AudioTrack.java revision ad67c9546494a7c4d9336b57889a7c19a7dbb945
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 /** Minimum value for sample rate */ 73 private static final int SAMPLE_RATE_HZ_MIN = 4000; 74 /** Maximum value for sample rate */ 75 private static final int SAMPLE_RATE_HZ_MAX = 48000; 76 77 /** indicates AudioTrack state is stopped */ 78 public static final int PLAYSTATE_STOPPED = 1; // matches SL_PLAYSTATE_STOPPED 79 /** indicates AudioTrack state is paused */ 80 public static final int PLAYSTATE_PAUSED = 2; // matches SL_PLAYSTATE_PAUSED 81 /** indicates AudioTrack state is playing */ 82 public static final int PLAYSTATE_PLAYING = 3; // matches SL_PLAYSTATE_PLAYING 83 84 // keep these values in sync with android_media_AudioTrack.cpp 85 /** 86 * Creation mode where audio data is transferred from Java to the native layer 87 * only once before the audio starts playing. 88 */ 89 public static final int MODE_STATIC = 0; 90 /** 91 * Creation mode where audio data is streamed from Java to the native layer 92 * as the audio is playing. 93 */ 94 public static final int MODE_STREAM = 1; 95 96 /** 97 * State of an AudioTrack that was not successfully initialized upon creation. 98 */ 99 public static final int STATE_UNINITIALIZED = 0; 100 /** 101 * State of an AudioTrack that is ready to be used. 102 */ 103 public static final int STATE_INITIALIZED = 1; 104 /** 105 * State of a successfully initialized AudioTrack that uses static data, 106 * but that hasn't received that data yet. 107 */ 108 public static final int STATE_NO_STATIC_DATA = 2; 109 110 // Error codes: 111 // to keep in sync with frameworks/base/core/jni/android_media_AudioTrack.cpp 112 /** 113 * Denotes a successful operation. 114 */ 115 public static final int SUCCESS = 0; 116 /** 117 * Denotes a generic operation failure. 118 */ 119 public static final int ERROR = -1; 120 /** 121 * Denotes a failure due to the use of an invalid value. 122 */ 123 public static final int ERROR_BAD_VALUE = -2; 124 /** 125 * Denotes a failure due to the improper use of a method. 126 */ 127 public static final int ERROR_INVALID_OPERATION = -3; 128 129 private static final int ERROR_NATIVESETUP_AUDIOSYSTEM = -16; 130 private static final int ERROR_NATIVESETUP_INVALIDCHANNELMASK = -17; 131 private static final int ERROR_NATIVESETUP_INVALIDFORMAT = -18; 132 private static final int ERROR_NATIVESETUP_INVALIDSTREAMTYPE = -19; 133 private static final int ERROR_NATIVESETUP_NATIVEINITFAILED = -20; 134 135 // Events: 136 // to keep in sync with frameworks/base/include/media/AudioTrack.h 137 /** 138 * Event id denotes when playback head has reached a previously set marker. 139 */ 140 private static final int NATIVE_EVENT_MARKER = 3; 141 /** 142 * Event id denotes when previously set update period has elapsed during playback. 143 */ 144 private static final int NATIVE_EVENT_NEW_POS = 4; 145 146 private final static String TAG = "AudioTrack-Java"; 147 148 149 //-------------------------------------------------------------------------- 150 // Member variables 151 //-------------------- 152 /** 153 * Indicates the state of the AudioTrack instance. 154 */ 155 private int mState = STATE_UNINITIALIZED; 156 /** 157 * Indicates the play state of the AudioTrack instance. 158 */ 159 private int mPlayState = PLAYSTATE_STOPPED; 160 /** 161 * Lock to make sure mPlayState updates are reflecting the actual state of the object. 162 */ 163 private final Object mPlayStateLock = new Object(); 164 /** 165 * The listener the AudioTrack notifies when the playback position reaches a marker 166 * or for periodic updates during the progression of the playback head. 167 * @see #setPlaybackPositionUpdateListener(OnPlaybackPositionUpdateListener) 168 */ 169 private OnPlaybackPositionUpdateListener mPositionListener = null; 170 /** 171 * Lock to protect event listener updates against event notifications. 172 */ 173 private final Object mPositionListenerLock = new Object(); 174 /** 175 * Size of the native audio buffer. 176 */ 177 private int mNativeBufferSizeInBytes = 0; 178 /** 179 * Handler for marker events coming from the native code. 180 */ 181 private NativeEventHandlerDelegate mEventHandlerDelegate = null; 182 /** 183 * Looper associated with the thread that creates the AudioTrack instance. 184 */ 185 private Looper mInitializationLooper = null; 186 /** 187 * The audio data sampling rate in Hz. 188 */ 189 private int mSampleRate; // initialized by all constructors 190 /** 191 * The number of audio output channels (1 is mono, 2 is stereo). 192 */ 193 private int mChannelCount = 1; 194 /** 195 * The audio channel mask. 196 */ 197 private int mChannels = AudioFormat.CHANNEL_OUT_MONO; 198 199 /** 200 * The type of the audio stream to play. See 201 * {@link AudioManager#STREAM_VOICE_CALL}, {@link AudioManager#STREAM_SYSTEM}, 202 * {@link AudioManager#STREAM_RING}, {@link AudioManager#STREAM_MUSIC}, 203 * {@link AudioManager#STREAM_ALARM}, {@link AudioManager#STREAM_NOTIFICATION}, and 204 * {@link AudioManager#STREAM_DTMF}. 205 */ 206 private int mStreamType = AudioManager.STREAM_MUSIC; 207 /** 208 * The way audio is consumed by the hardware, streaming or static. 209 */ 210 private int mDataLoadMode = MODE_STREAM; 211 /** 212 * The current audio channel configuration. 213 */ 214 private int mChannelConfiguration = AudioFormat.CHANNEL_OUT_MONO; 215 /** 216 * The encoding of the audio samples. 