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