AudioTrack.h revision e4756fe3a387615acb63c6a05788c8db9b5786cb
15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/* 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Copyright (C) 2007 The Android Open Source Project 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Licensed under the Apache License, Version 2.0 (the "License"); 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * you may not use this file except in compliance with the License. 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * You may obtain a copy of the License at 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 87d4cd473f85ac64c3747c96c277f9e506a0d2246Torne (Richard Coles) * http://www.apache.org/licenses/LICENSE-2.0 92a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) * 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Unless required by applicable law or agreed to in writing, software 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * distributed under the License is distributed on an "AS IS" BASIS, 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * See the License for the specific language governing permissions and 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * limitations under the License. 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 162a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifndef ANDROID_AUDIOTRACK_H 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#define ANDROID_AUDIOTRACK_H 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <stdint.h> 212a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#include <sys/types.h> 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <media/IAudioFlinger.h> 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <media/IAudioTrack.h> 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <media/AudioSystem.h> 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <utils/RefBase.h> 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <utils/Errors.h> 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <binder/IInterface.h> 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <binder/IMemory.h> 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <cutils/sched_policy.h> 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <utils/threads.h> 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace android { 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// ---------------------------------------------------------------------------- 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class audio_track_cblk_t; 39 40// ---------------------------------------------------------------------------- 41 42class AudioTrack : virtual public RefBase 43{ 44public: 45 enum channel_index { 46 MONO = 0, 47 LEFT = 0, 48 RIGHT = 1 49 }; 50 51 /* Events used by AudioTrack callback function (audio_track_cblk_t). 52 * Keep in sync with frameworks/base/media/java/android/media/AudioTrack.java NATIVE_EVENT_*. 53 */ 54 enum event_type { 55 EVENT_MORE_DATA = 0, // Request to write more data to PCM buffer. 56 EVENT_UNDERRUN = 1, // PCM buffer underrun occurred. 57 EVENT_LOOP_END = 2, // Sample loop end was reached; playback restarted from 58 // loop start if loop count was not 0. 59 EVENT_MARKER = 3, // Playback head is at the specified marker position 60 // (See setMarkerPosition()). 61 EVENT_NEW_POS = 4, // Playback head is at a new position 62 // (See setPositionUpdatePeriod()). 63 EVENT_BUFFER_END = 5 // Playback head is at the end of the buffer. 64 }; 65 66 /* Client should declare Buffer on the stack and pass address to obtainBuffer() 67 * and releaseBuffer(). See also callback_t for EVENT_MORE_DATA. 68 */ 69 70 class Buffer 71 { 72 public: 73 size_t frameCount; // number of sample frames corresponding to size; 74 // on input it is the number of frames desired, 75 // on output is the number of frames actually filled 76 77 size_t size; // input/output in byte units 78 union { 79 void* raw; 80 short* i16; // signed 16-bit 81 int8_t* i8; // unsigned 8-bit, offset by 0x80 82 }; 83 }; 84 85 86 /* As a convenience, if a callback is supplied, a handler thread 87 * is automatically created with the appropriate priority. This thread 88 * invokes the callback when a new buffer becomes available or various conditions occur. 