1/*
2 * Copyright (C) 2013 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.annotation.IntDef;
20import android.annotation.NonNull;
21import android.annotation.Nullable;
22import android.media.MediaCodec;
23import android.media.MediaCodec.BufferInfo;
24import dalvik.system.CloseGuard;
25
26import java.io.FileDescriptor;
27import java.io.IOException;
28import java.io.RandomAccessFile;
29import java.lang.annotation.Retention;
30import java.lang.annotation.RetentionPolicy;
31import java.nio.ByteBuffer;
32import java.util.Map;
33
34/**
35 * MediaMuxer facilitates muxing elementary streams. Currently MediaMuxer supports MP4, Webm
36 * and 3GP file as the output. It also supports muxing B-frames in MP4 since Android Nougat.
37 * <p>
38 * It is generally used like this:
39 *
40 * <pre>
41 * MediaMuxer muxer = new MediaMuxer("temp.mp4", OutputFormat.MUXER_OUTPUT_MPEG_4);
42 * // More often, the MediaFormat will be retrieved from MediaCodec.getOutputFormat()
43 * // or MediaExtractor.getTrackFormat().
44 * MediaFormat audioFormat = new MediaFormat(...);
45 * MediaFormat videoFormat = new MediaFormat(...);
46 * int audioTrackIndex = muxer.addTrack(audioFormat);
47 * int videoTrackIndex = muxer.addTrack(videoFormat);
48 * ByteBuffer inputBuffer = ByteBuffer.allocate(bufferSize);
49 * boolean finished = false;
50 * BufferInfo bufferInfo = new BufferInfo();
51 *
52 * muxer.start();
53 * while(!finished) {
54 *   // getInputBuffer() will fill the inputBuffer with one frame of encoded
55 *   // sample from either MediaCodec or MediaExtractor, set isAudioSample to
56 *   // true when the sample is audio data, set up all the fields of bufferInfo,
57 *   // and return true if there are no more samples.
58 *   finished = getInputBuffer(inputBuffer, isAudioSample, bufferInfo);
59 *   if (!finished) {
60 *     int currentTrackIndex = isAudioSample ? audioTrackIndex : videoTrackIndex;
61 *     muxer.writeSampleData(currentTrackIndex, inputBuffer, bufferInfo);
62 *   }
63 * };
64 * muxer.stop();
65 * muxer.release();
66 * </pre>
67 *
68
69 <h4>Metadata Track</h4>
70 <p>
71  Per-frame metadata is useful in carrying extra information that correlated with video or audio to
72  facilitate offline processing, e.g. gyro signals from the sensor could help video stabilization when
73  doing offline processing. Metadata track is only supported in MP4 container. When adding a new
74  metadata track, track's mime format must start with prefix "application/", e.g. "applicaton/gyro".
75  Metadata's format/layout will be defined by the application. Writing metadata is nearly the same as
76  writing video/audio data except that the data will not be from mediacodec. Application just needs
77  to pass the bytebuffer that contains the metadata and also the associated timestamp to the
78  {@link #writeSampleData} api. The timestamp must be in the same time base as video and audio. The
79  generated MP4 file uses TextMetaDataSampleEntry defined in section 12.3.3.2 of the ISOBMFF to signal
80  the metadata's mime format. When using{@link android.media.MediaExtractor} to extract the file with
81  metadata track, the mime format of the metadata will be extracted into {@link android.media.MediaFormat}.
82
83 <pre class=prettyprint>
84   MediaMuxer muxer = new MediaMuxer("temp.mp4", OutputFormat.MUXER_OUTPUT_MPEG_4);
85   // SetUp Video/Audio Tracks.
86   MediaFormat audioFormat = new MediaFormat(...);
87   MediaFormat videoFormat = new MediaFormat(...);
88   int audioTrackIndex = muxer.addTrack(audioFormat);
89   int videoTrackIndex = muxer.addTrack(videoFormat);
90
91   // Setup Metadata Track
92   MediaFormat metadataFormat = new MediaFormat(...);
93   metadataFormat.setString(KEY_MIME, "application/gyro");
94   int metadataTrackIndex = muxer.addTrack(metadataFormat);
95
96   muxer.start();
97   while(..) {
98       // Allocate bytebuffer and write gyro data(x,y,z) into it.
