AudioTrack.java revision 1b8f499a14a4340d3422d95c7f6fdc8c0c72b3a4
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}, and 199 * {@link AudioManager#STREAM_DTMF}. 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 // mask of all the channels supported by this implementation 344 private static final int SUPPORTED_OUT_CHANNELS = 345 AudioFormat.CHANNEL_OUT_FRONT_LEFT | 346 AudioFormat.CHANNEL_OUT_FRONT_RIGHT | 347 AudioFormat.CHANNEL_OUT_FRONT_CENTER | 348 AudioFormat.CHANNEL_OUT_LOW_FREQUENCY | 349 AudioFormat.CHANNEL_OUT_BACK_LEFT | 350 AudioFormat.CHANNEL_OUT_BACK_RIGHT | 351 AudioFormat.CHANNEL_OUT_BACK_CENTER; 352 353 // Convenience method for the constructor's parameter checks. 354 // This is where constructor IllegalArgumentException-s are thrown 355 // postconditions: 356 // mStreamType is valid 357 // mChannelCount is valid 358 // mChannels is valid 359 // mAudioFormat is valid 360 // mSampleRate is valid 361 // mDataLoadMode is valid 362 private void audioParamCheck(int streamType, int sampleRateInHz, 363 int channelConfig, int audioFormat, int mode) { 364 365 //-------------- 366 // stream type 367 if( (streamType != AudioManager.STREAM_ALARM) && (streamType != AudioManager.STREAM_MUSIC) 368 && (streamType != AudioManager.STREAM_RING) && (streamType != AudioManager.STREAM_SYSTEM) 369 && (streamType != AudioManager.STREAM_VOICE_CALL) 370 && (streamType != AudioManager.STREAM_NOTIFICATION) 371 && (streamType != AudioManager.STREAM_BLUETOOTH_SCO) 372 && (streamType != AudioManager.STREAM_DTMF)) { 373 throw (new IllegalArgumentException("Invalid stream type.")); 374 } else { 375 mStreamType = streamType; 376 } 377 378 //-------------- 379 // sample rate, note these values are subject to change 380 if ( (sampleRateInHz < 4000) || (sampleRateInHz > 48000) ) { 381 throw (new IllegalArgumentException(sampleRateInHz 382 + "Hz is not a supported sample rate.")); 383 } else { 384 mSampleRate = sampleRateInHz; 385 } 386 387 //-------------- 388 // channel config 389 mChannelConfiguration = channelConfig; 390 391 switch (channelConfig) { 392 case AudioFormat.CHANNEL_OUT_DEFAULT: //AudioFormat.CHANNEL_CONFIGURATION_DEFAULT 393 case AudioFormat.CHANNEL_OUT_MONO: 394 case AudioFormat.CHANNEL_CONFIGURATION_MONO: 395 mChannelCount = 1; 396 mChannels = AudioFormat.CHANNEL_OUT_MONO; 397 break; 398 case AudioFormat.CHANNEL_OUT_STEREO: 399 case AudioFormat.CHANNEL_CONFIGURATION_STEREO: 400 mChannelCount = 2; 401 mChannels = AudioFormat.CHANNEL_OUT_STEREO; 402 break; 403 default: 404 if ((channelConfig & SUPPORTED_OUT_CHANNELS) != channelConfig) { 405 // input channel configuration features unsupported channels 406 mChannelCount = 0; 407 mChannels = AudioFormat.CHANNEL_INVALID; 408 mChannelConfiguration = AudioFormat.CHANNEL_INVALID; 409 throw(new IllegalArgumentException("Unsupported channel configuration.")); 410 } else { 411 mChannels = channelConfig; 412 mChannelCount = Integer.bitCount(channelConfig); 413 } 414 } 415 416 //-------------- 417 // audio format 418 switch (audioFormat) { 419 case AudioFormat.ENCODING_DEFAULT: 420 mAudioFormat = AudioFormat.ENCODING_PCM_16BIT; 421 break; 422 case AudioFormat.ENCODING_PCM_16BIT: 423 case AudioFormat.ENCODING_PCM_8BIT: 424 mAudioFormat = audioFormat; 425 break; 426 default: 427 mAudioFormat = AudioFormat.ENCODING_INVALID; 428 throw(new IllegalArgumentException("Unsupported sample encoding." 429 + " Should be ENCODING_PCM_8BIT or ENCODING_PCM_16BIT.")); 430 } 431 432 //-------------- 433 // audio load mode 434 if ( (mode != MODE_STREAM) && (mode != MODE_STATIC) ) { 435 throw(new IllegalArgumentException("Invalid mode.")); 436 } else { 437 mDataLoadMode = mode; 438 } 439 } 440 441 442 // Convenience method for the contructor's audio buffer size check. 