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/*
* 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 AudioNode_h
#define AudioNode_h
#include <wtf/OwnPtr.h>
#include <wtf/PassOwnPtr.h>
#include <wtf/RefPtr.h>
#include <wtf/Vector.h>
#define DEBUG_AUDIONODE_REFERENCES 0
namespace WebCore {
class AudioContext;
class AudioNodeInput;
class AudioNodeOutput;
// 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:
enum { ProcessingSizeInFrames = 128 };
AudioNode(AudioContext*, double sampleRate);
virtual ~AudioNode();
AudioContext* context() { return m_context.get(); }
enum NodeType {
NodeTypeUnknown,
NodeTypeDestination,
NodeTypeAudioBufferSource,
NodeTypeJavaScript,
NodeTypeLowPass2Filter,
NodeTypeHighPass2Filter,
NodeTypePanner,
NodeTypeConvolver,
NodeTypeDelay,
NodeTypeGain,
NodeTypeChannelSplitter,
NodeTypeChannelMerger,
NodeTypeAnalyser,
NodeTypeEnd
};
NodeType type() const { return m_type; }
void setType(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, RefTypeDisabled };
// 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);
// connect() / disconnect() return true on success.
// Called from main thread by corresponding JavaScript methods.
bool connect(AudioNode* destination, unsigned outputIndex = 0, unsigned inputIndex = 0);
bool disconnect(unsigned outputIndex = 0);
double 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; }
protected:
// Inputs and outputs must be created before the AudioNode is initialized.
void addInput(PassOwnPtr<AudioNodeInput>);
void addOutput(PassOwnPtr<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);
private:
volatile bool m_isInitialized;
NodeType m_type;
RefPtr<AudioContext> m_context;
double m_sampleRate;
Vector<OwnPtr<AudioNodeInput> > m_inputs;
Vector<OwnPtr<AudioNodeOutput> > m_outputs;
double m_lastProcessingTime;
// Ref-counting
volatile int m_normalRefCount;
volatile int m_connectionRefCount;
volatile int m_disabledRefCount;
bool m_isMarkedForDeletion;
bool m_isDisabled;
#if DEBUG_AUDIONODE_REFERENCES
static bool s_isNodeCountInitialized;
static int s_nodeCount[NodeTypeEnd];
#endif
};
} // namespace WebCore
#endif // AudioNode_h
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