MediaRecorder.java revision f1febe470ac30f8992066cb263c10f58493c4c34
1/* 2 * Copyright (C) 2007 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 android.media.CamcorderProfile; 20import android.hardware.Camera; 21import android.os.Handler; 22import android.os.Looper; 23import android.os.Message; 24import android.util.Log; 25import android.view.Surface; 26import java.io.IOException; 27import java.io.FileNotFoundException; 28import java.io.FileOutputStream; 29import java.io.FileDescriptor; 30import java.lang.ref.WeakReference; 31 32/** 33 * Used to record audio and video. The recording control is based on a 34 * simple state machine (see below). 35 * 36 * <p><img src="{@docRoot}images/mediarecorder_state_diagram.gif" border="0" /> 37 * </p> 38 * 39 * <p>A common case of using MediaRecorder to record audio works as follows: 40 * 41 * <pre>MediaRecorder recorder = new MediaRecorder(); 42 * recorder.setAudioSource(MediaRecorder.AudioSource.MIC); 43 * recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP); 44 * recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB); 45 * recorder.setOutputFile(PATH_NAME); 46 * recorder.prepare(); 47 * recorder.start(); // Recording is now started 48 * ... 49 * recorder.stop(); 50 * recorder.reset(); // You can reuse the object by going back to setAudioSource() step 51 * recorder.release(); // Now the object cannot be reused 52 * </pre> 53 * 54 * <p>See the <a href="{@docRoot}guide/topics/media/index.html">Audio and Video</a> 55 * documentation for additional help with using MediaRecorder. 56 * <p>Note: Currently, MediaRecorder does not work on the emulator. 57 */ 58public class MediaRecorder 59{ 60 static { 61 System.loadLibrary("media_jni"); 62 native_init(); 63 } 64 private final static String TAG = "MediaRecorder"; 65 66 // The two fields below are accessed by native methods 67 @SuppressWarnings("unused") 68 private int mNativeContext; 69 70 @SuppressWarnings("unused") 71 private Surface mSurface; 72 73 private String mPath; 74 private FileDescriptor mFd; 75 private EventHandler mEventHandler; 76 private OnErrorListener mOnErrorListener; 77 private OnInfoListener mOnInfoListener; 78 79 /** 80 * Default constructor. 81 */ 82 public MediaRecorder() { 83 84 Looper looper; 85 if ((looper = Looper.myLooper()) != null) { 86 mEventHandler = new EventHandler(this, looper); 87 } else if ((looper = Looper.getMainLooper()) != null) { 88 mEventHandler = new EventHandler(this, looper); 89 } else { 90 mEventHandler = null; 91 } 92 93 /* Native setup requires a weak reference to our object. 94 * It's easier to create it here than in C++. 95 */ 96 native_setup(new WeakReference<MediaRecorder>(this)); 97 } 98 99 /** 100 * Sets a Camera to use for recording. Use this function to switch 101 * quickly between preview and capture mode without a teardown of 102 * the camera object. Must call before prepare(). 103 * 104 * @param c the Camera to use for recording 105 */ 106 public native void setCamera(Camera c); 107 108 /** 109 * Sets a Surface to show a preview of recorded media (video). Calls this 110 * before prepare() to make sure that the desirable preview display is 111 * set. 112 * 113 * @param sv the Surface to use for the preview 114 */ 115 public void setPreviewDisplay(Surface sv) { 116 mSurface = sv; 117 } 118 119 /** 120 * Defines the audio source. These constants are used with 121 * {@link MediaRecorder#setAudioSource(int)}. 122 */ 123 public final class AudioSource { 124 /* Do not change these values without updating their counterparts 125 * in include/media/mediarecorder.h! 126 */ 127 private AudioSource() {} 128 public static final int DEFAULT = 0; 129 /** Microphone audio source */ 130 public static final int MIC = 1; 131 132 /** Voice call uplink (Tx) audio source */ 133 public static final int VOICE_UPLINK = 2; 134 135 /** Voice call downlink (Rx) audio source */ 136 public static final int VOICE_DOWNLINK = 3; 137 138 /** Voice call uplink + downlink audio source */ 139 public static final int VOICE_CALL = 4; 140 141 /** Microphone audio source with same orientation as camera if available, the main 142 * device microphone otherwise */ 143 public static final int CAMCORDER = 5; 144 145 /** Microphone audio source tuned for voice recognition if available, behaves like 146 * {@link #DEFAULT} otherwise. */ 147 public static final int VOICE_RECOGNITION = 6; 148 } 149 150 /** 151 * Defines the video source. These constants are used with 152 * {@link MediaRecorder#setVideoSource(int)}. 