99       ByteBuffer metaData = ByteBuffer.allocate(bufferSize);
100       metaData.putFloat(x);
101       metaData.putFloat(y);
102       metaData.putFloat(z);
103       BufferInfo metaInfo = new BufferInfo();
104       // Associate this metadata with the video frame by setting
105       // the same timestamp as the video frame.
106       metaInfo.presentationTimeUs = currentVideoTrackTimeUs;
107       metaInfo.offset = 0;
108       metaInfo.flags = 0;
109       metaInfo.size = bufferSize;
110       muxer.writeSampleData(metadataTrackIndex, metaData, metaInfo);
111   };
112   muxer.stop();
113   muxer.release();
114 }</pre>
115
116 <h2 id=History><a name="History"></a>Features and API History</h2>
117 <p>
118 The following table summarizes the feature support in different API version and containers.
119 For API version numbers, see {@link android.os.Build.VERSION_CODES}.
120
121 <style>
122 .api > tr > th, .api > tr > td { text-align: center; padding: 4px 4px; }
123 .api > tr > th     { vertical-align: bottom; }
124 .api > tr > td     { vertical-align: middle; }
125 .sml > tr > th, .sml > tr > td { text-align: center; padding: 2px 4px; }
126 .fn { text-align: center; }
127 </style>
128
129 <table align="right" style="width: 0%">
130  <thead>
131   <tbody class=api>
132    <tr><th>Symbol</th>
133    <th>Meaning</th></tr>
134   </tbody>
135  </thead>
136  <tbody class=sml>
137   <tr><td>&#9679;</td><td>Supported</td></tr>
138   <tr><td>&#9675;</td><td>Not supported</td></tr>
139   <tr><td>&#9639;</td><td>Supported in MP4/WebM/3GP</td></tr>
140   <tr><td>&#8277;</td><td>Only Supported in MP4</td></tr>
141  </tbody>
142 </table>
143<table align="center" style="width: 100%;">
144  <thead class=api>
145   <tr>
146    <th rowspan=2>Feature</th>
147    <th colspan="24">SDK Version</th>
148   </tr>
149   <tr>
150    <th>18</th>
151    <th>19</th>
152    <th>20</th>
153    <th>21</th>
154    <th>22</th>
155    <th>23</th>
156    <th>24</th>
157    <th>25</th>
158    <th>26+</th>
159   </tr>
160  </thead>
161 <tbody class=api>
162   <tr>
163    <td align="center">MP4 container</td>
164    <td>&#9679;</td>
165    <td>&#9679;</td>
166    <td>&#9679;</td>
167    <td>&#9679;</td>
168    <td>&#9679;</td>
169    <td>&#9679;</td>
170    <td>&#9679;</td>
171    <td>&#9679;</td>
172    <td>&#9679;</td>
173   </tr>
174    <td align="center">WebM container</td>
175    <td>&#9675;</td>
176    <td>&#9675;</td>
177    <td>&#9675;</td>
178    <td>&#9679;</td>
179    <td>&#9679;</td>
180    <td>&#9679;</td>
181    <td>&#9679;</td>
182    <td>&#9679;</td>
183    <td>&#9679;</td>
184   </tr>
185    <td align="center">3GP container</td>
186    <td>&#9675;</td>
187    <td>&#9675;</td>
188    <td>&#9675;</td>
189    <td>&#9675;</td>
190    <td>&#9675;</td>
191    <td>&#9675;</td>
192    <td>&#9675;</td>
193    <td>&#9675;</td>
194    <td>&#9679;</td>
195   </tr>
196    <td align="center">Muxing B-Frames(bi-directional predicted frames)</td>
197    <td>&#9675;</td>
198    <td>&#9675;</td>
199    <td>&#9675;</td>
200    <td>&#9675;</td>
201    <td>&#9675;</td>
202    <td>&#9675;</td>
203    <td>&#8277;</td>
204    <td>&#8277;</td>
205    <td>&#8277;</td>
206   </tr>
207   </tr>
208    <td align="center">Muxing Single Video/Audio Track</td>
209    <td>&#9639;</td>
210    <td>&#9639;</td>
211    <td>&#9639;</td>
212    <td>&#9639;</td>
213    <td>&#9639;</td>
214    <td>&#9639;</td>
215    <td>&#9639;</td>
216    <td>&#9639;</td>
217    <td>&#9639;</td>
218   </tr>
219   </tr>
220    <td align="center">Muxing Multiple Video/Audio Tracks</td>
221    <td>&#9675;</td>
222    <td>&#9675;</td>
223    <td>&#9675;</td>
224    <td>&#9675;</td>
225    <td>&#9675;</td>
226    <td>&#9675;</td>
227    <td>&#9675;</td>
228    <td>&#9675;</td>
229    <td>&#8277;</td>
230   </tr>
231   </tr>
232    <td align="center">Muxing Metadata Tracks</td>
233    <td>&#9675;</td>
234    <td>&#9675;</td>
235    <td>&#9675;</td>
236    <td>&#9675;</td>
237    <td>&#9675;</td>
238    <td>&#9675;</td>
239    <td>&#9675;</td>
240    <td>&#9675;</td>
241    <td>&#8277;</td>
242   </tr>
243   </tbody>
244 </table>
245 */
246
247final public class MediaMuxer {
248
249    static {
250        System.loadLibrary("media_jni");
251    }
252
253    /**
254     * Defines the output format. These constants are used with constructor.