443 // preconditions: 444 // mChannelCount is valid 445 // mAudioFormat is valid 446 // postcondition: 447 // mNativeBufferSizeInBytes is valid (multiple of frame size, positive) 448 private void audioBuffSizeCheck(int audioBufferSize) { 449 // NB: this section is only valid with PCM data. 450 // To update when supporting compressed formats 451 int frameSizeInBytes = mChannelCount 452 * (mAudioFormat == AudioFormat.ENCODING_PCM_8BIT ? 1 : 2); 453 if ((audioBufferSize % frameSizeInBytes != 0) || (audioBufferSize < 1)) { 454 throw (new IllegalArgumentException("Invalid audio buffer size.")); 455 } 456 457 mNativeBufferSizeInBytes = audioBufferSize; 458 } 459 460 461 /** 462 * Releases the native AudioTrack resources. 463 */ 464 public void release() { 465 // even though native_release() stops the native AudioTrack, we need to stop 466 // AudioTrack subclasses too. 467 try { 468 stop(); 469 } catch(IllegalStateException ise) { 470 // don't raise an exception, we're releasing the resources. 471 } 472 native_release(); 473 mState = STATE_UNINITIALIZED; 474 } 475 476 @Override 477 protected void finalize() { 478 native_finalize(); 479 } 480 481 //-------------------------------------------------------------------------- 482 // Getters 483 //-------------------- 484 /** 485 * Returns the minimum valid volume value. Volume values set under this one will 486 * be clamped at this value. 487 * @return the minimum volume expressed as a linear attenuation. 488 */ 489 static public float getMinVolume() { 490 return AudioTrack.VOLUME_MIN; 491 } 492 493 /** 494 * Returns the maximum valid volume value. Volume values set above this one will 495 * be clamped at this value. 496 * @return the maximum volume expressed as a linear attenuation. 497 */ 498 static public float getMaxVolume() { 499 return AudioTrack.VOLUME_MAX; 500 } 501 502 /** 503 * Returns the configured audio data sample rate in Hz 504 */ 505 public int getSampleRate() { 506 return mSampleRate; 507 } 508 509 /** 510 * Returns the current playback rate in Hz. 511 */ 512 public int getPlaybackRate() { 513 return native_get_playback_rate(); 514 } 515 516 /** 517 * Returns the configured audio data format. See {@link AudioFormat#ENCODING_PCM_16BIT} 518 * and {@link AudioFormat#ENCODING_PCM_8BIT}. 519 */ 520 public int getAudioFormat() { 521 return mAudioFormat; 522 } 523 524 /** 525 * Returns the type of audio stream this AudioTrack is configured for. 526 * Compare the result against {@link AudioManager#STREAM_VOICE_CALL}, 527 * {@link AudioManager#STREAM_SYSTEM}, {@link AudioManager#STREAM_RING}, 528 * {@link AudioManager#STREAM_MUSIC}, {@link AudioManager#STREAM_ALARM}, 529 * {@link AudioManager#STREAM_NOTIFICATION}, or {@link AudioManager#STREAM_DTMF}. 530 */ 531 public int getStreamType() { 532 return mStreamType; 533 } 534 535 /** 536 * Returns the configured channel configuration. 537 538 * See {@link AudioFormat#CHANNEL_OUT_MONO} 539 * and {@link AudioFormat#CHANNEL_OUT_STEREO}. 540 */ 541 public int getChannelConfiguration() { 542 return mChannelConfiguration; 543 } 544 545 /** 546 * Returns the configured number of channels. 547 */ 548 public int getChannelCount() { 549 return mChannelCount; 550 } 551 552 /** 553 * Returns the state of the AudioTrack instance. This is useful after the 554 * AudioTrack instance has been created to check if it was initialized 555 * properly. This ensures that the appropriate hardware resources have been 556 * acquired. 557 * @see #STATE_INITIALIZED 558 * @see #STATE_NO_STATIC_DATA 559 * @see #STATE_UNINITIALIZED 560 */ 561 public int getState() { 562 return mState; 563 } 564 565 /** 566 * Returns the playback state of the AudioTrack instance. 567 * @see #PLAYSTATE_STOPPED 568 * @see #PLAYSTATE_PAUSED 569 * @see #PLAYSTATE_PLAYING 570 */ 571 public int getPlayState() { 572 synchronized (mPlayStateLock) { 573 return mPlayState; 574 } 575 } 576 577 /** 578 * Returns the native frame count used by the hardware. 