AudioTrack.java revision 5c17a820f9e46e0756c11795b3e6f89105f2f539
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 streaming 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 {@code write()} methods. These are blocking and return when the data has been 39 * transferred from the Java layer to the native layer and queued for playback. The streaming 40 * mode is most useful when playing blocks of audio data that for instance are: 41 * 42 * <ul> 43 * <li>too big to fit in memory because of the duration of the sound to play,</li> 44 * <li>too big to fit in memory because of the characteristics of the audio data 45 * (high sampling rate, bits per sample ...)</li> 46 * <li>received or generated while previously queued audio is playing.</li> 47 * </ul> 48 * 49 * The static mode should be chosen when dealing with short sounds that fit in memory and 50 * that need to be played with the smallest latency possible. The static mode will 51 * therefore be preferred for UI and game sounds that are played often, and with the 52 * smallest overhead possible. 53 * 54 * <p>Upon creation, an AudioTrack object initializes its associated audio buffer. 55 * The size of this buffer, specified during the construction, determines how long an AudioTrack 56 * can play before running out of data.<br> 57 * For an AudioTrack using the static mode, this size is the maximum size of the sound that can 58 * be played from it.<br> 59 * For the streaming mode, data will be written to the hardware in chunks of 60 * sizes less than or equal to the total buffer size. 61 */ 62public class AudioTrack 63{ 64 //--------------------------------------------------------- 65 // Constants 66 //-------------------- 67 /** Minimum value for a channel volume */ 68 private static final float VOLUME_MIN = 0.0f; 69 /** Maximum value for a channel volume */ 70 private static final float VOLUME_MAX = 1.0f; 71 72 /** indicates AudioTrack state is stopped */ 73 public static final int PLAYSTATE_STOPPED = 1; // matches SL_PLAYSTATE_STOPPED 74 /** indicates AudioTrack state is paused */ 75 public static final int PLAYSTATE_PAUSED = 2; // matches SL_PLAYSTATE_PAUSED 76 /** indicates AudioTrack state is playing */ 77 public static final int PLAYSTATE_PLAYING = 3; // matches SL_PLAYSTATE_PLAYING 78 79 // keep these values in sync with android_media_AudioTrack.cpp 80 /** 81 * Creation mode where audio data is transferred from Java to the native layer 82 * only once before the audio starts playing. 83 */ 84 public static final int MODE_STATIC = 0; 85 /** 86 * Creation mode where audio data is streamed from Java to the native layer 87 * as the audio is playing. 88 */ 89 public static final int MODE_STREAM = 1; 90 91 /** 92 * State of an AudioTrack that was not successfully initialized upon creation. 93 */ 94 public static final int STATE_UNINITIALIZED = 0; 95 /** 96 * State of an AudioTrack that is ready to be used. 97 */ 98 public static final int STATE_INITIALIZED = 1; 99 /** 100 * State of a successfully initialized AudioTrack that uses static data, 101 * but that hasn't received that data yet. 102 */ 103 public static final int STATE_NO_STATIC_DATA = 2; 104 105 // Error codes: 106 // to keep in sync with frameworks/base/core/jni/android_media_AudioTrack.cpp 107 /** 108 * Denotes a successful operation. 109 */ 110 public static final int SUCCESS = 0; 111 /** 112 * Denotes a generic operation failure. 113 */ 114 public static final int ERROR = -1; 115 /** 116 * Denotes a failure due to the use of an invalid value. 117 */ 118 public static final int ERROR_BAD_VALUE = -2; 119 /** 120 * Denotes a failure due to the improper use of a method. 121 */ 122 public static final int ERROR_INVALID_OPERATION = -3; 123 124 private static final int ERROR_NATIVESETUP_AUDIOSYSTEM = -16; 125 private static final int ERROR_NATIVESETUP_INVALIDCHANNELMASK = -17; 126 private static final int ERROR_NATIVESETUP_INVALIDFORMAT = -18; 127 private static final int ERROR_NATIVESETUP_INVALIDSTREAMTYPE = -19; 128 private static final int ERROR_NATIVESETUP_NATIVEINITFAILED = -20; 129 130 // Events: 131 // to keep in sync with frameworks/base/include/media/AudioTrack.h 132 /** 133 * Event id denotes when playback head has reached a previously set marker. 134 */ 135 private static final int NATIVE_EVENT_MARKER = 3; 136 /** 137 * Event id denotes when previously set update period has elapsed during playback. 138 */ 139 private static final int NATIVE_EVENT_NEW_POS = 4; 140 141 private final static String TAG = "AudioTrack-Java"; 142 143 144 //-------------------------------------------------------------------------- 145 // Member variables 146 //-------------------- 147 /** 148 * Indicates the state of the AudioTrack instance. 149 */ 150 private int mState = STATE_UNINITIALIZED; 151 /** 152 * Indicates the play state of the AudioTrack instance. 153 */ 154 private int mPlayState = PLAYSTATE_STOPPED; 155 /** 156 * Lock to make sure mPlayState updates are reflecting the actual state of the object. 157 */ 158 private final Object mPlayStateLock = new Object(); 159 /** 160 * The listener the AudioTrack notifies when the playback position reaches a marker 161 * or for periodic updates during the progression of the playback head. 162 * @see #setPlaybackPositionUpdateListener(OnPlaybackPositionUpdateListener) 163 */ 164 private OnPlaybackPositionUpdateListener mPositionListener = null; 165 /** 166 * Lock to protect event listener updates against event notifications. 