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 (!isMultichannelConfigSupported(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 to check that the channel configuration (a.k.a channel mask) is supported 443 * @param channelConfig the mask to validate 444 * @return false if the AudioTrack can't be used with such a mask 445 */ 446 private static boolean isMultichannelConfigSupported(int channelConfig) { 447 // check for unsupported channels 448 if ((channelConfig & SUPPORTED_OUT_CHANNELS) != channelConfig) { 449 Log.e(TAG, "Channel configuration features unsupported channels"); 450 return false; 451 } 452 // check for unsupported multichannel combinations: 453 // - FL/FR must be present 454 // - L/R channels must be paired (e.g. no single L channel) 455 final int frontPair = 456 AudioFormat.CHANNEL_OUT_FRONT_LEFT | AudioFormat.CHANNEL_OUT_FRONT_RIGHT; 457 if ((channelConfig & frontPair) != frontPair) { 458 Log.e(TAG, "Front channels must be present in multichannel configurations"); 459 return false; 460 } 461 final int backPair = 462 AudioFormat.CHANNEL_OUT_BACK_LEFT | AudioFormat.CHANNEL_OUT_BACK_RIGHT; 463 if ((channelConfig & backPair) != 0) { 464 if ((channelConfig & backPair) != backPair) { 465 Log.e(TAG, "Rear channels can't be used independently"); 466 return false; 467 } 468 } 469 return true; 470 } 471 472 473 // Convenience method for the contructor's audio buffer size check. 474 // preconditions: 475 // mChannelCount is valid 476 // mAudioFormat is valid 477 // postcondition: 478 // mNativeBufferSizeInBytes is valid (multiple of frame size, positive) 479 private void audioBuffSizeCheck(int audioBufferSize) { 480 // NB: this section is only valid with PCM data. 481 // To update when supporting compressed formats 482 int frameSizeInBytes = mChannelCount 483 * (mAudioFormat == AudioFormat.ENCODING_PCM_8BIT ? 1 : 2); 484 if ((audioBufferSize % frameSizeInBytes != 0) || (audioBufferSize < 1)) { 485 throw (new IllegalArgumentException("Invalid audio buffer size.")); 486 } 487 488 mNativeBufferSizeInBytes = audioBufferSize; 489 } 490 491 492 /** 493 * Releases the native AudioTrack resources. 494 */ 495 public void release() { 496 // even though native_release() stops the native AudioTrack, we need to stop 497 // AudioTrack subclasses too. 498 try { 499 stop(); 500 } catch(IllegalStateException ise) { 501 // don't raise an exception, we're releasing the resources. 502 } 503 native_release(); 504 mState = STATE_UNINITIALIZED; 505 } 506 507 @Override 508 protected void finalize() { 509 native_finalize(); 510 } 511 512 //-------------------------------------------------------------------------- 513 // Getters 514 //-------------------- 515 /** 516 * Returns the minimum valid volume value. Volume values set under this one will 517 * be clamped at this value. 518 * @return the minimum volume expressed as a linear attenuation. 519 */ 520 static public float getMinVolume() { 521 return AudioTrack.VOLUME_MIN; 522 } 523 524 /** 525 * Returns the maximum valid volume value. Volume values set above this one will 526 * be clamped at this value. 527 * @return the maximum volume expressed as a linear attenuation. 528 */ 529 static public float getMaxVolume() { 530 return AudioTrack.VOLUME_MAX; 531 } 532 533 /** 534 * Returns the configured audio data sample rate in Hz 535 */ 536 public int getSampleRate() { 537 return mSampleRate; 538 } 539 540 /** 541 * Returns the current playback rate in Hz. 542 */ 543 public int getPlaybackRate() { 544 return native_get_playback_rate(); 545 } 546 547 /** 548 * Returns the configured audio data format. See {@link AudioFormat#ENCODING_PCM_16BIT} 549 * and {@link AudioFormat#ENCODING_PCM_8BIT}. 550 */ 551 public int getAudioFormat() { 552 return mAudioFormat; 553 } 554 555 /** 556 * Returns the type of audio stream this AudioTrack is configured for. 557 * Compare the result against {@link AudioManager#STREAM_VOICE_CALL}, 558 * {@link AudioManager#STREAM_SYSTEM}, {@link AudioManager#STREAM_RING}, 559 * {@link AudioManager#STREAM_MUSIC}, {@link AudioManager#STREAM_ALARM}, 560 * {@link AudioManager#STREAM_NOTIFICATION}, or {@link AudioManager#STREAM_DTMF}. 