AudioTrack.java revision 619346f902241736d933657a4fe10f10c50a1ba8
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 17package android.media; 18 19import java.lang.ref.WeakReference; 20import java.lang.IllegalArgumentException; 21import java.lang.IllegalStateException; 22 23import android.os.Handler; 24import android.os.Looper; 25import android.os.Message; 26import android.media.AudioManager; 27import android.util.Log; 28 29 30/** 31 * The AudioTrack class manages and plays a single audio resource for Java applications. 32 * It allows to stream PCM audio buffers to the audio hardware for playback. This is 33 * achieved by "pushing" the data to the AudioTrack object using one of the 34 * {@link #write(byte[], int, int)} and {@link #write(short[], int, int)} methods. 35 * 36 * <p>An AudioTrack instance can operate under two modes: static or streaming.<br> 37 * In Streaming mode, the application writes a continuous stream of data to the AudioTrack, using 38 * one of the write() methods. These are blocking and return when the data has been transferred 39 * from the Java layer to the native layer and queued for playback. The streaming mode 40 * is most useful when playing blocks of audio data that for instance are: 41 * <ul> 42 * <li>too big to fit in memory because of the duration of the sound to play,</li> 43 * <li>too big to fit in memory because of the characteristics of the audio data 44 * (high sampling rate, bits per sample ...)</li> 45 * <li>received or generated while previously queued audio is playing.</li> 46 * </ul> 47 * The static mode is to be chosen when dealing with short sounds that fit in memory and 48 * that need to be played with the smallest latency possible. AudioTrack instances in static mode 49 * can play the sound without the need to transfer the audio data from Java to native layer 50 * each time the sound is to be played. The static mode will therefore be preferred for UI and 51 * game sounds that are played often, and with the smallest overhead possible. 52 * 53 * <p>Upon creation, an AudioTrack object initializes its associated audio buffer. 54 * The size of this buffer, specified during the construction, determines how long an AudioTrack 55 * can play before running out of data.<br> 56 * For an AudioTrack using the static mode, this size is the maximum size of the sound that can 57 * be played from it.<br> 58 * For the streaming mode, data will be written to the hardware in chunks of 59 * sizes inferior to the total buffer size. 60 */ 61public class AudioTrack 62{ 63 //--------------------------------------------------------- 64 // Constants 65 //-------------------- 66 /** Minimum value for a channel volume */ 67 private static final float VOLUME_MIN = 0.0f; 68 /** Maximum value for a channel volume */ 69 private static final float VOLUME_MAX = 1.0f; 70 71 /** indicates AudioTrack state is stopped */ 72 public static final int PLAYSTATE_STOPPED = 1; // matches SL_PLAYSTATE_STOPPED 73 /** indicates AudioTrack state is paused */ 74 public static final int PLAYSTATE_PAUSED = 2; // matches SL_PLAYSTATE_PAUSED 75 /** indicates AudioTrack state is playing */ 76 public static final int PLAYSTATE_PLAYING = 3; // matches SL_PLAYSTATE_PLAYING 77 78 /** 79 * Creation mode where audio data is transferred from Java to the native layer 80 * only once before the audio starts playing. 81 */ 82 public static final int MODE_STATIC = 0; 83 /** 84 * Creation mode where audio data is streamed from Java to the native layer 85 * as the audio is playing. 86 */ 87 public static final int MODE_STREAM = 1; 88 89 /** 90 * State of an AudioTrack that was not successfully initialized upon creation. 91 */ 92 public static final int STATE_UNINITIALIZED = 0; 93 /** 94 * State of an AudioTrack that is ready to be used. 95 */ 96 public static final int STATE_INITIALIZED = 1; 97 /** 98 * State of a successfully initialized AudioTrack that uses static data, 99 * but that hasn't received that data yet. 100 */ 101 public static final int STATE_NO_STATIC_DATA = 2; 102 103 // Error codes: 104 // to keep in sync with frameworks/base/core/jni/android_media_AudioTrack.cpp 105 /** 106 * Denotes a successful operation. 107 */ 108 public static final int SUCCESS = 0; 109 /** 110 * Denotes a generic operation failure. 111 */ 112 public static final int ERROR = -1; 113 /** 114 * Denotes a failure due to the use of an invalid value. 115 */ 116 public static final int ERROR_BAD_VALUE = -2; 117 /** 118 * Denotes a failure due to the improper use of a method. 119 */ 120 public static final int ERROR_INVALID_OPERATION = -3; 121 122 private static final int ERROR_NATIVESETUP_AUDIOSYSTEM = -16; 123 private static final int ERROR_NATIVESETUP_INVALIDCHANNELMASK = -17; 124 private static final int ERROR_NATIVESETUP_INVALIDFORMAT = -18; 125 private static final int ERROR_NATIVESETUP_INVALIDSTREAMTYPE = -19; 126 private static final int ERROR_NATIVESETUP_NATIVEINITFAILED = -20; 127 128 // Events: 129 // to keep in sync with frameworks/base/include/media/AudioTrack.h 130 /** 131 * Event id denotes when playback head has reached a previously set marker. 