579 */ 580 protected int getNativeFrameCount() { 581 return native_get_native_frame_count(); 582 } 583 584 /** 585 * Returns marker position expressed in frames. 586 */ 587 public int getNotificationMarkerPosition() { 588 return native_get_marker_pos(); 589 } 590 591 /** 592 * Returns the notification update period expressed in frames. 593 */ 594 public int getPositionNotificationPeriod() { 595 return native_get_pos_update_period(); 596 } 597 598 /** 599 * Returns the playback head position expressed in frames 600 */ 601 public int getPlaybackHeadPosition() { 602 return native_get_position(); 603 } 604 605 /** 606 * Returns the hardware output sample rate 607 */ 608 static public int getNativeOutputSampleRate(int streamType) { 609 return native_get_output_sample_rate(streamType); 610 } 611 612 /** 613 * Returns the minimum buffer size required for the successful creation of an AudioTrack 614 * object to be created in the {@link #MODE_STREAM} mode. Note that this size doesn't 615 * guarantee a smooth playback under load, and higher values should be chosen according to 616 * the expected frequency at which the buffer will be refilled with additional data to play. 617 * @param sampleRateInHz the sample rate expressed in Hertz. 618 * @param channelConfig describes the configuration of the audio channels. 619 * See {@link AudioFormat#CHANNEL_OUT_MONO} and 620 * {@link AudioFormat#CHANNEL_OUT_STEREO} 621 * @param audioFormat the format in which the audio data is represented. 622 * See {@link AudioFormat#ENCODING_PCM_16BIT} and 623 * {@link AudioFormat#ENCODING_PCM_8BIT} 624 * @return {@link #ERROR_BAD_VALUE} if an invalid parameter was passed, 625 * or {@link #ERROR} if the implementation was unable to query the hardware for its output 626 * properties, 627 * or the minimum buffer size expressed in bytes. 628 */ 629 static public int getMinBufferSize(int sampleRateInHz, int channelConfig, int audioFormat) { 630 int channelCount = 0; 631 switch(channelConfig) { 632 case AudioFormat.CHANNEL_OUT_MONO: 633 case AudioFormat.CHANNEL_CONFIGURATION_MONO: 634 channelCount = 1; 635 break; 636 case AudioFormat.CHANNEL_OUT_STEREO: 637 case AudioFormat.CHANNEL_CONFIGURATION_STEREO: 638 channelCount = 2; 639 break; 640 default: 641 if ((channelConfig & SUPPORTED_OUT_CHANNELS) != channelConfig) { 642 // input channel configuration features unsupported channels 643 loge("getMinBufferSize(): Invalid channel configuration."); 644 return AudioTrack.ERROR_BAD_VALUE; 645 } else { 646 channelCount = Integer.bitCount(channelConfig); 647 } 648 } 649 650 if ((audioFormat != AudioFormat.ENCODING_PCM_16BIT) 651 && (audioFormat != AudioFormat.ENCODING_PCM_8BIT)) { 652 loge("getMinBufferSize(): Invalid audio format."); 653 return AudioTrack.ERROR_BAD_VALUE; 654 } 655 656 // sample rate, note these values are subject to change 657 if ( (sampleRateInHz < 4000) || (sampleRateInHz > 48000) ) { 658 loge("getMinBufferSize(): " + sampleRateInHz +"Hz is not a supported sample rate."); 659 return AudioTrack.ERROR_BAD_VALUE; 660 } 661 662 int size = native_get_min_buff_size(sampleRateInHz, channelCount, audioFormat); 663 if ((size == -1) || (size == 0)) { 664 loge("getMinBufferSize(): error querying hardware"); 665 return AudioTrack.ERROR; 666 } 667 else { 668 return size; 669 } 670 } 671 672 /** 673 * Returns the audio session ID. 674 * 675 * @return the ID of the audio session this AudioTrack belongs to. 676 */ 677 public int getAudioSessionId() { 678 return mSessionId; 679 } 680 681 //-------------------------------------------------------------------------- 682 // Initialization / configuration 683 //-------------------- 684 /** 685 * Sets the listener the AudioTrack notifies when a previously set marker is reached or 686 * for each periodic playback head position update. 687 * Notifications will be received in the same thread as the one in which the AudioTrack 688 * instance was created. 