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