132 */ 133 private static final int NATIVE_EVENT_MARKER = 3; 134 /** 135 * Event id denotes when previously set update period has elapsed during playback. 136 */ 137 private static final int NATIVE_EVENT_NEW_POS = 4; 138 139 private final static String TAG = "AudioTrack-Java"; 140 141 142 //-------------------------------------------------------------------------- 143 // Member variables 144 //-------------------- 145 /** 146 * Indicates the state of the AudioTrack instance. 147 */ 148 private int mState = STATE_UNINITIALIZED; 149 /** 150 * Indicates the play state of the AudioTrack instance. 151 */ 152 private int mPlayState = PLAYSTATE_STOPPED; 153 /** 154 * Lock to make sure mPlayState updates are reflecting the actual state of the object. 155 */ 156 private final Object mPlayStateLock = new Object(); 157 /** 158 * The listener the AudioTrack notifies when the playback position reaches a marker 159 * or for periodic updates during the progression of the playback head. 160 * @see #setPlaybackPositionUpdateListener(OnPlaybackPositionUpdateListener) 161 */ 162 private OnPlaybackPositionUpdateListener mPositionListener = null; 163 /** 164 * Lock to protect event listener updates against event notifications. 165 */ 166 private final Object mPositionListenerLock = new Object(); 167 /** 168 * Size of the native audio buffer. 169 */ 170 private int mNativeBufferSizeInBytes = 0; 171 /** 172 * Handler for marker events coming from the native code. 173 */ 174 private NativeEventHandlerDelegate mEventHandlerDelegate = null; 175 /** 176 * Looper associated with the thread that creates the AudioTrack instance. 177 */ 178 private Looper mInitializationLooper = null; 179 /** 180 * The audio data sampling rate in Hz. 181 */ 182 private int mSampleRate = 22050; 183 /** 184 * The number of audio output channels (1 is mono, 2 is stereo). 185 */ 186 private int mChannelCount = 1; 187 /** 188 * The audio channel mask. 189 */ 190 private int mChannels = AudioFormat.CHANNEL_OUT_MONO; 191 192 /** 193 * The type of the audio stream to play. See 194 * {@link AudioManager#STREAM_VOICE_CALL}, {@link AudioManager#STREAM_SYSTEM}, 195 * {@link AudioManager#STREAM_RING}, {@link AudioManager#STREAM_MUSIC} and 196 * {@link AudioManager#STREAM_ALARM} 197 */ 198 private int mStreamType = AudioManager.STREAM_MUSIC; 199 /** 200 * The way audio is consumed by the hardware, streaming or static. 201 */ 202 private int mDataLoadMode = MODE_STREAM; 203 /** 204 * The current audio channel configuration. 205 */ 206 private int mChannelConfiguration = AudioFormat.CHANNEL_OUT_MONO; 207 /** 208 * The encoding of the audio samples. 209 * @see AudioFormat#ENCODING_PCM_8BIT 210 * @see AudioFormat#ENCODING_PCM_16BIT 211 */ 212 private int mAudioFormat = AudioFormat.ENCODING_PCM_16BIT; 213 /** 214 * Audio session ID 215 */ 216 private int mSessionId = 0; 217 218 219 //-------------------------------- 220 // Used exclusively by native code 221 //-------------------- 222 /** 223 * Accessed by native methods: provides access to C++ AudioTrack object. 224 */ 225 @SuppressWarnings("unused") 226 private int mNativeTrackInJavaObj; 227 /** 228 * Accessed by native methods: provides access to the JNI data (i.e. resources used by 229 * the native AudioTrack object, but not stored in it). 230 */ 231 @SuppressWarnings("unused") 232 private int mJniData; 233 234 235 //-------------------------------------------------------------------------- 236 // Constructor, Finalize 237 //-------------------- 238 /** 239 * Class constructor. 240 * @param streamType the type of the audio stream. See 241 * {@link AudioManager#STREAM_VOICE_CALL}, {@link AudioManager#STREAM_SYSTEM}, 242 * {@link AudioManager#STREAM_RING}, {@link AudioManager#STREAM_MUSIC} and 243 * {@link AudioManager#STREAM_ALARM} 244 * @param sampleRateInHz the sample rate expressed in Hertz. Examples of rates are (but 245 * not limited to) 44100, 22050 and 11025. 246 * @param channelConfig describes the configuration of the audio channels. 247 * See {@link AudioFormat#CHANNEL_OUT_MONO} and 248 * {@link AudioFormat#CHANNEL_OUT_STEREO} 249 * @param audioFormat the format in which the audio data is represented. 250 * See {@link AudioFormat#ENCODING_PCM_16BIT} and 251 * {@link AudioFormat#ENCODING_PCM_8BIT} 252 * @param bufferSizeInBytes the total size (in bytes) of the buffer where audio data is read 253 * from for playback. If using the AudioTrack in streaming mode, you can write data into 254 * this buffer in smaller chunks than this size. If using the AudioTrack in static mode, 255 * this is the maximum size of the sound that will be played for this instance. 256 * See {@link #getMinBufferSize(int, int, int)} to determine the minimum required buffer size 257 * for the successful creation of an AudioTrack instance in streaming mode. Using values 258 * smaller than getMinBufferSize() will result in an initialization failure. 