| OLD | NEW |
| (Empty) |
| 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | |
| 2 // Use of this source code is governed by a BSD-style license that can be | |
| 3 // found in the LICENSE file. | |
| 4 | |
| 5 // Audio rendering unit utilizing an AudioRendererSink to output data. | |
| 6 // | |
| 7 // This class lives inside three threads during it's lifetime, namely: | |
| 8 // 1. Render thread | |
| 9 // Where the object is created. | |
| 10 // 2. Media thread (provided via constructor) | |
| 11 // All AudioDecoder methods are called on this thread. | |
| 12 // 3. Audio thread created by the AudioRendererSink. | |
| 13 // Render() is called here where audio data is decoded into raw PCM data. | |
| 14 // | |
| 15 // AudioRendererImpl talks to an AudioRendererAlgorithm that takes care of | |
| 16 // queueing audio data and stretching/shrinking audio data when playback rate != | |
| 17 // 1.0 or 0.0. | |
| 18 | |
| 19 #ifndef MEDIA_FILTERS_AUDIO_RENDERER_IMPL_H_ | |
| 20 #define MEDIA_FILTERS_AUDIO_RENDERER_IMPL_H_ | |
| 21 | |
| 22 #include <deque> | |
| 23 | |
| 24 #include "base/gtest_prod_util.h" | |
| 25 #include "base/memory/scoped_ptr.h" | |
| 26 #include "base/memory/weak_ptr.h" | |
| 27 #include "base/synchronization/lock.h" | |
| 28 #include "media/base/audio_decoder.h" | |
| 29 #include "media/base/audio_renderer.h" | |
| 30 #include "media/base/audio_renderer_sink.h" | |
| 31 #include "media/base/decryptor.h" | |
| 32 #include "media/base/media_log.h" | |
| 33 #include "media/base/time_source.h" | |
| 34 #include "media/filters/audio_renderer_algorithm.h" | |
| 35 #include "media/filters/decoder_stream.h" | |
| 36 | |
| 37 namespace base { | |
| 38 class SingleThreadTaskRunner; | |
| 39 } | |
| 40 | |
| 41 namespace media { | |
| 42 | |
| 43 class AudioBufferConverter; | |
| 44 class AudioBus; | |
| 45 class AudioClock; | |
| 46 class AudioHardwareConfig; | |
| 47 class AudioSplicer; | |
| 48 class DecryptingDemuxerStream; | |
| 49 | |
| 50 class MEDIA_EXPORT AudioRendererImpl | |
| 51 : public AudioRenderer, | |
| 52 public TimeSource, | |
| 53 NON_EXPORTED_BASE(public AudioRendererSink::RenderCallback) { | |
| 54 public: | |
| 55 // |task_runner| is the thread on which AudioRendererImpl will execute. | |
| 56 // | |
| 57 // |sink| is used as the destination for the rendered audio. | |
| 58 // | |
| 59 // |decoders| contains the AudioDecoders to use when initializing. | |
| 60 AudioRendererImpl( | |
| 61 const scoped_refptr<base::SingleThreadTaskRunner>& task_runner, | |
| 62 AudioRendererSink* sink, | |
| 63 ScopedVector<AudioDecoder> decoders, | |
| 64 const AudioHardwareConfig& hardware_config, | |
| 65 const scoped_refptr<MediaLog>& media_log); | |
| 66 ~AudioRendererImpl() override; | |
| 67 | |
| 68 // TimeSource implementation. | |
| 69 void StartTicking() override; | |
| 70 void StopTicking() override; | |
| 71 void SetPlaybackRate(float rate) override; | |
| 72 void SetMediaTime(base::TimeDelta time) override; | |
| 73 base::TimeDelta CurrentMediaTime() override; | |
| 74 base::TimeDelta CurrentMediaTimeForSyncingVideo() override; | |
| 75 | |
| 76 // AudioRenderer implementation. | |
| 77 void Initialize(DemuxerStream* stream, | |
| 78 const PipelineStatusCB& init_cb, | |
| 79 const SetDecryptorReadyCB& set_decryptor_ready_cb, | |
| 80 const StatisticsCB& statistics_cb, | |
| 81 const BufferingStateCB& buffering_state_cb, | |
| 82 const base::Closure& ended_cb, | |
| 83 const PipelineStatusCB& error_cb) override; | |
| 84 TimeSource* GetTimeSource() override; | |
| 85 void Flush(const base::Closure& callback) override; | |
| 86 void StartPlaying() override; | |
| 87 void SetVolume(float volume) override; | |
| 88 | |
| 89 private: | |
| 90 friend class AudioRendererImplTest; | |
| 91 | |
| 92 // Important detail: being in kPlaying doesn't imply that audio is being | |