561 */ 562 public int getStreamType() { 563 return mStreamType; 564 } 565 566 /** 567 * Returns the configured channel configuration. 568 569 * See {@link AudioFormat#CHANNEL_OUT_MONO} 570 * and {@link AudioFormat#CHANNEL_OUT_STEREO}. 571 */ 572 public int getChannelConfiguration() { 573 return mChannelConfiguration; 574 } 575 576 /** 577 * Returns the configured number of channels. 578 */ 579 public int getChannelCount() { 580 return mChannelCount; 581 } 582 583 /** 584 * Returns the state of the AudioTrack instance. This is useful after the 585 * AudioTrack instance has been created to check if it was initialized 586 * properly. This ensures that the appropriate hardware resources have been 587 * acquired. 588 * @see #STATE_INITIALIZED 589 * @see #STATE_NO_STATIC_DATA 590 * @see #STATE_UNINITIALIZED 591 */ 592 public int getState() { 593 return mState; 594 } 595 596 /** 597 * Returns the playback state of the AudioTrack instance. 598 * @see #PLAYSTATE_STOPPED 599 * @see #PLAYSTATE_PAUSED 600 * @see #PLAYSTATE_PLAYING 601 */ 602 public int getPlayState() { 603 synchronized (mPlayStateLock) { 604 return mPlayState; 605 } 606 } 607 608 /** 609 * Returns the native frame count used by the hardware. 610 */ 611 protected int getNativeFrameCount() { 612 return native_get_native_frame_count(); 613 } 614 615 /** 616 * Returns marker position expressed in frames. 617 */ 618 public int getNotificationMarkerPosition() { 619 return native_get_marker_pos(); 620 } 621 622 /** 623 * Returns the notification update period expressed in frames. 624 */ 625 public int getPositionNotificationPeriod() { 626 return native_get_pos_update_period(); 627 } 628 629 /** 630 * Returns the playback head position expressed in frames 631 */ 632 public int getPlaybackHeadPosition() { 633 return native_get_position(); 634 } 635 636 /** 637 * Returns the hardware output sample rate 638 */ 639 static public int getNativeOutputSampleRate(int streamType) { 640 return native_get_output_sample_rate(streamType); 641 } 642 643 /** 644 * Returns the minimum buffer size required for the successful creation of an AudioTrack 645 * object to be created in the {@link #MODE_STREAM} mode. Note that this size doesn't 646 * guarantee a smooth playback under load, and higher values should be chosen according to 647 * the expected frequency at which the buffer will be refilled with additional data to play. 648 * @param sampleRateInHz the sample rate expressed in Hertz. 649 * @param channelConfig describes the configuration of the audio channels. 650 * See {@link AudioFormat#CHANNEL_OUT_MONO} and 651 * {@link AudioFormat#CHANNEL_OUT_STEREO} 652 * @param audioFormat the format in which the audio data is represented. 653 * See {@link AudioFormat#ENCODING_PCM_16BIT} and 654 * {@link AudioFormat#ENCODING_PCM_8BIT} 655 * @return {@link #ERROR_BAD_VALUE} if an invalid parameter was passed, 656 * or {@link #ERROR} if the implementation was unable to query the hardware for its output 657 * properties, 658 * or the minimum buffer size expressed in bytes. 659 */ 660 static public int getMinBufferSize(int sampleRateInHz, int channelConfig, int audioFormat) { 661 int channelCount = 0; 662 switch(channelConfig) { 663 case AudioFormat.CHANNEL_OUT_MONO: 664 case AudioFormat.CHANNEL_CONFIGURATION_MONO: 665 channelCount = 1; 666 break; 667 case AudioFormat.CHANNEL_OUT_STEREO: 668 case AudioFormat.CHANNEL_CONFIGURATION_STEREO: 669 channelCount = 2; 670 break; 671 default: 672 if ((channelConfig & SUPPORTED_OUT_CHANNELS) != channelConfig) { 673 // input channel configuration features unsupported channels 674 loge("getMinBufferSize(): Invalid channel configuration."); 675 return AudioTrack.ERROR_BAD_VALUE; 676 } else { 677 channelCount = Integer.bitCount(channelConfig); 678 } 679 } 680 681 if ((audioFormat != AudioFormat.ENCODING_PCM_16BIT) 682 && (audioFormat != AudioFormat.ENCODING_PCM_8BIT)) { 683 loge("getMinBufferSize(): Invalid audio format."); 684 return AudioTrack.ERROR_BAD_VALUE; 685 } 686 687 // sample rate, note these values are subject to change 688 if ( (sampleRateInHz < 4000) || (sampleRateInHz > 48000) ) { 689 loge("getMinBufferSize(): " + sampleRateInHz +"Hz is not a supported sample rate."); 690 return AudioTrack.ERROR_BAD_VALUE; 691 } 692 693 int size = native_get_min_buff_size(sampleRateInHz, channelCount, audioFormat); 694 if ((size == -1) || (size == 0)) { 695 loge("getMinBufferSize(): error querying hardware"); 696 return AudioTrack.ERROR; 697 } 698 else { 699 return size; 700 } 701 } 702 703 /** 704 * Returns the audio session ID. 705 * 706 * @return the ID of the audio session this AudioTrack belongs to. 707 */ 708 public int getAudioSessionId() { 709 return mSessionId; 710 } 711 712 //-------------------------------------------------------------------------- 713 // Initialization / configuration 714 //-------------------- 715 /** 716 * Sets the listener the AudioTrack notifies when a previously set marker is reached or 717 * for each periodic playback head position update. 718 * Notifications will be received in the same thread as the one in which the AudioTrack 719 * instance was created. 720 * @param listener 721 */ 722 public void setPlaybackPositionUpdateListener(OnPlaybackPositionUpdateListener listener) { 723 setPlaybackPositionUpdateListener(listener, null); 724 } 725 726 /** 727 * Sets the listener the AudioTrack notifies when a previously set marker is reached or 728 * for each periodic playback head position update. 729 * Use this method to receive AudioTrack events in the Handler associated with another 730 * thread than the one in which you created the AudioTrack instance. 731 * @param listener 732 * @param handler the Handler that will receive the event notification messages. 733 */ 734 public void setPlaybackPositionUpdateListener(OnPlaybackPositionUpdateListener listener, 735 Handler handler) { 736 synchronized (mPositionListenerLock) { 737 mPositionListener = listener; 738 } 739 if (listener != null) { 740 mEventHandlerDelegate = new NativeEventHandlerDelegate(this, handler); 741 } 742 743 } 744 745 746 747 /** 748 * Sets the specified left/right output volume values on the AudioTrack. Values are clamped 749 * to the ({@link #getMinVolume()}, {@link #getMaxVolume()}) interval if outside this range. 750 * @param leftVolume output attenuation for the left channel. A value of 0.0f is silence, 751 * a value of 1.0f is no attenuation. 752 * @param rightVolume output attenuation for the right channel 753 * @return error code or success, see {@link #SUCCESS}, 754 * {@link #ERROR_INVALID_OPERATION} 755 */ 756 public int setStereoVolume(float leftVolume, float rightVolume) { 757 if (mState != STATE_INITIALIZED) { 758 return ERROR_INVALID_OPERATION; 759 } 760 761 // clamp the volumes 762 if (leftVolume < getMinVolume()) { 763 leftVolume = getMinVolume(); 764 } 765 if (leftVolume > getMaxVolume()) { 766 leftVolume = getMaxVolume(); 767 } 768 if (rightVolume < getMinVolume()) { 769 rightVolume = getMinVolume(); 770 } 771 if (rightVolume > getMaxVolume()) { 772 rightVolume = getMaxVolume(); 773 } 774 775 native_setVolume(leftVolume, rightVolume); 776 777 return SUCCESS; 778 } 779 780 781 /** 782 * Sets the playback sample rate for this track. This sets the sampling rate at which 783 * the audio data will be consumed and played back, not the original sampling rate of the 784 * content. Setting it to half the sample rate of the content will cause the playback to 785 * last twice as long, but will also result in a negative pitch shift. 786 * The valid sample rate range is from 1Hz to twice the value returned by 787 * {@link #getNativeOutputSampleRate(int)}. 788 * @param sampleRateInHz the sample rate expressed in Hz 789 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 790 * {@link #ERROR_INVALID_OPERATION} 791 */ 792 public int setPlaybackRate(int sampleRateInHz) { 793 if (mState != STATE_INITIALIZED) { 794 return ERROR_INVALID_OPERATION; 795 } 796 if (sampleRateInHz <= 0) { 797 return ERROR_BAD_VALUE; 798 } 799 return native_set_playback_rate(sampleRateInHz); 800 } 801 802 803 /** 804 * Sets the position of the notification marker. 