217 * @see AudioFormat#ENCODING_PCM_8BIT 218 * @see AudioFormat#ENCODING_PCM_16BIT 219 */ 220 private int mAudioFormat = AudioFormat.ENCODING_PCM_16BIT; 221 /** 222 * Audio session ID 223 */ 224 private int mSessionId = 0; 225 226 227 //-------------------------------- 228 // Used exclusively by native code 229 //-------------------- 230 /** 231 * Accessed by native methods: provides access to C++ AudioTrack object. 232 */ 233 @SuppressWarnings("unused") 234 private int mNativeTrackInJavaObj; 235 /** 236 * Accessed by native methods: provides access to the JNI data (i.e. resources used by 237 * the native AudioTrack object, but not stored in it). 238 */ 239 @SuppressWarnings("unused") 240 private int mJniData; 241 242 243 //-------------------------------------------------------------------------- 244 // Constructor, Finalize 245 //-------------------- 246 /** 247 * Class constructor. 248 * @param streamType the type of the audio stream. See 249 * {@link AudioManager#STREAM_VOICE_CALL}, {@link AudioManager#STREAM_SYSTEM}, 250 * {@link AudioManager#STREAM_RING}, {@link AudioManager#STREAM_MUSIC}, 251 * {@link AudioManager#STREAM_ALARM}, and {@link AudioManager#STREAM_NOTIFICATION}. 252 * @param sampleRateInHz the sample rate expressed in Hertz. 253 * @param channelConfig describes the configuration of the audio channels. 254 * See {@link AudioFormat#CHANNEL_OUT_MONO} and 255 * {@link AudioFormat#CHANNEL_OUT_STEREO} 256 * @param audioFormat the format in which the audio data is represented. 257 * See {@link AudioFormat#ENCODING_PCM_16BIT} and 258 * {@link AudioFormat#ENCODING_PCM_8BIT} 259 * @param bufferSizeInBytes the total size (in bytes) of the buffer where audio data is read 260 * from for playback. If using the AudioTrack in streaming mode, you can write data into 261 * this buffer in smaller chunks than this size. If using the AudioTrack in static mode, 262 * this is the maximum size of the sound that will be played for this instance. 263 * See {@link #getMinBufferSize(int, int, int)} to determine the minimum required buffer size 264 * for the successful creation of an AudioTrack instance in streaming mode. Using values 265 * smaller than getMinBufferSize() will result in an initialization failure. 266 * @param mode streaming or static buffer. See {@link #MODE_STATIC} and {@link #MODE_STREAM} 267 * @throws java.lang.IllegalArgumentException 268 */ 269 public AudioTrack(int streamType, int sampleRateInHz, int channelConfig, int audioFormat, 270 int bufferSizeInBytes, int mode) 271 throws IllegalArgumentException { 272 this(streamType, sampleRateInHz, channelConfig, audioFormat, 273 bufferSizeInBytes, mode, 0); 274 } 275 276 /** 277 * Class constructor with audio session. Use this constructor when the AudioTrack must be 278 * attached to a particular audio session. The primary use of the audio session ID is to 279 * associate audio effects to a particular instance of AudioTrack: if an audio session ID 280 * is provided when creating an AudioEffect, this effect will be applied only to audio tracks 281 * and media players in the same session and not to the output mix. 282 * When an AudioTrack is created without specifying a session, it will create its own session 283 * which can be retreived by calling the {@link #getAudioSessionId()} method. 284 * If a non-zero session ID is provided, this AudioTrack will share effects attached to this 285 * session 286 * with all other media players or audio tracks in the same session, otherwise a new session 287 * will be created for this track if none is supplied. 288 * @param streamType the type of the audio stream. See 289 * {@link AudioManager#STREAM_VOICE_CALL}, {@link AudioManager#STREAM_SYSTEM}, 290 * {@link AudioManager#STREAM_RING}, {@link AudioManager#STREAM_MUSIC}, 291 * {@link AudioManager#STREAM_ALARM}, and {@link AudioManager#STREAM_NOTIFICATION}. 292 * @param sampleRateInHz the sample rate expressed in Hertz. 293 * @param channelConfig describes the configuration of the audio channels. 294 * See {@link AudioFormat#CHANNEL_OUT_MONO} and 295 * {@link AudioFormat#CHANNEL_OUT_STEREO} 296 * @param audioFormat the format in which the audio data is represented. 297 * See {@link AudioFormat#ENCODING_PCM_16BIT} and 298 * {@link AudioFormat#ENCODING_PCM_8BIT} 299 * @param bufferSizeInBytes the total size (in bytes) of the buffer where audio data is read 300 * from for playback. If using the AudioTrack in streaming mode, you can write data into 301 * this buffer in smaller chunks than this size. If using the AudioTrack in static mode, 302 * this is the maximum size of the sound that will be played for this instance. 303 * See {@link #getMinBufferSize(int, int, int)} to determine the minimum required buffer size 304 * for the successful creation of an AudioTrack instance in streaming mode. Using values 305 * smaller than getMinBufferSize() will result in an initialization failure. 