153 */ 154 public final class VideoSource { 155 /* Do not change these values without updating their counterparts 156 * in include/media/mediarecorder.h! 157 */ 158 private VideoSource() {} 159 public static final int DEFAULT = 0; 160 /** Camera video source */ 161 public static final int CAMERA = 1; 162 } 163 164 /** 165 * Defines the output format. These constants are used with 166 * {@link MediaRecorder#setOutputFormat(int)}. 167 */ 168 public final class OutputFormat { 169 /* Do not change these values without updating their counterparts 170 * in include/media/mediarecorder.h! 171 */ 172 private OutputFormat() {} 173 public static final int DEFAULT = 0; 174 /** 3GPP media file format*/ 175 public static final int THREE_GPP = 1; 176 /** MPEG4 media file format*/ 177 public static final int MPEG_4 = 2; 178 179 /** The following formats are audio only .aac or .amr formats **/ 180 /** @deprecated Deprecated in favor of AMR_NB */ 181 /** TODO: change link when AMR_NB is exposed. Deprecated in favor of MediaRecorder.OutputFormat.AMR_NB */ 182 public static final int RAW_AMR = 3; 183 /** @hide AMR NB file format */ 184 public static final int AMR_NB = 3; 185 /** @hide AMR WB file format */ 186 public static final int AMR_WB = 4; 187 /** @hide AAC ADIF file format */ 188 public static final int AAC_ADIF = 5; 189 /** @hide AAC ADTS file format */ 190 public static final int AAC_ADTS = 6; 191 192 /** @hide Stream over a socket, limited to a single stream */ 193 public static final int OUTPUT_FORMAT_RTP_AVP = 7; 194 195 /** @hide H.264/AAC data encapsulated in MPEG2/TS */ 196 public static final int OUTPUT_FORMAT_MPEG2TS = 8; 197 }; 198 199 /** 200 * Defines the audio encoding. These constants are used with 201 * {@link MediaRecorder#setAudioEncoder(int)}. 202 */ 203 public final class AudioEncoder { 204 /* Do not change these values without updating their counterparts 205 * in include/media/mediarecorder.h! 206 */ 207 private AudioEncoder() {} 208 public static final int DEFAULT = 0; 209 /** AMR (Narrowband) audio codec */ 210 public static final int AMR_NB = 1; 211 /** @hide AMR (Wideband) audio codec */ 212 public static final int AMR_WB = 2; 213 /** @hide AAC audio codec */ 214 public static final int AAC = 3; 215 /** @hide enhanced AAC audio codec */ 216 public static final int AAC_PLUS = 4; 217 /** @hide enhanced AAC plus audio codec */ 218 public static final int EAAC_PLUS = 5; 219 } 220 221 /** 222 * Defines the video encoding. These constants are used with 223 * {@link MediaRecorder#setVideoEncoder(int)}. 224 */ 225 public final class VideoEncoder { 226 /* Do not change these values without updating their counterparts 227 * in include/media/mediarecorder.h! 228 */ 229 private VideoEncoder() {} 230 public static final int DEFAULT = 0; 231 public static final int H263 = 1; 232 public static final int H264 = 2; 233 public static final int MPEG_4_SP = 3; 234 } 235 236 /** 237 * Sets the audio source to be used for recording. If this method is not 238 * called, the output file will not contain an audio track. The source needs 239 * to be specified before setting recording-parameters or encoders. Call 240 * this only before setOutputFormat(). 241 * 242 * @param audio_source the audio source to use 243 * @throws IllegalStateException if it is called after setOutputFormat() 244 * @see android.media.MediaRecorder.AudioSource 245 */ 246 public native void setAudioSource(int audio_source) 247 throws IllegalStateException; 248 249 /** 250 * Gets the maximum value for audio sources. 251 * @see android.media.MediaRecorder.AudioSource 252 */ 253 public static final int getAudioSourceMax() { return AudioSource.VOICE_RECOGNITION; } 254 255 /** 256 * Sets the video source to be used for recording. If this method is not 257 * called, the output file will not contain an video track. The source needs 258 * to be specified before setting recording-parameters or encoders. Call 259 * this only before setOutputFormat(). 