805 * @param markerInFrames marker in frames 806 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 807 * {@link #ERROR_INVALID_OPERATION} 808 */ 809 public int setNotificationMarkerPosition(int markerInFrames) { 810 if (mState != STATE_INITIALIZED) { 811 return ERROR_INVALID_OPERATION; 812 } 813 return native_set_marker_pos(markerInFrames); 814 } 815 816 817 /** 818 * Sets the period for the periodic notification event. 819 * @param periodInFrames update period expressed in frames 820 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_INVALID_OPERATION} 821 */ 822 public int setPositionNotificationPeriod(int periodInFrames) { 823 if (mState != STATE_INITIALIZED) { 824 return ERROR_INVALID_OPERATION; 825 } 826 return native_set_pos_update_period(periodInFrames); 827 } 828 829 830 /** 831 * Sets the playback head position. The track must be stopped for the position to be changed. 832 * @param positionInFrames playback head position expressed in frames 833 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 834 * {@link #ERROR_INVALID_OPERATION} 835 */ 836 public int setPlaybackHeadPosition(int positionInFrames) { 837 synchronized(mPlayStateLock) { 838 if ((mPlayState == PLAYSTATE_STOPPED) || (mPlayState == PLAYSTATE_PAUSED)) { 839 return native_set_position(positionInFrames); 840 } else { 841 return ERROR_INVALID_OPERATION; 842 } 843 } 844 } 845 846 /** 847 * Sets the loop points and the loop count. The loop can be infinite. 848 * @param startInFrames loop start marker expressed in frames 849 * @param endInFrames loop end marker expressed in frames 850 * @param loopCount the number of times the loop is looped. 851 * A value of -1 means infinite looping. 852 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 853 * {@link #ERROR_INVALID_OPERATION} 854 */ 855 public int setLoopPoints(int startInFrames, int endInFrames, int loopCount) { 856 if (mDataLoadMode == MODE_STREAM) { 857 return ERROR_INVALID_OPERATION; 858 } 859 return native_set_loop(startInFrames, endInFrames, loopCount); 860 } 861 862 /** 863 * Sets the initialization state of the instance. To be used in an AudioTrack subclass 864 * constructor to set a subclass-specific post-initialization state. 865 * @param state the state of the AudioTrack instance 866 */ 867 protected void setState(int state) { 868 mState = state; 869 } 870 871 872 //--------------------------------------------------------- 873 // Transport control methods 874 //-------------------- 875 /** 876 * Starts playing an AudioTrack. 877 * 878 * @throws IllegalStateException 879 */ 880 public void play() 881 throws IllegalStateException { 882 if (mState != STATE_INITIALIZED) { 883 throw(new IllegalStateException("play() called on uninitialized AudioTrack.")); 884 } 885 886 synchronized(mPlayStateLock) { 887 native_start(); 888 mPlayState = PLAYSTATE_PLAYING; 889 } 890 } 891 892 /** 893 * Stops playing the audio data. 894 * When used on an instance created in {@link #MODE_STREAM} mode, audio will stop playing 895 * after the last buffer that was written has been played. For an immediate stop, use 896 * {@link #pause()}, followed by {@link #flush()} to discard audio data that hasn't been played 897 * back yet. 898 * @throws IllegalStateException 899 */ 900 public void stop() 901 throws IllegalStateException { 902 if (mState != STATE_INITIALIZED) { 903 throw(new IllegalStateException("stop() called on uninitialized AudioTrack.")); 904 } 905 906 // stop playing 907 synchronized(mPlayStateLock) { 908 native_stop(); 909 mPlayState = PLAYSTATE_STOPPED; 910 } 911 } 912 913 /** 914 * Pauses the playback of the audio data. Data that has not been played 915 * back will not be discarded. Subsequent calls to {@link #play} will play 916 * this data back. See {@link #flush()} to discard this data. 917 * 918 * @throws IllegalStateException 919 */ 920 public void pause() 921 throws IllegalStateException { 922 if (mState != STATE_INITIALIZED) { 923 throw(new IllegalStateException("pause() called on uninitialized AudioTrack.")); 924 } 925 //logd("pause()"); 926 927 // pause playback 928 synchronized(mPlayStateLock) { 929 native_pause(); 930 mPlayState = PLAYSTATE_PAUSED; 931 } 932 } 933 934 935 //--------------------------------------------------------- 936 // Audio data supply 937 //-------------------- 938 939 /** 940 * Flushes the audio data currently queued for playback. Any data that has 941 * not been played back will be discarded. 