259 * @param mode streaming or static buffer. See {@link #MODE_STATIC} and {@link #MODE_STREAM} 260 * @throws java.lang.IllegalArgumentException 261 */ 262 public AudioTrack(int streamType, int sampleRateInHz, int channelConfig, int audioFormat, 263 int bufferSizeInBytes, int mode) 264 throws IllegalArgumentException { 265 this(streamType, sampleRateInHz, channelConfig, audioFormat, 266 bufferSizeInBytes, mode, 0); 267 } 268 269 /** 270 * Class constructor with audio session. Use this constructor when the AudioTrack must be 271 * attached to a particular audio session. The primary use of the audio session ID is to 272 * associate audio effects to a particular instance of AudioTrack: if an audio session ID 273 * is provided when creating an AudioEffect, this effect will be applied only to audio tracks 274 * and media players in the same session and not to the output mix. 275 * When an AudioTrack is created without specifying a session, it will create its own session 276 * which can be retreived by calling the {@link #getAudioSessionId()} method. 277 * If a session ID is provided, this AudioTrack will share effects attached to this session 278 * with all other media players or audio tracks in the same session. 279 * @param streamType the type of the audio stream. See 280 * {@link AudioManager#STREAM_VOICE_CALL}, {@link AudioManager#STREAM_SYSTEM}, 281 * {@link AudioManager#STREAM_RING}, {@link AudioManager#STREAM_MUSIC} and 282 * {@link AudioManager#STREAM_ALARM} 283 * @param sampleRateInHz the sample rate expressed in Hertz. Examples of rates are (but 284 * not limited to) 44100, 22050 and 11025. 285 * @param channelConfig describes the configuration of the audio channels. 286 * See {@link AudioFormat#CHANNEL_OUT_MONO} and 287 * {@link AudioFormat#CHANNEL_OUT_STEREO} 288 * @param audioFormat the format in which the audio data is represented. 289 * See {@link AudioFormat#ENCODING_PCM_16BIT} and 290 * {@link AudioFormat#ENCODING_PCM_8BIT} 291 * @param bufferSizeInBytes the total size (in bytes) of the buffer where audio data is read 292 * from for playback. If using the AudioTrack in streaming mode, you can write data into 293 * this buffer in smaller chunks than this size. If using the AudioTrack in static mode, 294 * this is the maximum size of the sound that will be played for this instance. 295 * See {@link #getMinBufferSize(int, int, int)} to determine the minimum required buffer size 296 * for the successful creation of an AudioTrack instance in streaming mode. Using values 297 * smaller than getMinBufferSize() will result in an initialization failure. 298 * @param mode streaming or static buffer. See {@link #MODE_STATIC} and {@link #MODE_STREAM} 299 * @param sessionId Id of audio session the AudioTrack must be attached to 300 * @throws java.lang.IllegalArgumentException 301 // FIXME: unhide. 302 * @hide 303 */ 304 public AudioTrack(int streamType, int sampleRateInHz, int channelConfig, int audioFormat, 305 int bufferSizeInBytes, int mode, int sessionId) 306 throws IllegalArgumentException { 307 mState = STATE_UNINITIALIZED; 308 309 // remember which looper is associated with the AudioTrack instanciation 310 if ((mInitializationLooper = Looper.myLooper()) == null) { 311 mInitializationLooper = Looper.getMainLooper(); 312 } 313 314 audioParamCheck(streamType, sampleRateInHz, channelConfig, audioFormat, mode); 315 316 audioBuffSizeCheck(bufferSizeInBytes); 317 318 if (sessionId < 0) { 319 throw (new IllegalArgumentException("Invalid audio session ID: "+sessionId)); 320 } 321 322 int[] session = new int[1]; 323 session[0] = sessionId; 324 // native initialization 325 int initResult = native_setup(new WeakReference<AudioTrack>(this), 326 mStreamType, mSampleRate, mChannels, mAudioFormat, 327 mNativeBufferSizeInBytes, mDataLoadMode, session); 328 if (initResult != SUCCESS) { 329 loge("Error code "+initResult+" when initializing AudioTrack."); 330 return; // with mState == STATE_UNINITIALIZED 331 } 332 333 mSessionId = session[0]; 334 335 if (mDataLoadMode == MODE_STATIC) { 336 mState = STATE_NO_STATIC_DATA; 337 } else { 338 mState = STATE_INITIALIZED; 339 } 340 } 341 342 343 // Convenience method for the constructor's parameter checks. 344 // This is where constructor IllegalArgumentException-s are thrown 345 // postconditions: 346 // mStreamType is valid 347 // mChannelCount is valid 348 // mChannels is valid 349 // mAudioFormat is valid 350 // mSampleRate is valid 351 // mDataLoadMode is valid 352 private void audioParamCheck(int streamType, int sampleRateInHz, 353 int channelConfig, int audioFormat, int mode) { 354 355 //-------------- 356 // stream type 357 if( (streamType != AudioManager.STREAM_ALARM) && (streamType != AudioManager.STREAM_MUSIC) 358 && (streamType != AudioManager.STREAM_RING) && (streamType != AudioManager.STREAM_SYSTEM) 359 && (streamType != AudioManager.STREAM_VOICE_CALL) 360 && (streamType != AudioManager.STREAM_NOTIFICATION) 361 && (streamType != AudioManager.STREAM_BLUETOOTH_SCO) 362 && (streamType != AudioManager.STREAM_DTMF)) { 363 throw (new IllegalArgumentException("Invalid stream type.")); 364 } else { 365 mStreamType = streamType; 366 } 367 368 //-------------- 369 // sample rate 370 if ( (sampleRateInHz < 4000) || (sampleRateInHz > 48000) ) { 371 throw (new IllegalArgumentException(sampleRateInHz 372 + "Hz is not a supported sample rate.")); 373 } else { 374 mSampleRate = sampleRateInHz; 375 } 376 377 //-------------- 378 // channel config 379 mChannelConfiguration = channelConfig; 380 381 switch (channelConfig) { 382 case AudioFormat.CHANNEL_OUT_DEFAULT: //AudioFormat.CHANNEL_CONFIGURATION_DEFAULT 383 case AudioFormat.CHANNEL_OUT_MONO: 384 case AudioFormat.CHANNEL_CONFIGURATION_MONO: 385 mChannelCount = 1; 386 mChannels = AudioFormat.CHANNEL_OUT_MONO; 387 break; 388 case AudioFormat.CHANNEL_OUT_STEREO: 389 case AudioFormat.CHANNEL_CONFIGURATION_STEREO: 390 mChannelCount = 2; 391 mChannels = AudioFormat.CHANNEL_OUT_STEREO; 392 break; 393 default: 394 mChannelCount = 0; 395 mChannels = AudioFormat.CHANNEL_INVALID; 396 mChannelConfiguration = AudioFormat.CHANNEL_CONFIGURATION_INVALID; 397 throw(new IllegalArgumentException("Unsupported channel configuration.")); 398 } 399 400 //-------------- 401 // audio format 402 switch (audioFormat) { 403 case AudioFormat.ENCODING_DEFAULT: 404 mAudioFormat = AudioFormat.ENCODING_PCM_16BIT; 405 break; 406 case AudioFormat.ENCODING_PCM_16BIT: 407 case AudioFormat.ENCODING_PCM_8BIT: 408 mAudioFormat = audioFormat; 409 break; 410 default: 411 mAudioFormat = AudioFormat.ENCODING_INVALID; 412 throw(new IllegalArgumentException("Unsupported sample encoding." 413 + " Should be ENCODING_PCM_8BIT or ENCODING_PCM_16BIT.")); 414 } 415 416 //-------------- 417 // audio load mode 418 if ( (mode != MODE_STREAM) && (mode != MODE_STATIC) ) { 419 throw(new IllegalArgumentException("Invalid mode.")); 420 } else { 421 mDataLoadMode = mode; 422 } 423 } 424 425 426 // Convenience method for the contructor's audio buffer size check. 427 // preconditions: 428 // mChannelCount is valid 429 // mAudioFormat is valid 430 // postcondition: 431 // mNativeBufferSizeInBytes is valid (multiple of frame size, positive) 432 private void audioBuffSizeCheck(int audioBufferSize) { 433 // NB: this section is only valid with PCM data. 434 // To update when supporting compressed formats 435 int frameSizeInBytes = mChannelCount 436 * (mAudioFormat == AudioFormat.ENCODING_PCM_8BIT ? 1 : 2); 437 if ((audioBufferSize % frameSizeInBytes != 0) || (audioBufferSize < 1)) { 438 throw (new IllegalArgumentException("Invalid audio buffer size.")); 439 } 440 441 mNativeBufferSizeInBytes = audioBufferSize; 442 } 443 444 445 /** 446 * Releases the native AudioTrack resources. 447 */ 448 public void release() { 449 // even though native_release() stops the native AudioTrack, we need to stop 450 // AudioTrack subclasses too. 451 try { 452 stop(); 453 } catch(IllegalStateException ise) { 454 // don't raise an exception, we're releasing the resources. 455 } 456 native_release(); 457 mState = STATE_UNINITIALIZED; 458 } 459 460 @Override 461 protected void finalize() { 462 native_finalize(); 463 } 464 465 //-------------------------------------------------------------------------- 466 // Getters 467 //-------------------- 468 /** 469 * Returns the minimum valid volume value. Volume values set under this one will 470 * be clamped at this value. 471 * @return the minimum volume expressed as a linear attenuation. 472 */ 473 static public float getMinVolume() { 474 return AudioTrack.VOLUME_MIN; 475 } 476 477 /** 478 * Returns the maximum valid volume value. Volume values set above this one will 479 * be clamped at this value. 480 * @return the maximum volume expressed as a linear attenuation. 481 */ 482 static public float getMaxVolume() { 483 return AudioTrack.VOLUME_MAX; 484 } 485 486 /** 487 * Returns the configured audio data sample rate in Hz 488 */ 489 public int getSampleRate() { 490 return mSampleRate; 491 } 492 493 /** 494 * Returns the current playback rate in Hz. 495 */ 496 public int getPlaybackRate() { 497 return native_get_playback_rate(); 498 } 499 500 /** 501 * Returns the configured audio data format. See {@link AudioFormat#ENCODING_PCM_16BIT} 502 * and {@link AudioFormat#ENCODING_PCM_8BIT}. 503 */ 504 public int getAudioFormat() { 505 return mAudioFormat; 506 } 507 508 /** 509 * Returns the type of audio stream this AudioTrack is configured for. 510 * Compare the result against {@link AudioManager#STREAM_VOICE_CALL}, 511 * {@link AudioManager#STREAM_SYSTEM}, {@link AudioManager#STREAM_RING}, 512 * {@link AudioManager#STREAM_MUSIC} or {@link AudioManager#STREAM_ALARM} 513 */ 514 public int getStreamType() { 515 return mStreamType; 516 } 517 518 /** 519 * Returns the configured channel configuration. 520 521 * See {@link AudioFormat#CHANNEL_OUT_MONO} 522 * and {@link AudioFormat#CHANNEL_OUT_STEREO}. 523 */ 524 public int getChannelConfiguration() { 525 return mChannelConfiguration; 526 } 527 528 /** 529 * Returns the configured number of channels. 