AudioRecord.h revision 26ba972eafde73a26271ecf027a1d5988ce50eb8
1/* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#ifndef AUDIORECORD_H_ 18#define AUDIORECORD_H_ 19 20#include <binder/IMemory.h> 21#include <cutils/sched_policy.h> 22#include <media/AudioSystem.h> 23#include <media/IAudioRecord.h> 24#include <system/audio.h> 25#include <utils/RefBase.h> 26#include <utils/Errors.h> 27#include <utils/threads.h> 28 29namespace android { 30 31class audio_track_cblk_t; 32 33// ---------------------------------------------------------------------------- 34 35class AudioRecord : virtual public RefBase 36{ 37public: 38 39 static const int DEFAULT_SAMPLE_RATE = 8000; 40 41 /* Events used by AudioRecord callback function (callback_t). 42 * Keep in sync with frameworks/base/media/java/android/media/AudioRecord.java NATIVE_EVENT_*. 43 */ 44 enum event_type { 45 EVENT_MORE_DATA = 0, // Request to read more data from PCM buffer. 46 EVENT_OVERRUN = 1, // PCM buffer overrun occurred. 47 EVENT_MARKER = 2, // Record head is at the specified marker position 48 // (See setMarkerPosition()). 49 EVENT_NEW_POS = 3, // Record head is at a new position 50 // (See setPositionUpdatePeriod()). 51 }; 52 53 /* Client should declare Buffer on the stack and pass address to obtainBuffer() 54 * and releaseBuffer(). See also callback_t for EVENT_MORE_DATA. 55 */ 56 57 class Buffer 58 { 59 public: 60 size_t frameCount; // number of sample frames corresponding to size; 61 // on input it is the number of frames available, 62 // on output is the number of frames actually drained 63 64 size_t size; // total size in bytes == frameCount * frameSize 65 union { 66 void* raw; 67 short* i16; // signed 16-bit 68 int8_t* i8; // unsigned 8-bit, offset by 0x80 69 }; 70 }; 71 72 /* As a convenience, if a callback is supplied, a handler thread 73 * is automatically created with the appropriate priority. This thread 74 * invokes the callback when a new buffer becomes ready or various conditions occur. 75 * Parameters: 76 * 77 * event: type of event notified (see enum AudioRecord::event_type). 78 * user: Pointer to context for use by the callback receiver. 79 * info: Pointer to optional parameter according to event type: 80 * - EVENT_MORE_DATA: pointer to AudioRecord::Buffer struct. The callback must not read 81 * more bytes than indicated by 'size' field and update 'size' if fewer bytes are 82 * consumed. 83 * - EVENT_OVERRUN: unused. 84 * - EVENT_MARKER: pointer to const uint32_t containing the marker position in frames. 85 * - EVENT_NEW_POS: pointer to const uint32_t containing the new position in frames. 86 */ 87 88 typedef void (*callback_t)(int event, void* user, void *info); 89 90 /* Returns the minimum frame count required for the successful creation of 91 * an AudioRecord object. 92 * Returned status (from utils/Errors.h) can be: 93 * - NO_ERROR: successful operation 94 * - NO_INIT: audio server or audio hardware not initialized 95 * - BAD_VALUE: unsupported configuration 96 */ 97 98 static status_t getMinFrameCount(int* frameCount, 99 uint32_t sampleRate, 100 audio_format_t format, 101 audio_channel_mask_t channelMask); 102 103 /* Constructs an uninitialized AudioRecord. No connection with 104 * AudioFlinger takes place. 105 */ 106 AudioRecord(); 107 108 /* Creates an AudioRecord object and registers it with AudioFlinger. 109 * Once created, the track needs to be started before it can be used. 110 * Unspecified values are set to the audio hardware's current 111 * values. 112 * 113 * Parameters: 114 * 115 * inputSource: Select the audio input to record to (e.g. AUDIO_SOURCE_DEFAULT). 116 * sampleRate: Track sampling rate in Hz. 117 * format: Audio format (e.g AUDIO_FORMAT_PCM_16_BIT for signed 118 * 16 bits per sample). 119 * channelMask: Channel mask. 120 * frameCount: Minimum size of track PCM buffer in frames. This defines the 121 * application's contribution to the 122 * latency of the track. The actual size selected by the AudioRecord could 123 * be larger if the requested size is not compatible with current audio HAL 124 * latency. Zero means to use a default value. 125 * cbf: Callback function. If not null, this function is called periodically 126 * to consume new PCM data. 127 * user: Context for use by the callback receiver. 128 * notificationFrames: The callback function is called each time notificationFrames PCM 129 * frames are ready in record track output buffer. 130 * sessionId: Not yet supported. 