306 * @param mode streaming or static buffer. See {@link #MODE_STATIC} and {@link #MODE_STREAM} 307 * @param sessionId Id of audio session the AudioTrack must be attached to 308 * @throws java.lang.IllegalArgumentException 309 */ 310 public AudioTrack(int streamType, int sampleRateInHz, int channelConfig, int audioFormat, 311 int bufferSizeInBytes, int mode, int sessionId) 312 throws IllegalArgumentException { 313 mState = STATE_UNINITIALIZED; 314 315 // remember which looper is associated with the AudioTrack instantiation 316 if ((mInitializationLooper = Looper.myLooper()) == null) { 317 mInitializationLooper = Looper.getMainLooper(); 318 } 319 320 audioParamCheck(streamType, sampleRateInHz, channelConfig, audioFormat, mode); 321 322 audioBuffSizeCheck(bufferSizeInBytes); 323 324 if (sessionId < 0) { 325 throw (new IllegalArgumentException("Invalid audio session ID: "+sessionId)); 326 } 327 328 int[] session = new int[1]; 329 session[0] = sessionId; 330 // native initialization 331 int initResult = native_setup(new WeakReference<AudioTrack>(this), 332 mStreamType, mSampleRate, mChannels, mAudioFormat, 333 mNativeBufferSizeInBytes, mDataLoadMode, session); 334 if (initResult != SUCCESS) { 335 loge("Error code "+initResult+" when initializing AudioTrack."); 336 return; // with mState == STATE_UNINITIALIZED 337 } 338 339 mSessionId = session[0]; 340 341 if (mDataLoadMode == MODE_STATIC) { 342 mState = STATE_NO_STATIC_DATA; 343 } else { 344 mState = STATE_INITIALIZED; 345 } 346 } 347 348 // mask of all the channels supported by this implementation 349 private static final int SUPPORTED_OUT_CHANNELS = 350 AudioFormat.CHANNEL_OUT_FRONT_LEFT | 351 AudioFormat.CHANNEL_OUT_FRONT_RIGHT | 352 AudioFormat.CHANNEL_OUT_FRONT_CENTER | 353 AudioFormat.CHANNEL_OUT_LOW_FREQUENCY | 354 AudioFormat.CHANNEL_OUT_BACK_LEFT | 355 AudioFormat.CHANNEL_OUT_BACK_RIGHT | 356 AudioFormat.CHANNEL_OUT_BACK_CENTER; 357 358 // Convenience method for the constructor's parameter checks. 359 // This is where constructor IllegalArgumentException-s are thrown 360 // postconditions: 361 // mStreamType is valid 362 // mChannelCount is valid 363 // mChannels is valid 364 // mAudioFormat is valid 365 // mSampleRate is valid 366 // mDataLoadMode is valid 367 private void audioParamCheck(int streamType, int sampleRateInHz, 368 int channelConfig, int audioFormat, int mode) { 369 370 //-------------- 371 // stream type 372 if( (streamType != AudioManager.STREAM_ALARM) && (streamType != AudioManager.STREAM_MUSIC) 373 && (streamType != AudioManager.STREAM_RING) && (streamType != AudioManager.STREAM_SYSTEM) 374 && (streamType != AudioManager.STREAM_VOICE_CALL) 375 && (streamType != AudioManager.STREAM_NOTIFICATION) 376 && (streamType != AudioManager.STREAM_BLUETOOTH_SCO) 377 && (streamType != AudioManager.STREAM_DTMF)) { 378 throw (new IllegalArgumentException("Invalid stream type.")); 379 } else { 380 mStreamType = streamType; 381 } 382 383 //-------------- 384 // sample rate, note these values are subject to change 385 if ( (sampleRateInHz < 4000) || (sampleRateInHz > 48000) ) { 386 throw (new IllegalArgumentException(sampleRateInHz 387 + "Hz is not a supported sample rate.")); 388 } else { 389 mSampleRate = sampleRateInHz; 390 } 391 392 //-------------- 393 // channel config 394 mChannelConfiguration = channelConfig; 395 396 switch (channelConfig) { 397 case AudioFormat.CHANNEL_OUT_DEFAULT: //AudioFormat.CHANNEL_CONFIGURATION_DEFAULT 398 case AudioFormat.CHANNEL_OUT_MONO: 399 case AudioFormat.CHANNEL_CONFIGURATION_MONO: 400 mChannelCount = 1; 401 mChannels = AudioFormat.CHANNEL_OUT_MONO; 402 break; 403 case AudioFormat.CHANNEL_OUT_STEREO: 404 case AudioFormat.CHANNEL_CONFIGURATION_STEREO: 405 mChannelCount = 2; 406 mChannels = AudioFormat.CHANNEL_OUT_STEREO; 407 break; 408 default: 409 if (!isMultichannelConfigSupported(channelConfig)) { 410 // input channel configuration features unsupported channels 411 mChannelCount = 0; 412 mChannels = AudioFormat.CHANNEL_INVALID; 413 mChannelConfiguration = AudioFormat.CHANNEL_INVALID; 414 throw(new IllegalArgumentException("Unsupported channel configuration.")); 415 } else { 416 mChannels = channelConfig; 417 mChannelCount = Integer.bitCount(channelConfig); 418 } 419 } 420 421 //-------------- 422 // audio format 423 switch (audioFormat) { 424 case AudioFormat.ENCODING_DEFAULT: 425 mAudioFormat = AudioFormat.ENCODING_PCM_16BIT; 426 break; 427 case AudioFormat.ENCODING_PCM_16BIT: 428 case AudioFormat.ENCODING_PCM_8BIT: 429 mAudioFormat = audioFormat; 430 break; 431 default: 432 mAudioFormat = AudioFormat.ENCODING_INVALID; 433 throw(new IllegalArgumentException("Unsupported sample encoding." 434 + " Should be ENCODING_PCM_8BIT or ENCODING_PCM_16BIT.")); 435 } 436 437 //-------------- 438 // audio load mode 439 if ( (mode != MODE_STREAM) && (mode != MODE_STATIC) ) { 440 throw(new IllegalArgumentException("Invalid mode.")); 441 } else { 442 mDataLoadMode = mode; 443 } 444 } 445 446 /** 447 * Convenience method to check that the channel configuration (a.k.a channel mask) is supported 448 * @param channelConfig the mask to validate 449 * @return false if the AudioTrack can't be used with such a mask 450 */ 451 private static boolean isMultichannelConfigSupported(int channelConfig) { 452 // check for unsupported channels 453 if ((channelConfig & SUPPORTED_OUT_CHANNELS) != channelConfig) { 454 Log.e(TAG, "Channel configuration features unsupported channels"); 455 return false; 456 } 457 // check for unsupported multichannel combinations: 458 // - FL/FR must be present 459 // - L/R channels must be paired (e.g. no single L channel) 460 final int frontPair = 461 AudioFormat.CHANNEL_OUT_FRONT_LEFT | AudioFormat.CHANNEL_OUT_FRONT_RIGHT; 462 if ((channelConfig & frontPair) != frontPair) { 463 Log.e(TAG, "Front channels must be present in multichannel configurations"); 464 return false; 465 } 466 final int backPair = 467 AudioFormat.CHANNEL_OUT_BACK_LEFT | AudioFormat.CHANNEL_OUT_BACK_RIGHT; 468 if ((channelConfig & backPair) != 0) { 469 if ((channelConfig & backPair) != backPair) { 470 Log.e(TAG, "Rear channels can't be used independently"); 471 return false; 472 } 473 } 474 return true; 475 } 476 477 478 // Convenience method for the contructor's audio buffer size check. 