167 */ 168 private final Object mPositionListenerLock = new Object(); 169 /** 170 * Size of the native audio buffer. 171 */ 172 private int mNativeBufferSizeInBytes = 0; 173 /** 174 * Handler for marker events coming from the native code. 175 */ 176 private NativeEventHandlerDelegate mEventHandlerDelegate = null; 177 /** 178 * Looper associated with the thread that creates the AudioTrack instance. 179 */ 180 private Looper mInitializationLooper = null; 181 /** 182 * The audio data sampling rate in Hz. 183 */ 184 private int mSampleRate; // initialized by all constructors 185 /** 186 * The number of audio output channels (1 is mono, 2 is stereo). 187 */ 188 private int mChannelCount = 1; 189 /** 190 * The audio channel mask. 191 */ 192 private int mChannels = AudioFormat.CHANNEL_OUT_MONO; 193 194 /** 195 * The type of the audio stream to play. See 196 * {@link AudioManager#STREAM_VOICE_CALL}, {@link AudioManager#STREAM_SYSTEM}, 197 * {@link AudioManager#STREAM_RING}, {@link AudioManager#STREAM_MUSIC}, 198 * {@link AudioManager#STREAM_ALARM}, {@link AudioManager#STREAM_NOTIFICATION}, 199 * {@link AudioManager#STREAM_DTMF}, and {@link AudioManager#STREAM_BLUETOOTH_SCO}. 200 */ 201 private int mStreamType = AudioManager.STREAM_MUSIC; 202 /** 203 * The way audio is consumed by the hardware, streaming or static. 204 */ 205 private int mDataLoadMode = MODE_STREAM; 206 /** 207 * The current audio channel configuration. 208 */ 209 private int mChannelConfiguration = AudioFormat.CHANNEL_OUT_MONO; 210 /** 211 * The encoding of the audio samples. 212 * @see AudioFormat#ENCODING_PCM_8BIT 213 * @see AudioFormat#ENCODING_PCM_16BIT 214 */ 215 private int mAudioFormat = AudioFormat.ENCODING_PCM_16BIT; 216 /** 217 * Audio session ID 218 */ 219 private int mSessionId = 0; 220 221 222 //-------------------------------- 223 // Used exclusively by native code 224 //-------------------- 225 /** 226 * Accessed by native methods: provides access to C++ AudioTrack object. 227 */ 228 @SuppressWarnings("unused") 229 private int mNativeTrackInJavaObj; 230 /** 231 * Accessed by native methods: provides access to the JNI data (i.e. resources used by 232 * the native AudioTrack object, but not stored in it). 233 */ 234 @SuppressWarnings("unused") 235 private int mJniData; 236 237 238 //-------------------------------------------------------------------------- 239 // Constructor, Finalize 240 //-------------------- 241 /** 242 * Class constructor. 243 * @param streamType the type of the audio stream. See 244 * {@link AudioManager#STREAM_VOICE_CALL}, {@link AudioManager#STREAM_SYSTEM}, 245 * {@link AudioManager#STREAM_RING}, {@link AudioManager#STREAM_MUSIC}, 246 * {@link AudioManager#STREAM_ALARM}, and {@link AudioManager#STREAM_NOTIFICATION}. 247 * @param sampleRateInHz the sample rate expressed in Hertz. 248 * @param channelConfig describes the configuration of the audio channels. 249 * See {@link AudioFormat#CHANNEL_OUT_MONO} and 250 * {@link AudioFormat#CHANNEL_OUT_STEREO} 251 * @param audioFormat the format in which the audio data is represented. 252 * See {@link AudioFormat#ENCODING_PCM_16BIT} and 253 * {@link AudioFormat#ENCODING_PCM_8BIT} 254 * @param bufferSizeInBytes the total size (in bytes) of the buffer where audio data is read 255 * from for playback. If using the AudioTrack in streaming mode, you can write data into 256 * this buffer in smaller chunks than this size. If using the AudioTrack in static mode, 257 * this is the maximum size of the sound that will be played for this instance. 258 * See {@link #getMinBufferSize(int, int, int)} to determine the minimum required buffer size 259 * for the successful creation of an AudioTrack instance in streaming mode. Using values 260 * smaller than getMinBufferSize() will result in an initialization failure. 261 * @param mode streaming or static buffer. See {@link #MODE_STATIC} and {@link #MODE_STREAM} 262 * @throws java.lang.IllegalArgumentException 263 */ 264 public AudioTrack(int streamType, int sampleRateInHz, int channelConfig, int audioFormat, 265 int bufferSizeInBytes, int mode) 266 throws IllegalArgumentException { 267 this(streamType, sampleRateInHz, channelConfig, audioFormat, 268 bufferSizeInBytes, mode, 0); 269 } 270 271 /** 272 * Class constructor with audio session. Use this constructor when the AudioTrack must be 273 * attached to a particular audio session. The primary use of the audio session ID is to 274 * associate audio effects to a particular instance of AudioTrack: if an audio session ID 275 * is provided when creating an AudioEffect, this effect will be applied only to audio tracks 276 * and media players in the same session and not to the output mix. 277 * When an AudioTrack is created without specifying a session, it will create its own session 278 * which can be retreived by calling the {@link #getAudioSessionId()} method. 279 * If a non-zero session ID is provided, this AudioTrack will share effects attached to this 280 * session 281 * with all other media players or audio tracks in the same session, otherwise a new session 282 * will be created for this track if none is supplied. 