689 * @param listener 690 */ 691 public void setPlaybackPositionUpdateListener(OnPlaybackPositionUpdateListener listener) { 692 setPlaybackPositionUpdateListener(listener, null); 693 } 694 695 /** 696 * Sets the listener the AudioTrack notifies when a previously set marker is reached or 697 * for each periodic playback head position update. 698 * Use this method to receive AudioTrack events in the Handler associated with another 699 * thread than the one in which you created the AudioTrack instance. 700 * @param listener 701 * @param handler the Handler that will receive the event notification messages. 702 */ 703 public void setPlaybackPositionUpdateListener(OnPlaybackPositionUpdateListener listener, 704 Handler handler) { 705 synchronized (mPositionListenerLock) { 706 mPositionListener = listener; 707 } 708 if (listener != null) { 709 mEventHandlerDelegate = new NativeEventHandlerDelegate(this, handler); 710 } 711 712 } 713 714 715 716 /** 717 * Sets the specified left/right output volume values on the AudioTrack. Values are clamped 718 * to the ({@link #getMinVolume()}, {@link #getMaxVolume()}) interval if outside this range. 719 * @param leftVolume output attenuation for the left channel. A value of 0.0f is silence, 720 * a value of 1.0f is no attenuation. 721 * @param rightVolume output attenuation for the right channel 722 * @return error code or success, see {@link #SUCCESS}, 723 * {@link #ERROR_INVALID_OPERATION} 724 */ 725 public int setStereoVolume(float leftVolume, float rightVolume) { 726 if (mState != STATE_INITIALIZED) { 727 return ERROR_INVALID_OPERATION; 728 } 729 730 // clamp the volumes 731 if (leftVolume < getMinVolume()) { 732 leftVolume = getMinVolume(); 733 } 734 if (leftVolume > getMaxVolume()) { 735 leftVolume = getMaxVolume(); 736 } 737 if (rightVolume < getMinVolume()) { 738 rightVolume = getMinVolume(); 739 } 740 if (rightVolume > getMaxVolume()) { 741 rightVolume = getMaxVolume(); 742 } 743 744 native_setVolume(leftVolume, rightVolume); 745 746 return SUCCESS; 747 } 748 749 750 /** 751 * Sets the playback sample rate for this track. This sets the sampling rate at which 752 * the audio data will be consumed and played back, not the original sampling rate of the 753 * content. Setting it to half the sample rate of the content will cause the playback to 754 * last twice as long, but will also result in a negative pitch shift. 755 * The valid sample rate range is from 1Hz to twice the value returned by 756 * {@link #getNativeOutputSampleRate(int)}. 757 * @param sampleRateInHz the sample rate expressed in Hz 758 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 759 * {@link #ERROR_INVALID_OPERATION} 760 */ 761 public int setPlaybackRate(int sampleRateInHz) { 762 if (mState != STATE_INITIALIZED) { 763 return ERROR_INVALID_OPERATION; 764 } 765 if (sampleRateInHz <= 0) { 766 return ERROR_BAD_VALUE; 767 } 768 return native_set_playback_rate(sampleRateInHz); 769 } 770 771 772 /** 773 * Sets the position of the notification marker. 774 * @param markerInFrames marker in frames 775 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 776 * {@link #ERROR_INVALID_OPERATION} 777 */ 778 public int setNotificationMarkerPosition(int markerInFrames) { 779 if (mState != STATE_INITIALIZED) { 780 return ERROR_INVALID_OPERATION; 781 } 782 return native_set_marker_pos(markerInFrames); 783 } 784 785 786 /** 787 * Sets the period for the periodic notification event. 788 * @param periodInFrames update period expressed in frames 789 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_INVALID_OPERATION} 790 */ 791 public int setPositionNotificationPeriod(int periodInFrames) { 792 if (mState != STATE_INITIALIZED) { 793 return ERROR_INVALID_OPERATION; 794 } 795 return native_set_pos_update_period(periodInFrames); 796 } 797 798 799 /** 800 * Sets the playback head position. The track must be stopped for the position to be changed. 