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* Copyright (C) 2012 Google Inc. All rights reserved.
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
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* its contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
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* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#ifndef AudioScheduledSourceNode_h
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#define AudioScheduledSourceNode_h
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#include "AudioSourceNode.h"
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class AudioScheduledSourceNode : public AudioSourceNode {
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// These are the possible states an AudioScheduledSourceNode can be in:
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// UNSCHEDULED_STATE - Initial playback state. Created, but not yet scheduled.
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// SCHEDULED_STATE - Scheduled to play (via noteOn() or noteGrainOn()), but not yet playing.
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// PLAYING_STATE - Generating sound.
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// FINISHED_STATE - Finished generating sound.
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// The state can only transition to the next state, except for the FINISHED_STATE which can
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// These must be defined with the same names and values as in the .idl file.
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UNSCHEDULED_STATE = 0,
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AudioScheduledSourceNode(AudioContext*, float sampleRate);
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void start(double when);
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void stop(double when);
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#if ENABLE(LEGACY_WEB_AUDIO)
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void noteOn(double when);
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void noteOff(double when);
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unsigned short playbackState() const { return static_cast<unsigned short>(m_playbackState); }
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bool isPlayingOrScheduled() const { return m_playbackState == PLAYING_STATE || m_playbackState == SCHEDULED_STATE; }
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bool hasFinished() const { return m_playbackState == FINISHED_STATE; }
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// Get frame information for the current time quantum.
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// We handle the transition into PLAYING_STATE and FINISHED_STATE here,
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// zeroing out portions of the outputBus which are outside the range of startFrame and endFrame.
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// Each frame time is relative to the context's currentSampleFrame().
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// quantumFrameOffset : Offset frame in this time quantum to start rendering.
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// nonSilentFramesToProcess : Number of frames rendering non-silence (will be <= quantumFrameSize).
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void updateSchedulingInfo(size_t quantumFrameSize,
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size_t& quantumFrameOffset,
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size_t& nonSilentFramesToProcess);
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// Called when we have no more sound to play or the noteOff() time has been reached.
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virtual void finish();
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PlaybackState m_playbackState;
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// 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").
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double m_startTime; // in seconds
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// 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").
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// 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
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double m_endTime; // in seconds
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static const double UnknownTime;
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} // namespace WebCore
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#endif // AudioScheduledSourceNode_h