283 * @param streamType the type of the audio stream. See 284 * {@link AudioManager#STREAM_VOICE_CALL}, {@link AudioManager#STREAM_SYSTEM}, 285 * {@link AudioManager#STREAM_RING}, {@link AudioManager#STREAM_MUSIC}, 286 * {@link AudioManager#STREAM_ALARM}, and {@link AudioManager#STREAM_NOTIFICATION}. 287 * @param sampleRateInHz the sample rate expressed in Hertz. 288 * @param channelConfig describes the configuration of the audio channels. 289 * See {@link AudioFormat#CHANNEL_OUT_MONO} and 290 * {@link AudioFormat#CHANNEL_OUT_STEREO} 291 * @param audioFormat the format in which the audio data is represented. 292 * See {@link AudioFormat#ENCODING_PCM_16BIT} and 293 * {@link AudioFormat#ENCODING_PCM_8BIT} 294 * @param bufferSizeInBytes the total size (in bytes) of the buffer where audio data is read 295 * from for playback. If using the AudioTrack in streaming mode, you can write data into 296 * this buffer in smaller chunks than this size. If using the AudioTrack in static mode, 297 * this is the maximum size of the sound that will be played for this instance. 298 * See {@link #getMinBufferSize(int, int, int)} to determine the minimum required buffer size 299 * for the successful creation of an AudioTrack instance in streaming mode. Using values 300 * smaller than getMinBufferSize() will result in an initialization failure. 301 * @param mode streaming or static buffer. See {@link #MODE_STATIC} and {@link #MODE_STREAM} 302 * @param sessionId Id of audio session the AudioTrack must be attached to 303 * @throws java.lang.IllegalArgumentException 304 */ 305 public AudioTrack(int streamType, int sampleRateInHz, int channelConfig, int audioFormat, 306 int bufferSizeInBytes, int mode, int sessionId) 307 throws IllegalArgumentException { 308 mState = STATE_UNINITIALIZED; 309 310 // remember which looper is associated with the AudioTrack instantiation 311 if ((mInitializationLooper = Looper.myLooper()) == null) { 312 mInitializationLooper = Looper.getMainLooper(); 313 } 314 315 audioParamCheck(streamType, sampleRateInHz, channelConfig, audioFormat, mode); 316 317 audioBuffSizeCheck(bufferSizeInBytes); 318 319 if (sessionId < 0) { 320 throw (new IllegalArgumentException("Invalid audio session ID: "+sessionId)); 321 } 322 323 int[] session = new int[1]; 324 session[0] = sessionId; 325 // native initialization 326 int initResult = native_setup(new WeakReference<AudioTrack>(this), 327 mStreamType, mSampleRate, mChannels, mAudioFormat, 328 mNativeBufferSizeInBytes, mDataLoadMode, session); 329 if (initResult != SUCCESS) { 330 loge("Error code "+initResult+" when initializing AudioTrack."); 331 return; // with mState == STATE_UNINITIALIZED 332 } 333 334 mSessionId = session[0]; 335 336 if (mDataLoadMode == MODE_STATIC) { 337 mState = STATE_NO_STATIC_DATA; 338 } else { 339 mState = STATE_INITIALIZED; 340 } 341 } 342 343 344 // Convenience method for the constructor's parameter checks. 345 // This is where constructor IllegalArgumentException-s are thrown 346 // postconditions: 347 // mStreamType is valid 348 // mChannelCount is valid 349 // mChannels is valid 350 // mAudioFormat is valid 351 // mSampleRate is valid 352 // mDataLoadMode is valid 353 private void audioParamCheck(int streamType, int sampleRateInHz, 354 int channelConfig, int audioFormat, int mode) { 355 356 //-------------- 357 // stream type 358 if( (streamType != AudioManager.STREAM_ALARM) && (streamType != AudioManager.STREAM_MUSIC) 359 && (streamType != AudioManager.STREAM_RING) && (streamType != AudioManager.STREAM_SYSTEM) 360 && (streamType != AudioManager.STREAM_VOICE_CALL) 361 && (streamType != AudioManager.STREAM_NOTIFICATION) 362 && (streamType != AudioManager.STREAM_BLUETOOTH_SCO) 363 && (streamType != AudioManager.STREAM_DTMF)) { 364 throw (new IllegalArgumentException("Invalid stream type.")); 365 } else { 366 mStreamType = streamType; 367 } 368 369 //-------------- 370 // sample rate, note these values are subject to change 371 if ( (sampleRateInHz < 4000) || (sampleRateInHz > 48000) ) { 372 throw (new IllegalArgumentException(sampleRateInHz 373 + "Hz is not a supported sample rate.")); 374 } else { 375 mSampleRate = sampleRateInHz; 376 } 377 378 //-------------- 379 // channel config 380 mChannelConfiguration = channelConfig; 381 382 switch (channelConfig) { 383 case AudioFormat.CHANNEL_OUT_DEFAULT: //AudioFormat.CHANNEL_CONFIGURATION_DEFAULT 384 case AudioFormat.CHANNEL_OUT_MONO: 385 case AudioFormat.CHANNEL_CONFIGURATION_MONO: 386 mChannelCount = 1; 387 mChannels = AudioFormat.CHANNEL_OUT_MONO; 388 break; 389 case AudioFormat.CHANNEL_OUT_STEREO: 390 case AudioFormat.CHANNEL_CONFIGURATION_STEREO: 391 mChannelCount = 2; 392 mChannels = AudioFormat.CHANNEL_OUT_STEREO; 393 break; 394 default: 395 mChannelCount = 0; 396 mChannels = AudioFormat.CHANNEL_INVALID; 397 mChannelConfiguration = AudioFormat.CHANNEL_CONFIGURATION_INVALID; 398 throw(new IllegalArgumentException("Unsupported channel configuration.")); 399 } 400 401 //-------------- 402 // audio format 403 switch (audioFormat) { 404 case AudioFormat.ENCODING_DEFAULT: 405 mAudioFormat = AudioFormat.ENCODING_PCM_16BIT; 406 break; 407 case AudioFormat.ENCODING_PCM_16BIT: 408 case AudioFormat.ENCODING_PCM_8BIT: 409 mAudioFormat = audioFormat; 410 break; 411 default: 412 mAudioFormat = AudioFormat.ENCODING_INVALID; 413 throw(new IllegalArgumentException("Unsupported sample encoding." 