89 * Parameters: 90 * 91 * event: type of event notified (see enum AudioTrack::event_type). 92 * user: Pointer to context for use by the callback receiver. 93 * info: Pointer to optional parameter according to event type: 94 * - EVENT_MORE_DATA: pointer to AudioTrack::Buffer struct. The callback must not write 95 * more bytes than indicated by 'size' field and update 'size' if fewer bytes are 96 * written. 97 * - EVENT_UNDERRUN: unused. 98 * - EVENT_LOOP_END: pointer to an int indicating the number of loops remaining. 99 * - EVENT_MARKER: pointer to an uint32_t containing the marker position in frames. 100 * - EVENT_NEW_POS: pointer to an uint32_t containing the new position in frames. 101 * - EVENT_BUFFER_END: unused. 102 */ 103 104 typedef void (*callback_t)(int event, void* user, void *info); 105 106 /* Returns the minimum frame count required for the successful creation of 107 * an AudioTrack object. 108 * Returned status (from utils/Errors.h) can be: 109 * - NO_ERROR: successful operation 110 * - NO_INIT: audio server or audio hardware not initialized 111 */ 112 113 static status_t getMinFrameCount(size_t* frameCount, 114 audio_stream_type_t streamType = AUDIO_STREAM_DEFAULT, 115 uint32_t sampleRate = 0); 116 117 /* Constructs an uninitialized AudioTrack. No connection with 118 * AudioFlinger takes place. 119 */ 120 AudioTrack(); 121 122 /* Creates an AudioTrack object and registers it with AudioFlinger. 123 * Once created, the track needs to be started before it can be used. 124 * Unspecified values are set to the audio hardware's current 125 * values. 126 * 127 * Parameters: 128 * 129 * streamType: Select the type of audio stream this track is attached to 130 * (e.g. AUDIO_STREAM_MUSIC). 131 * sampleRate: Track sampling rate in Hz. 132 * format: Audio format (e.g AUDIO_FORMAT_PCM_16_BIT for signed 133 * 16 bits per sample). 134 * channelMask: Channel mask. 135 * frameCount: Minimum size of track PCM buffer in frames. This defines the 136 * application's contribution to the 137 * latency of the track. The actual size selected by the AudioTrack could be 138 * larger if the requested size is not compatible with current audio HAL 139 * latency. Zero means to use a default value. 140 * flags: See comments on audio_output_flags_t in <system/audio.h>. 141 * cbf: Callback function. If not null, this function is called periodically 142 * to provide new PCM data. 143 * user: Context for use by the callback receiver. 144 * notificationFrames: The callback function is called each time notificationFrames PCM 145 * frames have been consumed from track input buffer. 146 * sessionId: Specific session ID, or zero to use default. 147 * threadCanCallJava: Whether callbacks are made from an attached thread and thus can call JNI. 148 * If not present in parameter list, then fixed at false. 149 */ 150 151 AudioTrack( audio_stream_type_t streamType, 152 uint32_t sampleRate = 0, 153 audio_format_t format = AUDIO_FORMAT_DEFAULT, 154 audio_channel_mask_t channelMask = 0, 155 int frameCount = 0, 156 audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE, 157 callback_t cbf = NULL, 158 void* user = NULL, 159 int notificationFrames = 0, 160 int sessionId = 0); 161 162 /* Creates an audio track and registers it with AudioFlinger. With this constructor, 163 * the PCM data to be rendered by AudioTrack is passed in a shared memory buffer 164 * identified by the argument sharedBuffer. This prototype is for static buffer playback. 165 * PCM data must be present in memory before the AudioTrack is started. 166 * The write() and flush() methods are not supported in this case. 167 * It is recommended to pass a callback function to be notified of playback end by an 168 * EVENT_UNDERRUN event. 