1 /* 2 * Copyright (C) 2012 Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of 14 * its contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY 18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY 21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #ifndef AudioScheduledSourceNode_h 30 #define AudioScheduledSourceNode_h 31 32 #include "modules/webaudio/AudioSourceNode.h" 33 34 namespace blink { 35 36 class AudioBus; 37 38 class AudioScheduledSourceNode : public AudioSourceNode { 39 public: 40 // These are the possible states an AudioScheduledSourceNode can be in: 41 // 42 // UNSCHEDULED_STATE - Initial playback state. Created, but not yet scheduled. 43 // SCHEDULED_STATE - Scheduled to play (via start()), but not yet playing. 44 // PLAYING_STATE - Generating sound. 45 // FINISHED_STATE - Finished generating sound. 46 // 47 // The state can only transition to the next state, except for the FINISHED_STATE which can 48 // never be changed. 49 enum PlaybackState { 50 // These must be defined with the same names and values as in the .idl file. 51 UNSCHEDULED_STATE = 0, 52 SCHEDULED_STATE = 1, 53 PLAYING_STATE = 2, 54 FINISHED_STATE = 3 55 }; 56 57 AudioScheduledSourceNode(AudioContext*, float sampleRate); 58 59 // Scheduling. start(ExceptionState & exceptionState)60 void start(ExceptionState& exceptionState) { start(0.0, exceptionState); } 61 void start(double when, ExceptionState&); stop(ExceptionState & exceptionState)62 void stop(ExceptionState& exceptionState) { stop(0.0, exceptionState); } 63 void stop(double when, ExceptionState&); 64 playbackState()65 unsigned short playbackState() const { return static_cast<unsigned short>(m_playbackState); } isPlayingOrScheduled()66 bool isPlayingOrScheduled() const { return m_playbackState == PLAYING_STATE || m_playbackState == SCHEDULED_STATE; } hasFinished()67 bool hasFinished() const { return m_playbackState == FINISHED_STATE; } 68 onended()69 EventListener* onended() { return getAttributeEventListener(EventTypeNames::ended); } 70 void setOnended(PassRefPtr<EventListener>); 71 72 protected: 73 // Get frame information for the current time quantum. 74 // We handle the transition into PLAYING_STATE and FINISHED_STATE here, 75 // zeroing out portions of the outputBus which are outside the range of startFrame and endFrame. 76 // 77 // Each frame time is relative to the context's currentSampleFrame(). 78 // quantumFrameOffset : Offset frame in this time quantum to start rendering. 79 // nonSilentFramesToProcess : Number of frames rendering non-silence (will be <= quantumFrameSize). 80 void updateSchedulingInfo(size_t quantumFrameSize, 81 AudioBus* outputBus, 82 size_t& quantumFrameOffset, 83 size_t& nonSilentFramesToProcess); 84 85 // Called when we have no more sound to play or the noteOff() time has been reached. 86 virtual void finish(); 87 88 void notifyEnded(); 89 90 PlaybackState m_playbackState; 91 92 // 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"). 93 double m_startTime; // in seconds 94 95 // 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"). 96 // 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 97 // has been reached. 98 double m_endTime; // in seconds 99 100 bool m_hasEndedListener; 101 102 static const double UnknownTime; 103 }; 104 105 } // namespace blink 106 107 #endif // AudioScheduledSourceNode_h 108