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