479 // preconditions: 480 // mChannelCount is valid 481 // mAudioFormat is valid 482 // postcondition: 483 // mNativeBufferSizeInBytes is valid (multiple of frame size, positive) 484 private void audioBuffSizeCheck(int audioBufferSize) { 485 // NB: this section is only valid with PCM data. 486 // To update when supporting compressed formats 487 int frameSizeInBytes = mChannelCount 488 * (mAudioFormat == AudioFormat.ENCODING_PCM_8BIT ? 1 : 2); 489 if ((audioBufferSize % frameSizeInBytes != 0) || (audioBufferSize < 1)) { 490 throw (new IllegalArgumentException("Invalid audio buffer size.")); 491 } 492 493 mNativeBufferSizeInBytes = audioBufferSize; 494 } 495 496 497 /** 498 * Releases the native AudioTrack resources. 499 */ 500 public void release() { 501 // even though native_release() stops the native AudioTrack, we need to stop 502 // AudioTrack subclasses too. 503 try { 504 stop(); 505 } catch(IllegalStateException ise) { 506 // don't raise an exception, we're releasing the resources. 507 } 508 native_release(); 509 mState = STATE_UNINITIALIZED; 510 } 511 512 @Override 513 protected void finalize() { 514 native_finalize(); 515 } 516 517 //-------------------------------------------------------------------------- 518 // Getters 519 //-------------------- 520 /** 521 * Returns the minimum valid volume value. Volume values set under this one will 522 * be clamped at this value. 523 * @return the minimum volume expressed as a linear attenuation. 524 */ 525 static public float getMinVolume() { 526 return AudioTrack.VOLUME_MIN; 527 } 528 529 /** 530 * Returns the maximum valid volume value. Volume values set above this one will 531 * be clamped at this value. 532 * @return the maximum volume expressed as a linear attenuation. 533 */ 534 static public float getMaxVolume() { 535 return AudioTrack.VOLUME_MAX; 536 } 537 538 /** 539 * Returns the configured audio data sample rate in Hz 540 */ 541 public int getSampleRate() { 542 return mSampleRate; 543 } 544 545 /** 546 * Returns the current playback rate in Hz. 547 */ 548 public int getPlaybackRate() { 549 return native_get_playback_rate(); 550 } 551 552 /** 553 * Returns the configured audio data format. See {@link AudioFormat#ENCODING_PCM_16BIT} 554 * and {@link AudioFormat#ENCODING_PCM_8BIT}. 555 */ 556 public int getAudioFormat() { 557 return mAudioFormat; 558 } 559 560 /** 561 * Returns the type of audio stream this AudioTrack is configured for. 562 * Compare the result against {@link AudioManager#STREAM_VOICE_CALL}, 563 * {@link AudioManager#STREAM_SYSTEM}, {@link AudioManager#STREAM_RING}, 564 * {@link AudioManager#STREAM_MUSIC}, {@link AudioManager#STREAM_ALARM}, 565 * {@link AudioManager#STREAM_NOTIFICATION}, or {@link AudioManager#STREAM_DTMF}. 566 */ 567 public int getStreamType() { 568 return mStreamType; 569 } 570 571 /** 572 * Returns the configured channel configuration. 573 574 * See {@link AudioFormat#CHANNEL_OUT_MONO} 575 * and {@link AudioFormat#CHANNEL_OUT_STEREO}. 576 */ 577 public int getChannelConfiguration() { 578 return mChannelConfiguration; 579 } 580 581 /** 582 * Returns the configured number of channels. 583 */ 584 public int getChannelCount() { 585 return mChannelCount; 586 } 587 588 /** 589 * Returns the state of the AudioTrack instance. This is useful after the 590 * AudioTrack instance has been created to check if it was initialized 591 * properly. This ensures that the appropriate hardware resources have been 592 * acquired. 593 * @see #STATE_INITIALIZED 594 * @see #STATE_NO_STATIC_DATA 595 * @see #STATE_UNINITIALIZED 596 */ 597 public int getState() { 598 return mState; 599 } 600 601 /** 602 * Returns the playback state of the AudioTrack instance. 603 * @see #PLAYSTATE_STOPPED 604 * @see #PLAYSTATE_PAUSED 605 * @see #PLAYSTATE_PLAYING 606 */ 607 public int getPlayState() { 608 synchronized (mPlayStateLock) { 609 return mPlayState; 610 } 611 } 612 613 /** 614 * Returns the native frame count used by the hardware. 615 */ 616 protected int getNativeFrameCount() { 617 return native_get_native_frame_count(); 618 } 619 620 /** 621 * Returns marker position expressed in frames. 622 */ 623 public int getNotificationMarkerPosition() { 624 return native_get_marker_pos(); 625 } 626 627 /** 628 * Returns the notification update period expressed in frames. 629 */ 630 public int getPositionNotificationPeriod() { 631 return native_get_pos_update_period(); 632 } 633 634 /** 635 * Returns the playback head position expressed in frames 636 */ 637 public int getPlaybackHeadPosition() { 638 return native_get_position(); 639 } 640 641 /** 642 * Returns the hardware output sample rate 643 */ 644 static public int getNativeOutputSampleRate(int streamType) { 645 return native_get_output_sample_rate(streamType); 646 } 647 648 /** 649 * Returns the minimum buffer size required for the successful creation of an AudioTrack 650 * object to be created in the {@link #MODE_STREAM} mode. Note that this size doesn't 651 * guarantee a smooth playback under load, and higher values should be chosen according to 652 * the expected frequency at which the buffer will be refilled with additional data to play. 653 * @param sampleRateInHz the sample rate expressed in Hertz. 654 * @param channelConfig describes the configuration of the audio channels. 655 * See {@link AudioFormat#CHANNEL_OUT_MONO} and 656 * {@link AudioFormat#CHANNEL_OUT_STEREO} 657 * @param audioFormat the format in which the audio data is represented. 