530 */ 531 public int getChannelCount() { 532 return mChannelCount; 533 } 534 535 /** 536 * Returns the state of the AudioTrack instance. This is useful after the 537 * AudioTrack instance has been created to check if it was initialized 538 * properly. This ensures that the appropriate hardware resources have been 539 * acquired. 540 * @see #STATE_INITIALIZED 541 * @see #STATE_NO_STATIC_DATA 542 * @see #STATE_UNINITIALIZED 543 */ 544 public int getState() { 545 return mState; 546 } 547 548 /** 549 * Returns the playback state of the AudioTrack instance. 550 * @see #PLAYSTATE_STOPPED 551 * @see #PLAYSTATE_PAUSED 552 * @see #PLAYSTATE_PLAYING 553 */ 554 public int getPlayState() { 555 return mPlayState; 556 } 557 558 /** 559 * Returns the native frame count used by the hardware. 560 */ 561 protected int getNativeFrameCount() { 562 return native_get_native_frame_count(); 563 } 564 565 /** 566 * Returns marker position expressed in frames. 567 */ 568 public int getNotificationMarkerPosition() { 569 return native_get_marker_pos(); 570 } 571 572 /** 573 * Returns the notification update period expressed in frames. 574 */ 575 public int getPositionNotificationPeriod() { 576 return native_get_pos_update_period(); 577 } 578 579 /** 580 * Returns the playback head position expressed in frames 581 */ 582 public int getPlaybackHeadPosition() { 583 return native_get_position(); 584 } 585 586 /** 587 * Returns the hardware output sample rate 588 */ 589 static public int getNativeOutputSampleRate(int streamType) { 590 return native_get_output_sample_rate(streamType); 591 } 592 593 /** 594 * Returns the minimum buffer size required for the successful creation of an AudioTrack 595 * object to be created in the {@link #MODE_STREAM} mode. Note that this size doesn't 596 * guarantee a smooth playback under load, and higher values should be chosen according to 597 * the expected frequency at which the buffer will be refilled with additional data to play. 598 * @param sampleRateInHz the sample rate expressed in Hertz. 599 * @param channelConfig describes the configuration of the audio channels. 600 * See {@link AudioFormat#CHANNEL_OUT_MONO} and 601 * {@link AudioFormat#CHANNEL_OUT_STEREO} 602 * @param audioFormat the format in which the audio data is represented. 603 * See {@link AudioFormat#ENCODING_PCM_16BIT} and 604 * {@link AudioFormat#ENCODING_PCM_8BIT} 605 * @return {@link #ERROR_BAD_VALUE} if an invalid parameter was passed, 606 * or {@link #ERROR} if the implementation was unable to query the hardware for its output 607 * properties, 608 * or the minimum buffer size expressed in bytes. 609 */ 610 static public int getMinBufferSize(int sampleRateInHz, int channelConfig, int audioFormat) { 611 int channelCount = 0; 612 switch(channelConfig) { 613 case AudioFormat.CHANNEL_OUT_MONO: 614 case AudioFormat.CHANNEL_CONFIGURATION_MONO: 615 channelCount = 1; 616 break; 617 case AudioFormat.CHANNEL_OUT_STEREO: 618 case AudioFormat.CHANNEL_CONFIGURATION_STEREO: 619 channelCount = 2; 620 break; 621 default: 622 loge("getMinBufferSize(): Invalid channel configuration."); 623 return AudioTrack.ERROR_BAD_VALUE; 624 } 625 626 if ((audioFormat != AudioFormat.ENCODING_PCM_16BIT) 627 && (audioFormat != AudioFormat.ENCODING_PCM_8BIT)) { 628 loge("getMinBufferSize(): Invalid audio format."); 629 return AudioTrack.ERROR_BAD_VALUE; 630 } 631 632 if ( (sampleRateInHz < 4000) || (sampleRateInHz > 48000) ) { 633 loge("getMinBufferSize(): " + sampleRateInHz +"Hz is not a supported sample rate."); 634 return AudioTrack.ERROR_BAD_VALUE; 635 } 636 637 int size = native_get_min_buff_size(sampleRateInHz, channelCount, audioFormat); 638 if ((size == -1) || (size == 0)) { 639 loge("getMinBufferSize(): error querying hardware"); 640 return AudioTrack.ERROR; 641 } 642 else { 643 return size; 644 } 645 } 646 647 /** 648 * Returns the audio session ID. 649 * 650 * @return the ID of the audio session this AudioTrack belongs to. 651 // FIXME: unhide. 652 // FIXME: link to AudioEffect class when public. 653 * @hide 654 */ 655 public int getAudioSessionId() { 656 return mSessionId; 657 } 658 659 //-------------------------------------------------------------------------- 660 // Initialization / configuration 661 //-------------------- 662 /** 663 * Sets the listener the AudioTrack notifies when a previously set marker is reached or 664 * for each periodic playback head position update. 665 * Notifications will be received in the same thread as the one in which the AudioTrack 666 * instance was created. 667 * @param listener 668 */ 669 public void setPlaybackPositionUpdateListener(OnPlaybackPositionUpdateListener listener) { 670 setPlaybackPositionUpdateListener(listener, null); 671 } 672 673 /** 674 * Sets the listener the AudioTrack notifies when a previously set marker is reached or 675 * for each periodic playback head position update. 676 * Use this method to receive AudioTrack events in the Handler associated with another 677 * thread than the one in which you created the AudioTrack instance. 