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#ifndef AudioBufferSourceNode_h 26#define AudioBufferSourceNode_h 27 28#include "AudioBuffer.h" 29#include "AudioBus.h" 30#include "AudioParam.h" 31#include "AudioScheduledSourceNode.h" 32#include "PannerNode.h" 33#include <wtf/OwnArrayPtr.h> 34#include <wtf/PassRefPtr.h> 35#include <wtf/RefPtr.h> 36#include <wtf/Threading.h> 37 38namespace WebCore { 39 40class AudioContext; 41 42// AudioBufferSourceNode is an AudioNode representing an audio source from an in-memory audio asset represented by an AudioBuffer. 43// It generally will be used for short sounds which require a high degree of scheduling flexibility (can playback in rhythmically perfect ways). 44 45class AudioBufferSourceNode : public AudioScheduledSourceNode { 46public: 47 static PassRefPtr<AudioBufferSourceNode> create(AudioContext*, float sampleRate); 48 49 virtual ~AudioBufferSourceNode(); 50 51 // AudioNode 52 virtual void process(size_t framesToProcess); 53 virtual void reset(); 54 55 // setBuffer() is called on the main thread. This is the buffer we use for playback. 56 // returns true on success. 57 bool setBuffer(AudioBuffer*); 58 AudioBuffer* buffer() { return m_buffer.get(); } 59 60 // numberOfChannels() returns the number of output channels. This value equals the number of channels from the buffer. 61 // If a new buffer is set with a different number of channels, then this value will dynamically change. 62 unsigned numberOfChannels(); 63 64 // Play-state 65 void startGrain(double when, double grainOffset); 66 void startGrain(double when, double grainOffset, double grainDuration); 67 68#if ENABLE(LEGACY_WEB_AUDIO) 69 void noteGrainOn(double when, double grainOffset, double grainDuration); 70#endif 71 72 // Note: the attribute was originally exposed as .looping, but to be more consistent in naming with <audio> 73 // and with how it's described in the specification, the proper attribute name is .loop 74 // The old attribute is kept for backwards compatibility. 75 bool loop() const { return m_isLooping; } 76 void setLoop(bool looping) { m_isLooping = looping; } 77 78 // Loop times in seconds. 79 double loopStart() const { return m_loopStart; } 80 double loopEnd() const { return m_loopEnd; } 81 void setLoopStart(double loopStart) { m_loopStart = loopStart; } 82 void setLoopEnd(double loopEnd) { m_loopEnd = loopEnd; } 83 84 // Deprecated. 85 bool looping(); 86 void setLooping(bool); 87 88 AudioParam* gain() { return m_gain.get(); } 89 AudioParam* playbackRate() { return m_playbackRate.get(); } 90 91 // If a panner node is set, then we can incorporate doppler shift into the playback pitch rate. 92 void setPannerNode(PannerNode*); 93 void clearPannerNode(); 94 95 // If we are no longer playing, propogate silence ahead to downstream nodes. 96 virtual bool propagatesSilence() const; 97 98 // AudioScheduledSourceNode 99 virtual void finish() OVERRIDE; 100 101private: 102 AudioBufferSourceNode(AudioContext*, float sampleRate); 103 104 virtual double tailTime() const OVERRIDE { return 0; } 105 virtual double latencyTime() const OVERRIDE { return 0; } 106 107 // Returns true on success. 108 bool renderFromBuffer(AudioBus*, unsigned destinationFrameOffset, size_t numberOfFrames); 109 110 // Render silence starting from "index" frame in AudioBus. 111 inline bool renderSilenceAndFinishIfNotLooping(AudioBus*, unsigned index, size_t framesToProcess); 112 113 // m_buffer holds the sample data which this node outputs. 114 RefPtr<AudioBuffer> m_buffer; 115 116 // Pointers for the buffer and destination. 117 OwnArrayPtr<const float*> m_sourceChannels; 118 OwnArrayPtr<float*> m_destinationChannels; 119 120 // Used for the "gain" and "playbackRate" attributes. 121 RefPtr<AudioParam> m_gain; 122 RefPtr<AudioParam> m_playbackRate; 123 124 // If m_isLooping is false, then this node will be done playing and become inactive after it reaches the end of the sample data in the buffer. 125 // If true, it will wrap around to the start of the buffer each time it reaches the end. 126 bool m_isLooping; 127 128 double m_loopStart; 129 double m_loopEnd; 130 131 // m_virtualReadIndex is a sample-frame index into our buffer representing the current playback position. 132 // Since it's floating-point, it has sub-sample accuracy. 133 double m_virtualReadIndex; 134 135 // Granular playback 136 bool m_isGrain; 137 double m_grainOffset; // in seconds 138 double m_grainDuration; // in seconds 139 140 // totalPitchRate() returns the instantaneous pitch rate (non-time preserving). 141 // It incorporates the base pitch rate, any sample-rate conversion factor from the buffer, and any doppler shift from an associated panner node. 142 double totalPitchRate(); 143 144 // m_lastGain provides continuity when we dynamically adjust the gain. 145 float m_lastGain; 146 147 // We optionally keep track of a panner node which has a doppler shift that is incorporated into 148 // the pitch rate. We manually manage ref-counting because we want to use RefTypeConnection. 149 PannerNode* m_pannerNode; 150 151 // This synchronizes process() with setBuffer() which can cause dynamic channel count changes. 152 mutable Mutex m_processLock; 153}; 154 155} // namespace WebCore 156 157#endif // AudioBufferSourceNode_h 158