255     */
256    public static final class OutputFormat {
257        /* Do not change these values without updating their counterparts
258         * in include/media/stagefright/MediaMuxer.h!
259         */
260        private OutputFormat() {}
261        /** MPEG4 media file format*/
262        public static final int MUXER_OUTPUT_MPEG_4 = 0;
263        /** WEBM media file format*/
264        public static final int MUXER_OUTPUT_WEBM   = 1;
265        /** 3GPP media file format*/
266        public static final int MUXER_OUTPUT_3GPP   = 2;
267    };
268
269    /** @hide */
270    @IntDef({
271        OutputFormat.MUXER_OUTPUT_MPEG_4,
272        OutputFormat.MUXER_OUTPUT_WEBM,
273        OutputFormat.MUXER_OUTPUT_3GPP,
274    })
275    @Retention(RetentionPolicy.SOURCE)
276    public @interface Format {}
277
278    // All the native functions are listed here.
279    private static native long nativeSetup(@NonNull FileDescriptor fd, int format)
280            throws IllegalArgumentException, IOException;
281    private static native void nativeRelease(long nativeObject);
282    private static native void nativeStart(long nativeObject);
283    private static native void nativeStop(long nativeObject);
284    private static native int nativeAddTrack(
285            long nativeObject, @NonNull String[] keys, @NonNull Object[] values);
286    private static native void nativeSetOrientationHint(
287            long nativeObject, int degrees);
288    private static native void nativeSetLocation(long nativeObject, int latitude, int longitude);
289    private static native void nativeWriteSampleData(
290            long nativeObject, int trackIndex, @NonNull ByteBuffer byteBuf,
291            int offset, int size, long presentationTimeUs, @MediaCodec.BufferFlag int flags);
292
293    // Muxer internal states.
294    private static final int MUXER_STATE_UNINITIALIZED  = -1;
295    private static final int MUXER_STATE_INITIALIZED    = 0;
296    private static final int MUXER_STATE_STARTED        = 1;
297    private static final int MUXER_STATE_STOPPED        = 2;
298
299    private int mState = MUXER_STATE_UNINITIALIZED;
300
301    private final CloseGuard mCloseGuard = CloseGuard.get();
302    private int mLastTrackIndex = -1;
303
304    private long mNativeObject;
305
306    /**
307     * Constructor.
308     * Creates a media muxer that writes to the specified path.
309     * @param path The path of the output media file.
310     * @param format The format of the output media file.
311     * @see android.media.MediaMuxer.OutputFormat
312     * @throws IllegalArgumentException if path is invalid or format is not supported.
313     * @throws IOException if failed to open the file for write.
314     */
315    public MediaMuxer(@NonNull String path, @Format int format) throws IOException {
316        if (path == null) {
317            throw new IllegalArgumentException("path must not be null");
318        }
319        // Use RandomAccessFile so we can open the file with RW access;
320        // RW access allows the native writer to memory map the output file.
321        RandomAccessFile file = null;
322        try {
323            file = new RandomAccessFile(path, "rws");
324            FileDescriptor fd = file.getFD();
325            setUpMediaMuxer(fd, format);
326        } finally {
327            if (file != null) {
328                file.close();
329            }
330        }
331    }
332
333    /**
334     * Constructor.