678 * @param listener 679 * @param handler the Handler that will receive the event notification messages. 680 */ 681 public void setPlaybackPositionUpdateListener(OnPlaybackPositionUpdateListener listener, 682 Handler handler) { 683 synchronized (mPositionListenerLock) { 684 mPositionListener = listener; 685 } 686 if (listener != null) { 687 mEventHandlerDelegate = new NativeEventHandlerDelegate(this, handler); 688 } 689 690 } 691 692 693 694 /** 695 * Sets the specified left/right output volume values on the AudioTrack. Values are clamped 696 * to the ({@link #getMinVolume()}, {@link #getMaxVolume()}) interval if outside this range. 697 * @param leftVolume output attenuation for the left channel. A value of 0.0f is silence, 698 * a value of 1.0f is no attenuation. 699 * @param rightVolume output attenuation for the right channel 700 * @return error code or success, see {@link #SUCCESS}, 701 * {@link #ERROR_INVALID_OPERATION} 702 */ 703 public int setStereoVolume(float leftVolume, float rightVolume) { 704 if (mState != STATE_INITIALIZED) { 705 return ERROR_INVALID_OPERATION; 706 } 707 708 // clamp the volumes 709 if (leftVolume < getMinVolume()) { 710 leftVolume = getMinVolume(); 711 } 712 if (leftVolume > getMaxVolume()) { 713 leftVolume = getMaxVolume(); 714 } 715 if (rightVolume < getMinVolume()) { 716 rightVolume = getMinVolume(); 717 } 718 if (rightVolume > getMaxVolume()) { 719 rightVolume = getMaxVolume(); 720 } 721 722 native_setVolume(leftVolume, rightVolume); 723 724 return SUCCESS; 725 } 726 727 728 /** 729 * Sets the playback sample rate for this track. This sets the sampling rate at which 730 * the audio data will be consumed and played back, not the original sampling rate of the 731 * content. Setting it to half the sample rate of the content will cause the playback to 732 * last twice as long, but will also result in a negative pitch shift. 733 * The valid sample rate range if from 1Hz to twice the value returned by 734 * {@link #getNativeOutputSampleRate(int)}. 735 * @param sampleRateInHz the sample rate expressed in Hz 736 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 737 * {@link #ERROR_INVALID_OPERATION} 738 */ 739 public int setPlaybackRate(int sampleRateInHz) { 740 if (mState != STATE_INITIALIZED) { 741 return ERROR_INVALID_OPERATION; 742 } 743 if (sampleRateInHz <= 0) { 744 return ERROR_BAD_VALUE; 745 } 746 return native_set_playback_rate(sampleRateInHz); 747 } 748 749 750 /** 751 * Sets the position of the notification marker. 752 * @param markerInFrames marker in frames 753 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 754 * {@link #ERROR_INVALID_OPERATION} 755 */ 756 public int setNotificationMarkerPosition(int markerInFrames) { 757 if (mState != STATE_INITIALIZED) { 758 return ERROR_INVALID_OPERATION; 759 } 760 return native_set_marker_pos(markerInFrames); 761 } 762 763 764 /** 765 * Sets the period for the periodic notification event. 766 * @param periodInFrames update period expressed in frames 767 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_INVALID_OPERATION} 768 */ 769 public int setPositionNotificationPeriod(int periodInFrames) { 770 if (mState != STATE_INITIALIZED) { 771 return ERROR_INVALID_OPERATION; 772 } 773 return native_set_pos_update_period(periodInFrames); 774 } 775 776 777 /** 778 * Sets the playback head position. The track must be stopped for the position to be changed. 779 * @param positionInFrames playback head position expressed in frames 780 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 781 * {@link #ERROR_INVALID_OPERATION} 782 */ 783 public int setPlaybackHeadPosition(int positionInFrames) { 784 synchronized(mPlayStateLock) { 785 if ((mPlayState == PLAYSTATE_STOPPED) || (mPlayState == PLAYSTATE_PAUSED)) { 786 return native_set_position(positionInFrames); 787 } else { 788 return ERROR_INVALID_OPERATION; 789 } 790 } 791 } 792 793 /** 794 * Sets the loop points and the loop count. The loop can be infinite. 795 * @param startInFrames loop start marker expressed in frames 796 * @param endInFrames loop end marker expressed in frames 797 * @param loopCount the number of times the loop is looped. 798 * A value of -1 means infinite looping. 799 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 800 * {@link #ERROR_INVALID_OPERATION} 801 */ 802 public int setLoopPoints(int startInFrames, int endInFrames, int loopCount) { 803 if (mDataLoadMode == MODE_STREAM) { 804 return ERROR_INVALID_OPERATION; 805 } 806 return native_set_loop(startInFrames, endInFrames, loopCount); 807 } 808 809 /** 810 * Sets the initialization state of the instance. To be used in an AudioTrack subclass 811 * constructor to set a subclass-specific post-initialization state. 812 * @param state the state of the AudioTrack instance 813 */ 814 protected void setState(int state) { 815 mState = state; 816 } 817 818 819 //--------------------------------------------------------- 820 // Transport control methods 821 //-------------------- 822 /** 823 * Starts playing an AudioTrack. 