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 AudioNodeInput_h 26 #define AudioNodeInput_h 27 28 #include "platform/audio/AudioBus.h" 29 #include "modules/webaudio/AudioNode.h" 30 #include "modules/webaudio/AudioSummingJunction.h" 31 #include "wtf/HashSet.h" 32 33 namespace blink { 34 35 class AudioNode; 36 class AudioNodeOutput; 37 38 // An AudioNodeInput represents an input to an AudioNode and can be connected from one or more AudioNodeOutputs. 39 // In the case of multiple connections, the input will act as a unity-gain summing junction, mixing all the outputs. 40 // The number of channels of the input's bus is the maximum of the number of channels of all its connections. 41 42 class AudioNodeInput FINAL : public AudioSummingJunction { 43 public: 44 static AudioNodeInput* create(AudioNode&); 45 46 // AudioSummingJunction 47 virtual void trace(Visitor*) OVERRIDE; 48 virtual void didUpdate() OVERRIDE; 49 50 // Can be called from any thread. node()51 AudioNode& node() const { return *m_node; } 52 53 // Must be called with the context's graph lock. 54 void connect(AudioNodeOutput&); 55 void disconnect(AudioNodeOutput&); 56 57 // disable() will take the output out of the active connections list and set aside in a disabled list. 58 // enable() will put the output back into the active connections list. 59 // Must be called with the context's graph lock. 60 void enable(AudioNodeOutput&); 61 void disable(AudioNodeOutput&); 62 63 // pull() processes all of the AudioNodes connected to us. 64 // In the case of multiple connections it sums the result into an internal summing bus. 65 // In the single connection case, it allows in-place processing where possible using inPlaceBus. 66 // It returns the bus which it rendered into, returning inPlaceBus if in-place processing was performed. 67 // Called from context's audio thread. 68 AudioBus* pull(AudioBus* inPlaceBus, size_t framesToProcess); 69 70 // bus() contains the rendered audio after pull() has been called for each time quantum. 71 // Called from context's audio thread. 72 AudioBus* bus(); 73 74 // updateInternalBus() updates m_internalSummingBus appropriately for the number of channels. 75 // This must be called when we own the context's graph lock in the audio thread at the very start or end of the render quantum. 76 void updateInternalBus(); 77 78 // The number of channels of the connection with the largest number of channels. 79 unsigned numberOfChannels() const; 80 81 private: 82 explicit AudioNodeInput(AudioNode&); 83 84 Member<AudioNode> m_node; 85 86 // m_disabledOutputs contains the AudioNodeOutputs which are disabled (will not be processed) by the audio graph rendering. 87 // But, from JavaScript's perspective, these outputs are still connected to us. 88 // Generally, these represent disabled connections from "notes" which have finished playing but are not yet garbage collected. 89 // Oilpan: Since items are added to the hash set by the audio thread (not registered to Oilpan), 90 // we cannot use a HeapHashSet. 91 GC_PLUGIN_IGNORE("http://crbug.com/404527") 92 HashSet<AudioNodeOutput*> m_disabledOutputs; 93 94 // Called from context's audio thread. 95 AudioBus* internalSummingBus(); 96 void sumAllConnections(AudioBus* summingBus, size_t framesToProcess); 97 98 RefPtr<AudioBus> m_internalSummingBus; 99 }; 100 101 } // namespace blink 102 103 #endif // AudioNodeInput_h 104