260 * 261 * @param video_source the video source to use 262 * @throws IllegalStateException if it is called after setOutputFormat() 263 * @see android.media.MediaRecorder.VideoSource 264 */ 265 public native void setVideoSource(int video_source) 266 throws IllegalStateException; 267 268 /** 269 * Uses the settings from a CamcorderProfile object for recording. This method should 270 * be called after the video AND audio sources are set, and before setOutputFile(). 271 * 272 * @param profile the CamcorderProfile to use 273 * @see android.media.CamcorderProfile 274 */ 275 public void setProfile(CamcorderProfile profile) { 276 setOutputFormat(profile.fileFormat); 277 setVideoFrameRate(profile.videoFrameRate); 278 setVideoSize(profile.videoFrameWidth, profile.videoFrameHeight); 279 setVideoEncodingBitRate(profile.videoBitRate); 280 setAudioEncodingBitRate(profile.audioBitRate); 281 setAudioChannels(profile.audioChannels); 282 setAudioSamplingRate(profile.audioSampleRate); 283 setVideoEncoder(profile.videoCodec); 284 setAudioEncoder(profile.audioCodec); 285 } 286 287 /** 288 * Set the rotation degrees for the video recording. This method should be called 289 * before start(). 290 * 291 * @param degrees the angle to be rotated clockwise. 292 * 293 * {@hide} 294 */ 295 public void setClockwiseRotation(int degrees) { 296 setParameter(String.format("video-param-clockwise-rotation-degrees=%d", degrees)); 297 } 298 299 /** 300 * Sets the format of the output file produced during recording. Call this 301 * after setAudioSource()/setVideoSource() but before prepare(). 302 * 303 * <p>It is recommended to always use 3GP format when using the H.263 304 * video encoder and AMR audio encoder. Using an MPEG-4 container format 305 * may confuse some desktop players.</p> 306 * 307 * @param output_format the output format to use. The output format 308 * needs to be specified before setting recording-parameters or encoders. 309 * @throws IllegalStateException if it is called after prepare() or before 310 * setAudioSource()/setVideoSource(). 311 * @see android.media.MediaRecorder.OutputFormat 312 */ 313 public native void setOutputFormat(int output_format) 314 throws IllegalStateException; 315 316 /** 317 * Sets the width and height of the video to be captured. Must be called 318 * after setVideoSource(). Call this after setOutFormat() but before 319 * prepare(). 320 * 321 * @param width the width of the video to be captured 322 * @param height the height of the video to be captured 323 * @throws IllegalStateException if it is called after 324 * prepare() or before setOutputFormat() 325 */ 326 public native void setVideoSize(int width, int height) 327 throws IllegalStateException; 328 329 /** 330 * Sets the frame rate of the video to be captured. Must be called 331 * after setVideoSource(). Call this after setOutFormat() but before 332 * prepare(). 333 * 334 * @param rate the number of frames per second of video to capture 335 * @throws IllegalStateException if it is called after 336 * prepare() or before setOutputFormat(). 337 * 338 * NOTE: On some devices that have auto-frame rate, this sets the 339 * maximum frame rate, not a constant frame rate. Actual frame rate 340 * will vary according to lighting conditions. 341 */ 342 public native void setVideoFrameRate(int rate) throws IllegalStateException; 343 344 /** 345 * Sets the maximum duration (in ms) of the recording session. 346 * Call this after setOutFormat() but before prepare(). 347 * After recording reaches the specified duration, a notification 348 * will be sent to the {@link android.media.MediaRecorder.OnInfoListener} 349 * with a "what" code of {@link #MEDIA_RECORDER_INFO_MAX_DURATION_REACHED} 350 * and recording will be stopped. Stopping happens asynchronously, there 351 * is no guarantee that the recorder will have stopped by the time the 352 * listener is notified. 353 * 354 * @param max_duration_ms the maximum duration in ms (if zero or negative, disables the duration limit) 355 * 356 */ 357 public native void setMaxDuration(int max_duration_ms) throws IllegalArgumentException; 358 359 /** 360 * Sets the maximum filesize (in bytes) of the recording session. 361 * Call this after setOutFormat() but before prepare(). 