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 "ConvolverNode.h" 30 31#include "AudioBuffer.h" 32#include "AudioContext.h" 33#include "AudioNodeInput.h" 34#include "AudioNodeOutput.h" 35#include "Reverb.h" 36#include <wtf/MainThread.h> 37 38// Note about empirical tuning: 39// The maximum FFT size affects reverb performance and accuracy. 40// If the reverb is single-threaded and processes entirely in the real-time audio thread, 41// it's important not to make this too high. In this case 8192 is a good value. 42// But, the Reverb object is multi-threaded, so we want this as high as possible without losing too much accuracy. 43// Very large FFTs will have worse phase errors. Given these constraints 32768 is a good compromise. 44const size_t MaxFFTSize = 32768; 45 46namespace WebCore { 47 48ConvolverNode::ConvolverNode(AudioContext* context, float sampleRate) 49 : AudioNode(context, sampleRate) 50 , m_normalize(true) 51{ 52 addInput(std::make_unique<AudioNodeInput>(this)); 53 addOutput(std::make_unique<AudioNodeOutput>(this, 2)); 54 55 // Node-specific default mixing rules. 56 m_channelCount = 2; 57 m_channelCountMode = ClampedMax; 58 m_channelInterpretation = AudioBus::Speakers; 59 60 setNodeType(NodeTypeConvolver); 61 62 initialize(); 63} 64 65ConvolverNode::~ConvolverNode() 66{ 67 uninitialize(); 68} 69 70void ConvolverNode::process(size_t framesToProcess) 71{ 72 AudioBus* outputBus = output(0)->bus(); 73 ASSERT(outputBus); 74 75 // Synchronize with possible dynamic changes to the impulse response. 76 std::unique_lock<std::mutex> lock(m_processMutex, std::try_to_lock); 77 if (!lock.owns_lock()) { 78 // Too bad - the try_lock() failed. We must be in the middle of setting a new impulse response. 79 outputBus->zero(); 80 return; 81 } 82 83 if (!isInitialized() || !m_reverb.get()) 84 outputBus->zero(); 85 else { 86 // Process using the convolution engine. 87 // Note that we can handle the case where nothing is connected to the input, in which case we'll just feed silence into the convolver. 88 // FIXME: If we wanted to get fancy we could try to factor in the 'tail time' and stop processing once the tail dies down if 89 // we keep getting fed silence. 90 m_reverb->process(input(0)->bus(), outputBus, framesToProcess); 91 } 92} 93 94void ConvolverNode::reset() 95{ 96 std::lock_guard<std::mutex> lock(m_processMutex); 97 if (m_reverb) 98 m_reverb->reset(); 99} 100 101void ConvolverNode::initialize() 102{ 103 if (isInitialized()) 104 return; 105 106 AudioNode::initialize(); 107} 108 109void ConvolverNode::uninitialize() 110{ 111 if (!isInitialized()) 112 return; 113 114 m_reverb = nullptr; 115 AudioNode::uninitialize(); 116} 117 118void ConvolverNode::setBuffer(AudioBuffer* buffer) 119{ 120 ASSERT(isMainThread()); 121 122 if (!buffer) 123 return; 124 125 unsigned numberOfChannels = buffer->numberOfChannels(); 126 size_t bufferLength = buffer->length(); 127 128 // The current implementation supports up to four channel impulse responses, which are interpreted as true-stereo (see Reverb class). 129 bool isBufferGood = numberOfChannels > 0 && numberOfChannels <= 4 && bufferLength; 130 ASSERT(isBufferGood); 131 if (!isBufferGood) 132 return; 133 134 // Wrap the AudioBuffer by an AudioBus. It's an efficient pointer set and not a memcpy(). 135 // This memory is simply used in the Reverb constructor and no reference to it is kept for later use in that class. 136 RefPtr<AudioBus> bufferBus = AudioBus::create(numberOfChannels, bufferLength, false); 137 for (unsigned i = 0; i < numberOfChannels; ++i) 138 bufferBus->setChannelMemory(i, buffer->getChannelData(i)->data(), bufferLength); 139 140 bufferBus->setSampleRate(buffer->sampleRate()); 141 142 // Create the reverb with the given impulse response. 143 bool useBackgroundThreads = !context()->isOfflineContext(); 144 auto reverb = std::make_unique<Reverb>(bufferBus.get(), AudioNode::ProcessingSizeInFrames, MaxFFTSize, 2, useBackgroundThreads, m_normalize); 145 146 { 147 // Synchronize with process(). 148 std::lock_guard<std::mutex> lock(m_processMutex); 149 m_reverb = WTF::move(reverb); 150 m_buffer = buffer; 151 } 152} 153 154AudioBuffer* ConvolverNode::buffer() 155{ 156 ASSERT(isMainThread()); 157 return m_buffer.get(); 158} 159 160double ConvolverNode::tailTime() const 161{ 162 return m_reverb ? m_reverb->impulseResponseLength() / static_cast<double>(sampleRate()) : 0; 163} 164 165double ConvolverNode::latencyTime() const 166{ 167 return m_reverb ? m_reverb->latencyFrames() / static_cast<double>(sampleRate()) : 0; 168} 169 170} // namespace WebCore 171 172#endif // ENABLE(WEB_AUDIO) 173