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 "AudioBus.h" |
28 | #include "AudioNode.h" |
29 | #include "AudioParam.h" |
30 | #include <wtf/HashSet.h> |
31 | #include <wtf/RefPtr.h> |
32 | |
33 | namespace WebCore { |
34 | |
35 | class AudioContext; |
36 | class AudioNodeInput; |
37 | |
38 | // AudioNodeOutput represents a single output for an AudioNode. |
39 | // It may be connected to one or more AudioNodeInputs. |
40 | |
41 | class AudioNodeOutput { |
42 | WTF_MAKE_NONCOPYABLE(AudioNodeOutput); |
43 | WTF_MAKE_FAST_ALLOCATED; |
44 | public: |
45 | // It's OK to pass 0 for numberOfChannels in which case setNumberOfChannels() must be called later on. |
46 | AudioNodeOutput(AudioNode*, unsigned numberOfChannels); |
47 | |
48 | // Can be called from any thread. |
49 | AudioNode* node() const { return m_node; } |
50 | AudioContext& context() { return m_node->context(); } |
51 | |
52 | // Causes our AudioNode to process if it hasn't already for this render quantum. |
53 | // It returns the bus containing the processed audio for this output, returning inPlaceBus if in-place processing was possible. |
54 | // Called from context's audio thread. |
55 | AudioBus* pull(AudioBus* inPlaceBus, size_t framesToProcess); |
56 | |
57 | // bus() will contain the rendered audio after pull() is called for each rendering time quantum. |
58 | // Called from context's audio thread. |
59 | AudioBus* bus() const; |
60 | |
61 | // renderingFanOutCount() is the number of AudioNodeInputs that we're connected to during rendering. |
62 | // Unlike fanOutCount() it will not change during the course of a render quantum. |
63 | unsigned renderingFanOutCount() const; |
64 | |
65 | // renderingParamFanOutCount() is the number of AudioParams that we're connected to during rendering. |
66 | // Unlike paramFanOutCount() it will not change during the course of a render quantum. |
67 | unsigned renderingParamFanOutCount() const; |
68 | |
69 | // Must be called with the context's graph lock. |
70 | void disconnectAll(); |
71 | |
72 | void setNumberOfChannels(unsigned); |
73 | unsigned numberOfChannels() const { return m_numberOfChannels; } |
74 | bool isChannelCountKnown() const { return numberOfChannels() > 0; } |
75 | |
76 | bool isConnected() { return fanOutCount() > 0 || paramFanOutCount() > 0; } |
77 | |
78 | // Disable/Enable happens when there are still JavaScript references to a node, but it has otherwise "finished" its work. |
79 | // For example, when a note has finished playing. It is kept around, because it may be played again at a later time. |
80 | // They must be called with the context's graph lock. |
81 | void disable(); |
82 | void enable(); |
83 | |
84 | // updateRenderingState() is called in the audio thread at the start or end of the render quantum to handle any recent changes to the graph state. |
85 | // It must be called with the context's graph lock. |
86 | void updateRenderingState(); |
87 | |
88 | private: |
89 | AudioNode* m_node; |
90 | |
91 | friend class AudioNodeInput; |
92 | friend class AudioParam; |
93 | |
94 | // These are called from AudioNodeInput. |
95 | // They must be called with the context's graph lock. |
96 | void addInput(AudioNodeInput*); |
97 | void removeInput(AudioNodeInput*); |
98 | void addParam(AudioParam*); |
99 | void removeParam(AudioParam*); |
100 | |
101 | // fanOutCount() is the number of AudioNodeInputs that we're connected to. |
102 | // This method should not be called in audio thread rendering code, instead renderingFanOutCount() should be used. |
103 | // It must be called with the context's graph lock. |
104 | unsigned fanOutCount(); |
105 | |
106 | // Similar to fanOutCount(), paramFanOutCount() is the number of AudioParams that we're connected to. |
107 | // This method should not be called in audio thread rendering code, instead renderingParamFanOutCount() should be used. |
108 | // It must be called with the context's graph lock. |
109 | unsigned paramFanOutCount(); |
110 | |
111 | // Must be called with the context's graph lock. |
112 | void disconnectAllInputs(); |
113 | void disconnectAllParams(); |
114 | |
115 | // updateInternalBus() updates m_internalBus appropriately for the number of channels. |
116 | // It is called in the constructor or in the audio thread with the context's graph lock. |
117 | void updateInternalBus(); |
118 | |
119 | // Announce to any nodes we're connected to that we changed our channel count for its input. |
120 | // It must be called in the audio thread with the context's graph lock. |
121 | void propagateChannelCount(); |
122 | |
123 | // updateNumberOfChannels() is called in the audio thread at the start or end of the render quantum to pick up channel changes. |
124 | // It must be called with the context's graph lock. |
125 | void updateNumberOfChannels(); |
126 | |
127 | // m_numberOfChannels will only be changed in the audio thread. |
128 | // The main thread sets m_desiredNumberOfChannels which will later get picked up in the audio thread in updateNumberOfChannels(). |
129 | unsigned m_numberOfChannels; |
130 | unsigned m_desiredNumberOfChannels; |
131 | |
132 | // m_internalBus and m_inPlaceBus must only be changed in the audio thread with the context's graph lock (or constructor). |
133 | RefPtr<AudioBus> m_internalBus; |
134 | RefPtr<AudioBus> m_inPlaceBus; |
135 | // If m_isInPlace is true, use m_inPlaceBus as the valid AudioBus; If false, use the default m_internalBus. |
136 | bool m_isInPlace; |
137 | |
138 | HashSet<AudioNodeInput*> m_inputs; |
139 | typedef HashSet<AudioNodeInput*>::iterator InputsIterator; |
140 | bool m_isEnabled; |
141 | |
142 | // For the purposes of rendering, keeps track of the number of inputs and AudioParams we're connected to. |
143 | // These value should only be changed at the very start or end of the rendering quantum. |
144 | unsigned m_renderingFanOutCount; |
145 | unsigned m_renderingParamFanOutCount; |
146 | |
147 | HashSet<RefPtr<AudioParam>> m_params; |
148 | typedef HashSet<RefPtr<AudioParam>>::iterator ParamsIterator; |
149 | }; |
150 | |
151 | } // namespace WebCore |
152 | |