801 * @param positionInFrames playback head position expressed in frames 802 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 803 * {@link #ERROR_INVALID_OPERATION} 804 */ 805 public int setPlaybackHeadPosition(int positionInFrames) { 806 synchronized(mPlayStateLock) { 807 if ((mPlayState == PLAYSTATE_STOPPED) || (mPlayState == PLAYSTATE_PAUSED)) { 808 return native_set_position(positionInFrames); 809 } else { 810 return ERROR_INVALID_OPERATION; 811 } 812 } 813 } 814 815 /** 816 * Sets the loop points and the loop count. The loop can be infinite. 817 * @param startInFrames loop start marker expressed in frames 818 * @param endInFrames loop end marker expressed in frames 819 * @param loopCount the number of times the loop is looped. 820 * A value of -1 means infinite looping. 821 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 822 * {@link #ERROR_INVALID_OPERATION} 823 */ 824 public int setLoopPoints(int startInFrames, int endInFrames, int loopCount) { 825 if (mDataLoadMode == MODE_STREAM) { 826 return ERROR_INVALID_OPERATION; 827 } 828 return native_set_loop(startInFrames, endInFrames, loopCount); 829 } 830 831 /** 832 * Sets the initialization state of the instance. To be used in an AudioTrack subclass 833 * constructor to set a subclass-specific post-initialization state. 834 * @param state the state of the AudioTrack instance 835 */ 836 protected void setState(int state) { 837 mState = state; 838 } 839 840 841 //--------------------------------------------------------- 842 // Transport control methods 843 //-------------------- 844 /** 845 * Starts playing an AudioTrack. 846 * 847 * @throws IllegalStateException 848 */ 849 public void play() 850 throws IllegalStateException { 851 if (mState != STATE_INITIALIZED) { 852 throw(new IllegalStateException("play() called on uninitialized AudioTrack.")); 853 } 854 855 synchronized(mPlayStateLock) { 856 native_start(); 857 mPlayState = PLAYSTATE_PLAYING; 858 } 859 } 860 861 /** 862 * Stops playing the audio data. 863 * When used on an instance created in {@link #MODE_STREAM} mode, audio will stop playing 864 * after the last buffer that was written has been played. For an immediate stop, use 865 * {@link #pause()}, followed by {@link #flush()} to discard audio data that hasn't been played 866 * back yet. 867 * @throws IllegalStateException 868 */ 869 public void stop() 870 throws IllegalStateException { 871 if (mState != STATE_INITIALIZED) { 872 throw(new IllegalStateException("stop() called on uninitialized AudioTrack.")); 873 } 874 875 // stop playing 876 synchronized(mPlayStateLock) { 877 native_stop(); 878 mPlayState = PLAYSTATE_STOPPED; 879 } 880 } 881 882 /** 883 * Pauses the playback of the audio data. Data that has not been played 884 * back will not be discarded. Subsequent calls to {@link #play} will play 885 * this data back. See {@link #flush()} to discard this data. 886 * 887 * @throws IllegalStateException 888 */ 889 public void pause() 890 throws IllegalStateException { 891 if (mState != STATE_INITIALIZED) { 892 throw(new IllegalStateException("pause() called on uninitialized AudioTrack.")); 893 } 894 //logd("pause()"); 895 896 // pause playback 897 synchronized(mPlayStateLock) { 898 native_pause(); 899 mPlayState = PLAYSTATE_PAUSED; 900 } 901 } 902 903 904 //--------------------------------------------------------- 905 // Audio data supply 906 //-------------------- 907 908 /** 909 * Flushes the audio data currently queued for playback. Any data that has 910 * not been played back will be discarded. 911 */ 912 public void flush() { 913 if (mState == STATE_INITIALIZED) { 914 // flush the data in native layer 915 native_flush(); 916 } 917 918 } 919 920 /** 921 * Writes the audio data to the audio hardware for playback. Will block until 922 * all data has been written to the audio mixer. 