| 93 // rendered. Rather, it means that the renderer is ready to go. The actual | |
| 94 // rendering of audio is controlled via Start/StopRendering(). | |
| 95 // | |
| 96 // kUninitialized | |
| 97 // | Initialize() | |
| 98 // | | |
| 99 // V | |
| 100 // kInitializing | |
| 101 // | Decoders initialized | |
| 102 // | | |
| 103 // V Decoders reset | |
| 104 // kFlushed <------------------ kFlushing | |
| 105 // | StartPlaying() ^ | |
| 106 // | | | |
| 107 // | | Flush() | |
| 108 // `---------> kPlaying --------' | |
| 109 enum State { | |
| 110 kUninitialized, | |
| 111 kInitializing, | |
| 112 kFlushing, | |
| 113 kFlushed, | |
| 114 kPlaying | |
| 115 }; | |
| 116 | |
| 117 // Callback from the audio decoder delivering decoded audio samples. | |
| 118 void DecodedAudioReady(AudioBufferStream::Status status, | |
| 119 const scoped_refptr<AudioBuffer>& buffer); | |
| 120 | |
| 121 // Handles buffers that come out of |splicer_|. | |
| 122 // Returns true if more buffers are needed. | |
| 123 bool HandleSplicerBuffer_Locked(const scoped_refptr<AudioBuffer>& buffer); | |
| 124 | |
| 125 // Helper functions for AudioDecoder::Status values passed to | |
| 126 // DecodedAudioReady(). | |
| 127 void HandleAbortedReadOrDecodeError(bool is_decode_error); | |
| 128 | |
| 129 void StartRendering_Locked(); | |
| 130 void StopRendering_Locked(); | |
| 131 | |
| 132 // AudioRendererSink::RenderCallback implementation. | |
| 133 // | |
| 134 // NOTE: These are called on the audio callback thread! | |
| 135 // | |
| 136 // Render() fills the given buffer with audio data by delegating to its | |
| 137 // |algorithm_|. Render() also takes care of updating the clock. | |
| 138 // Returns the number of frames copied into |audio_bus|, which may be less | |
| 139 // than or equal to the initial number of frames in |audio_bus| | |
| 140 // | |
| 141 // If this method returns fewer frames than the initial number of frames in | |
| 142 // |audio_bus|, it could be a sign that the pipeline is stalled or unable to | |
| 143 // stream the data fast enough. In such scenarios, the callee should zero out | |
| 144 // unused portions of their buffer to play back silence. | |
| 145 // | |
| 146 // Render() updates the pipeline's playback timestamp. If Render() is | |
| 147 // not called at the same rate as audio samples are played, then the reported | |
| 148 // timestamp in the pipeline will be ahead of the actual audio playback. In | |
| 149 // this case |audio_delay_milliseconds| should be used to indicate when in the | |
| 150 // future should the filled buffer be played. | |
| 151 int Render(AudioBus* audio_bus, int audio_delay_milliseconds) override; | |
| 152 void OnRenderError() override; | |
| 153 | |
| 154 // Helper methods that schedule an asynchronous read from the decoder as long | |
| 155 // as there isn't a pending read. | |
| 156 // | |
| 157 // Must be called on |task_runner_|. | |
| 158 void AttemptRead(); | |
| 159 void AttemptRead_Locked(); | |
| 160 bool CanRead_Locked(); | |
| 161 void ChangeState_Locked(State new_state); | |
| 162 | |
| 163 // Returns true if the data in the buffer is all before |start_timestamp_|. | |
| 164 // This can only return true while in the kPlaying state. | |
| 165 bool IsBeforeStartTime(const scoped_refptr<AudioBuffer>& buffer); | |
| 166 | |
| 167 // Called upon AudioBufferStream initialization, or failure thereof (indicated | |
| 168 // by the value of |success|). | |
| 169 void OnAudioBufferStreamInitialized(bool succes); | |
| 170 | |
| 171 // Used to initiate the flush operation once all pending reads have | |
| 172 // completed. | |
| 173 void DoFlush_Locked(); | |
| 174 | |
| 175 // Calls |decoder_|.Reset() and arranges for ResetDecoderDone() to get | |
| 176 // called when the reset completes. | |
| 177 void ResetDecoder(); | |
| 178 | |
| 179 // Called when the |decoder_|.Reset() has completed. | |
| 180 void ResetDecoderDone(); | |