824 * @throws IllegalStateException 825 */ 826 public void play() 827 throws IllegalStateException { 828 if (mState != STATE_INITIALIZED) { 829 throw(new IllegalStateException("play() called on uninitialized AudioTrack.")); 830 } 831 832 synchronized(mPlayStateLock) { 833 native_start(); 834 mPlayState = PLAYSTATE_PLAYING; 835 } 836 } 837 838 /** 839 * Stops playing the audio data. 840 * @throws IllegalStateException 841 */ 842 public void stop() 843 throws IllegalStateException { 844 if (mState != STATE_INITIALIZED) { 845 throw(new IllegalStateException("stop() called on uninitialized AudioTrack.")); 846 } 847 848 // stop playing 849 synchronized(mPlayStateLock) { 850 native_stop(); 851 mPlayState = PLAYSTATE_STOPPED; 852 } 853 } 854 855 /** 856 * Pauses the playback of the audio data. 857 * @throws IllegalStateException 858 */ 859 public void pause() 860 throws IllegalStateException { 861 if (mState != STATE_INITIALIZED) { 862 throw(new IllegalStateException("pause() called on uninitialized AudioTrack.")); 863 } 864 //logd("pause()"); 865 866 // pause playback 867 synchronized(mPlayStateLock) { 868 native_pause(); 869 mPlayState = PLAYSTATE_PAUSED; 870 } 871 } 872 873 874 //--------------------------------------------------------- 875 // Audio data supply 876 //-------------------- 877 878 /** 879 * Flushes the audio data currently queued for playback. 880 */ 881 882 public void flush() { 883 if (mState == STATE_INITIALIZED) { 884 // flush the data in native layer 885 native_flush(); 886 } 887 888 } 889 890 /** 891 * Writes the audio data to the audio hardware for playback. 892 * @param audioData the array that holds the data to play. 893 * @param offsetInBytes the offset expressed in bytes in audioData where the data to play 894 * starts. 895 * @param sizeInBytes the number of bytes to read in audioData after the offset. 896 * @return the number of bytes that were written or {@link #ERROR_INVALID_OPERATION} 897 * if the object wasn't properly initialized, or {@link #ERROR_BAD_VALUE} if 898 * the parameters don't resolve to valid data and indexes. 899 */ 900 901 public int write(byte[] audioData,int offsetInBytes, int sizeInBytes) { 902 if ((mDataLoadMode == MODE_STATIC) 903 && (mState == STATE_NO_STATIC_DATA) 904 && (sizeInBytes > 0)) { 905 mState = STATE_INITIALIZED; 906 } 907 908 if (mState != STATE_INITIALIZED) { 909 return ERROR_INVALID_OPERATION; 910 } 911 912 if ( (audioData == null) || (offsetInBytes < 0 ) || (sizeInBytes < 0) 913 || (offsetInBytes + sizeInBytes > audioData.length)) { 914 return ERROR_BAD_VALUE; 915 } 916 917 return native_write_byte(audioData, offsetInBytes, sizeInBytes, mAudioFormat); 918 } 919 920 921 /** 922 * Writes the audio data to the audio hardware for playback. 923 * @param audioData the array that holds the data to play. 924 * @param offsetInShorts the offset expressed in shorts in audioData where the data to play 925 * starts. 926 * @param sizeInShorts the number of bytes to read in audioData after the offset. 927 * @return the number of shorts that were written or {@link #ERROR_INVALID_OPERATION} 928 * if the object wasn't properly initialized, or {@link #ERROR_BAD_VALUE} if 929 * the parameters don't resolve to valid data and indexes. 930 */ 931 932 public int write(short[] audioData, int offsetInShorts, int sizeInShorts) { 933 if ((mDataLoadMode == MODE_STATIC) 934 && (mState == STATE_NO_STATIC_DATA) 935 && (sizeInShorts > 0)) { 936 mState = STATE_INITIALIZED; 937 } 938 939 if (mState != STATE_INITIALIZED) { 940 return ERROR_INVALID_OPERATION; 941 } 942 943 if ( (audioData == null) || (offsetInShorts < 0 ) || (sizeInShorts < 0) 944 || (offsetInShorts + sizeInShorts > audioData.length)) { 945 return ERROR_BAD_VALUE; 946 } 947 948 return native_write_short(audioData, offsetInShorts, sizeInShorts, mAudioFormat); 949 } 950 951 952 /** 953 * Notifies the native resource to reuse the audio data already loaded in the native 954 * layer. This call is only valid with AudioTrack instances that don't use the streaming 955 * model. 956 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 957 * {@link #ERROR_INVALID_OPERATION} 958 */ 959 public int reloadStaticData() { 960 if (mDataLoadMode == MODE_STREAM) { 961 return ERROR_INVALID_OPERATION; 962 } 963 return native_reload_static(); 964 } 965 966 967 //--------------------------------------------------------- 968 // Interface definitions 969 //-------------------- 970 /** 971 * Interface definition for a callback to be invoked when the playback head position of 972 * an AudioTrack has reached a notification marker or has increased by a certain period. 973 */ 974 public interface OnPlaybackPositionUpdateListener { 975 /** 976 * Called on the listener to notify it that the previously set marker has been reached 977 * by the playback head. 978 */ 979 void onMarkerReached(AudioTrack track); 980 981 /** 982 * Called on the listener to periodically notify it that the playback head has reached 983 * a multiple of the notification period. 