942 */ 943 public void flush() { 944 if (mState == STATE_INITIALIZED) { 945 // flush the data in native layer 946 native_flush(); 947 } 948 949 } 950 951 /** 952 * Writes the audio data to the audio hardware for playback. Will block until 953 * all data has been written to the audio mixer. 954 * Note that the actual playback of this data might occur after this function 955 * returns. This function is thread safe with respect to {@link #stop} calls, 956 * in which case all of the specified data might not be written to the mixer. 957 * 958 * @param audioData the array that holds the data to play. 959 * @param offsetInBytes the offset expressed in bytes in audioData where the data to play 960 * starts. 961 * @param sizeInBytes the number of bytes to read in audioData after the offset. 962 * @return the number of bytes that were written or {@link #ERROR_INVALID_OPERATION} 963 * if the object wasn't properly initialized, or {@link #ERROR_BAD_VALUE} if 964 * the parameters don't resolve to valid data and indexes. 965 */ 966 967 public int write(byte[] audioData, int offsetInBytes, int sizeInBytes) { 968 if ((mDataLoadMode == MODE_STATIC) 969 && (mState == STATE_NO_STATIC_DATA) 970 && (sizeInBytes > 0)) { 971 mState = STATE_INITIALIZED; 972 } 973 974 if (mState != STATE_INITIALIZED) { 975 return ERROR_INVALID_OPERATION; 976 } 977 978 if ( (audioData == null) || (offsetInBytes < 0 ) || (sizeInBytes < 0) 979 || (offsetInBytes + sizeInBytes > audioData.length)) { 980 return ERROR_BAD_VALUE; 981 } 982 983 return native_write_byte(audioData, offsetInBytes, sizeInBytes, mAudioFormat); 984 } 985 986 987 /** 988 * Writes the audio data to the audio hardware for playback. Will block until 989 * all data has been written to the audio mixer. 990 * Note that the actual playback of this data might occur after this function 991 * returns. This function is thread safe with respect to {@link #stop} calls, 992 * in which case all of the specified data might not be written to the mixer. 993 * 994 * @param audioData the array that holds the data to play. 995 * @param offsetInShorts the offset expressed in shorts in audioData where the data to play 996 * starts. 997 * @param sizeInShorts the number of bytes to read in audioData after the offset. 998 * @return the number of shorts that were written or {@link #ERROR_INVALID_OPERATION} 999 * if the object wasn't properly initialized, or {@link #ERROR_BAD_VALUE} if 1000 * the parameters don't resolve to valid data and indexes. 1001 */ 1002 1003 public int write(short[] audioData, int offsetInShorts, int sizeInShorts) { 1004 if ((mDataLoadMode == MODE_STATIC) 1005 && (mState == STATE_NO_STATIC_DATA) 1006 && (sizeInShorts > 0)) { 1007 mState = STATE_INITIALIZED; 1008 } 1009 1010 if (mState != STATE_INITIALIZED) { 1011 return ERROR_INVALID_OPERATION; 1012 } 1013 1014 if ( (audioData == null) || (offsetInShorts < 0 ) || (sizeInShorts < 0) 1015 || (offsetInShorts + sizeInShorts > audioData.length)) { 1016 return ERROR_BAD_VALUE; 1017 } 1018 1019 return native_write_short(audioData, offsetInShorts, sizeInShorts, mAudioFormat); 1020 } 1021 1022 1023 /** 1024 * Notifies the native resource to reuse the audio data already loaded in the native 1025 * layer. This call is only valid with AudioTrack instances that don't use the streaming 1026 * model. 1027 * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE}, 1028 * {@link #ERROR_INVALID_OPERATION} 1029 */ 1030 public int reloadStaticData() { 1031 if (mDataLoadMode == MODE_STREAM) { 1032 return ERROR_INVALID_OPERATION; 1033 } 1034 return native_reload_static(); 1035 } 1036 1037 //-------------------------------------------------------------------------- 1038 // Audio effects management 1039 //-------------------- 1040 1041 /** 1042 * Attaches an auxiliary effect to the audio track. A typical auxiliary 1043 * effect is a reverberation effect which can be applied on any sound source 1044 * that directs a certain amount of its energy to this effect. This amount 1045 * is defined by setAuxEffectSendLevel(). 