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/*
* Copyright (C) 2012 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.
* 3. Neither the name of Apple Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE 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 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 "ActiveDOMObject.h"
#include "AudioNode.h"
namespace WebCore {
class AudioScheduledSourceNode : public AudioNode, public ActiveDOMObject {
WTF_MAKE_TZONE_OR_ISO_ALLOCATED(AudioScheduledSourceNode);
public:
// ActiveDOMObject.
void ref() const final { AudioNode::ref(); }
void deref() const final { AudioNode::deref(); }
// These are the possible states an AudioScheduledSourceNode can be in:
//
// UNSCHEDULED_STATE - Initial playback state. Created, but not yet scheduled.
// SCHEDULED_STATE - Scheduled to play but not yet playing.
// PLAYING_STATE - Generating sound.
// FINISHED_STATE - Finished generating sound.
//
// The state can only transition to the next state, except for the FINISHED_STATE which can
// never be changed.
enum PlaybackState {
// These must be defined with the same names and values as in the .idl file.
UNSCHEDULED_STATE = 0,
SCHEDULED_STATE = 1,
PLAYING_STATE = 2,
FINISHED_STATE = 3
};
ExceptionOr<void> startLater(double when);
ExceptionOr<void> stopLater(double when);
unsigned short playbackState() const { return static_cast<unsigned short>(m_playbackState); }
bool isPlayingOrScheduled() const { return m_playbackState == PLAYING_STATE || m_playbackState == SCHEDULED_STATE; }
bool hasFinished() const { return m_playbackState == FINISHED_STATE; }
protected:
AudioScheduledSourceNode(BaseAudioContext&, NodeType);
// Get frame information for the current time quantum.
// We handle the transition into PLAYING_STATE and FINISHED_STATE here,
// zeroing out portions of the outputBus which are outside the range of startFrame and endFrame.
// Each frame time is relative to the context's currentSampleFrame().
// quantumFrameOffset: Offset frame in this time quantum to start rendering.
// nonSilentFramesToProcess: Number of frames rendering non-silence (will be <= quantumFrameSize).
// startFrameOffset : The fractional frame offset from quantumFrameOffset and the actual starting
// time of the source. This is non-zero only when transitioning from the
// SCHEDULED_STATE to the PLAYING_STATE.
void updateSchedulingInfo(size_t quantumFrameSize, AudioBus& outputBus, size_t& quantumFrameOffset, size_t& nonSilentFramesToProcess, double& startFrameOffset);
// Called when we have no more sound to play or the noteOff() time has been reached.
virtual void finish();
// ActiveDOMObject.
bool virtualHasPendingActivity() const final;
void eventListenersDidChange() final;
bool requiresTailProcessing() const final { return false; }
// This is accessed from the main thread and the audio thread.
std::atomic<PlaybackState> m_playbackState { UNSCHEDULED_STATE };
// m_startTime is the time to start playing based on the context's timeline (0 or a time less than the context's current time means "now").
double m_startTime { 0 }; // in seconds
// m_endTime is the time to stop playing based on the context's timeline (0 or a time less than the context's current time means "now").
// If it hasn't been set explicitly, then the sound will not stop playing (if looping) or will stop when the end of the AudioBuffer
// has been reached.
std::optional<double> m_endTime; // in seconds
bool m_hasEndedEventListener { false };
};
} // namespace WebCore
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