923 * Note that the actual playback of this data might occur after this function 924 * returns. This function is thread safe with respect to {@link #stop} calls, 925 * in which case all of the specified data might not be written to the mixer. 926 * 927 * @param audioData the array that holds the data to play. 928 * @param offsetInBytes the offset expressed in bytes in audioData where the data to play 929 * starts. 930 * @param sizeInBytes the number of bytes to read in audioData after the offset. 931 * @return the number of bytes that were written or {@link #ERROR_INVALID_OPERATION} 932 * if the object wasn't properly initialized, or {@link #ERROR_BAD_VALUE} if 933 * the parameters don't resolve to valid data and indexes. 934 */ 935 936 public int write(byte[] audioData, int offsetInBytes, int sizeInBytes) { 937 if ((mDataLoadMode == MODE_STATIC) 938 && (mState == STATE_NO_STATIC_DATA) 939 && (sizeInBytes > 0)) { 940 mState = STATE_INITIALIZED; 941 } 942 943 if (mState != STATE_INITIALIZED) { 944 return ERROR_INVALID_OPERATION; 945 } 946 947 if ( (audioData == null) || (offsetInBytes < 0 ) || (sizeInBytes < 0) 948 || (offsetInBytes + sizeInBytes > audioData.length)) { 949 return ERROR_BAD_VALUE; 950 } 951 952 return native_write_byte(audioData, offsetInBytes, sizeInBytes, mAudioFormat); 953 } 954 955 956 /** 957 * Writes the audio data to the audio hardware for playback. Will block until 958 * all data has been written to the audio mixer. 959 * Note that the actual playback of this data might occur after this function 960 * returns. This function is thread safe with respect to {@link #stop} calls, 961 * in which case all of the specified data might not be written to the mixer. 962 * 963 * @param audioData the array that holds the data to play. 964 * @param offsetInShorts the offset expressed in shorts in audioData where the data to play 965 * starts. 966 * @param sizeInShorts the number of bytes to read in audioData after the offset. 967 * @return the number of shorts that were written or {@link #ERROR_INVALID_OPERATION} 968 * if the object wasn't properly initialized, or {@link #ERROR_BAD_VALUE} if 969 * the parameters don't resolve to valid data and indexes. 970 */ 971 972 public int write(short[] audioData, int offsetInShorts, int sizeInShorts) { 973 if ((mDataLoadMode == MODE_STATIC) 974 && (mState == STATE_NO_STATIC_DATA) 975 && (sizeInShorts > 0)) { 976 mState = STATE_INITIALIZED; 977 } 978 979 if (mState != STATE_INITIALIZED) { 980 return ERROR_INVALID_OPERATION; 981 } 982 983 if ( (audioData == null) || (offsetInShorts < 0 ) || (sizeInShorts < 0) 984 || (offsetInShorts + sizeInShorts > audioData.length)) { 985 return ERROR_BAD_VALUE; 986 } 987 988 return native_write_short(audioData, offsetInShorts, sizeInShorts, mAudioFormat); 989 } 990 991 992 /** 993 * Notifies the native resource to reuse the audio data already loaded in the native 994 * layer. This call is only valid with AudioTrack instances that don't use the streaming 995 * model. 996 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 997 * {@link #ERROR_INVALID_OPERATION} 998 */ 999 public int reloadStaticData() { 1000 if (mDataLoadMode == MODE_STREAM) { 1001 return ERROR_INVALID_OPERATION; 1002 } 1003 return native_reload_static(); 1004 } 1005 1006 //-------------------------------------------------------------------------- 1007 // Audio effects management 1008 //-------------------- 1009 1010 /** 1011 * Attaches an auxiliary effect to the audio track. A typical auxiliary 1012 * effect is a reverberation effect which can be applied on any sound source 1013 * that directs a certain amount of its energy to this effect. This amount 1014 * is defined by setAuxEffectSendLevel(). 1015 * {@see #setAuxEffectSendLevel(float)}. 