414 + " Should be ENCODING_PCM_8BIT or ENCODING_PCM_16BIT.")); 415 } 416 417 //-------------- 418 // audio load mode 419 if ( (mode != MODE_STREAM) && (mode != MODE_STATIC) ) { 420 throw(new IllegalArgumentException("Invalid mode.")); 421 } else { 422 mDataLoadMode = mode; 423 } 424 } 425 426 427 // Convenience method for the contructor's audio buffer size check. 428 // preconditions: 429 // mChannelCount is valid 430 // mAudioFormat is valid 431 // postcondition: 432 // mNativeBufferSizeInBytes is valid (multiple of frame size, positive) 433 private void audioBuffSizeCheck(int audioBufferSize) { 434 // NB: this section is only valid with PCM data. 435 // To update when supporting compressed formats 436 int frameSizeInBytes = mChannelCount 437 * (mAudioFormat == AudioFormat.ENCODING_PCM_8BIT ? 1 : 2); 438 if ((audioBufferSize % frameSizeInBytes != 0) || (audioBufferSize < 1)) { 439 throw (new IllegalArgumentException("Invalid audio buffer size.")); 440 } 441 442 mNativeBufferSizeInBytes = audioBufferSize; 443 } 444 445 446 /** 447 * Releases the native AudioTrack resources. 448 */ 449 public void release() { 450 // even though native_release() stops the native AudioTrack, we need to stop 451 // AudioTrack subclasses too. 452 try { 453 stop(); 454 } catch(IllegalStateException ise) { 455 // don't raise an exception, we're releasing the resources. 456 } 457 native_release(); 458 mState = STATE_UNINITIALIZED; 459 } 460 461 @Override 462 protected void finalize() { 463 native_finalize(); 464 } 465 466 //-------------------------------------------------------------------------- 467 // Getters 468 //-------------------- 469 /** 470 * Returns the minimum valid volume value. Volume values set under this one will 471 * be clamped at this value. 472 * @return the minimum volume expressed as a linear attenuation. 473 */ 474 static public float getMinVolume() { 475 return AudioTrack.VOLUME_MIN; 476 } 477 478 /** 479 * Returns the maximum valid volume value. Volume values set above this one will 480 * be clamped at this value. 481 * @return the maximum volume expressed as a linear attenuation. 482 */ 483 static public float getMaxVolume() { 484 return AudioTrack.VOLUME_MAX; 485 } 486 487 /** 488 * Returns the configured audio data sample rate in Hz 489 */ 490 public int getSampleRate() { 491 return mSampleRate; 492 } 493 494 /** 495 * Returns the current playback rate in Hz. 496 */ 497 public int getPlaybackRate() { 498 return native_get_playback_rate(); 499 } 500 501 /** 502 * Returns the configured audio data format. See {@link AudioFormat#ENCODING_PCM_16BIT} 503 * and {@link AudioFormat#ENCODING_PCM_8BIT}. 504 */ 505 public int getAudioFormat() { 506 return mAudioFormat; 507 } 508 509 /** 510 * Returns the type of audio stream this AudioTrack is configured for. 511 * Compare the result against {@link AudioManager#STREAM_VOICE_CALL}, 512 * {@link AudioManager#STREAM_SYSTEM}, {@link AudioManager#STREAM_RING}, 513 * {@link AudioManager#STREAM_MUSIC}, {@link AudioManager#STREAM_ALARM}, 514 * {@link AudioManager#STREAM_NOTIFICATION}, {@link AudioManager#STREAM_DTMF}, 515 * or {@link AudioManager#STREAM_BLUETOOTH_SCO}. 516 */ 517 public int getStreamType() { 518 return mStreamType; 519 } 520 521 /** 522 * Returns the configured channel configuration. 523 524 * See {@link AudioFormat#CHANNEL_OUT_MONO} 525 * and {@link AudioFormat#CHANNEL_OUT_STEREO}. 526 */ 527 public int getChannelConfiguration() { 528 return mChannelConfiguration; 529 } 530 531 /** 532 * Returns the configured number of channels. 533 */ 534 public int getChannelCount() { 535 return mChannelCount; 536 } 537 538 /** 539 * Returns the state of the AudioTrack instance. This is useful after the 540 * AudioTrack instance has been created to check if it was initialized 541 * properly. This ensures that the appropriate hardware resources have been 542 * acquired. 543 * @see #STATE_INITIALIZED 544 * @see #STATE_NO_STATIC_DATA 545 * @see #STATE_UNINITIALIZED 546 */ 547 public int getState() { 548 return mState; 549 } 550 551 /** 552 * Returns the playback state of the AudioTrack instance. 553 * @see #PLAYSTATE_STOPPED 554 * @see #PLAYSTATE_PAUSED 555 * @see #PLAYSTATE_PLAYING 556 */ 557 public int getPlayState() { 558 synchronized (mPlayStateLock) { 559 return mPlayState; 560 } 561 } 562 563 /** 564 * Returns the native frame count used by the hardware. 565 */ 566 protected int getNativeFrameCount() { 567 return native_get_native_frame_count(); 568 } 569 570 /** 571 * Returns marker position expressed in frames. 572 */ 573 public int getNotificationMarkerPosition() { 574 return native_get_marker_pos(); 575 } 576 577 /** 578 * Returns the notification update period expressed in frames. 579 */ 580 public int getPositionNotificationPeriod() { 581 return native_get_pos_update_period(); 582 } 583 584 /** 585 * Returns the playback head position expressed in frames 586 */ 587 public int getPlaybackHeadPosition() { 588 return native_get_position(); 589 } 590 591 /** 592 * Returns the hardware output sample rate 593 */ 594 static public int getNativeOutputSampleRate(int streamType) { 595 return native_get_output_sample_rate(streamType); 596 } 597 598 /** 599 * Returns the minimum buffer size required for the successful creation of an AudioTrack 600 * object to be created in the {@link #MODE_STREAM} mode. Note that this size doesn't 601 * guarantee a smooth playback under load, and higher values should be chosen according to 602 * the expected frequency at which the buffer will be refilled with additional data to play. 603 * @param sampleRateInHz the sample rate expressed in Hertz. 