/* * 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 ScriptProcessorNode_h #define ScriptProcessorNode_h #include "ActiveDOMObject.h" #include "AudioBus.h" #include "AudioNode.h" #include "EventListener.h" #include "EventTarget.h" #include <wtf/Forward.h> #include <wtf/PassRefPtr.h> #include <wtf/RefPtr.h> #include <wtf/Vector.h> namespace WebCore { class AudioBuffer; class AudioContext; class AudioProcessingEvent; // ScriptProcessorNode is an AudioNode which allows for arbitrary synthesis or processing directly using JavaScript. // The API allows for a variable number of inputs and outputs, although it must have at least one input or output. // This basic implementation supports no more than one input and output. // The "onaudioprocess" attribute is an event listener which will get called periodically with an AudioProcessingEvent which has // AudioBuffers for each input and output. class ScriptProcessorNode : public AudioNode { public: // bufferSize must be one of the following values: 256, 512, 1024, 2048, 4096, 8192, 16384. // This value controls how frequently the onaudioprocess event handler is called and how many sample-frames need to be processed each call. // Lower numbers for bufferSize will result in a lower (better) latency. Higher numbers will be necessary to avoid audio breakup and glitches. // The value chosen must carefully balance between latency and audio quality. static RefPtr<ScriptProcessorNode> create(AudioContext*, float sampleRate, size_t bufferSize, unsigned numberOfInputChannels, unsigned numberOfOutputChannels); virtual ~ScriptProcessorNode(); // AudioNode virtual void process(size_t framesToProcess) override; virtual void reset() override; virtual void initialize() override; virtual void uninitialize() override; size_t bufferSize() const { return m_bufferSize; } private: virtual double tailTime() const override; virtual double latencyTime() const override; ScriptProcessorNode(AudioContext*, float sampleRate, size_t bufferSize, unsigned numberOfInputChannels, unsigned numberOfOutputChannels); static void fireProcessEventDispatch(void* userData); void fireProcessEvent(); bool addEventListener(const AtomicString& eventType, PassRefPtr<EventListener>, bool useCapture) override; bool removeEventListener(const AtomicString& eventType, EventListener*, bool useCapture) override; void removeAllEventListeners() override; // Double buffering unsigned doubleBufferIndex() const { return m_doubleBufferIndex; } void swapBuffers() { m_doubleBufferIndex = 1 - m_doubleBufferIndex; } unsigned m_doubleBufferIndex; unsigned m_doubleBufferIndexForEvent; Vector<RefPtr<AudioBuffer>> m_inputBuffers; Vector<RefPtr<AudioBuffer>> m_outputBuffers; size_t m_bufferSize; unsigned m_bufferReadWriteIndex; volatile bool m_isRequestOutstanding; unsigned m_numberOfInputChannels; unsigned m_numberOfOutputChannels; RefPtr<AudioBus> m_internalInputBus; bool m_hasAudioProcessListener; }; } // namespace WebCore #endif // ScriptProcessorNode_h