/* * 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. */ #pragma once #include "AudioBus.h" #include "EventTarget.h" #include "ExceptionOr.h" #include <wtf/Forward.h> #define DEBUG_AUDIONODE_REFERENCES 0 namespace WebCore { class AudioContext; class AudioNodeInput; class AudioNodeOutput; class AudioParam; // An AudioNode is the basic building block for handling audio within an AudioContext. // It may be an audio source, an intermediate processing module, or an audio destination. // Each AudioNode can have inputs and/or outputs. An AudioSourceNode has no inputs and a single output. // An AudioDestinationNode has one input and no outputs and represents the final destination to the audio hardware. // Most processing nodes such as filters will have one input and one output, although multiple inputs and outputs are possible. class AudioNode : public EventTargetWithInlineData { WTF_MAKE_NONCOPYABLE(AudioNode); WTF_MAKE_FAST_ALLOCATED; public: enum { ProcessingSizeInFrames = 128 }; AudioNode(AudioContext&, float sampleRate); virtual ~AudioNode(); AudioContext& context() { return m_context.get(); } const AudioContext& context() const { return m_context.get(); } enum NodeType { NodeTypeUnknown, NodeTypeDestination, NodeTypeOscillator, NodeTypeAudioBufferSource, NodeTypeMediaElementAudioSource, NodeTypeMediaStreamAudioDestination, NodeTypeMediaStreamAudioSource, NodeTypeJavaScript, NodeTypeBiquadFilter, NodeTypePanner, NodeTypeConvolver, NodeTypeDelay, NodeTypeGain, NodeTypeChannelSplitter, NodeTypeChannelMerger, NodeTypeAnalyser, NodeTypeDynamicsCompressor, NodeTypeWaveShaper, NodeTypeEnd }; enum ChannelCountMode { Max, ClampedMax, Explicit }; NodeType nodeType() const { return m_nodeType; } void setNodeType(NodeType); // We handle our own ref-counting because of the threading issues and subtle nature of // how AudioNodes can continue processing (playing one-shot sound) after there are no more // JavaScript references to the object. enum RefType { RefTypeNormal, RefTypeConnection }; // Can be called from main thread or context's audio thread. void ref(RefType refType = RefTypeNormal); void deref(RefType refType = RefTypeNormal); // Can be called from main thread or context's audio thread. It must be called while the context's graph lock is held. void finishDeref(RefType refType); // The AudioNodeInput(s) (if any) will already have their input data available when process() is called. // Subclasses will take this input data and put the results in the AudioBus(s) of its AudioNodeOutput(s) (if any). // Called from context's audio thread. virtual void process(size_t framesToProcess) = 0; // Resets DSP processing state (clears delay lines, filter memory, etc.) // Called from context's audio thread. virtual void reset() = 0; // No significant resources should be allocated until initialize() is called. // Processing may not occur until a node is initialized. virtual void initialize(); virtual void uninitialize(); bool isInitialized() const { return m_isInitialized; } void lazyInitialize(); unsigned numberOfInputs() const { return m_inputs.size(); } unsigned numberOfOutputs() const { return m_outputs.size(); } AudioNodeInput* input(unsigned); AudioNodeOutput* output(unsigned); // Called from main thread by corresponding JavaScript methods. virtual ExceptionOr<void> connect(AudioNode&, unsigned outputIndex, unsigned inputIndex); ExceptionOr<void> connect(AudioParam&, unsigned outputIndex); virtual ExceptionOr<void> disconnect(unsigned outputIndex); virtual float sampleRate() const { return m_sampleRate; } // processIfNecessary() is called by our output(s) when the rendering graph needs this AudioNode to process. // This method ensures that the AudioNode will only process once per rendering time quantum even if it's called repeatedly. // This handles the case of "fanout" where an output is connected to multiple AudioNode inputs. // Called from context's audio thread. void processIfNecessary(size_t framesToProcess); // Called when a new connection has been made to one of our inputs or the connection number of channels has changed. // This potentially gives us enough information to perform a lazy initialization or, if necessary, a re-initialization. // Called from main thread. virtual void checkNumberOfChannelsForInput(AudioNodeInput*); #if DEBUG_AUDIONODE_REFERENCES static void printNodeCounts(); #endif bool isMarkedForDeletion() const { return m_isMarkedForDeletion; } // tailTime() is the length of time (not counting latency time) where non-zero output may occur after continuous silent input. virtual double tailTime() const = 0; // latencyTime() is the length of time it takes for non-zero output to appear after non-zero input is provided. This only applies to // processing delay which is an artifact of the processing algorithm chosen and is *not* part of the intrinsic desired effect. For // example, a "delay" effect is expected to delay the signal, and thus would not be considered latency. virtual double latencyTime() const = 0; // propagatesSilence() should return true if the node will generate silent output when given silent input. By default, AudioNode // will take tailTime() and latencyTime() into account when determining whether the node will propagate silence. virtual bool propagatesSilence() const; bool inputsAreSilent(); void silenceOutputs(); void enableOutputsIfNecessary(); void disableOutputsIfNecessary(); unsigned channelCount(); virtual ExceptionOr<void> setChannelCount(unsigned); String channelCountMode(); ExceptionOr<void> setChannelCountMode(const String&); String channelInterpretation(); ExceptionOr<void> setChannelInterpretation(const String&); ChannelCountMode internalChannelCountMode() const { return m_channelCountMode; } AudioBus::ChannelInterpretation internalChannelInterpretation() const { return m_channelInterpretation; } // EventTarget EventTargetInterface eventTargetInterface() const override; ScriptExecutionContext* scriptExecutionContext() const final; protected: // Inputs and outputs must be created before the AudioNode is initialized. void addInput(std::unique_ptr<AudioNodeInput>); void addOutput(std::unique_ptr<AudioNodeOutput>); // Called by processIfNecessary() to cause all parts of the rendering graph connected to us to process. // Each rendering quantum, the audio data for each of the AudioNode's inputs will be available after this method is called. // Called from context's audio thread. virtual void pullInputs(size_t framesToProcess); // Force all inputs to take any channel interpretation changes into account. void updateChannelsForInputs(); private: volatile bool m_isInitialized; NodeType m_nodeType; Ref<AudioContext> m_context; float m_sampleRate; Vector<std::unique_ptr<AudioNodeInput>> m_inputs; Vector<std::unique_ptr<AudioNodeOutput>> m_outputs; double m_lastProcessingTime; double m_lastNonSilentTime; // Ref-counting std::atomic<int> m_normalRefCount; std::atomic<int> m_connectionRefCount; bool m_isMarkedForDeletion; bool m_isDisabled; #if DEBUG_AUDIONODE_REFERENCES static bool s_isNodeCountInitialized; static int s_nodeCount[NodeTypeEnd]; #endif void refEventTarget() override { ref(); } void derefEventTarget() override { deref(); } protected: unsigned m_channelCount; ChannelCountMode m_channelCountMode; AudioBus::ChannelInterpretation m_channelInterpretation; }; } // namespace WebCore