604 * @param channelConfig describes the configuration of the audio channels. 605 * See {@link AudioFormat#CHANNEL_OUT_MONO} and 606 * {@link AudioFormat#CHANNEL_OUT_STEREO} 607 * @param audioFormat the format in which the audio data is represented. 608 * See {@link AudioFormat#ENCODING_PCM_16BIT} and 609 * {@link AudioFormat#ENCODING_PCM_8BIT} 610 * @return {@link #ERROR_BAD_VALUE} if an invalid parameter was passed, 611 * or {@link #ERROR} if the implementation was unable to query the hardware for its output 612 * properties, 613 * or the minimum buffer size expressed in bytes. 614 */ 615 static public int getMinBufferSize(int sampleRateInHz, int channelConfig, int audioFormat) { 616 int channelCount = 0; 617 switch(channelConfig) { 618 case AudioFormat.CHANNEL_OUT_MONO: 619 case AudioFormat.CHANNEL_CONFIGURATION_MONO: 620 channelCount = 1; 621 break; 622 case AudioFormat.CHANNEL_OUT_STEREO: 623 case AudioFormat.CHANNEL_CONFIGURATION_STEREO: 624 channelCount = 2; 625 break; 626 default: 627 loge("getMinBufferSize(): Invalid channel configuration."); 628 return AudioTrack.ERROR_BAD_VALUE; 629 } 630 631 if ((audioFormat != AudioFormat.ENCODING_PCM_16BIT) 632 && (audioFormat != AudioFormat.ENCODING_PCM_8BIT)) { 633 loge("getMinBufferSize(): Invalid audio format."); 634 return AudioTrack.ERROR_BAD_VALUE; 635 } 636 637 // sample rate, note these values are subject to change 638 if ( (sampleRateInHz < 4000) || (sampleRateInHz > 48000) ) { 639 loge("getMinBufferSize(): " + sampleRateInHz +"Hz is not a supported sample rate."); 640 return AudioTrack.ERROR_BAD_VALUE; 641 } 642 643 int size = native_get_min_buff_size(sampleRateInHz, channelCount, audioFormat); 644 if ((size == -1) || (size == 0)) { 645 loge("getMinBufferSize(): error querying hardware"); 646 return AudioTrack.ERROR; 647 } 648 else { 649 return size; 650 } 651 } 652 653 /** 654 * Returns the audio session ID. 655 * 656 * @return the ID of the audio session this AudioTrack belongs to. 657 */ 658 public int getAudioSessionId() { 659 return mSessionId; 660 } 661 662 //-------------------------------------------------------------------------- 663 // Initialization / configuration 664 //-------------------- 665 /** 666 * Sets the listener the AudioTrack notifies when a previously set marker is reached or 667 * for each periodic playback head position update. 668 * Notifications will be received in the same thread as the one in which the AudioTrack 669 * instance was created. 670 * @param listener 671 */ 672 public void setPlaybackPositionUpdateListener(OnPlaybackPositionUpdateListener listener) { 673 setPlaybackPositionUpdateListener(listener, null); 674 } 675 676 /** 677 * Sets the listener the AudioTrack notifies when a previously set marker is reached or 678 * for each periodic playback head position update. 679 * Use this method to receive AudioTrack events in the Handler associated with another 680 * thread than the one in which you created the AudioTrack instance. 681 * @param listener 682 * @param handler the Handler that will receive the event notification messages. 683 */ 684 public void setPlaybackPositionUpdateListener(OnPlaybackPositionUpdateListener listener, 685 Handler handler) { 686 synchronized (mPositionListenerLock) { 687 mPositionListener = listener; 688 } 689 if (listener != null) { 690 mEventHandlerDelegate = new NativeEventHandlerDelegate(this, handler); 691 } 692 693 } 694 695 696 697 /** 698 * Sets the specified left/right output volume values on the AudioTrack. Values are clamped 699 * to the ({@link #getMinVolume()}, {@link #getMaxVolume()}) interval if outside this range. 700 * @param leftVolume output attenuation for the left channel. A value of 0.0f is silence, 701 * a value of 1.0f is no attenuation. 702 * @param rightVolume output attenuation for the right channel 703 * @return error code or success, see {@link #SUCCESS}, 704 * {@link #ERROR_INVALID_OPERATION} 705 */ 706 public int setStereoVolume(float leftVolume, float rightVolume) { 707 if (mState != STATE_INITIALIZED) { 708 return ERROR_INVALID_OPERATION; 709 } 710 711 // clamp the volumes 712 if (leftVolume < getMinVolume()) { 713 leftVolume = getMinVolume(); 714 } 715 if (leftVolume > getMaxVolume()) { 716 leftVolume = getMaxVolume(); 717 } 718 if (rightVolume < getMinVolume()) { 719 rightVolume = getMinVolume(); 720 } 721 if (rightVolume > getMaxVolume()) { 722 rightVolume = getMaxVolume(); 723 } 724 725 native_setVolume(leftVolume, rightVolume); 726 727 return SUCCESS; 728 } 729 730 731 /** 732 * Sets the playback sample rate for this track. This sets the sampling rate at which 733 * the audio data will be consumed and played back, not the original sampling rate of the 734 * content. Setting it to half the sample rate of the content will cause the playback to 735 * last twice as long, but will also result in a negative pitch shift. 736 * The valid sample rate range is from 1Hz to twice the value returned by 737 * {@link #getNativeOutputSampleRate(int)}. 738 * @param sampleRateInHz the sample rate expressed in Hz 739 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 740 * {@link #ERROR_INVALID_OPERATION} 741 */ 742 public int setPlaybackRate(int sampleRateInHz) { 743 if (mState != STATE_INITIALIZED) { 744 return ERROR_INVALID_OPERATION; 745 } 746 if (sampleRateInHz <= 0) { 747 return ERROR_BAD_VALUE; 748 } 749 return native_set_playback_rate(sampleRateInHz); 750 } 751 752 753 /** 754 * Sets the position of the notification marker. 