362 * After recording reaches the specified filesize, a notification 363 * will be sent to the {@link android.media.MediaRecorder.OnInfoListener} 364 * with a "what" code of {@link #MEDIA_RECORDER_INFO_MAX_FILESIZE_REACHED} 365 * and recording will be stopped. Stopping happens asynchronously, there 366 * is no guarantee that the recorder will have stopped by the time the 367 * listener is notified. 368 * 369 * @param max_filesize_bytes the maximum filesize in bytes (if zero or negative, disables the limit) 370 * 371 */ 372 public native void setMaxFileSize(long max_filesize_bytes) throws IllegalArgumentException; 373 374 /** 375 * Sets the audio encoder to be used for recording. If this method is not 376 * called, the output file will not contain an audio track. Call this after 377 * setOutputFormat() but before prepare(). 378 * 379 * @param audio_encoder the audio encoder to use. 380 * @throws IllegalStateException if it is called before 381 * setOutputFormat() or after prepare(). 382 * @see android.media.MediaRecorder.AudioEncoder 383 */ 384 public native void setAudioEncoder(int audio_encoder) 385 throws IllegalStateException; 386 387 /** 388 * Sets the video encoder to be used for recording. If this method is not 389 * called, the output file will not contain an video track. Call this after 390 * setOutputFormat() and before prepare(). 391 * 392 * @param video_encoder the video encoder to use. 393 * @throws IllegalStateException if it is called before 394 * setOutputFormat() or after prepare() 395 * @see android.media.MediaRecorder.VideoEncoder 396 */ 397 public native void setVideoEncoder(int video_encoder) 398 throws IllegalStateException; 399 400 /** 401 * Sets the audio sampling rate for recording. Call this method before prepare(). 402 * Prepare() may perform additional checks on the parameter to make sure whether 403 * the specified audio sampling rate is applicable. The sampling rate really depends 404 * on the format for the audio recording, as well as the capabilities of the platform. 405 * For instance, the sampling rate supported by AAC audio coding standard ranges 406 * from 8 to 96 kHz. Please consult with the related audio coding standard for the 407 * supported audio sampling rate. 408 * 409 * @param samplingRate the sampling rate for audio in samples per second. 410 */ 411 public void setAudioSamplingRate(int samplingRate) { 412 if (samplingRate <= 0) { 413 throw new IllegalArgumentException("Audio sampling rate is not positive"); 414 } 415 setParameter(String.format("audio-param-sampling-rate=%d", samplingRate)); 416 } 417 418 /** 419 * Sets the number of audio channels for recording. Call this method before prepare(). 420 * Prepare() may perform additional checks on the parameter to make sure whether the 421 * specified number of audio channels are applicable. 422 * 423 * @param numChannels the number of audio channels. Usually it is either 1 (mono) or 2 424 * (stereo). 425 */ 426 public void setAudioChannels(int numChannels) { 427 if (numChannels <= 0) { 428 throw new IllegalArgumentException("Number of channels is not positive"); 429 } 430 setParameter(String.format("audio-param-number-of-channels=%d", numChannels)); 431 } 432 433 /** 434 * Sets the audio encoding bit rate for recording. Call this method before prepare(). 435 * Prepare() may perform additional checks on the parameter to make sure whether the 436 * specified bit rate is applicable, and sometimes the passed bitRate will be clipped 437 * internally to ensure the audio recording can proceed smoothly based on the 438 * capabilities of the platform. 439 * 440 * @param bitRate the audio encoding bit rate in bits per second. 441 */ 442 public void setAudioEncodingBitRate(int bitRate) { 443 if (bitRate <= 0) { 444 throw new IllegalArgumentException("Audio encoding bit rate is not positive"); 445 } 446 setParameter(String.format("audio-param-encoding-bitrate=%d", bitRate)); 447 } 448 449 /** 450 * Sets the video encoding bit rate for recording. Call this method before prepare(). 451 * Prepare() may perform additional checks on the parameter to make sure whether the 452 * specified bit rate is applicable, and sometimes the passed bitRate will be 453 * clipped internally to ensure the video recording can proceed smoothly based on 454 * the capabilities of the platform. 455 * 456 * @param bitRate the video encoding bit rate in bits per second. 