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 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 16 * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY 17 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 18 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 19 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 20 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 22 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 23 */ 24 25#include "config.h" 26 27#if ENABLE(WEB_AUDIO) 28 29#include "AudioBasicProcessorNode.h" 30 31#include "AudioBus.h" 32#include "AudioContext.h" 33#include "AudioNodeInput.h" 34#include "AudioNodeOutput.h" 35#include "AudioProcessor.h" 36 37namespace WebCore { 38 39AudioBasicProcessorNode::AudioBasicProcessorNode(AudioContext* context, double sampleRate) 40 : AudioNode(context, sampleRate) 41{ 42 addInput(adoptPtr(new AudioNodeInput(this))); 43 addOutput(adoptPtr(new AudioNodeOutput(this, 0))); 44 45 // The subclass must create m_processor. 46} 47 48void AudioBasicProcessorNode::initialize() 49{ 50 if (isInitialized()) 51 return; 52 53 ASSERT(processor()); 54 processor()->initialize(); 55 56 AudioNode::initialize(); 57} 58 59void AudioBasicProcessorNode::uninitialize() 60{ 61 if (!isInitialized()) 62 return; 63 64 ASSERT(processor()); 65 processor()->uninitialize(); 66 67 AudioNode::uninitialize(); 68} 69 70void AudioBasicProcessorNode::process(size_t framesToProcess) 71{ 72 AudioBus* destinationBus = output(0)->bus(); 73 74 // The realtime thread can't block on this lock, so we call tryLock() instead. 75 if (m_processLock.tryLock()) { 76 if (!isInitialized() || !processor()) 77 destinationBus->zero(); 78 else { 79 AudioBus* sourceBus = input(0)->bus(); 80 81 // FIXME: if we take "tail time" into account, then we can avoid calling processor()->process() once the tail dies down. 82 if (!input(0)->isConnected()) 83 sourceBus->zero(); 84 85 processor()->process(sourceBus, destinationBus, framesToProcess); 86 } 87 88 m_processLock.unlock(); 89 } else { 90 // Too bad - the tryLock() failed. We must be in the middle of re-connecting and were already outputting silence anyway... 91 destinationBus->zero(); 92 } 93} 94 95// Nice optimization in the very common case allowing for "in-place" processing 96void AudioBasicProcessorNode::pullInputs(size_t framesToProcess) 97{ 98 // Render input stream - suggest to the input to render directly into output bus for in-place processing in process() if possible. 99 input(0)->pull(output(0)->bus(), framesToProcess); 100} 101 102void AudioBasicProcessorNode::reset() 103{ 104 if (processor()) 105 processor()->reset(); 106} 107 108// As soon as we know the channel count of our input, we can lazily initialize. 109// Sometimes this may be called more than once with different channel counts, in which case we must safely 110// uninitialize and then re-initialize with the new channel count. 111void AudioBasicProcessorNode::checkNumberOfChannelsForInput(AudioNodeInput* input) 112{ 113 ASSERT(context()->isAudioThread() && context()->isGraphOwner()); 114 115 ASSERT(input == this->input(0)); 116 if (input != this->input(0)) 117 return; 118 119 ASSERT(processor()); 120 if (!processor()) 121 return; 122 123 unsigned numberOfChannels = input->numberOfChannels(); 124 125 if (isInitialized() && numberOfChannels != output(0)->numberOfChannels()) { 126 // We're already initialized but the channel count has changed. 127 // We need to be careful since we may be actively processing right now, so synchronize with process(). 128 MutexLocker locker(m_processLock); 129 uninitialize(); 130 } 131 132 if (!isInitialized()) { 133 // This will propagate the channel count to any nodes connected further down the chain... 134 output(0)->setNumberOfChannels(numberOfChannels); 135 136 // Re-initialize the processor with the new channel count. 137 processor()->setNumberOfChannels(numberOfChannels); 138 initialize(); 139 } 140} 141 142unsigned AudioBasicProcessorNode::numberOfChannels() 143{ 144 return output(0)->numberOfChannels(); 145} 146 147} // namespace WebCore 148 149#endif // ENABLE(WEB_AUDIO) 150