755 * @param markerInFrames marker in frames 756 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 757 * {@link #ERROR_INVALID_OPERATION} 758 */ 759 public int setNotificationMarkerPosition(int markerInFrames) { 760 if (mState != STATE_INITIALIZED) { 761 return ERROR_INVALID_OPERATION; 762 } 763 return native_set_marker_pos(markerInFrames); 764 } 765 766 767 /** 768 * Sets the period for the periodic notification event. 769 * @param periodInFrames update period expressed in frames 770 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_INVALID_OPERATION} 771 */ 772 public int setPositionNotificationPeriod(int periodInFrames) { 773 if (mState != STATE_INITIALIZED) { 774 return ERROR_INVALID_OPERATION; 775 } 776 return native_set_pos_update_period(periodInFrames); 777 } 778 779 780 /** 781 * Sets the playback head position. The track must be stopped for the position to be changed. 782 * @param positionInFrames playback head position expressed in frames 783 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 784 * {@link #ERROR_INVALID_OPERATION} 785 */ 786 public int setPlaybackHeadPosition(int positionInFrames) { 787 synchronized(mPlayStateLock) { 788 if ((mPlayState == PLAYSTATE_STOPPED) || (mPlayState == PLAYSTATE_PAUSED)) { 789 return native_set_position(positionInFrames); 790 } else { 791 return ERROR_INVALID_OPERATION; 792 } 793 } 794 } 795 796 /** 797 * Sets the loop points and the loop count. The loop can be infinite. 798 * @param startInFrames loop start marker expressed in frames 799 * @param endInFrames loop end marker expressed in frames 800 * @param loopCount the number of times the loop is looped. 801 * A value of -1 means infinite looping. 802 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 803 * {@link #ERROR_INVALID_OPERATION} 804 */ 805 public int setLoopPoints(int startInFrames, int endInFrames, int loopCount) { 806 if (mDataLoadMode == MODE_STREAM) { 807 return ERROR_INVALID_OPERATION; 808 } 809 return native_set_loop(startInFrames, endInFrames, loopCount); 810 } 811 812 /** 813 * Sets the initialization state of the instance. To be used in an AudioTrack subclass 814 * constructor to set a subclass-specific post-initialization state. 815 * @param state the state of the AudioTrack instance 816 */ 817 protected void setState(int state) { 818 mState = state; 819 } 820 821 822 //--------------------------------------------------------- 823 // Transport control methods 824 //-------------------- 825 /** 826 * Starts playing an AudioTrack. 827 * 828 * @throws IllegalStateException 829 */ 830 public void play() 831 throws IllegalStateException { 832 if (mState != STATE_INITIALIZED) { 833 throw(new IllegalStateException("play() called on uninitialized AudioTrack.")); 834 } 835 836 synchronized(mPlayStateLock) { 837 native_start(); 838 mPlayState = PLAYSTATE_PLAYING; 839 } 840 } 841 842 /** 843 * Stops playing the audio data. 844 * 845 * @throws IllegalStateException 846 */ 847 public void stop() 848 throws IllegalStateException { 849 if (mState != STATE_INITIALIZED) { 850 throw(new IllegalStateException("stop() called on uninitialized AudioTrack.")); 851 } 852 853 // stop playing 854 synchronized(mPlayStateLock) { 855 native_stop(); 856 mPlayState = PLAYSTATE_STOPPED; 857 } 858 } 859 860 /** 861 * Pauses the playback of the audio data. Data that has not been played 862 * back will not be discarded. Subsequent calls to {@link #play} will play 863 * this data back. 864 * 865 * @throws IllegalStateException 866 */ 867 public void pause() 868 throws IllegalStateException { 869 if (mState != STATE_INITIALIZED) { 870 throw(new IllegalStateException("pause() called on uninitialized AudioTrack.")); 871 } 872 //logd("pause()"); 873 874 // pause playback 875 synchronized(mPlayStateLock) { 876 native_pause(); 877 mPlayState = PLAYSTATE_PAUSED; 878 } 879 } 880 881 882 //--------------------------------------------------------- 883 // Audio data supply 884 //-------------------- 885 886 /** 887 * Flushes the audio data currently queued for playback. Any data that has 888 * not been played back will be discarded. 889 */ 890 public void flush() { 891 if (mState == STATE_INITIALIZED) { 892 // flush the data in native layer 893 native_flush(); 894 } 895 896 } 897 898 /** 899 * Writes the audio data to the audio hardware for playback. Will block until 900 * all data has been written to the audio mixer. 901 * Note that the actual playback of this data might occur after this function 902 * returns. This function is thread safe with respect to {@link #stop} calls, 903 * in which case all of the specified data might not be written to the mixer. 904 * 905 * @param audioData the array that holds the data to play. 906 * @param offsetInBytes the offset expressed in bytes in audioData where the data to play 907 * starts. 908 * @param sizeInBytes the number of bytes to read in audioData after the offset. 909 * @return the number of bytes that were written or {@link #ERROR_INVALID_OPERATION} 910 * if the object wasn't properly initialized, or {@link #ERROR_BAD_VALUE} if 911 * the parameters don't resolve to valid data and indexes. 