658 * See {@link AudioFormat#ENCODING_PCM_16BIT} and 659 * {@link AudioFormat#ENCODING_PCM_8BIT} 660 * @return {@link #ERROR_BAD_VALUE} if an invalid parameter was passed, 661 * or {@link #ERROR} if the implementation was unable to query the hardware for its output 662 * properties, 663 * or the minimum buffer size expressed in bytes. 664 */ 665 static public int getMinBufferSize(int sampleRateInHz, int channelConfig, int audioFormat) { 666 int channelCount = 0; 667 switch(channelConfig) { 668 case AudioFormat.CHANNEL_OUT_MONO: 669 case AudioFormat.CHANNEL_CONFIGURATION_MONO: 670 channelCount = 1; 671 break; 672 case AudioFormat.CHANNEL_OUT_STEREO: 673 case AudioFormat.CHANNEL_CONFIGURATION_STEREO: 674 channelCount = 2; 675 break; 676 default: 677 if ((channelConfig & SUPPORTED_OUT_CHANNELS) != channelConfig) { 678 // input channel configuration features unsupported channels 679 loge("getMinBufferSize(): Invalid channel configuration."); 680 return AudioTrack.ERROR_BAD_VALUE; 681 } else { 682 channelCount = Integer.bitCount(channelConfig); 683 } 684 } 685 686 if ((audioFormat != AudioFormat.ENCODING_PCM_16BIT) 687 && (audioFormat != AudioFormat.ENCODING_PCM_8BIT)) { 688 loge("getMinBufferSize(): Invalid audio format."); 689 return AudioTrack.ERROR_BAD_VALUE; 690 } 691 692 // sample rate, note these values are subject to change 693 if ( (sampleRateInHz < SAMPLE_RATE_HZ_MIN) || (sampleRateInHz > SAMPLE_RATE_HZ_MAX) ) { 694 loge("getMinBufferSize(): " + sampleRateInHz + " Hz is not a supported sample rate."); 695 return AudioTrack.ERROR_BAD_VALUE; 696 } 697 698 int size = native_get_min_buff_size(sampleRateInHz, channelCount, audioFormat); 699 if ((size == -1) || (size == 0)) { 700 loge("getMinBufferSize(): error querying hardware"); 701 return AudioTrack.ERROR; 702 } 703 else { 704 return size; 705 } 706 } 707 708 /** 709 * Returns the audio session ID. 710 * 711 * @return the ID of the audio session this AudioTrack belongs to. 712 */ 713 public int getAudioSessionId() { 714 return mSessionId; 715 } 716 717 //-------------------------------------------------------------------------- 718 // Initialization / configuration 719 //-------------------- 720 /** 721 * Sets the listener the AudioTrack notifies when a previously set marker is reached or 722 * for each periodic playback head position update. 723 * Notifications will be received in the same thread as the one in which the AudioTrack 724 * instance was created. 725 * @param listener 726 */ 727 public void setPlaybackPositionUpdateListener(OnPlaybackPositionUpdateListener listener) { 728 setPlaybackPositionUpdateListener(listener, null); 729 } 730 731 /** 732 * Sets the listener the AudioTrack notifies when a previously set marker is reached or 733 * for each periodic playback head position update. 734 * Use this method to receive AudioTrack events in the Handler associated with another 735 * thread than the one in which you created the AudioTrack instance. 736 * @param listener 737 * @param handler the Handler that will receive the event notification messages. 738 */ 739 public void setPlaybackPositionUpdateListener(OnPlaybackPositionUpdateListener listener, 740 Handler handler) { 741 synchronized (mPositionListenerLock) { 742 mPositionListener = listener; 743 } 744 if (listener != null) { 745 mEventHandlerDelegate = new NativeEventHandlerDelegate(this, handler); 746 } 747 748 } 749 750 751 752 /** 753 * Sets the specified left/right output volume values on the AudioTrack. Values are clamped 754 * to the ({@link #getMinVolume()}, {@link #getMaxVolume()}) interval if outside this range. 755 * @param leftVolume output attenuation for the left channel. A value of 0.0f is silence, 756 * a value of 1.0f is no attenuation. 757 * @param rightVolume output attenuation for the right channel 758 * @return error code or success, see {@link #SUCCESS}, 759 * {@link #ERROR_INVALID_OPERATION} 760 */ 761 public int setStereoVolume(float leftVolume, float rightVolume) { 762 if (mState != STATE_INITIALIZED) { 763 return ERROR_INVALID_OPERATION; 764 } 765 766 // clamp the volumes 767 if (leftVolume < getMinVolume()) { 768 leftVolume = getMinVolume(); 769 } 770 if (leftVolume > getMaxVolume()) { 771 leftVolume = getMaxVolume(); 772 } 773 if (rightVolume < getMinVolume()) { 774 rightVolume = getMinVolume(); 775 } 776 if (rightVolume > getMaxVolume()) { 777 rightVolume = getMaxVolume(); 778 } 779 780 native_setVolume(leftVolume, rightVolume); 781 782 return SUCCESS; 783 } 784 785 786 /** 787 * Similar, except set volume of all channels to same value. 788 * @hide 789 */ 790 public int setVolume(float volume) { 791 return setStereoVolume(volume, volume); 792 } 793 794 795 /** 796 * Sets the playback sample rate for this track. This sets the sampling rate at which 797 * the audio data will be consumed and played back, not the original sampling rate of the 798 * content. Setting it to half the sample rate of the content will cause the playback to 799 * last twice as long, but will also result in a negative pitch shift. 800 * The valid sample rate range is from 1Hz to twice the value returned by 801 * {@link #getNativeOutputSampleRate(int)}. 802 * @param sampleRateInHz the sample rate expressed in Hz 803 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 804 * {@link #ERROR_INVALID_OPERATION} 805 */ 806 public int setPlaybackRate(int sampleRateInHz) { 807 if (mState != STATE_INITIALIZED) { 808 return ERROR_INVALID_OPERATION; 809 } 810 if (sampleRateInHz <= 0) { 811 return ERROR_BAD_VALUE; 812 } 813 return native_set_playback_rate(sampleRateInHz); 814 } 815 816 817 /** 818 * Sets the position of the notification marker. 