169 */ 170 171 AudioTrack( audio_stream_type_t streamType, 172 uint32_t sampleRate = 0, 173 audio_format_t format = AUDIO_FORMAT_DEFAULT, 174 audio_channel_mask_t channelMask = 0, 175 const sp<IMemory>& sharedBuffer = 0, 176 audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE, 177 callback_t cbf = NULL, 178 void* user = NULL, 179 int notificationFrames = 0, 180 int sessionId = 0); 181 182 /* Terminates the AudioTrack and unregisters it from AudioFlinger. 183 * Also destroys all resources associated with the AudioTrack. 184 */ 185 ~AudioTrack(); 186 187 188 /* Initialize an uninitialized AudioTrack. 189 * Returned status (from utils/Errors.h) can be: 190 * - NO_ERROR: successful initialization 191 * - INVALID_OPERATION: AudioTrack is already initialized 192 * - BAD_VALUE: invalid parameter (channelMask, format, sampleRate...) 193 * - NO_INIT: audio server or audio hardware not initialized 194 */ 195 status_t set(audio_stream_type_t streamType = AUDIO_STREAM_DEFAULT, 196 uint32_t sampleRate = 0, 197 audio_format_t format = AUDIO_FORMAT_DEFAULT, 198 audio_channel_mask_t channelMask = 0, 199 int frameCount = 0, 200 audio_output_flags_t flags = AUDIO_OUTPUT_FLAG_NONE, 201 callback_t cbf = NULL, 202 void* user = NULL, 203 int notificationFrames = 0, 204 const sp<IMemory>& sharedBuffer = 0, 205 bool threadCanCallJava = false, 206 int sessionId = 0); 207 208 209 /* Result of constructing the AudioTrack. This must be checked 210 * before using any AudioTrack API (except for set()), because using 211 * an uninitialized AudioTrack produces undefined results. 212 * See set() method above for possible return codes. 213 */ 214 status_t initCheck() const { return mStatus; } 215 216 /* Returns this track's estimated latency in milliseconds. 217 * This includes the latency due to AudioTrack buffer size, AudioMixer (if any) 218 * and audio hardware driver. 219 */ 220 uint32_t latency() const { return mLatency; } 221 222 /* getters, see constructors and set() */ 223 224 audio_stream_type_t streamType() const { return mStreamType; } 225 audio_format_t format() const { return mFormat; } 226 227 /* Return channelCount * (bit depth per channel / 8). 228 * channelCount is determined from channelMask, and bit depth comes from format. 229 */ 230 uint32_t channelCount() const { return mChannelCount; } 231 232 uint32_t frameCount() const { return mFrameCount; } 233 size_t frameSize() const { return mFrameSize; } 234 235 sp<IMemory> sharedBuffer() const { return mSharedBuffer; } 236 237 238 /* After it's created the track is not active. Call start() to 239 * make it active. If set, the callback will start being called. 240 */ 241 void start(); 242 243 /* Stop a track. If set, the callback will cease being called and 244 * obtainBuffer returns STOPPED. Note that obtainBuffer() still works 245 * and will fill up buffers until the pool is exhausted. 246 */ 247 void stop(); 248 bool stopped() const; 249 250 /* Flush a stopped track. All pending buffers are discarded. 251 * This function has no effect if the track is not stopped. 252 */ 253 void flush(); 254 255 /* Pause a track. If set, the callback will cease being called and 256 * obtainBuffer returns STOPPED. Note that obtainBuffer() still works 257 * and will fill up buffers until the pool is exhausted. 258 */ 259 void pause(); 260 261 /* Set volume for this track, mostly used for games' sound effects 262 * left and right volumes. Levels must be >= 0.0 and <= 1.0. 263 * This is the older API. New applications should use setVolume(float) when possible. 264 */ 265 status_t setVolume(float left, float right); 266 267 /* Set volume for all channels. This is the preferred API for new applications, 268 * especially for multi-channel content. 269 */ 270 status_t setVolume(float volume); 271 272 /* Set the send level for this track. An auxiliary effect should be attached 273 * to the track with attachEffect(). Level must be >= 0.0 and <= 1.0. 