335     * Creates a media muxer that writes to the specified FileDescriptor. File descriptor
336     * must be seekable and writable. Application should not use the file referenced
337     * by this file descriptor until {@link #stop}. It is the application's responsibility
338     * to close the file descriptor. It is safe to do so as soon as this call returns.
339     * @param fd The FileDescriptor of the output media file.
340     * @param format The format of the output media file.
341     * @see android.media.MediaMuxer.OutputFormat
342     * @throws IllegalArgumentException if fd is invalid or format is not supported.
343     * @throws IOException if failed to open the file for write.
344     */
345    public MediaMuxer(@NonNull FileDescriptor fd, @Format int format) throws IOException {
346        setUpMediaMuxer(fd, format);
347    }
348
349    private void setUpMediaMuxer(@NonNull FileDescriptor fd, @Format int format) throws IOException {
350        if (format != OutputFormat.MUXER_OUTPUT_MPEG_4 && format != OutputFormat.MUXER_OUTPUT_WEBM
351                && format != OutputFormat.MUXER_OUTPUT_3GPP) {
352            throw new IllegalArgumentException("format: " + format + " is invalid");
353        }
354        mNativeObject = nativeSetup(fd, format);
355        mState = MUXER_STATE_INITIALIZED;
356        mCloseGuard.open("release");
357    }
358
359    /**
360     * Sets the orientation hint for output video playback.
361     * <p>This method should be called before {@link #start}. Calling this
362     * method will not rotate the video frame when muxer is generating the file,
363     * but add a composition matrix containing the rotation angle in the output
364     * video if the output format is
365     * {@link OutputFormat#MUXER_OUTPUT_MPEG_4} so that a video player can
366     * choose the proper orientation for playback. Note that some video players
367     * may choose to ignore the composition matrix in a video during playback.
368     * By default, the rotation degree is 0.</p>
369     * @param degrees the angle to be rotated clockwise in degrees.
370     * The supported angles are 0, 90, 180, and 270 degrees.
371     * @throws IllegalArgumentException if degree is not supported.
372     * @throws IllegalStateException If this method is called after {@link #start}.
373     */
374    public void setOrientationHint(int degrees) {
375        if (degrees != 0 && degrees != 90  && degrees != 180 && degrees != 270) {
376            throw new IllegalArgumentException("Unsupported angle: " + degrees);
377        }
378        if (mState == MUXER_STATE_INITIALIZED) {
379            nativeSetOrientationHint(mNativeObject, degrees);
380        } else {
381            throw new IllegalStateException("Can't set rotation degrees due" +
382                    " to wrong state.");
383        }
384    }
385
386    /**
387     * Set and store the geodata (latitude and longitude) in the output file.
388     * This method should be called before {@link #start}. The geodata is stored
389     * in udta box if the output format is
390     * {@link OutputFormat#MUXER_OUTPUT_MPEG_4}, and is ignored for other output
391     * formats. The geodata is stored according to ISO-6709 standard.
392     *
393     * @param latitude Latitude in degrees. Its value must be in the range [-90,
394     * 90].
395     * @param longitude Longitude in degrees. Its value must be in the range
396     * [-180, 180].
397     * @throws IllegalArgumentException If the given latitude or longitude is out
398     * of range.
399     * @throws IllegalStateException If this method is called after {@link #start}.
400     */
401    public void setLocation(float latitude, float longitude) {
402        int latitudex10000  = (int) (latitude * 10000 + 0.5);
403        int longitudex10000 = (int) (longitude * 10000 + 0.5);
404
405        if (latitudex10000 > 900000 || latitudex10000 < -900000) {
406            String msg = "Latitude: " + latitude + " out of range.";
407            throw new IllegalArgumentException(msg);
408        }
409        if (longitudex10000 > 1800000 || longitudex10000 < -1800000) {
410            String msg = "Longitude: " + longitude + " out of range";
411            throw new IllegalArgumentException(msg);
412        }
413
414        if (mState == MUXER_STATE_INITIALIZED && mNativeObject != 0) {
415            nativeSetLocation(mNativeObject, latitudex10000, longitudex10000);
416        } else {
417            throw new IllegalStateException("Can't set location due to wrong state.");
418        }
419    }
420
421    /**
422     * Starts the muxer.
