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25 #ifndef AudioNodeOutput_h
26 #define AudioNodeOutput_h
28 #include "platform/audio/AudioBus.h"
29 #include "modules/webaudio/AudioNode.h"
30 #include "modules/webaudio/AudioParam.h"
31 #include "wtf/HashSet.h"
32 #include "wtf/RefPtr.h"
39 // AudioNodeOutput represents a single output for an AudioNode.
40 // It may be connected to one or more AudioNodeInputs.
41 class AudioNodeOutput : public GarbageCollectedFinalized<AudioNodeOutput> {
43 // It's OK to pass 0 for numberOfChannels in which case
44 // setNumberOfChannels() must be called later on.
45 static AudioNodeOutput* create(AudioNode*, unsigned numberOfChannels);
49 // Can be called from any thread.
50 AudioNode* node() const { return m_node; }
51 AudioContext* context() { return m_node->context(); }
53 // Causes our AudioNode to process if it hasn't already for this render quantum.
54 // It returns the bus containing the processed audio for this output, returning inPlaceBus if in-place processing was possible.
55 // Called from context's audio thread.
56 AudioBus* pull(AudioBus* inPlaceBus, size_t framesToProcess);
58 // bus() will contain the rendered audio after pull() is called for each rendering time quantum.
59 // Called from context's audio thread.
60 AudioBus* bus() const;
62 // renderingFanOutCount() is the number of AudioNodeInputs that we're connected to during rendering.
63 // Unlike fanOutCount() it will not change during the course of a render quantum.
64 unsigned renderingFanOutCount() const;
66 // Must be called with the context's graph lock.
69 void setNumberOfChannels(unsigned);
70 unsigned numberOfChannels() const { return m_numberOfChannels; }
71 bool isChannelCountKnown() const { return numberOfChannels() > 0; }
73 bool isConnected() { return fanOutCount() > 0 || paramFanOutCount() > 0; }
75 // Disable/Enable happens when there are still JavaScript references to a node, but it has otherwise "finished" its work.
76 // For example, when a note has finished playing. It is kept around, because it may be played again at a later time.
77 // They must be called with the context's graph lock.
81 // 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.
82 // It must be called with the context's graph lock.
83 void updateRenderingState();
86 AudioNodeOutput(AudioNode*, unsigned numberOfChannels);
88 Member<AudioNode> m_node;
90 friend class AudioNodeInput;
91 friend class AudioParam;
93 // These are called from AudioNodeInput.
94 // They must be called with the context's graph lock.
95 void addInput(AudioNodeInput&);
96 void removeInput(AudioNodeInput&);
97 void addParam(AudioParam&);
98 void removeParam(AudioParam&);
100 // fanOutCount() is the number of AudioNodeInputs that we're connected to.
101 // This method should not be called in audio thread rendering code, instead renderingFanOutCount() should be used.
102 // It must be called with the context's graph lock.
103 unsigned fanOutCount();
105 // Similar to fanOutCount(), paramFanOutCount() is the number of AudioParams that we're connected to.
106 // This method should not be called in audio thread rendering code, instead renderingParamFanOutCount() should be used.
107 // It must be called with the context's graph lock.
108 unsigned paramFanOutCount();
110 // Must be called with the context's graph lock.
111 void disconnectAllInputs();
112 void disconnectAllParams();
114 // updateInternalBus() updates m_internalBus appropriately for the number of channels.
115 // It is called in the constructor or in the audio thread with the context's graph lock.
116 void updateInternalBus();
118 // Announce to any nodes we're connected to that we changed our channel count for its input.
119 // It must be called in the audio thread with the context's graph lock.
120 void propagateChannelCount();
122 // updateNumberOfChannels() is called in the audio thread at the start or end of the render quantum to pick up channel changes.
123 // It must be called with the context's graph lock.
124 void updateNumberOfChannels();
126 // m_numberOfChannels will only be changed in the audio thread.
127 // The main thread sets m_desiredNumberOfChannels which will later get picked up in the audio thread in updateNumberOfChannels().
128 unsigned m_numberOfChannels;
129 unsigned m_desiredNumberOfChannels;
131 // m_internalBus and m_inPlaceBus must only be changed in the audio thread with the context's graph lock (or constructor).
132 RefPtr<AudioBus> m_internalBus;
133 RefPtr<AudioBus> m_inPlaceBus;
134 // If m_isInPlace is true, use m_inPlaceBus as the valid AudioBus; If false, use the default m_internalBus.
137 // Oilpan: This HashMap holds connection references. We must call
138 // AudioNode::makeConnection when we add an AudioNode to this, and must call
139 // AudioNode::breakConnection() when we remove an AudioNode from this.
140 HeapHashMap<Member<AudioNodeInput>, Member<AudioNode> > m_inputs;
141 typedef HeapHashMap<Member<AudioNodeInput>, Member<AudioNode> >::iterator InputsIterator;
145 bool m_didCallDispose;
148 // For the purposes of rendering, keeps track of the number of inputs and AudioParams we're connected to.
149 // These value should only be changed at the very start or end of the rendering quantum.
150 unsigned m_renderingFanOutCount;
151 unsigned m_renderingParamFanOutCount;
153 HeapHashSet<Member<AudioParam> > m_params;
158 #endif // AudioNodeOutput_h