274 */ 275 status_t setAuxEffectSendLevel(float level); 276 void getAuxEffectSendLevel(float* level) const; 277 278 /* Set sample rate for this track in Hz, mostly used for games' sound effects 279 */ 280 status_t setSampleRate(uint32_t sampleRate); 281 282 /* Return current sample rate in Hz, or 0 if unknown */ 283 uint32_t getSampleRate() const; 284 285 /* Enables looping and sets the start and end points of looping. 286 * 287 * Parameters: 288 * 289 * loopStart: loop start expressed as the number of PCM frames played since AudioTrack start. 290 * loopEnd: loop end expressed as the number of PCM frames played since AudioTrack start. 291 * loopCount: number of loops to execute. Calling setLoop() with loopCount == 0 cancels any 292 * pending or active loop. loopCount = -1 means infinite looping. 293 * 294 * For proper operation the following condition must be respected: 295 * (loopEnd-loopStart) <= framecount() 296 */ 297 status_t setLoop(uint32_t loopStart, uint32_t loopEnd, int loopCount); 298 299 /* Sets marker position. When playback reaches the number of frames specified, a callback with 300 * event type EVENT_MARKER is called. Calling setMarkerPosition with marker == 0 cancels marker 301 * notification callback. 302 * If the AudioTrack has been opened with no callback function associated, the operation will 303 * fail. 304 * 305 * Parameters: 306 * 307 * marker: marker position expressed in frames. 308 * 309 * Returned status (from utils/Errors.h) can be: 310 * - NO_ERROR: successful operation 311 * - INVALID_OPERATION: the AudioTrack has no callback installed. 312 */ 313 status_t setMarkerPosition(uint32_t marker); 314 status_t getMarkerPosition(uint32_t *marker) const; 315 316 317 /* Sets position update period. Every time the number of frames specified has been played, 318 * a callback with event type EVENT_NEW_POS is called. 319 * Calling setPositionUpdatePeriod with updatePeriod == 0 cancels new position notification 320 * callback. 321 * If the AudioTrack has been opened with no callback function associated, the operation will 322 * fail. 323 * 324 * Parameters: 325 * 326 * updatePeriod: position update notification period expressed in frames. 327 * 328 * Returned status (from utils/Errors.h) can be: 329 * - NO_ERROR: successful operation 330 * - INVALID_OPERATION: the AudioTrack has no callback installed. 331 */ 332 status_t setPositionUpdatePeriod(uint32_t updatePeriod); 333 status_t getPositionUpdatePeriod(uint32_t *updatePeriod) const; 334 335 /* Sets playback head position within AudioTrack buffer. The new position is specified 336 * in number of frames. 337 * This method must be called with the AudioTrack in paused or stopped state. 338 * Note that the actual position set is <position> modulo the AudioTrack buffer size in frames. 339 * Therefore using this method makes sense only when playing a "static" audio buffer 340 * as opposed to streaming. 341 * The getPosition() method on the other hand returns the total number of frames played since 342 * playback start. 343 * 344 * Parameters: 345 * 346 * position: New playback head position within AudioTrack buffer. 347 * 348 * Returned status (from utils/Errors.h) can be: 349 * - NO_ERROR: successful operation 350 * - INVALID_OPERATION: the AudioTrack is not stopped. 351 * - BAD_VALUE: The specified position is beyond the number of frames present in AudioTrack 352 * buffer 353 */ 354 status_t setPosition(uint32_t position); 355 status_t getPosition(uint32_t *position); 356 357 /* Forces AudioTrack buffer full condition. When playing a static buffer, this method avoids 358 * rewriting the buffer before restarting playback after a stop. 359 * This method must be called with the AudioTrack in paused or stopped state. 360 * 361 * Returned status (from utils/Errors.h) can be: 362 * - NO_ERROR: successful operation 363 * - INVALID_OPERATION: the AudioTrack is not stopped. 364 */ 365 status_t reload(); 366 367 /* Returns a handle on the audio output used by this AudioTrack. 