423     * <p>Make sure this is called after {@link #addTrack} and before
424     * {@link #writeSampleData}.</p>
425     * @throws IllegalStateException If this method is called after {@link #start}
426     * or Muxer is released
427     */
428    public void start() {
429        if (mNativeObject == 0) {
430            throw new IllegalStateException("Muxer has been released!");
431        }
432        if (mState == MUXER_STATE_INITIALIZED) {
433            nativeStart(mNativeObject);
434            mState = MUXER_STATE_STARTED;
435        } else {
436            throw new IllegalStateException("Can't start due to wrong state.");
437        }
438    }
439
440    /**
441     * Stops the muxer.
442     * <p>Once the muxer stops, it can not be restarted.</p>
443     * @throws IllegalStateException if muxer is in the wrong state.
444     */
445    public void stop() {
446        if (mState == MUXER_STATE_STARTED) {
447            nativeStop(mNativeObject);
448            mState = MUXER_STATE_STOPPED;
449        } else {
450            throw new IllegalStateException("Can't stop due to wrong state.");
451        }
452    }
453
454    @Override
455    protected void finalize() throws Throwable {
456        try {
457            if (mCloseGuard != null) {
458                mCloseGuard.warnIfOpen();
459            }
460            if (mNativeObject != 0) {
461                nativeRelease(mNativeObject);
462                mNativeObject = 0;
463            }
464        } finally {
465            super.finalize();
466        }
467    }
468
469    /**
470     * Adds a track with the specified format.
471     * <p>
472     * The following table summarizes support for specific format keys across android releases.
473     * Keys marked with '+:' are required.
474     *
475     * <table style="width: 0%">
476     *  <thead>
477     *   <tr>
478     *    <th rowspan=2>OS Version(s)</th>
479     *    <td colspan=3>{@code MediaFormat} keys used for</th>
480     *   </tr><tr>
481     *    <th>All Tracks</th>
482     *    <th>Audio Tracks</th>
483     *    <th>Video Tracks</th>
484     *   </tr>
485     *  </thead>
486     *  <tbody>
487     *   <tr>
488     *    <td>{@link android.os.Build.VERSION_CODES#JELLY_BEAN_MR2}</td>
489     *    <td rowspan=7>+: {@link MediaFormat#KEY_MIME}</td>
490     *    <td rowspan=3>+: {@link MediaFormat#KEY_SAMPLE_RATE},<br>
491     *        +: {@link MediaFormat#KEY_CHANNEL_COUNT},<br>
492     *        +: <strong>codec-specific data<sup>AAC</sup></strong></td>
493     *    <td rowspan=5>+: {@link MediaFormat#KEY_WIDTH},<br>
494     *        +: {@link MediaFormat#KEY_HEIGHT},<br>
495     *        no {@code KEY_ROTATION},
496     *        use {@link #setOrientationHint setOrientationHint()}<sup>.mp4</sup>,<br>
497     *        +: <strong>codec-specific data<sup>AVC, MPEG4</sup></strong></td>
498     *   </tr><tr>
499     *    <td>{@link android.os.Build.VERSION_CODES#KITKAT}</td>
500     *   </tr><tr>
501     *    <td>{@link android.os.Build.VERSION_CODES#KITKAT_WATCH}</td>
502     *   </tr><tr>
503     *    <td>{@link android.os.Build.VERSION_CODES#LOLLIPOP}</td>
504     *    <td rowspan=4>as above, plus<br>
505     *        +: <strong>codec-specific data<sup>Vorbis & .webm</sup></strong></td>
506     *   </tr><tr>
507     *    <td>{@link android.os.Build.VERSION_CODES#LOLLIPOP_MR1}</td>
508     *   </tr><tr>
509     *    <td>{@link android.os.Build.VERSION_CODES#M}</td>
510     *    <td>as above, plus<br>
511     *        {@link MediaFormat#KEY_BIT_RATE}<sup>AAC</sup></td>