1046 * {@see #setAuxEffectSendLevel(float)}. 1047 * <p>After creating an auxiliary effect (e.g. 1048 * {@link android.media.audiofx.EnvironmentalReverb}), retrieve its ID with 1049 * {@link android.media.audiofx.AudioEffect#getId()} and use it when calling 1050 * this method to attach the audio track to the effect. 1051 * <p>To detach the effect from the audio track, call this method with a 1052 * null effect id. 1053 * 1054 * @param effectId system wide unique id of the effect to attach 1055 * @return error code or success, see {@link #SUCCESS}, 1056 * {@link #ERROR_INVALID_OPERATION}, {@link #ERROR_BAD_VALUE} 1057 */ 1058 public int attachAuxEffect(int effectId) { 1059 if (mState != STATE_INITIALIZED) { 1060 return ERROR_INVALID_OPERATION; 1061 } 1062 return native_attachAuxEffect(effectId); 1063 } 1064 1065 /** 1066 * Sets the send level of the audio track to the attached auxiliary effect 1067 * {@link #attachAuxEffect(int)}. The level value range is 0 to 1.0. 1068 * <p>By default the send level is 0, so even if an effect is attached to the player 1069 * this method must be called for the effect to be applied. 1070 * <p>Note that the passed level value is a raw scalar. UI controls should be scaled 1071 * logarithmically: the gain applied by audio framework ranges from -72dB to 0dB, 1072 * so an appropriate conversion from linear UI input x to level is: 1073 * x == 0 -> level = 0 1074 * 0 < x <= R -> level = 10^(72*(x-R)/20/R) 1075 * 1076 * @param level send level scalar 1077 * @return error code or success, see {@link #SUCCESS}, 1078 * {@link #ERROR_INVALID_OPERATION} 1079 */ 1080 public int setAuxEffectSendLevel(float level) { 1081 if (mState != STATE_INITIALIZED) { 1082 return ERROR_INVALID_OPERATION; 1083 } 1084 // clamp the level 1085 if (level < getMinVolume()) { 1086 level = getMinVolume(); 1087 } 1088 if (level > getMaxVolume()) { 1089 level = getMaxVolume(); 1090 } 1091 native_setAuxEffectSendLevel(level); 1092 return SUCCESS; 1093 } 1094 1095 //--------------------------------------------------------- 1096 // Interface definitions 1097 //-------------------- 1098 /** 1099 * Interface definition for a callback to be invoked when the playback head position of 1100 * an AudioTrack has reached a notification marker or has increased by a certain period. 1101 */ 1102 public interface OnPlaybackPositionUpdateListener { 1103 /** 1104 * Called on the listener to notify it that the previously set marker has been reached 1105 * by the playback head. 1106 */ 1107 void onMarkerReached(AudioTrack track); 1108 1109 /** 1110 * Called on the listener to periodically notify it that the playback head has reached 1111 * a multiple of the notification period. 1112 */ 1113 void onPeriodicNotification(AudioTrack track); 1114 } 1115 1116 1117 //--------------------------------------------------------- 1118 // Inner classes 1119 //-------------------- 1120 /** 1121 * Helper class to handle the forwarding of native events to the appropriate listener 1122 * (potentially) handled in a different thread 1123 */ 1124 private class NativeEventHandlerDelegate { 1125 private final AudioTrack mAudioTrack; 1126 private final Handler mHandler; 1127 1128 NativeEventHandlerDelegate(AudioTrack track, Handler handler) { 1129 mAudioTrack = track; 1130 // find the looper for our new event handler 1131 Looper looper; 1132 if (handler != null) { 1133 looper = handler.getLooper(); 1134 } else { 1135 // no given handler, use the looper the AudioTrack was created in 1136 looper = mInitializationLooper; 1137 } 1138 1139 // construct the event handler with this looper 1140 if (looper != null) { 1141 // implement the event handler delegate 1142 mHandler = new Handler(looper) { 1143 @Override 1144 