819 * @param markerInFrames marker in frames 820 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 821 * {@link #ERROR_INVALID_OPERATION} 822 */ 823 public int setNotificationMarkerPosition(int markerInFrames) { 824 if (mState != STATE_INITIALIZED) { 825 return ERROR_INVALID_OPERATION; 826 } 827 return native_set_marker_pos(markerInFrames); 828 } 829 830 831 /** 832 * Sets the period for the periodic notification event. 833 * @param periodInFrames update period expressed in frames 834 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_INVALID_OPERATION} 835 */ 836 public int setPositionNotificationPeriod(int periodInFrames) { 837 if (mState != STATE_INITIALIZED) { 838 return ERROR_INVALID_OPERATION; 839 } 840 return native_set_pos_update_period(periodInFrames); 841 } 842 843 844 /** 845 * Sets the playback head position. The track must be stopped for the position to be changed. 846 * @param positionInFrames playback head position expressed in frames 847 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 848 * {@link #ERROR_INVALID_OPERATION} 849 */ 850 public int setPlaybackHeadPosition(int positionInFrames) { 851 synchronized(mPlayStateLock) { 852 if ((mPlayState == PLAYSTATE_STOPPED) || (mPlayState == PLAYSTATE_PAUSED)) { 853 return native_set_position(positionInFrames); 854 } else { 855 return ERROR_INVALID_OPERATION; 856 } 857 } 858 } 859 860 /** 861 * Sets the loop points and the loop count. The loop can be infinite. 862 * @param startInFrames loop start marker expressed in frames 863 * @param endInFrames loop end marker expressed in frames 864 * @param loopCount the number of times the loop is looped. 865 * A value of -1 means infinite looping. 866 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 867 * {@link #ERROR_INVALID_OPERATION} 868 */ 869 public int setLoopPoints(int startInFrames, int endInFrames, int loopCount) { 870 if (mDataLoadMode == MODE_STREAM) { 871 return ERROR_INVALID_OPERATION; 872 } 873 return native_set_loop(startInFrames, endInFrames, loopCount); 874 } 875 876 /** 877 * Sets the initialization state of the instance. To be used in an AudioTrack subclass 878 * constructor to set a subclass-specific post-initialization state. 879 * @param state the state of the AudioTrack instance 880 */ 881 protected void setState(int state) { 882 mState = state; 883 } 884 885 886 //--------------------------------------------------------- 887 // Transport control methods 888 //-------------------- 889 /** 890 * Starts playing an AudioTrack. 891 * 892 * @throws IllegalStateException 893 */ 894 public void play() 895 throws IllegalStateException { 896 if (mState != STATE_INITIALIZED) { 897 throw(new IllegalStateException("play() called on uninitialized AudioTrack.")); 898 } 899 900 synchronized(mPlayStateLock) { 901 native_start(); 902 mPlayState = PLAYSTATE_PLAYING; 903 } 904 } 905 906 /** 907 * Stops playing the audio data. 908 * When used on an instance created in {@link #MODE_STREAM} mode, audio will stop playing 909 * after the last buffer that was written has been played. For an immediate stop, use 910 * {@link #pause()}, followed by {@link #flush()} to discard audio data that hasn't been played 911 * back yet. 912 * @throws IllegalStateException 913 */ 914 public void stop() 915 throws IllegalStateException { 916 if (mState != STATE_INITIALIZED) { 917 throw(new IllegalStateException("stop() called on uninitialized AudioTrack.")); 918 } 919 920 // stop playing 921 synchronized(mPlayStateLock) { 922 native_stop(); 923 mPlayState = PLAYSTATE_STOPPED; 924 } 925 } 926 927 /** 928 * Pauses the playback of the audio data. Data that has not been played 929 * back will not be discarded. Subsequent calls to {@link #play} will play 930 * this data back. See {@link #flush()} to discard this data. 931 * 932 * @throws IllegalStateException 933 */ 934 public void pause() 935 throws IllegalStateException { 936 if (mState != STATE_INITIALIZED) { 937 throw(new IllegalStateException("pause() called on uninitialized AudioTrack.")); 938 } 939 //logd("pause()"); 940 941 // pause playback 942 synchronized(mPlayStateLock) { 943 native_pause(); 944 mPlayState = PLAYSTATE_PAUSED; 945 } 946 } 947 948 949 //--------------------------------------------------------- 950 // Audio data supply 951 //-------------------- 952 953 /** 954 * Flushes the audio data currently queued for playback. Any data that has 955 * not been played back will be discarded. 956 */ 957 public void flush() { 958 if (mState == STATE_INITIALIZED) { 959 // flush the data in native layer 960 native_flush(); 961 } 962 963 } 964 965 /** 966 * Writes the audio data to the audio hardware for playback. Will block until 967 * all data has been written to the audio mixer. 968 * Note that the actual playback of this data might occur after this function 969 * returns. This function is thread safe with respect to {@link #stop} calls, 970 * in which case all of the specified data might not be written to the mixer. 971 * 972 * @param audioData the array that holds the data to play. 973 * @param offsetInBytes the offset expressed in bytes in audioData where the data to play 974 * starts. 975 * @param sizeInBytes the number of bytes to read in audioData after the offset. 