512     *   </tr><tr>
513     *    <td>{@link android.os.Build.VERSION_CODES#N}</td>
514     *    <td>as above, plus<br>
515     *        <!-- {link MediaFormat#KEY_MAX_BIT_RATE}<sup>AAC, MPEG4</sup>,<br> -->
516     *        {@link MediaFormat#KEY_BIT_RATE}<sup>MPEG4</sup>,<br>
517     *        {@link MediaFormat#KEY_HDR_STATIC_INFO}<sup>#, .webm</sup>,<br>
518     *        {@link MediaFormat#KEY_COLOR_STANDARD}<sup>#</sup>,<br>
519     *        {@link MediaFormat#KEY_COLOR_TRANSFER}<sup>#</sup>,<br>
520     *        {@link MediaFormat#KEY_COLOR_RANGE}<sup>#</sup>,<br>
521     *        +: <strong>codec-specific data<sup>HEVC</sup></strong>,<br>
522     *        codec-specific data<sup>VP9</sup></td>
523     *   </tr>
524     *   <tr>
525     *    <td colspan=4>
526     *     <p class=note><strong>Notes:</strong><br>
527     *      #: storing into container metadata.<br>
528     *      .mp4, .webm&hellip;: for listed containers<br>
529     *      MPEG4, AAC&hellip;: for listed codecs
530     *    </td>
531     *   </tr><tr>
532     *    <td colspan=4>
533     *     <p class=note>Note that the codec-specific data for the track must be specified using
534     *     this method. Furthermore, codec-specific data must not be passed/specified via the
535     *     {@link #writeSampleData writeSampleData()} call.
536     *    </td>
537     *   </tr>
538     *  </tbody>
539     * </table>
540     *
541     * <p>
542     * The following table summarizes codec support for containers across android releases:
543     *
544     * <table style="width: 0%">
545     *  <thead>
546     *   <tr>
547     *    <th rowspan=2>OS Version(s)</th>
548     *    <td colspan=3>Codec support</th>
549     *   </tr><tr>
550     *    <th>{@linkplain OutputFormat#MUXER_OUTPUT_MPEG_4 MP4}</th>
551     *    <th>{@linkplain OutputFormat#MUXER_OUTPUT_WEBM WEBM}</th>
552     *   </tr>
553     *  </thead>
554     *  <tbody>
555     *   <tr>
556     *    <td>{@link android.os.Build.VERSION_CODES#JELLY_BEAN_MR2}</td>
557     *    <td rowspan=6>{@link MediaFormat#MIMETYPE_AUDIO_AAC AAC},<br>
558     *        {@link MediaFormat#MIMETYPE_AUDIO_AMR_NB NB-AMR},<br>
559     *        {@link MediaFormat#MIMETYPE_AUDIO_AMR_WB WB-AMR},<br>
560     *        {@link MediaFormat#MIMETYPE_VIDEO_H263 H.263},<br>
561     *        {@link MediaFormat#MIMETYPE_VIDEO_MPEG4 MPEG-4},<br>
562     *        {@link MediaFormat#MIMETYPE_VIDEO_AVC AVC} (H.264)</td>
563     *    <td rowspan=3>Not supported</td>
564     *   </tr><tr>
565     *    <td>{@link android.os.Build.VERSION_CODES#KITKAT}</td>
566     *   </tr><tr>
567     *    <td>{@link android.os.Build.VERSION_CODES#KITKAT_WATCH}</td>
568     *   </tr><tr>
569     *    <td>{@link android.os.Build.VERSION_CODES#LOLLIPOP}</td>
570     *    <td rowspan=3>{@link MediaFormat#MIMETYPE_AUDIO_VORBIS Vorbis},<br>
571     *        {@link MediaFormat#MIMETYPE_VIDEO_VP8 VP8}</td>
572     *   </tr><tr>
573     *    <td>{@link android.os.Build.VERSION_CODES#LOLLIPOP_MR1}</td>
574     *   </tr><tr>
575     *    <td>{@link android.os.Build.VERSION_CODES#M}</td>
576     *   </tr><tr>
577     *    <td>{@link android.os.Build.VERSION_CODES#N}</td>
578     *    <td>as above, plus<br>
579     *        {@link MediaFormat#MIMETYPE_VIDEO_HEVC HEVC} (H.265)</td>
580     *    <td>as above, plus<br>
581     *        {@link MediaFormat#MIMETYPE_VIDEO_VP9 VP9}</td>
582     *   </tr>
583     *  </tbody>
584     * </table>
585     *
586     * @param format The media format for the track.  This must not be an empty
587     *               MediaFormat.