984 */ 985 void onPeriodicNotification(AudioTrack track); 986 } 987 988 989 //--------------------------------------------------------- 990 // Inner classes 991 //-------------------- 992 /** 993 * Helper class to handle the forwarding of native events to the appropriate listener 994 * (potentially) handled in a different thread 995 */ 996 private class NativeEventHandlerDelegate { 997 private final AudioTrack mAudioTrack; 998 private final Handler mHandler; 999 1000 NativeEventHandlerDelegate(AudioTrack track, Handler handler) { 1001 mAudioTrack = track; 1002 // find the looper for our new event handler 1003 Looper looper; 1004 if (handler != null) { 1005 looper = handler.getLooper(); 1006 } else { 1007 // no given handler, use the looper the AudioTrack was created in 1008 looper = mInitializationLooper; 1009 } 1010 1011 // construct the event handler with this looper 1012 if (looper != null) { 1013 // implement the event handler delegate 1014 mHandler = new Handler(looper) { 1015 @Override 1016 public void handleMessage(Message msg) { 1017 if (mAudioTrack == null) { 1018 return; 1019 } 1020 OnPlaybackPositionUpdateListener listener = null; 1021 synchronized (mPositionListenerLock) { 1022 listener = mAudioTrack.mPositionListener; 1023 } 1024 switch(msg.what) { 1025 case NATIVE_EVENT_MARKER: 1026 if (listener != null) { 1027 listener.onMarkerReached(mAudioTrack); 1028 } 1029 break; 1030 case NATIVE_EVENT_NEW_POS: 1031 if (listener != null) { 1032 listener.onPeriodicNotification(mAudioTrack); 1033 } 1034 break; 1035 default: 1036 Log.e(TAG, "[ android.media.AudioTrack.NativeEventHandler ] " + 1037 "Unknown event type: " + msg.what); 1038 break; 1039 } 1040 } 1041 }; 1042 } else { 1043 mHandler = null; 1044 } 1045 } 1046 1047 Handler getHandler() { 1048 return mHandler; 1049 } 1050 } 1051 1052 1053 //--------------------------------------------------------- 1054 // Java methods called from the native side 1055 //-------------------- 1056 @SuppressWarnings("unused") 1057 private static void postEventFromNative(Object audiotrack_ref, 1058 int what, int arg1, int arg2, Object obj) { 1059 //logd("Event posted from the native side: event="+ what + " args="+ arg1+" "+arg2); 1060 AudioTrack track = (AudioTrack)((WeakReference)audiotrack_ref).get(); 1061 if (track == null) { 1062 return; 1063 } 1064 1065 if (track.mEventHandlerDelegate != null) { 1066 Message m = 1067 track.mEventHandlerDelegate.getHandler().obtainMessage(what, arg1, arg2, obj); 1068 track.mEventHandlerDelegate.getHandler().sendMessage(m); 1069 } 1070 1071 } 1072 1073 1074 //--------------------------------------------------------- 1075 // Native methods called from the Java side 1076 //-------------------- 1077 1078 private native final int native_setup(Object audiotrack_this, 1079 int streamType, int sampleRate, int nbChannels, int audioFormat, 1080 int buffSizeInBytes, int mode, int[] sessionId); 1081 1082 private native final void native_finalize(); 1083 1084 private native final void native_release(); 1085 1086 private native final void native_start(); 1087 1088 private native final void native_stop(); 1089 1090 private native final void native_pause(); 1091 1092 private native final void native_flush(); 1093 1094 private native final int native_write_byte(byte[] audioData, 1095 int offsetInBytes, int sizeInBytes, int format); 1096 1097 private native final int native_write_short(short[] audioData, 1098 int offsetInShorts, int sizeInShorts, int format); 1099 1100 private native final int native_reload_static(); 1101 1102 private native final int native_get_native_frame_count(); 1103 1104 private native final void native_setVolume(float leftVolume, float rightVolume); 1105 1106 private native final int native_set_playback_rate(int sampleRateInHz); 1107 private native final int native_get_playback_rate(); 1108 1109 private native final int native_set_marker_pos(int marker); 1110 private native final int native_get_marker_pos(); 1111 1112 private native final int native_set_pos_update_period(int updatePeriod); 1113 private native final int native_get_pos_update_period(); 1114 1115 private native final int native_set_position(int position); 1116 private native final int native_get_position(); 1117 1118 private native final int native_set_loop(int start, int end, int loopCount); 1119 1120 static private native final int native_get_output_sample_rate(int streamType); 1121 static private native final int native_get_min_buff_size( 1122 int sampleRateInHz, int channelConfig, int audioFormat); 1123 1124 private native final int native_get_session_id(); 1125 1126 //--------------------------------------------------------- 1127 // Utility methods 1128 //------------------ 1129 1130 private static void logd(String msg) { 1131 Log.d(TAG, "[ android.media.AudioTrack ] " + msg); 1132 } 1133 1134 private static void loge(String msg) { 1135 Log.e(TAG, "[ android.media.AudioTrack ] " + msg); 1136 } 1137 1138} 1139