public void handleMessage(Message msg) { 1145 if (mAudioTrack == null) { 1146 return; 1147 } 1148 OnPlaybackPositionUpdateListener listener = null; 1149 synchronized (mPositionListenerLock) { 1150 listener = mAudioTrack.mPositionListener; 1151 } 1152 switch(msg.what) { 1153 case NATIVE_EVENT_MARKER: 1154 if (listener != null) { 1155 listener.onMarkerReached(mAudioTrack); 1156 } 1157 break; 1158 case NATIVE_EVENT_NEW_POS: 1159 if (listener != null) { 1160 listener.onPeriodicNotification(mAudioTrack); 1161 } 1162 break; 1163 default: 1164 Log.e(TAG, "[ android.media.AudioTrack.NativeEventHandler ] " + 1165 "Unknown event type: " + msg.what); 1166 break; 1167 } 1168 } 1169 }; 1170 } else { 1171 mHandler = null; 1172 } 1173 } 1174 1175 Handler getHandler() { 1176 return mHandler; 1177 } 1178 } 1179 1180 1181 //--------------------------------------------------------- 1182 // Java methods called from the native side 1183 //-------------------- 1184 @SuppressWarnings("unused") 1185 private static void postEventFromNative(Object audiotrack_ref, 1186 int what, int arg1, int arg2, Object obj) { 1187 //logd("Event posted from the native side: event="+ what + " args="+ arg1+" "+arg2); 1188 AudioTrack track = (AudioTrack)((WeakReference)audiotrack_ref).get(); 1189 if (track == null) { 1190 return; 1191 } 1192 1193 if (track.mEventHandlerDelegate != null) { 1194 Message m = 1195 track.mEventHandlerDelegate.getHandler().obtainMessage(what, arg1, arg2, obj); 1196 track.mEventHandlerDelegate.getHandler().sendMessage(m); 1197 } 1198 1199 } 1200 1201 1202 //--------------------------------------------------------- 1203 // Native methods called from the Java side 1204 //-------------------- 1205 1206 private native final int native_setup(Object audiotrack_this, 1207 int streamType, int sampleRate, int nbChannels, int audioFormat, 1208 int buffSizeInBytes, int mode, int[] sessionId); 1209 1210 private native final void native_finalize(); 1211 1212 private native final void native_release(); 1213 1214 private native final void native_start(); 1215 1216 private native final void native_stop(); 1217 1218 private native final void native_pause(); 1219 1220 private native final void native_flush(); 1221 1222 private native final int native_write_byte(byte[] audioData, 1223 int offsetInBytes, int sizeInBytes, int format); 1224 1225 private native final int native_write_short(short[] audioData, 1226 int offsetInShorts, int sizeInShorts, int format); 1227 1228 private native final int native_reload_static(); 1229 1230 private native final int native_get_native_frame_count(); 1231 1232 private native final void native_setVolume(float leftVolume, float rightVolume); 1233 1234 private native final int native_set_playback_rate(int sampleRateInHz); 1235 private native final int native_get_playback_rate(); 1236 1237 private native final int native_set_marker_pos(int marker); 1238 private native final int native_get_marker_pos(); 1239 1240 private native final int native_set_pos_update_period(int updatePeriod); 1241 private native final int native_get_pos_update_period(); 1242 1243 private native final int native_set_position(int position); 1244 private native final int native_get_position(); 1245 1246 private native final int native_set_loop(int start, int end, int loopCount); 1247 1248 static private native final int native_get_output_sample_rate(int streamType); 1249 static private native final int native_get_min_buff_size( 1250 int sampleRateInHz, int channelConfig, int audioFormat); 1251 1252 private native final int native_get_session_id(); 1253 1254 private native final int native_attachAuxEffect(int effectId); 1255 private native final void native_setAuxEffectSendLevel(float level); 1256 1257 //--------------------------------------------------------- 1258 // Utility methods 1259 //------------------ 1260 1261 private static void logd(String msg) { 1262 Log.d(TAG, "[ android.media.AudioTrack ] " + msg); 1263 } 1264 1265 private static void loge(String msg) { 1266 Log.e(TAG, "[ android.media.AudioTrack ] " + msg); 1267 } 1268 1269} 1270