457 */ 458 public void setVideoEncodingBitRate(int bitRate) { 459 if (bitRate <= 0) { 460 throw new IllegalArgumentException("Video encoding bit rate is not positive"); 461 } 462 setParameter(String.format("video-param-encoding-bitrate=%d", bitRate)); 463 } 464 465 /** 466 * Pass in the file descriptor of the file to be written. Call this after 467 * setOutputFormat() but before prepare(). 468 * 469 * @param fd an open file descriptor to be written into. 470 * @throws IllegalStateException if it is called before 471 * setOutputFormat() or after prepare() 472 */ 473 public void setOutputFile(FileDescriptor fd) throws IllegalStateException 474 { 475 mPath = null; 476 mFd = fd; 477 } 478 479 /** 480 * Sets the path of the output file to be produced. Call this after 481 * setOutputFormat() but before prepare(). 482 * 483 * @param path The pathname to use. 484 * @throws IllegalStateException if it is called before 485 * setOutputFormat() or after prepare() 486 */ 487 public void setOutputFile(String path) throws IllegalStateException 488 { 489 mFd = null; 490 mPath = path; 491 } 492 493 // native implementation 494 private native void _setOutputFile(FileDescriptor fd, long offset, long length) 495 throws IllegalStateException, IOException; 496 private native void _prepare() throws IllegalStateException, IOException; 497 498 /** 499 * Prepares the recorder to begin capturing and encoding data. This method 500 * must be called after setting up the desired audio and video sources, 501 * encoders, file format, etc., but before start(). 502 * 503 * @throws IllegalStateException if it is called after 504 * start() or before setOutputFormat(). 505 * @throws IOException if prepare fails otherwise. 506 */ 507 public void prepare() throws IllegalStateException, IOException 508 { 509 if (mPath != null) { 510 FileOutputStream fos = new FileOutputStream(mPath); 511 try { 512 _setOutputFile(fos.getFD(), 0, 0); 513 } finally { 514 fos.close(); 515 } 516 } else if (mFd != null) { 517 _setOutputFile(mFd, 0, 0); 518 } else { 519 throw new IOException("No valid output file"); 520 } 521 _prepare(); 522 } 523 524 /** 525 * Begins capturing and encoding data to the file specified with 526 * setOutputFile(). Call this after prepare(). 527 * 528 * @throws IllegalStateException if it is called before 529 * prepare(). 530 */ 531 public native void start() throws IllegalStateException; 532 533 /** 534 * Stops recording. Call this after start(). Once recording is stopped, 535 * you will have to configure it again as if it has just been constructed. 536 * 537 * @throws IllegalStateException if it is called before start() 538 */ 539 public native void stop() throws IllegalStateException; 540 541 /** 542 * Restarts the MediaRecorder to its idle state. After calling 543 * this method, you will have to configure it again as if it had just been 544 * constructed. 545 */ 546 public void reset() { 547 native_reset(); 548 549 // make sure none of the listeners get called anymore 550 mEventHandler.removeCallbacksAndMessages(null); 551 } 552 553 private native void native_reset(); 554 555 /** 556 * Returns the maximum absolute amplitude that was sampled since the last 557 * call to this method. Call this only after the setAudioSource(). 558 * 559 * @return the maximum absolute amplitude measured since the last call, or 560 * 0 when called for the first time 561 * @throws IllegalStateException if it is called before 562 * the audio source has been set. 563 */ 564 public native int getMaxAmplitude() throws IllegalStateException; 565 566 /* Do not change this value without updating its counterpart 567 * in include/media/mediarecorder.h! 568 */ 569 /** Unspecified media recorder error. 570 * @see android.media.MediaRecorder.OnErrorListener 571 */ 572 public static final int MEDIA_RECORDER_ERROR_UNKNOWN = 1; 573 574 /** 575 * Interface definition for a callback to be invoked when an error 576 * occurs while recording. 577 */ 578 public interface OnErrorListener 579 { 580 /** 581 * Called when an error occurs while recording. 582 * 583 * @param mr the MediaRecorder that encountered the error 584 * @param what the type of error that has occurred: 585 * <ul> 586 * <li>{@link #MEDIA_RECORDER_ERROR_UNKNOWN} 587 * </ul> 588 * @param extra an extra code, specific to the error type 589 */ 590 void onError(MediaRecorder mr, int what, int extra); 591 } 592 593 /** 594 * Register a callback to be invoked when an error occurs while 595 * recording. 