976 * @return the number of bytes that were written or {@link #ERROR_INVALID_OPERATION} 977 * if the object wasn't properly initialized, or {@link #ERROR_BAD_VALUE} if 978 * the parameters don't resolve to valid data and indexes. 979 */ 980 981 public int write(byte[] audioData, int offsetInBytes, int sizeInBytes) { 982 if ((mDataLoadMode == MODE_STATIC) 983 && (mState == STATE_NO_STATIC_DATA) 984 && (sizeInBytes > 0)) { 985 mState = STATE_INITIALIZED; 986 } 987 988 if (mState != STATE_INITIALIZED) { 989 return ERROR_INVALID_OPERATION; 990 } 991 992 if ( (audioData == null) || (offsetInBytes < 0 ) || (sizeInBytes < 0) 993 || (offsetInBytes + sizeInBytes > audioData.length)) { 994 return ERROR_BAD_VALUE; 995 } 996 997 return native_write_byte(audioData, offsetInBytes, sizeInBytes, mAudioFormat); 998 } 999 1000 1001 /** 1002 * Writes the audio data to the audio hardware for playback. Will block until 1003 * all data has been written to the audio mixer. 1004 * Note that the actual playback of this data might occur after this function 1005 * returns. This function is thread safe with respect to {@link #stop} calls, 1006 * in which case all of the specified data might not be written to the mixer. 1007 * 1008 * @param audioData the array that holds the data to play. 1009 * @param offsetInShorts the offset expressed in shorts in audioData where the data to play 1010 * starts. 1011 * @param sizeInShorts the number of bytes to read in audioData after the offset. 1012 * @return the number of shorts that were written or {@link #ERROR_INVALID_OPERATION} 1013 * if the object wasn't properly initialized, or {@link #ERROR_BAD_VALUE} if 1014 * the parameters don't resolve to valid data and indexes. 1015 */ 1016 1017 public int write(short[] audioData, int offsetInShorts, int sizeInShorts) { 1018 if ((mDataLoadMode == MODE_STATIC) 1019 && (mState == STATE_NO_STATIC_DATA) 1020 && (sizeInShorts > 0)) { 1021 mState = STATE_INITIALIZED; 1022 } 1023 1024 if (mState != STATE_INITIALIZED) { 1025 return ERROR_INVALID_OPERATION; 1026 } 1027 1028 if ( (audioData == null) || (offsetInShorts < 0 ) || (sizeInShorts < 0) 1029 || (offsetInShorts + sizeInShorts > audioData.length)) { 1030 return ERROR_BAD_VALUE; 1031 } 1032 1033 return native_write_short(audioData, offsetInShorts, sizeInShorts, mAudioFormat); 1034 } 1035 1036 1037 /** 1038 * Notifies the native resource to reuse the audio data already loaded in the native 1039 * layer. This call is only valid with AudioTrack instances that don't use the streaming 1040 * model. 1041 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 1042 * {@link #ERROR_INVALID_OPERATION} 1043 */ 1044 public int reloadStaticData() { 1045 if (mDataLoadMode == MODE_STREAM) { 1046 return ERROR_INVALID_OPERATION; 1047 } 1048 return native_reload_static(); 1049 } 1050 1051 //-------------------------------------------------------------------------- 1052 // Audio effects management 1053 //-------------------- 1054 1055 /** 1056 * Attaches an auxiliary effect to the audio track. A typical auxiliary 1057 * effect is a reverberation effect which can be applied on any sound source 1058 * that directs a certain amount of its energy to this effect. This amount 1059 * is defined by setAuxEffectSendLevel(). 1060 * {@see #setAuxEffectSendLevel(float)}. 1061 * <p>After creating an auxiliary effect (e.g. 1062 * {@link android.media.audiofx.EnvironmentalReverb}), retrieve its ID with 1063 * {@link android.media.audiofx.AudioEffect#getId()} and use it when calling 1064 * this method to attach the audio track to the effect. 1065 * <p>To detach the effect from the audio track, call this method with a 1066 * null effect id. 1067 * 1068 * @param effectId system wide unique id of the effect to attach 1069 * @return error code or success, see {@link #SUCCESS}, 1070 * {@link #ERROR_INVALID_OPERATION}, {@link #ERROR_BAD_VALUE} 1071 */ 1072 public int attachAuxEffect(int effectId) { 1073 if (mState != STATE_INITIALIZED) { 1074 return ERROR_INVALID_OPERATION; 1075 } 1076 return native_attachAuxEffect(effectId); 1077 } 1078 1079 /** 1080 * Sets the send level of the audio track to the attached auxiliary effect 1081 * {@link #attachAuxEffect(int)}. The level value range is 0 to 1.0. 1082 * <p>By default the send level is 0, so even if an effect is attached to the player 1083 * this method must be called for the effect to be applied. 1084 * <p>Note that the passed level value is a raw scalar. UI controls should be scaled 1085 * logarithmically: the gain applied by audio framework ranges from -72dB to 0dB, 1086 * so an appropriate conversion from linear UI input x to level is: 1087 * x == 0 -> level = 0 1088 * 0 < x <= R -> level = 10^(72*(x-R)/20/R) 1089 * 1090 * @param level send level scalar 1091 * @return error code or success, see {@link #SUCCESS}, 1092 * {@link #ERROR_INVALID_OPERATION} 1093 */ 1094 public int setAuxEffectSendLevel(float level) { 1095 if (mState != STATE_INITIALIZED) { 1096 return ERROR_INVALID_OPERATION; 1097 } 1098 // clamp the level 1099 if (level < getMinVolume()) { 1100 level = getMinVolume(); 1101 } 1102 if (level > getMaxVolume()) { 1103 level = getMaxVolume(); 1104 } 1105 native_setAuxEffectSendLevel(level); 1106 return SUCCESS; 1107 } 1108 1109 //--------------------------------------------------------- 1110 // Interface definitions 1111 //-------------------- 1112 /** 1113 * Interface definition for a callback to be invoked when the playback head position of 1114 * an AudioTrack has reached a notification marker or has increased by a certain period. 