1016 * <p>After creating an auxiliary effect (e.g. 1017 * {@link android.media.audiofx.EnvironmentalReverb}), retrieve its ID with 1018 * {@link android.media.audiofx.AudioEffect#getId()} and use it when calling 1019 * this method to attach the audio track to the effect. 1020 * <p>To detach the effect from the audio track, call this method with a 1021 * null effect id. 1022 * 1023 * @param effectId system wide unique id of the effect to attach 1024 * @return error code or success, see {@link #SUCCESS}, 1025 * {@link #ERROR_INVALID_OPERATION}, {@link #ERROR_BAD_VALUE} 1026 */ 1027 public int attachAuxEffect(int effectId) { 1028 if (mState != STATE_INITIALIZED) { 1029 return ERROR_INVALID_OPERATION; 1030 } 1031 return native_attachAuxEffect(effectId); 1032 } 1033 1034 /** 1035 * Sets the send level of the audio track to the attached auxiliary effect 1036 * {@link #attachAuxEffect(int)}. The level value range is 0 to 1.0. 1037 * <p>By default the send level is 0, so even if an effect is attached to the player 1038 * this method must be called for the effect to be applied. 1039 * <p>Note that the passed level value is a raw scalar. UI controls should be scaled 1040 * logarithmically: the gain applied by audio framework ranges from -72dB to 0dB, 1041 * so an appropriate conversion from linear UI input x to level is: 1042 * x == 0 -> level = 0 1043 * 0 < x <= R -> level = 10^(72*(x-R)/20/R) 1044 * 1045 * @param level send level scalar 1046 * @return error code or success, see {@link #SUCCESS}, 1047 * {@link #ERROR_INVALID_OPERATION} 1048 */ 1049 public int setAuxEffectSendLevel(float level) { 1050 if (mState != STATE_INITIALIZED) { 1051 return ERROR_INVALID_OPERATION; 1052 } 1053 // clamp the level 1054 if (level < getMinVolume()) { 1055 level = getMinVolume(); 1056 } 1057 if (level > getMaxVolume()) { 1058 level = getMaxVolume(); 1059 } 1060 native_setAuxEffectSendLevel(level); 1061 return SUCCESS; 1062 } 1063 1064 //--------------------------------------------------------- 1065 // Interface definitions 1066 //-------------------- 1067 /** 1068 * Interface definition for a callback to be invoked when the playback head position of 1069 * an AudioTrack has reached a notification marker or has increased by a certain period. 1070 */ 1071 public interface OnPlaybackPositionUpdateListener { 1072 /** 1073 * Called on the listener to notify it that the previously set marker has been reached 1074 * by the playback head. 1075 */ 1076 void onMarkerReached(AudioTrack track); 1077 1078 /** 1079 * Called on the listener to periodically notify it that the playback head has reached 1080 * a multiple of the notification period. 1081 */ 1082 void onPeriodicNotification(AudioTrack track); 1083 } 1084 1085 1086 //--------------------------------------------------------- 1087 // Inner classes 1088 //-------------------- 1089 /** 1090 * Helper class to handle the forwarding of native events to the appropriate listener 1091 * (potentially) handled in a different thread 1092 */ 1093 private class NativeEventHandlerDelegate { 1094 private final AudioTrack mAudioTrack; 1095 private final Handler mHandler; 1096 1097 NativeEventHandlerDelegate(AudioTrack track, Handler handler) { 1098 mAudioTrack = track; 1099 // find the looper for our new event handler 1100 Looper looper; 1101 if (handler != null) { 1102 looper = handler.getLooper(); 1103 } else { 1104 // no given handler, use the looper the AudioTrack was created in 1105 looper = mInitializationLooper; 1106 } 1107 1108 // construct the event handler with this looper 1109 if (looper != null) { 1110 // implement the event handler delegate 1111 mHandler = new Handler(looper) { 1112 @Override 1113 public void handleMessage(Message msg) { 1114 if (mAudioTrack == null) { 1115 return; 1116 } 1117 OnPlaybackPositionUpdateListener listener = null; 1118 synchronized (mPositionListenerLock) { 1119 listener = mAudioTrack.mPositionListener; 1120 } 1121 switch(msg.what) { 1122 case NATIVE_EVENT_MARKER: 1123 if (listener != null) { 1124 listener.onMarkerReached(mAudioTrack); 1125 } 1126 break; 1127 case NATIVE_EVENT_NEW_POS: 1128 if (listener != null) { 1129 listener.onPeriodicNotification(mAudioTrack); 1130 } 1131 break; 1132 default: 1133 Log.e(TAG, "[ android.media.AudioTrack.NativeEventHandler ] " + 1134 "Unknown event type: " + msg.what); 1135 break; 1136 } 1137 } 1138 }; 1139 } else { 1140 mHandler = null; 1141 } 1142 } 1143 1144 Handler getHandler() { 1145 return mHandler; 1146 } 1147 } 1148 1149 1150 //--------------------------------------------------------- 1151 // Java methods called from the native side 1152 //-------------------- 1153 @SuppressWarnings("unused") 1154 private static void postEventFromNative(Object audiotrack_ref, 1155 int what, int arg1, int arg2, Object obj) { 1156 //logd("Event posted from the native side: event="+ what + " args="+ arg1+" "+arg2); 1157 AudioTrack track = (AudioTrack)((WeakReference)audiotrack_ref).get(); 1158 if (track == null) { 1159 return; 1160 } 1161 1162 if (track.mEventHandlerDelegate != null) { 1163 Message m = 1164 track.mEventHandlerDelegate.getHandler().obtainMessage(what, arg1, arg2, obj); 1165 track.mEventHandlerDelegate.getHandler().sendMessage(m); 1166 } 1167 1168 } 1169 1170 1171 //--------------------------------------------------------- 1172 // Native methods called from the Java side 1173 //-------------------- 1174 1175 private native final int native_setup(Object audiotrack_this, 1176 int streamType, int sampleRate, int nbChannels, int audioFormat, 1177 int buffSizeInBytes, int mode, int[] sessionId); 1178 1179 private native final void native_finalize(); 1180 1181 private native final void native_release(); 1182 1183 private native final void native_start(); 1184 1185 private native final void native_stop(); 1186 1187 private native final void native_pause(); 1188 1189 private native final void native_flush(); 1190 1191 private native final int native_write_byte(byte[] audioData, 1192 int offsetInBytes, int sizeInBytes, int format); 1193 1194 private native final int native_write_short(short[] audioData, 1195 int offsetInShorts, int sizeInShorts, int format); 1196 1197 private native final int native_reload_static(); 1198 1199 private native final int native_get_native_frame_count(); 1200 1201 private native final void native_setVolume(float leftVolume, float rightVolume); 1202 1203 private native final int native_set_playback_rate(int sampleRateInHz); 1204 private native final int native_get_playback_rate(); 1205 1206 private native final int native_set_marker_pos(int marker); 1207 private native final int native_get_marker_pos(); 1208 1209 private native final int native_set_pos_update_period(int updatePeriod); 1210 private native final int native_get_pos_update_period(); 1211 1212 private native final int native_set_position(int position); 1213 private native final int native_get_position(); 1214 1215 private native final int native_set_loop(int start, int end, int loopCount); 1216 1217 static private native final int native_get_output_sample_rate(int streamType); 1218 static private native final int native_get_min_buff_size( 1219 int sampleRateInHz, int channelConfig, int audioFormat); 1220 1221 private native final int native_get_session_id(); 1222 1223 private native final int native_attachAuxEffect(int effectId); 1224 private native final void native_setAuxEffectSendLevel(float level); 1225 1226 //--------------------------------------------------------- 1227 // Utility methods 1228 //------------------ 1229 1230 private static void logd(String msg) { 1231 Log.d(TAG, "[ android.media.AudioTrack ] " + msg); 1232 } 1233 1234 private static void loge(String msg) { 1235 Log.e(TAG, "[ android.media.AudioTrack ] " + msg); 1236 } 1237 1238} 1239