912 */ 913 914 public int write(byte[] audioData, int offsetInBytes, int sizeInBytes) { 915 if ((mDataLoadMode == MODE_STATIC) 916 && (mState == STATE_NO_STATIC_DATA) 917 && (sizeInBytes > 0)) { 918 mState = STATE_INITIALIZED; 919 } 920 921 if (mState != STATE_INITIALIZED) { 922 return ERROR_INVALID_OPERATION; 923 } 924 925 if ( (audioData == null) || (offsetInBytes < 0 ) || (sizeInBytes < 0) 926 || (offsetInBytes + sizeInBytes > audioData.length)) { 927 return ERROR_BAD_VALUE; 928 } 929 930 return native_write_byte(audioData, offsetInBytes, sizeInBytes, mAudioFormat); 931 } 932 933 934 /** 935 * Writes the audio data to the audio hardware for playback. Will block until 936 * all data has been written to the audio mixer. 937 * Note that the actual playback of this data might occur after this function 938 * returns. This function is thread safe with respect to {@link #stop} calls, 939 * in which case all of the specified data might not be written to the mixer. 940 * 941 * @param audioData the array that holds the data to play. 942 * @param offsetInShorts the offset expressed in shorts in audioData where the data to play 943 * starts. 944 * @param sizeInShorts the number of bytes to read in audioData after the offset. 945 * @return the number of shorts that were written or {@link #ERROR_INVALID_OPERATION} 946 * if the object wasn't properly initialized, or {@link #ERROR_BAD_VALUE} if 947 * the parameters don't resolve to valid data and indexes. 948 */ 949 950 public int write(short[] audioData, int offsetInShorts, int sizeInShorts) { 951 if ((mDataLoadMode == MODE_STATIC) 952 && (mState == STATE_NO_STATIC_DATA) 953 && (sizeInShorts > 0)) { 954 mState = STATE_INITIALIZED; 955 } 956 957 if (mState != STATE_INITIALIZED) { 958 return ERROR_INVALID_OPERATION; 959 } 960 961 if ( (audioData == null) || (offsetInShorts < 0 ) || (sizeInShorts < 0) 962 || (offsetInShorts + sizeInShorts > audioData.length)) { 963 return ERROR_BAD_VALUE; 964 } 965 966 return native_write_short(audioData, offsetInShorts, sizeInShorts, mAudioFormat); 967 } 968 969 970 /** 971 * Notifies the native resource to reuse the audio data already loaded in the native 972 * layer. This call is only valid with AudioTrack instances that don't use the streaming 973 * model. 974 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 975 * {@link #ERROR_INVALID_OPERATION} 976 */ 977 public int reloadStaticData() { 978 if (mDataLoadMode == MODE_STREAM) { 979 return ERROR_INVALID_OPERATION; 980 } 981 return native_reload_static(); 982 } 983 984 //-------------------------------------------------------------------------- 985 // Audio effects management 986 //-------------------- 987 988 /** 989 * Attaches an auxiliary effect to the audio track. A typical auxiliary 990 * effect is a reverberation effect which can be applied on any sound source 991 * that directs a certain amount of its energy to this effect. This amount 992 * is defined by setAuxEffectSendLevel(). 993 * {@see #setAuxEffectSendLevel(float)}. 994 * <p>After creating an auxiliary effect (e.g. 995 * {@link android.media.audiofx.EnvironmentalReverb}), retrieve its ID with 996 * {@link android.media.audiofx.AudioEffect#getId()} and use it when calling 997 * this method to attach the audio track to the effect. 998 * <p>To detach the effect from the audio track, call this method with a 999 * null effect id. 1000 * 1001 * @param effectId system wide unique id of the effect to attach 1002 * @return error code or success, see {@link #SUCCESS}, 1003 * {@link #ERROR_INVALID_OPERATION}, {@link #ERROR_BAD_VALUE} 1004 */ 1005 public int attachAuxEffect(int effectId) { 1006 if (mState != STATE_INITIALIZED) { 1007 return ERROR_INVALID_OPERATION; 1008 } 1009 return native_attachAuxEffect(effectId); 1010 } 1011 1012 /** 1013 * Sets the send level of the audio track to the attached auxiliary effect 1014 * {@link #attachAuxEffect(int)}. The level value range is 0 to 1.0. 1015 * <p>By default the send level is 0, so even if an effect is attached to the player 1016 * this method must be called for the effect to be applied. 1017 * <p>Note that the passed level value is a raw scalar. UI controls should be scaled 1018 * logarithmically: the gain applied by audio framework ranges from -72dB to 0dB, 1019 * so an appropriate conversion from linear UI input x to level is: 1020 * x == 0 -> level = 0 1021 * 0 < x <= R -> level = 10^(72*(x-R)/20/R) 1022 * 1023 * @param level send level scalar 1024 * @return error code or success, see {@link #SUCCESS}, 1025 * {@link #ERROR_INVALID_OPERATION} 1026 */ 1027 public int setAuxEffectSendLevel(float level) { 1028 if (mState != STATE_INITIALIZED) { 1029 return ERROR_INVALID_OPERATION; 1030 } 1031 // clamp the level 1032 if (level < getMinVolume()) { 1033 level = getMinVolume(); 1034 } 1035 if (level > getMaxVolume()) { 1036 level = getMaxVolume(); 1037 } 1038 native_setAuxEffectSendLevel(level); 1039 return SUCCESS; 1040 } 1041 1042 //--------------------------------------------------------- 1043 // Interface definitions 1044 //-------------------- 1045 /** 1046 * Interface definition for a callback to be invoked when the playback head position of 1047 * an AudioTrack has reached a notification marker or has increased by a certain period. 