1115 */ 1116 public interface OnPlaybackPositionUpdateListener { 1117 /** 1118 * Called on the listener to notify it that the previously set marker has been reached 1119 * by the playback head. 1120 */ 1121 void onMarkerReached(AudioTrack track); 1122 1123 /** 1124 * Called on the listener to periodically notify it that the playback head has reached 1125 * a multiple of the notification period. 1126 */ 1127 void onPeriodicNotification(AudioTrack track); 1128 } 1129 1130 1131 //--------------------------------------------------------- 1132 // Inner classes 1133 //-------------------- 1134 /** 1135 * Helper class to handle the forwarding of native events to the appropriate listener 1136 * (potentially) handled in a different thread 1137 */ 1138 private class NativeEventHandlerDelegate { 1139 private final AudioTrack mAudioTrack; 1140 private final Handler mHandler; 1141 1142 NativeEventHandlerDelegate(AudioTrack track, Handler handler) { 1143 mAudioTrack = track; 1144 // find the looper for our new event handler 1145 Looper looper; 1146 if (handler != null) { 1147 looper = handler.getLooper(); 1148 } else { 1149 // no given handler, use the looper the AudioTrack was created in 1150 looper = mInitializationLooper; 1151 } 1152 1153 // construct the event handler with this looper 1154 if (looper != null) { 1155 // implement the event handler delegate 1156 mHandler = new Handler(looper) { 1157 @Override 1158 public void handleMessage(Message msg) { 1159 if (mAudioTrack == null) { 1160 return; 1161 } 1162 OnPlaybackPositionUpdateListener listener = null; 1163 synchronized (mPositionListenerLock) { 1164 listener = mAudioTrack.mPositionListener; 1165 } 1166 switch(msg.what) { 1167 case NATIVE_EVENT_MARKER: 1168 if (listener != null) { 1169 listener.onMarkerReached(mAudioTrack); 1170 } 1171 break; 1172 case NATIVE_EVENT_NEW_POS: 1173 if (listener != null) { 1174 listener.onPeriodicNotification(mAudioTrack); 1175 } 1176 break; 1177 default: 1178 Log.e(TAG, "[ android.media.AudioTrack.NativeEventHandler ] " + 1179 "Unknown event type: " + msg.what); 1180 break; 1181 } 1182 } 1183 }; 1184 } else { 1185 mHandler = null; 1186 } 1187 } 1188 1189 Handler getHandler() { 1190 return mHandler; 1191 } 1192 } 1193 1194 1195 //--------------------------------------------------------- 1196 // Java methods called from the native side 1197 //-------------------- 1198 @SuppressWarnings("unused") 1199 private static void postEventFromNative(Object audiotrack_ref, 1200 int what, int arg1, int arg2, Object obj) { 1201 //logd("Event posted from the native side: event="+ what + " args="+ arg1+" "+arg2); 1202 AudioTrack track = (AudioTrack)((WeakReference)audiotrack_ref).get(); 1203 if (track == null) { 1204 return; 1205 } 1206 1207 if (track.mEventHandlerDelegate != null) { 1208 Message m = 1209 track.mEventHandlerDelegate.getHandler().obtainMessage(what, arg1, arg2, obj); 1210 track.mEventHandlerDelegate.getHandler().sendMessage(m); 1211 } 1212 1213 } 1214 1215 1216 //--------------------------------------------------------- 1217 // Native methods called from the Java side 1218 //-------------------- 1219 1220 private native final int native_setup(Object audiotrack_this, 1221 int streamType, int sampleRate, int nbChannels, int audioFormat, 1222 int buffSizeInBytes, int mode, int[] sessionId); 1223 1224 private native final void native_finalize(); 1225 1226 private native final void native_release(); 1227 1228 private native final void native_start(); 1229 1230 private native final void native_stop(); 1231 1232 private native final void native_pause(); 1233 1234 private native final void native_flush(); 1235 1236 private native final int native_write_byte(byte[] audioData, 1237 int offsetInBytes, int sizeInBytes, int format); 1238 1239 private native final int native_write_short(short[] audioData, 1240 int offsetInShorts, int sizeInShorts, int format); 1241 1242 private native final int native_reload_static(); 1243 1244 private native final int native_get_native_frame_count(); 1245 1246 private native final void native_setVolume(float leftVolume, float rightVolume); 1247 1248 private native final int native_set_playback_rate(int sampleRateInHz); 1249 private native final int native_get_playback_rate(); 1250 1251 private native final int native_set_marker_pos(int marker); 1252 private native final int native_get_marker_pos(); 1253 1254 private native final int native_set_pos_update_period(int updatePeriod); 1255 private native final int native_get_pos_update_period(); 1256 1257 private native final int native_set_position(int position); 1258 private native final int native_get_position(); 1259 1260 private native final int native_set_loop(int start, int end, int loopCount); 1261 1262 static private native final int native_get_output_sample_rate(int streamType); 1263 static private native final int native_get_min_buff_size( 1264 int sampleRateInHz, int channelConfig, int audioFormat); 1265 1266 private native final int native_get_session_id(); 1267 1268 private native final int native_attachAuxEffect(int effectId); 1269 private native final void native_setAuxEffectSendLevel(float level); 1270 1271 //--------------------------------------------------------- 1272 // Utility methods 1273 //------------------ 1274 1275 private static void logd(String msg) { 1276 Log.d(TAG, "[ android.media.AudioTrack ] " + msg); 1277 } 1278 1279 private static void loge(String msg) { 1280 Log.e(TAG, "[ android.media.AudioTrack ] " + msg); 1281 } 1282 1283} 1284