/* * Copyright (C) 2010, Google Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #ifndef AudioNodeOutput_h #define AudioNodeOutput_h #include "AudioBus.h" #include "AudioNode.h" #include "AudioParam.h" #include <wtf/HashSet.h> #include <wtf/RefPtr.h> #include <wtf/Vector.h> namespace WebCore { class AudioContext; class AudioNodeInput; // AudioNodeOutput represents a single output for an AudioNode. // It may be connected to one or more AudioNodeInputs. class AudioNodeOutput { public: // It's OK to pass 0 for numberOfChannels in which case setNumberOfChannels() must be called later on. AudioNodeOutput(AudioNode*, unsigned numberOfChannels); // Can be called from any thread. AudioNode* node() const { return m_node; } AudioContext* context() { return m_node->context(); } // Causes our AudioNode to process if it hasn't already for this render quantum. // It returns the bus containing the processed audio for this output, returning inPlaceBus if in-place processing was possible. // Called from context's audio thread. AudioBus* pull(AudioBus* inPlaceBus, size_t framesToProcess); // bus() will contain the rendered audio after pull() is called for each rendering time quantum. // Called from context's audio thread. AudioBus* bus() const; // renderingFanOutCount() is the number of AudioNodeInputs that we're connected to during rendering. // Unlike fanOutCount() it will not change during the course of a render quantum. unsigned renderingFanOutCount() const; // renderingParamFanOutCount() is the number of AudioParams that we're connected to during rendering. // Unlike paramFanOutCount() it will not change during the course of a render quantum. unsigned renderingParamFanOutCount() const; // Must be called with the context's graph lock. void disconnectAll(); void setNumberOfChannels(unsigned); unsigned numberOfChannels() const { return m_numberOfChannels; } bool isChannelCountKnown() const { return numberOfChannels() > 0; } bool isConnected() { return fanOutCount() > 0 || paramFanOutCount() > 0; } // Disable/Enable happens when there are still JavaScript references to a node, but it has otherwise "finished" its work. // For example, when a note has finished playing. It is kept around, because it may be played again at a later time. // They must be called with the context's graph lock. void disable(); void enable(); // 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. // It must be called with the context's graph lock. void updateRenderingState(); private: AudioNode* m_node; friend class AudioNodeInput; friend class AudioParam; // These are called from AudioNodeInput. // They must be called with the context's graph lock. void addInput(AudioNodeInput*); void removeInput(AudioNodeInput*); void addParam(AudioParam*); void removeParam(AudioParam*); // fanOutCount() is the number of AudioNodeInputs that we're connected to. // This method should not be called in audio thread rendering code, instead renderingFanOutCount() should be used. // It must be called with the context's graph lock. unsigned fanOutCount(); // Similar to fanOutCount(), paramFanOutCount() is the number of AudioParams that we're connected to. // This method should not be called in audio thread rendering code, instead renderingParamFanOutCount() should be used. // It must be called with the context's graph lock. unsigned paramFanOutCount(); // Must be called with the context's graph lock. void disconnectAllInputs(); void disconnectAllParams(); // updateInternalBus() updates m_internalBus appropriately for the number of channels. // It is called in the constructor or in the audio thread with the context's graph lock. void updateInternalBus(); // Announce to any nodes we're connected to that we changed our channel count for its input. // It must be called in the audio thread with the context's graph lock. void propagateChannelCount(); // updateNumberOfChannels() is called in the audio thread at the start or end of the render quantum to pick up channel changes. // It must be called with the context's graph lock. void updateNumberOfChannels(); // m_numberOfChannels will only be changed in the audio thread. // The main thread sets m_desiredNumberOfChannels which will later get picked up in the audio thread in updateNumberOfChannels(). unsigned m_numberOfChannels; unsigned m_desiredNumberOfChannels; // m_internalBus and m_inPlaceBus must only be changed in the audio thread with the context's graph lock (or constructor). RefPtr<AudioBus> m_internalBus; RefPtr<AudioBus> m_inPlaceBus; // If m_isInPlace is true, use m_inPlaceBus as the valid AudioBus; If false, use the default m_internalBus. bool m_isInPlace; HashSet<AudioNodeInput*> m_inputs; typedef HashSet<AudioNodeInput*>::iterator InputsIterator; bool m_isEnabled; // For the purposes of rendering, keeps track of the number of inputs and AudioParams we're connected to. // These value should only be changed at the very start or end of the rendering quantum. unsigned m_renderingFanOutCount; unsigned m_renderingParamFanOutCount; HashSet<RefPtr<AudioParam> > m_params; typedef HashSet<RefPtr<AudioParam> >::iterator ParamsIterator; }; } // namespace WebCore #endif // AudioNodeOutput_h