368 * 369 * Parameters: 370 * none. 371 * 372 * Returned value: 373 * handle on audio hardware output 374 */ 375 audio_io_handle_t getOutput(); 376 377 /* Returns the unique session ID associated with this track. 378 * 379 * Parameters: 380 * none. 381 * 382 * Returned value: 383 * AudioTrack session ID. 384 */ 385 int getSessionId() const { return mSessionId; } 386 387 /* Attach track auxiliary output to specified effect. Use effectId = 0 388 * to detach track from effect. 389 * 390 * Parameters: 391 * 392 * effectId: effectId obtained from AudioEffect::id(). 393 * 394 * Returned status (from utils/Errors.h) can be: 395 * - NO_ERROR: successful operation 396 * - INVALID_OPERATION: the effect is not an auxiliary effect. 397 * - BAD_VALUE: The specified effect ID is invalid 398 */ 399 status_t attachAuxEffect(int effectId); 400 401 /* Obtains a buffer of "frameCount" frames. The buffer must be 402 * filled entirely, and then released with releaseBuffer(). 403 * If the track is stopped, obtainBuffer() returns 404 * STOPPED instead of NO_ERROR as long as there are buffers available, 405 * at which point NO_MORE_BUFFERS is returned. 406 * Buffers will be returned until the pool 407 * is exhausted, at which point obtainBuffer() will either block 408 * or return WOULD_BLOCK depending on the value of the "blocking" 409 * parameter. 410 * 411 * Interpretation of waitCount: 412 * +n limits wait time to n * WAIT_PERIOD_MS, 413 * -1 causes an (almost) infinite wait time, 414 * 0 non-blocking. 415 * 416 * Buffer fields 417 * On entry: 418 * frameCount number of frames requested 419 * After error return: 420 * frameCount 0 421 * size 0 422 * raw undefined 423 * After successful return: 424 * frameCount actual number of frames available, <= number requested 425 * size actual number of bytes available 426 * raw pointer to the buffer 427 */ 428 429 enum { 430 NO_MORE_BUFFERS = 0x80000001, // same name in AudioFlinger.h, ok to be different value 431 STOPPED = 1 432 }; 433 434 status_t obtainBuffer(Buffer* audioBuffer, int32_t waitCount); 435 436 /* Release a filled buffer of "frameCount" frames for AudioFlinger to process. */ 437 void releaseBuffer(Buffer* audioBuffer); 438 439 /* As a convenience we provide a write() interface to the audio buffer. 440 * This is implemented on top of obtainBuffer/releaseBuffer. For best 441 * performance use callbacks. Returns actual number of bytes written >= 0, 442 * or one of the following negative status codes: 443 * INVALID_OPERATION AudioTrack is configured for shared buffer mode 444 * BAD_VALUE size is invalid 445 * STOPPED AudioTrack was stopped during the write 446 * NO_MORE_BUFFERS when obtainBuffer() returns same 447 * or any other error code returned by IAudioTrack::start() or restoreTrack_l(). 448 */ 449 ssize_t write(const void* buffer, size_t size); 450 451 /* 452 * Dumps the state of an audio track. 453 */ 454 status_t dump(int fd, const Vector<String16>& args) const; 455 456protected: 457 /* copying audio tracks is not allowed */ 458 AudioTrack(const AudioTrack& other); 459 AudioTrack& operator = (const AudioTrack& other); 460 461 /* a small internal class to handle the callback */ 462 class AudioTrackThread : public Thread 463 { 464 public: 465 AudioTrackThread(AudioTrack& receiver, bool bCanCallJava = false); 466 467 // Do not call Thread::requestExitAndWait() without first calling requestExit(). 468 // Thread::requestExitAndWait() is not virtual, and the implementation doesn't do enough. 469 virtual void requestExit(); 470 471 void pause(); // suspend thread from execution at next loop boundary 472 void resume(); // allow thread to execute, if not requested to exit 473 474 private: 475 friend class AudioTrack; 476 virtual bool threadLoop(); 477 AudioTrack& mReceiver; 478 ~AudioTrackThread(); 479 Mutex mMyLock; // Thread::mLock is private 480 Condition mMyCond; // Thread::mThreadExitedCondition is private 481 bool mPaused; // whether thread is currently paused 482 }; 483 484 // body of AudioTrackThread::threadLoop() 485 bool processAudioBuffer(const sp<AudioTrackThread>& thread); 