| 181 | |
| 182 // Called by the AudioBufferStream when a splice buffer is demuxed. | |
| 183 void OnNewSpliceBuffer(base::TimeDelta); | |
| 184 | |
| 185 // Called by the AudioBufferStream when a config change occurs. | |
| 186 void OnConfigChange(); | |
| 187 | |
| 188 // Updates |buffering_state_| and fires |buffering_state_cb_|. | |
| 189 void SetBufferingState_Locked(BufferingState buffering_state); | |
| 190 | |
| 191 scoped_refptr<base::SingleThreadTaskRunner> task_runner_; | |
| 192 | |
| 193 scoped_ptr<AudioSplicer> splicer_; | |
| 194 scoped_ptr<AudioBufferConverter> buffer_converter_; | |
| 195 | |
| 196 // Whether or not we expect to handle config changes. | |
| 197 bool expecting_config_changes_; | |
| 198 | |
| 199 // The sink (destination) for rendered audio. |sink_| must only be accessed | |
| 200 // on |task_runner_|. |sink_| must never be called under |lock_| or else we | |
| 201 // may deadlock between |task_runner_| and the audio callback thread. | |
| 202 scoped_refptr<media::AudioRendererSink> sink_; | |
| 203 | |
| 204 scoped_ptr<AudioBufferStream> audio_buffer_stream_; | |
| 205 | |
| 206 // Interface to the hardware audio params. | |
| 207 const AudioHardwareConfig& hardware_config_; | |
| 208 | |
| 209 // Cached copy of hardware params from |hardware_config_|. | |
| 210 AudioParameters audio_parameters_; | |
| 211 | |
| 212 // Callbacks provided during Initialize(). | |
| 213 PipelineStatusCB init_cb_; | |
| 214 BufferingStateCB buffering_state_cb_; | |
| 215 base::Closure ended_cb_; | |
| 216 PipelineStatusCB error_cb_; | |
| 217 | |
| 218 // Callback provided to Flush(). | |
| 219 base::Closure flush_cb_; | |
| 220 | |
| 221 // After Initialize() has completed, all variables below must be accessed | |
| 222 // under |lock_|. ------------------------------------------------------------ | |
| 223 base::Lock lock_; | |
| 224 | |
| 225 // Algorithm for scaling audio. | |
| 226 float playback_rate_; | |
| 227 scoped_ptr<AudioRendererAlgorithm> algorithm_; | |
| 228 | |
| 229 // Simple state tracking variable. | |
| 230 State state_; | |
| 231 | |
| 232 BufferingState buffering_state_; | |
| 233 | |
| 234 // Keep track of whether or not the sink is playing and whether we should be | |
| 235 // rendering. | |
| 236 bool rendering_; | |
| 237 bool sink_playing_; | |
| 238 | |
| 239 // Keep track of our outstanding read to |decoder_|. | |
| 240 bool pending_read_; | |
| 241 | |
| 242 // Keeps track of whether we received and rendered the end of stream buffer. | |
| 243 bool received_end_of_stream_; | |
| 244 bool rendered_end_of_stream_; | |
| 245 | |
| 246 scoped_ptr<AudioClock> audio_clock_; | |
| 247 | |
| 248 // The media timestamp to begin playback at after seeking. Set via | |
| 249 // SetMediaTime(). | |
| 250 base::TimeDelta start_timestamp_; | |
| 251 | |
| 252 // The media timestamp to signal end of audio playback. Determined during | |
| 253 // Render() when writing the final frames of decoded audio data. | |
| 254 base::TimeDelta ended_timestamp_; | |
| 255 | |
| 256 // Set every Render() and used to provide an interpolated time value to | |
| 257 // CurrentMediaTimeForSyncingVideo(). | |
| 258 base::TimeTicks last_render_ticks_; | |
| 259 | |
| 260 // Set upon receipt of the first decoded buffer after a StartPlayingFrom(). | |
| 261 // Used to determine how long to delay playback. | |
| 262 base::TimeDelta first_packet_timestamp_; | |
| 263 | |
| 264 // End variables which must be accessed under |lock_|. ---------------------- | |
| 265 | |
| 266 // NOTE: Weak pointers must be invalidated before all other member variables. | |
| 267 base::WeakPtrFactory<AudioRendererImpl> weak_factory_; | |
| 268 | |
| 269 DISALLOW_COPY_AND_ASSIGN(AudioRendererImpl); | |
| 270 }; | |
| 271 | |
| 272 } // namespace media | |
| 273 | |
| 274 #endif // MEDIA_FILTERS_AUDIO_RENDERER_IMPL_H_ | |
| OLD | NEW |