588     * @return The track index for this newly added track, and it should be used
589     * in the {@link #writeSampleData}.
590     * @throws IllegalArgumentException if format is invalid.
591     * @throws IllegalStateException if muxer is in the wrong state.
592     */
593    public int addTrack(@NonNull MediaFormat format) {
594        if (format == null) {
595            throw new IllegalArgumentException("format must not be null.");
596        }
597        if (mState != MUXER_STATE_INITIALIZED) {
598            throw new IllegalStateException("Muxer is not initialized.");
599        }
600        if (mNativeObject == 0) {
601            throw new IllegalStateException("Muxer has been released!");
602        }
603        int trackIndex = -1;
604        // Convert the MediaFormat into key-value pairs and send to the native.
605        Map<String, Object> formatMap = format.getMap();
606
607        String[] keys = null;
608        Object[] values = null;
609        int mapSize = formatMap.size();
610        if (mapSize > 0) {
611            keys = new String[mapSize];
612            values = new Object[mapSize];
613            int i = 0;
614            for (Map.Entry<String, Object> entry : formatMap.entrySet()) {
615                keys[i] = entry.getKey();
616                values[i] = entry.getValue();
617                ++i;
618            }
619            trackIndex = nativeAddTrack(mNativeObject, keys, values);
620        } else {
621            throw new IllegalArgumentException("format must not be empty.");
622        }
623
624        // Track index number is expected to incremented as addTrack succeed.
625        // However, if format is invalid, it will get a negative trackIndex.
626        if (mLastTrackIndex >= trackIndex) {
627            throw new IllegalArgumentException("Invalid format.");
628        }
629        mLastTrackIndex = trackIndex;
630        return trackIndex;
631    }
632
633    /**
634     * Writes an encoded sample into the muxer.
635     * <p>The application needs to make sure that the samples are written into
636     * the right tracks. Also, it needs to make sure the samples for each track
637     * are written in chronological order (e.g. in the order they are provided
638     * by the encoder.)</p>
639     * @param byteBuf The encoded sample.
640     * @param trackIndex The track index for this sample.
641     * @param bufferInfo The buffer information related to this sample.
642     * @throws IllegalArgumentException if trackIndex, byteBuf or bufferInfo is  invalid.
643     * @throws IllegalStateException if muxer is in wrong state.
644     * MediaMuxer uses the flags provided in {@link MediaCodec.BufferInfo},
645     * to signal sync frames.
646     */
647    public void writeSampleData(int trackIndex, @NonNull ByteBuffer byteBuf,
648            @NonNull BufferInfo bufferInfo) {
649        if (trackIndex < 0 || trackIndex > mLastTrackIndex) {
650            throw new IllegalArgumentException("trackIndex is invalid");
651        }
652
653        if (byteBuf == null) {
654            throw new IllegalArgumentException("byteBuffer must not be null");
655        }
656
657        if (bufferInfo == null) {
658            throw new IllegalArgumentException("bufferInfo must not be null");
659        }
660        if (bufferInfo.size < 0 || bufferInfo.offset < 0
661                || (bufferInfo.offset + bufferInfo.size) > byteBuf.capacity()
662                || bufferInfo.presentationTimeUs < 0) {
663            throw new IllegalArgumentException("bufferInfo must specify a" +
664                    " valid buffer offset, size and presentation time");
665        }
666
667        if (mNativeObject == 0) {
668            throw new IllegalStateException("Muxer has been released!");
669        }
670
671        if (mState != MUXER_STATE_STARTED) {
672            throw new IllegalStateException("Can't write, muxer is not started");
673        }
674
675        nativeWriteSampleData(mNativeObject, trackIndex, byteBuf,
676                bufferInfo.offset, bufferInfo.size,
677                bufferInfo.presentationTimeUs, bufferInfo.flags);
678    }
679
680    /**
681     * Make sure you call this when you're done to free up any resources
682     * instead of relying on the garbage collector to do this for you at
683     * some point in the future.
684     */
685    public void release() {
686        if (mState == MUXER_STATE_STARTED) {
687            stop();
688        }
689        if (mNativeObject != 0) {
690            nativeRelease(mNativeObject);
691            mNativeObject = 0;
692            mCloseGuard.close();
693        }
694        mState = MUXER_STATE_UNINITIALIZED;
695    }
696}
697