486 487 // caller must hold lock on mLock for all _l methods 488 status_t createTrack_l(audio_stream_type_t streamType, 489 uint32_t sampleRate, 490 audio_format_t format, 491 size_t frameCount, 492 audio_output_flags_t flags, 493 const sp<IMemory>& sharedBuffer, 494 audio_io_handle_t output); 495 void flush_l(); 496 status_t setLoop_l(uint32_t loopStart, uint32_t loopEnd, int loopCount); 497 audio_io_handle_t getOutput_l(); 498 status_t restoreTrack_l(audio_track_cblk_t*& cblk, bool fromStart); 499 bool stopped_l() const { return !mActive; } 500 501 sp<IAudioTrack> mAudioTrack; 502 sp<IMemory> mCblkMemory; 503 sp<AudioTrackThread> mAudioTrackThread; 504 505 float mVolume[2]; 506 float mSendLevel; 507 size_t mFrameCount; // corresponds to current IAudioTrack 508 size_t mReqFrameCount; // frame count to request the next time a new 509 // IAudioTrack is needed 510 511 audio_track_cblk_t* mCblk; // re-load after mLock.unlock() 512 513 // Starting address of buffers in shared memory. If there is a shared buffer, mBuffers 514 // is the value of pointer() for the shared buffer, otherwise mBuffers points 515 // immediately after the control block. This address is for the mapping within client 516 // address space. AudioFlinger::TrackBase::mBuffer is for the server address space. 517 void* mBuffers; 518 519 audio_format_t mFormat; // as requested by client, not forced to 16-bit 520 audio_stream_type_t mStreamType; 521 uint32_t mChannelCount; 522 audio_channel_mask_t mChannelMask; 523 524 // mFrameSize is equal to mFrameSizeAF for non-PCM or 16-bit PCM data. 525 // For 8-bit PCM data, mFrameSizeAF is 526 // twice as large because data is expanded to 16-bit before being stored in buffer. 527 size_t mFrameSize; // app-level frame size 528 size_t mFrameSizeAF; // AudioFlinger frame size 529 530 status_t mStatus; 531 uint32_t mLatency; 532 533 bool mActive; // protected by mLock 534 535 callback_t mCbf; // callback handler for events, or NULL 536 void* mUserData; // for client callback handler 537 538 // for notification APIs 539 uint32_t mNotificationFramesReq; // requested number of frames between each 540 // notification callback 541 uint32_t mNotificationFramesAct; // actual number of frames between each 542 // notification callback 543 sp<IMemory> mSharedBuffer; 544 int mLoopCount; 545 uint32_t mRemainingFrames; 546 uint32_t mMarkerPosition; // in frames 547 bool mMarkerReached; 548 uint32_t mNewPosition; // in frames 549 uint32_t mUpdatePeriod; // in frames 550 551 bool mFlushed; // FIXME will be made obsolete by making flush() synchronous 552 audio_output_flags_t mFlags; 553 int mSessionId; 554 int mAuxEffectId; 555 556 // When locking both mLock and mCblk->lock, must lock in this order to avoid deadlock: 557 // 1. mLock 558 // 2. mCblk->lock 559 // It is OK to lock only mCblk->lock. 560 mutable Mutex mLock; 561 562 bool mIsTimed; 563 int mPreviousPriority; // before start() 564 SchedPolicy mPreviousSchedulingGroup; 565}; 566 567class TimedAudioTrack : public AudioTrack 568{ 569public: 570 TimedAudioTrack(); 571 572 /* allocate a shared memory buffer that can be passed to queueTimedBuffer */ 573 status_t allocateTimedBuffer(size_t size, sp<IMemory>* buffer); 574 575 /* queue a buffer obtained via allocateTimedBuffer for playback at the 576 given timestamp. PTS units are microseconds on the media time timeline. 577 The media time transform (set with setMediaTimeTransform) set by the 578 audio producer will handle converting from media time to local time 579 (perhaps going through the common time timeline in the case of 580 synchronized multiroom audio case) */ 581 status_t queueTimedBuffer(const sp<IMemory>& buffer, int64_t pts); 582 583 /* define a transform between media time and either common time or 584 local time */ 585 enum TargetTimeline {LOCAL_TIME, COMMON_TIME}; 586 status_t setMediaTimeTransform(const LinearTransform& xform, 587 TargetTimeline target); 588}; 589 590}; // namespace android 591 592#endif // ANDROID_AUDIOTRACK_H 593