1048 */ 1049 public interface OnPlaybackPositionUpdateListener { 1050 /** 1051 * Called on the listener to notify it that the previously set marker has been reached 1052 * by the playback head. 1053 */ 1054 void onMarkerReached(AudioTrack track); 1055 1056 /** 1057 * Called on the listener to periodically notify it that the playback head has reached 1058 * a multiple of the notification period. 1059 */ 1060 void onPeriodicNotification(AudioTrack track); 1061 } 1062 1063 1064 //--------------------------------------------------------- 1065 // Inner classes 1066 //-------------------- 1067 /** 1068 * Helper class to handle the forwarding of native events to the appropriate listener 1069 * (potentially) handled in a different thread 1070 */ 1071 private class NativeEventHandlerDelegate { 1072 private final AudioTrack mAudioTrack; 1073 private final Handler mHandler; 1074 1075 NativeEventHandlerDelegate(AudioTrack track, Handler handler) { 1076 mAudioTrack = track; 1077 // find the looper for our new event handler 1078 Looper looper; 1079 if (handler != null) { 1080 looper = handler.getLooper(); 1081 } else { 1082 // no given handler, use the looper the AudioTrack was created in 1083 looper = mInitializationLooper; 1084 } 1085 1086 // construct the event handler with this looper 1087 if (looper != null) { 1088 // implement the event handler delegate 1089 mHandler = new Handler(looper) { 1090 @Override 1091 public void handleMessage(Message msg) { 1092 if (mAudioTrack == null) { 1093 return; 1094 } 1095 OnPlaybackPositionUpdateListener listener = null; 1096 synchronized (mPositionListenerLock) { 1097 listener = mAudioTrack.mPositionListener; 1098 } 1099 switch(msg.what) { 1100 case NATIVE_EVENT_MARKER: 1101 if (listener != null) { 1102 listener.onMarkerReached(mAudioTrack); 1103 } 1104 break; 1105 case NATIVE_EVENT_NEW_POS: 1106 if (listener != null) { 1107 listener.onPeriodicNotification(mAudioTrack); 1108 } 1109 break; 1110 default: 1111 Log.e(TAG, "[ android.media.AudioTrack.NativeEventHandler ] " + 1112 "Unknown event type: " + msg.what); 1113 break; 1114 } 1115 } 1116 }; 1117 } else { 1118 mHandler = null; 1119 } 1120 } 1121 1122 Handler getHandler() { 1123 return mHandler; 1124 } 1125 } 1126 1127 1128 //--------------------------------------------------------- 1129 // Java methods called from the native side 1130 //-------------------- 1131 @SuppressWarnings("unused") 1132 private static void postEventFromNative(Object audiotrack_ref, 1133 int what, int arg1, int arg2, Object obj) { 1134 //logd("Event posted from the native side: event="+ what + " args="+ arg1+" "+arg2); 1135 AudioTrack track = (AudioTrack)((WeakReference)audiotrack_ref).get(); 1136 if (track == null) { 1137 return; 1138 } 1139 1140 if (track.mEventHandlerDelegate != null) { 1141 Message m = 1142 track.mEventHandlerDelegate.getHandler().obtainMessage(what, arg1, arg2, obj); 1143 track.mEventHandlerDelegate.getHandler().sendMessage(m); 1144 } 1145 1146 } 1147 1148 1149 //--------------------------------------------------------- 1150 // Native methods called from the Java side 1151 //-------------------- 1152 1153 private native final int native_setup(Object audiotrack_this, 1154 int streamType, int sampleRate, int nbChannels, int audioFormat, 1155 int buffSizeInBytes, int mode, int[] sessionId); 1156 1157 private native final void native_finalize(); 1158 1159 private native final void native_release(); 1160 1161 private native final void native_start(); 1162 1163 private native final void native_stop(); 1164 1165 private native final void native_pause(); 1166 1167 private native final void native_flush(); 1168 1169 private native final int native_write_byte(byte[] audioData, 1170 int offsetInBytes, int sizeInBytes, int format); 1171 1172 private native final int native_write_short(short[] audioData, 1173 int offsetInShorts, int sizeInShorts, int format); 1174 1175 private native final int native_reload_static(); 1176 1177 private native final int native_get_native_frame_count(); 1178 1179 private native final void native_setVolume(float leftVolume, float rightVolume); 1180 1181 private native final int native_set_playback_rate(int sampleRateInHz); 1182 private native final int native_get_playback_rate(); 1183 1184 private native final int native_set_marker_pos(int marker); 1185 private native final int native_get_marker_pos(); 1186 1187 private native final int native_set_pos_update_period(int updatePeriod); 1188 private native final int native_get_pos_update_period(); 1189 1190 private native final int native_set_position(int position); 1191 private native final int native_get_position(); 1192 1193 private native final int native_set_loop(int start, int end, int loopCount); 1194 1195 static private native final int native_get_output_sample_rate(int streamType); 1196 static private native final int native_get_min_buff_size( 1197 int sampleRateInHz, int channelConfig, int audioFormat); 1198 1199 private native final int native_get_session_id(); 1200 1201 private native final int native_attachAuxEffect(int effectId); 1202 private native final void native_setAuxEffectSendLevel(float level); 1203 1204 //--------------------------------------------------------- 1205 // Utility methods 1206 //------------------ 1207 1208 private static void logd(String msg) { 1209 Log.d(TAG, "[ android.media.AudioTrack ] " + msg); 1210 } 1211 1212 private static void loge(String msg) { 1213 Log.e(TAG, "[ android.media.AudioTrack ] " + msg); 1214 } 1215 1216} 1217