 AudioFIFO::AudioFIFO(unsigned numberOfChannels, size_t fifoLength) |
| 34 : m_fifoAudioBus(AudioBus::create(numberOfChannels, fifoLength)), |
| 35 m_fifoLength(fifoLength), |
| 36 m_framesInFifo(0), |
| 37 m_readIndex(0), |
| 38 m_writeIndex(0) {} |
| 39 |
| 40 void AudioFIFO::consume(AudioBus* destination, size_t framesToConsume) { |
| 41 bool isGood = destination && (framesToConsume <= m_fifoLength) && |
| 42 (framesToConsume <= m_framesInFifo) && |
| 43 (destination->length() >= framesToConsume); |
| 44 ASSERT(isGood); |
| 45 if (!isGood) |
| 46 return; |
| 47 |
| 48 // Copy the requested number of samples to the destination. |
| 49 |
| 50 size_t part1Length; |
| 51 size_t part2Length; |
| 52 findWrapLengths(m_readIndex, framesToConsume, part1Length, part2Length); |
| 53 |
| 54 size_t numberOfChannels = m_fifoAudioBus->numberOfChannels(); |
| 55 |
| 56 for (size_t channelIndex = 0; channelIndex < numberOfChannels; |
| 57 ++channelIndex) { |
| 58 float* destinationData = destination->channel(channelIndex)->mutableData(); |
| 59 const float* sourceData = m_fifoAudioBus->channel(channelIndex)->data(); |
| 60 |
| 61 bool isCopyGood = ((m_readIndex < m_fifoLength) && |
| 62 (m_readIndex + part1Length) <= m_fifoLength && |
| 63 (part1Length <= destination->length()) && |
| 64 (part1Length + part2Length) <= destination->length()); |
| 65 ASSERT(isCopyGood); |
| 66 if (!isCopyGood) |
| 67 return; |
| 68 |
| 69 memcpy(destinationData, sourceData + m_readIndex, |
| 70 part1Length * sizeof(*sourceData)); |
| 71 // Handle wrap around of the FIFO, if needed. |
| 72 if (part2Length) |
| 73 memcpy(destinationData + part1Length, sourceData, |
| 74 part2Length * sizeof(*sourceData)); |
| 75 } |
| 76 m_readIndex = updateIndex(m_readIndex, framesToConsume); |
| 77 ASSERT(m_framesInFifo >= framesToConsume); |
| 78 m_framesInFifo -= framesToConsume; |
| 79 } |
| 80 |
| 81 void AudioFIFO::push(const AudioBus* sourceBus) { |
| 82 // Copy the sourceBus into the FIFO buffer. |
| 83 |
| 84 bool isGood = |
| 85 sourceBus && (m_framesInFifo + sourceBus->length() <= m_fifoLength); |
| 86 if (!isGood) |
| 87 return; |
| 88 |
| 89 size_t sourceLength = sourceBus->length(); |
| 90 size_t part1Length; |
| 91 size_t part2Length; |
| 92 findWrapLengths(m_writeIndex, sourceLength, part1Length, part2Length); |
| 93 |
| 94 size_t numberOfChannels = m_fifoAudioBus->numberOfChannels(); |
| 95 |
| 96 for (size_t channelIndex = 0; channelIndex < numberOfChannels; |
| 97 ++channelIndex) { |
| 98 float* destination = m_fifoAudioBus->channel(channelIndex)->mutableData(); |
| 99 const float* source = sourceBus->channel(channelIndex)->data(); |
| 100 |
| 101 bool isCopyGood = ((m_writeIndex < m_fifoLength) && |
| 102 (m_writeIndex + part1Length) <= m_fifoLength && |
| 103 part2Length < m_fifoLength && |
| 104 part1Length + part2Length <= sourceLength); |
| 105 ASSERT(isCopyGood); |
| 106 if (!isCopyGood) |
| 107 return; |
| 108 |
| 109 memcpy(destination + m_writeIndex, source, |
| 110 part1Length * sizeof(*destination)); |
| 111 |
| 112 // Handle wrap around of the FIFO, if needed. |
| 113 if (part2Length) |
| 114 memcpy(destination, source + part1Length, |
| 115 part2Length * sizeof(*destination)); |
| 116 } |
| 117 |
| 118 m_framesInFifo += sourceLength; |
| 119 ASSERT(m_framesInFifo <= m_fifoLength); |
| 120 m_writeIndex = updateIndex(m_writeIndex, sourceLength); |
| 121 } |
| 122 |
| 123 void AudioFIFO::findWrapLengths(size_t index, |
| 124 size_t size, |
| 125 size_t& part1Length, |
| 126 size_t& part2Length) { |
| 127 SECURITY_DCHECK(index < m_fifoLength && size <= m_fifoLength); |
| 128 if (index < m_fifoLength && size <= m_fifoLength) { |
| 129 if (index + size > m_fifoLength) { |
| 130 // Need to wrap. Figure out the length of each piece. |
| 131 part1Length = m_fifoLength - index; |
| 132 part2Length = size - part1Length; |
| 133 } else { |
| 134 // No wrap needed. |
| 135 part1Length = size; |
| 136 part2Length = 0; |
| 137 } |
| 138 } else { |
| 139 // Invalid values for index or size. Set the part lengths to zero so nothing |
| 140 // is copied. |
| 141 part1Length = 0; |
| 142 part2Length = 0; |
| 143 } |
| 144 } |
| 145 |
| 146 } // namespace blink |
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