131 */ 132 133 AudioRecord(audio_source_t inputSource, 134 uint32_t sampleRate = 0, 135 audio_format_t format = AUDIO_FORMAT_DEFAULT, 136 audio_channel_mask_t channelMask = AUDIO_CHANNEL_IN_MONO, 137 int frameCount = 0, 138 callback_t cbf = NULL, 139 void* user = NULL, 140 int notificationFrames = 0, 141 int sessionId = 0); 142 143 144 /* Terminates the AudioRecord and unregisters it from AudioFlinger. 145 * Also destroys all resources associated with the AudioRecord. 146 */ 147 ~AudioRecord(); 148 149 150 /* Initialize an uninitialized AudioRecord. 151 * Returned status (from utils/Errors.h) can be: 152 * - NO_ERROR: successful intialization 153 * - INVALID_OPERATION: AudioRecord is already intitialized or record device is already in use 154 * - BAD_VALUE: invalid parameter (channels, format, sampleRate...) 155 * - NO_INIT: audio server or audio hardware not initialized 156 * - PERMISSION_DENIED: recording is not allowed for the requesting process 157 */ 158 status_t set(audio_source_t inputSource = AUDIO_SOURCE_DEFAULT, 159 uint32_t sampleRate = 0, 160 audio_format_t format = AUDIO_FORMAT_DEFAULT, 161 audio_channel_mask_t channelMask = AUDIO_CHANNEL_IN_MONO, 162 int frameCount = 0, 163 callback_t cbf = NULL, 164 void* user = NULL, 165 int notificationFrames = 0, 166 bool threadCanCallJava = false, 167 int sessionId = 0); 168 169 170 /* Result of constructing the AudioRecord. This must be checked 171 * before using any AudioRecord API (except for set()), because using 172 * an uninitialized AudioRecord produces undefined results. 173 * See set() method above for possible return codes. 174 */ 175 status_t initCheck() const; 176 177 /* Returns this track's estimated latency in milliseconds. 178 * This includes the latency due to AudioRecord buffer size, 179 * and audio hardware driver. 180 */ 181 uint32_t latency() const; 182 183 /* getters, see constructor and set() */ 184 185 audio_format_t format() const; 186 int channelCount() const; 187 uint32_t frameCount() const; 188 size_t frameSize() const; 189 audio_source_t inputSource() const; 190 191 192 /* After it's created the track is not active. Call start() to 193 * make it active. If set, the callback will start being called. 194 * If event is not AudioSystem::SYNC_EVENT_NONE, the capture start will be delayed until 195 * the specified event occurs on the specified trigger session. 196 */ 197 status_t start(AudioSystem::sync_event_t event = AudioSystem::SYNC_EVENT_NONE, 198 int triggerSession = 0); 199 200 /* Stop a track. If set, the callback will cease being called and 201 * obtainBuffer returns STOPPED. Note that obtainBuffer() still works 202 * and will drain buffers until the pool is exhausted. 203 */ 204 void stop(); 205 bool stopped() const; 206 207 /* Get sample rate for this record track in Hz. 208 */ 209 uint32_t getSampleRate() const; 210 211 /* Sets marker position. When record reaches the number of frames specified, 212 * a callback with event type EVENT_MARKER is called. Calling setMarkerPosition 213 * with marker == 0 cancels marker notification callback. 214 * If the AudioRecord has been opened with no callback function associated, 215 * the operation will fail. 216 * 217 * Parameters: 218 * 219 * marker: marker position expressed in frames. 220 * 221 * Returned status (from utils/Errors.h) can be: 222 * - NO_ERROR: successful operation 223 * - INVALID_OPERATION: the AudioRecord has no callback installed. 224 */ 225 status_t setMarkerPosition(uint32_t marker); 226 status_t getMarkerPosition(uint32_t *marker) const; 227 228 229 /* Sets position update period. Every time the number of frames specified has been recorded, 230 * a callback with event type EVENT_NEW_POS is called. 231 * Calling setPositionUpdatePeriod with updatePeriod == 0 cancels new position notification 232 * callback. 233 * If the AudioRecord has been opened with no callback function associated, 234 * the operation will fail. 235 * 236 * Parameters: 237 * 238 * updatePeriod: position update notification period expressed in frames. 239 * 240 * Returned status (from utils/Errors.h) can be: 241 * - NO_ERROR: successful operation 242 * - INVALID_OPERATION: the AudioRecord has no callback installed. 243 */ 244 status_t setPositionUpdatePeriod(uint32_t updatePeriod); 245 status_t getPositionUpdatePeriod(uint32_t *updatePeriod) const; 246 247 248 /* Gets record head position. The position is the total number of frames 249 * recorded since record start. 250 * 251 * Parameters: 252 * 253 * position: Address where to return record head position within AudioRecord buffer. 254 * 255 * Returned status (from utils/Errors.h) can be: 256 * - NO_ERROR: successful operation 257 * - BAD_VALUE: position is NULL 258 */ 259 status_t getPosition(uint32_t *position) const; 260 261 /* Returns a handle on the audio input used by this AudioRecord. 