596 * 597 * @param l the callback that will be run 598 */ 599 public void setOnErrorListener(OnErrorListener l) 600 { 601 mOnErrorListener = l; 602 } 603 604 /* Do not change these values without updating their counterparts 605 * in include/media/mediarecorder.h! 606 */ 607 /** Unspecified media recorder error. 608 * @see android.media.MediaRecorder.OnInfoListener 609 */ 610 public static final int MEDIA_RECORDER_INFO_UNKNOWN = 1; 611 /** A maximum duration had been setup and has now been reached. 612 * @see android.media.MediaRecorder.OnInfoListener 613 */ 614 public static final int MEDIA_RECORDER_INFO_MAX_DURATION_REACHED = 800; 615 /** A maximum filesize had been setup and has now been reached. 616 * @see android.media.MediaRecorder.OnInfoListener 617 */ 618 public static final int MEDIA_RECORDER_INFO_MAX_FILESIZE_REACHED = 801; 619 620 /** 621 * Interface definition for a callback to be invoked when an error 622 * occurs while recording. 623 */ 624 public interface OnInfoListener 625 { 626 /** 627 * Called when an error occurs while recording. 628 * 629 * @param mr the MediaRecorder that encountered the error 630 * @param what the type of error that has occurred: 631 * <ul> 632 * <li>{@link #MEDIA_RECORDER_INFO_UNKNOWN} 633 * <li>{@link #MEDIA_RECORDER_INFO_MAX_DURATION_REACHED} 634 * <li>{@link #MEDIA_RECORDER_INFO_MAX_FILESIZE_REACHED} 635 * </ul> 636 * @param extra an extra code, specific to the error type 637 */ 638 void onInfo(MediaRecorder mr, int what, int extra); 639 } 640 641 /** 642 * Register a callback to be invoked when an informational event occurs while 643 * recording. 644 * 645 * @param listener the callback that will be run 646 */ 647 public void setOnInfoListener(OnInfoListener listener) 648 { 649 mOnInfoListener = listener; 650 } 651 652 private class EventHandler extends Handler 653 { 654 private MediaRecorder mMediaRecorder; 655 656 public EventHandler(MediaRecorder mr, Looper looper) { 657 super(looper); 658 mMediaRecorder = mr; 659 } 660 661 /* Do not change these values without updating their counterparts 662 * in include/media/mediarecorder.h! 663 */ 664 private static final int MEDIA_RECORDER_EVENT_ERROR = 1; 665 private static final int MEDIA_RECORDER_EVENT_INFO = 2; 666 667 @Override 668 public void handleMessage(Message msg) { 669 if (mMediaRecorder.mNativeContext == 0) { 670 Log.w(TAG, "mediarecorder went away with unhandled events"); 671 return; 672 } 673 switch(msg.what) { 674 case MEDIA_RECORDER_EVENT_ERROR: 675 if (mOnErrorListener != null) 676 mOnErrorListener.onError(mMediaRecorder, msg.arg1, msg.arg2); 677 678 return; 679 680 case MEDIA_RECORDER_EVENT_INFO: 681 if (mOnInfoListener != null) 682 mOnInfoListener.onInfo(mMediaRecorder, msg.arg1, msg.arg2); 683 684 return; 685 686 default: 687 Log.e(TAG, "Unknown message type " + msg.what); 688 return; 689 } 690 } 691 } 692 693 /** 694 * Called from native code when an interesting event happens. This method 695 * just uses the EventHandler system to post the event back to the main app thread. 696 * We use a weak reference to the original MediaRecorder object so that the native 697 * code is safe from the object disappearing from underneath it. (This is 698 * the cookie passed to native_setup().) 699 */ 700 private static void postEventFromNative(Object mediarecorder_ref, 701 int what, int arg1, int arg2, Object obj) 702 { 703 MediaRecorder mr = (MediaRecorder)((WeakReference)mediarecorder_ref).get(); 704 if (mr == null) { 705 return; 706 } 707 708 if (mr.mEventHandler != null) { 709 Message m = mr.mEventHandler.obtainMessage(what, arg1, arg2, obj); 710 mr.mEventHandler.sendMessage(m); 711 } 712 } 713 714 /** 715 * Releases resources associated with this MediaRecorder object. 716 * It is good practice to call this method when you're done 717 * using the MediaRecorder. 718 */ 719 public native void release(); 720 721 private static native final void native_init(); 722 723 private native final void native_setup(Object mediarecorder_this) throws IllegalStateException; 724 725 private native final void native_finalize(); 726 727 private native void setParameter(String nameValuePair); 728 729 @Override 730 protected void finalize() { native_finalize(); } 731} 732