gecko-dev/content/media/nsAudioAvailableEventManager.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef nsAudioAvailableEventManager_h__
#define nsAudioAvailableEventManager_h__
#include "nsCOMPtr.h"
#include "nsIRunnable.h"
#include "nsBuiltinDecoder.h"
#include "nsBuiltinDecoderReader.h"
using namespace mozilla;
class nsAudioAvailableEventManager
{
public:
nsAudioAvailableEventManager(nsBuiltinDecoder* aDecoder);
~nsAudioAvailableEventManager();
// Initialize the event manager with audio metadata. Called before
// audio begins to get queued or events are dispatched.
void Init(uint32_t aChannels, uint32_t aRate);
// Dispatch pending MozAudioAvailable events in the queue. Called
// from the state machine thread.
void DispatchPendingEvents(uint64_t aCurrentTime);
// Queues audio sample data and re-packages it into equal sized
// framebuffers. Called from the audio thread.
void QueueWrittenAudioData(AudioDataValue* aAudioData,
uint32_t aAudioDataLength,
uint64_t aEndTimeSampleOffset);
// Clears the queue of any existing events. Called from both the state
// machine and audio threads.
void Clear();
// Fires one last event for any extra samples that didn't fit in a whole
// framebuffer. This is meant to be called only once when the audio finishes.
// Called from the state machine thread.
void Drain(uint64_t aTime);
// Sets the size of the signal buffer.
// Called from the main and the state machine thread.
void SetSignalBufferLength(uint32_t aLength);
// Called by the media element to notify the manager that there is a
// listener on the "MozAudioAvailable" event, and that we need to dispatch
// such events. Called from the main thread.
void NotifyAudioAvailableListener();
private:
// The decoder associated with the event manager. The event manager shares
// the same lifetime as the decoder (the decoder holds a reference to the
// manager).
nsBuiltinDecoder* mDecoder;
// The number of samples per second.
float mSamplesPerSecond;
// A buffer for audio data to be dispatched in DOM events.
nsAutoArrayPtr<float> mSignalBuffer;
// The current size of the signal buffer, may change due to DOM calls.
uint32_t mSignalBufferLength;
// The size of the new signal buffer, may change due to DOM calls.
uint32_t mNewSignalBufferLength;
// The position of the first available item in mSignalBuffer
uint32_t mSignalBufferPosition;
// The MozAudioAvailable events to be dispatched. This queue is shared
// between the state machine and audio threads.
nsTArray< nsCOMPtr<nsIRunnable> > mPendingEvents;
// ReentrantMonitor for shared access to mPendingEvents queue or
// buffer length.
ReentrantMonitor mReentrantMonitor;
// True if something in the owning document has a listener on the
// "MozAudioAvailable" event. If not, we don't need to bother copying played
// audio data and dispatching the event. Synchronized by mReentrantMonitor.
bool mHasListener;
};
#endif