262 * 263 * Parameters: 264 * none. 265 * 266 * Returned value: 267 * handle on audio hardware input 268 */ 269 audio_io_handle_t getInput() const; 270 271 /* Returns the audio session ID associated with this AudioRecord. 272 * 273 * Parameters: 274 * none. 275 * 276 * Returned value: 277 * AudioRecord session ID. 278 */ 279 int getSessionId() const; 280 281 /* Obtains a buffer of "frameCount" frames. The buffer must be 282 * drained entirely, and then released with releaseBuffer(). 283 * If the track is stopped, obtainBuffer() returns 284 * STOPPED instead of NO_ERROR as long as there are buffers available, 285 * at which point NO_MORE_BUFFERS is returned. 286 * Buffers will be returned until the pool 287 * is exhausted, at which point obtainBuffer() will either block 288 * or return WOULD_BLOCK depending on the value of the "blocking" 289 * parameter. 290 * 291 * Interpretation of waitCount: 292 * +n limits wait time to n * WAIT_PERIOD_MS, 293 * -1 causes an (almost) infinite wait time, 294 * 0 non-blocking. 295 */ 296 297 enum { 298 NO_MORE_BUFFERS = 0x80000001, // same name in AudioFlinger.h, ok to be different value 299 STOPPED = 1 300 }; 301 302 status_t obtainBuffer(Buffer* audioBuffer, int32_t waitCount); 303 304 /* Release an emptied buffer of "frameCount" frames for AudioFlinger to re-fill. */ 305 void releaseBuffer(Buffer* audioBuffer); 306 307 308 /* As a convenience we provide a read() interface to the audio buffer. 309 * This is implemented on top of obtainBuffer/releaseBuffer. 310 */ 311 ssize_t read(void* buffer, size_t size); 312 313 /* Return the number of input frames lost in the audio driver since the last call of this 314 * function. Audio driver is expected to reset the value to 0 and restart counting upon 315 * returning the current value by this function call. Such loss typically occurs when the 316 * user space process is blocked longer than the capacity of audio driver buffers. 317 * Units: the number of input audio frames. 318 */ 319 unsigned int getInputFramesLost() const; 320 321private: 322 /* copying audio record objects is not allowed */ 323 AudioRecord(const AudioRecord& other); 324 AudioRecord& operator = (const AudioRecord& other); 325 326 /* a small internal class to handle the callback */ 327 class AudioRecordThread : public Thread 328 { 329 public: 330 AudioRecordThread(AudioRecord& receiver, bool bCanCallJava = false); 331 332 // Do not call Thread::requestExitAndWait() without first calling requestExit(). 333 // Thread::requestExitAndWait() is not virtual, and the implementation doesn't do enough. 334 virtual void requestExit(); 335 336 void pause(); // suspend thread from execution at next loop boundary 337 void resume(); // allow thread to execute, if not requested to exit 338 339 private: 340 friend class AudioRecord; 341 virtual bool threadLoop(); 342 AudioRecord& mReceiver; 343 virtual ~AudioRecordThread(); 344 Mutex mMyLock; // Thread::mLock is private 345 Condition mMyCond; // Thread::mThreadExitedCondition is private 346 bool mPaused; // whether thread is currently paused 347 }; 348 349 // body of AudioRecordThread::threadLoop() 350 bool processAudioBuffer(const sp<AudioRecordThread>& thread); 351 352 status_t openRecord_l(uint32_t sampleRate, 353 audio_format_t format, 354 audio_channel_mask_t channelMask, 355 int frameCount, 356 audio_io_handle_t input); 357 audio_io_handle_t getInput_l(); 358 status_t restoreRecord_l(audio_track_cblk_t*& cblk); 359 360 sp<AudioRecordThread> mAudioRecordThread; 361 mutable Mutex mLock; 362 363 bool mActive; // protected by mLock 364 365 // for client callback handler 366 callback_t mCbf; // callback handler for events, or NULL 367 void* mUserData; 368 369 // for notification APIs 370 uint32_t mNotificationFrames; 371 uint32_t mRemainingFrames; 372 uint32_t mMarkerPosition; // in frames 373 bool mMarkerReached; 374 uint32_t mNewPosition; // in frames 375 uint32_t mUpdatePeriod; // in ms 376 377 // constant after constructor or set() 378 uint32_t mFrameCount; 379 audio_format_t mFormat; 380 uint8_t mChannelCount; 381 audio_source_t mInputSource; 382 status_t mStatus; 383 uint32_t mLatency; 384 audio_channel_mask_t mChannelMask; 385 audio_io_handle_t mInput; // returned by AudioSystem::getInput() 386 int mSessionId; 387 388 // may be changed if IAudioRecord object is re-created 389 sp<IAudioRecord> mAudioRecord; 390 sp<IMemory> mCblkMemory; 391 audio_track_cblk_t* mCblk; 392 393 int mPreviousPriority; // before start() 394 SchedPolicy mPreviousSchedulingGroup; 395}; 396 397}; // namespace android 398 399#endif /*AUDIORECORD_H_*/ 400