1 /*
2  * Copyright (C) 2012 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 
17 package android.media;
18 
19 import android.annotation.IntDef;
20 import android.annotation.NonNull;
21 import android.annotation.Nullable;
22 import android.content.ContentResolver;
23 import android.content.Context;
24 import android.content.res.AssetFileDescriptor;
25 import android.media.MediaCodec;
26 import android.media.MediaFormat;
27 import android.media.MediaHTTPService;
28 import android.net.Uri;
29 import android.os.Bundle;
30 import android.os.IBinder;
31 import android.os.PersistableBundle;
32 
33 import com.android.internal.util.Preconditions;
34 
35 import java.io.FileDescriptor;
36 import java.io.IOException;
37 import java.lang.annotation.Retention;
38 import java.lang.annotation.RetentionPolicy;
39 import java.nio.ByteBuffer;
40 import java.nio.ByteOrder;
41 import java.util.Collections;
42 import java.util.HashMap;
43 import java.util.List;
44 import java.util.Map;
45 import java.util.UUID;
46 
47 /**
48  * MediaExtractor facilitates extraction of demuxed, typically encoded,  media data
49  * from a data source.
50  * <p>It is generally used like this:
51  * <pre>
52  * MediaExtractor extractor = new MediaExtractor();
53  * extractor.setDataSource(...);
54  * int numTracks = extractor.getTrackCount();
55  * for (int i = 0; i &lt; numTracks; ++i) {
56  *   MediaFormat format = extractor.getTrackFormat(i);
57  *   String mime = format.getString(MediaFormat.KEY_MIME);
58  *   if (weAreInterestedInThisTrack) {
59  *     extractor.selectTrack(i);
60  *   }
61  * }
62  * ByteBuffer inputBuffer = ByteBuffer.allocate(...)
63  * while (extractor.readSampleData(inputBuffer, ...) &gt;= 0) {
64  *   int trackIndex = extractor.getSampleTrackIndex();
65  *   long presentationTimeUs = extractor.getSampleTime();
66  *   ...
67  *   extractor.advance();
68  * }
69  *
70  * extractor.release();
71  * extractor = null;
72  * </pre>
73  *
74  * <p>This class requires the {@link android.Manifest.permission#INTERNET} permission
75  * when used with network-based content.
76  */
77 final public class MediaExtractor {
MediaExtractor()78     public MediaExtractor() {
79         native_setup();
80     }
81 
82     /**
83      * Sets the data source (MediaDataSource) to use.
84      *
85      * @param dataSource the MediaDataSource for the media you want to extract from
86      *
87      * @throws IllegalArgumentException if dataSource is invalid.
88      */
setDataSource(@onNull MediaDataSource dataSource)89     public native final void setDataSource(@NonNull MediaDataSource dataSource)
90         throws IOException;
91 
92     /**
93      * Sets the data source as a content Uri.
94      *
95      * @param context the Context to use when resolving the Uri
96      * @param uri the Content URI of the data you want to extract from.
97      *
98      * <p>When <code>uri</code> refers to a network file the
99      * {@link android.Manifest.permission#INTERNET} permission is required.
100      *
101      * @param headers the headers to be sent together with the request for the data.
102      *        This can be {@code null} if no specific headers are to be sent with the
103      *        request.
104      */
setDataSource( @onNull Context context, @NonNull Uri uri, @Nullable Map<String, String> headers)105     public final void setDataSource(
106             @NonNull Context context, @NonNull Uri uri, @Nullable Map<String, String> headers)
107         throws IOException {
108         String scheme = uri.getScheme();
109         if (scheme == null || scheme.equals("file")) {
110             setDataSource(uri.getPath());
111             return;
112         }
113 
114         AssetFileDescriptor fd = null;
115         try {
116             ContentResolver resolver = context.getContentResolver();
117             fd = resolver.openAssetFileDescriptor(uri, "r");
118             if (fd == null) {
119                 return;
120             }
121             // Note: using getDeclaredLength so that our behavior is the same
122             // as previous versions when the content provider is returning
123             // a full file.
124             if (fd.getDeclaredLength() < 0) {
125                 setDataSource(fd.getFileDescriptor());
126             } else {
127                 setDataSource(
128                         fd.getFileDescriptor(),
129                         fd.getStartOffset(),
130                         fd.getDeclaredLength());
131             }
132             return;
133         } catch (SecurityException ex) {
134         } catch (IOException ex) {
135         } finally {
136             if (fd != null) {
137                 fd.close();
138             }
139         }
140 
141         setDataSource(uri.toString(), headers);
142     }
143 
144     /**
145      * Sets the data source (file-path or http URL) to use.
146      *
147      * @param path the path of the file, or the http URL
148      *
149      * <p>When <code>path</code> refers to a network file the
150      * {@link android.Manifest.permission#INTERNET} permission is required.
151      *
152      * @param headers the headers associated with the http request for the stream you want to play.
153      *        This can be {@code null} if no specific headers are to be sent with the
154      *        request.
155      */
setDataSource(@onNull String path, @Nullable Map<String, String> headers)156     public final void setDataSource(@NonNull String path, @Nullable Map<String, String> headers)
157         throws IOException {
158         String[] keys = null;
159         String[] values = null;
160 
161         if (headers != null) {
162             keys = new String[headers.size()];
163             values = new String[headers.size()];
164 
165             int i = 0;
166             for (Map.Entry<String, String> entry: headers.entrySet()) {
167                 keys[i] = entry.getKey();
168                 values[i] = entry.getValue();
169                 ++i;
170             }
171         }
172 
173         nativeSetDataSource(
174                 MediaHTTPService.createHttpServiceBinderIfNecessary(path),
175                 path,
176                 keys,
177                 values);
178     }
179 
nativeSetDataSource( @onNull IBinder httpServiceBinder, @NonNull String path, @Nullable String[] keys, @Nullable String[] values)180     private native final void nativeSetDataSource(
181             @NonNull IBinder httpServiceBinder,
182             @NonNull String path,
183             @Nullable String[] keys,
184             @Nullable String[] values) throws IOException;
185 
186     /**
187      * Sets the data source (file-path or http URL) to use.
188      *
189      * @param path the path of the file, or the http URL of the stream
190      *
191      * <p>When <code>path</code> refers to a local file, the file may actually be opened by a
192      * process other than the calling application.  This implies that the pathname
193      * should be an absolute path (as any other process runs with unspecified current working
194      * directory), and that the pathname should reference a world-readable file.
195      * As an alternative, the application could first open the file for reading,
196      * and then use the file descriptor form {@link #setDataSource(FileDescriptor)}.
197      *
198      * <p>When <code>path</code> refers to a network file the
199      * {@link android.Manifest.permission#INTERNET} permission is required.
200      */
setDataSource(@onNull String path)201     public final void setDataSource(@NonNull String path) throws IOException {
202         nativeSetDataSource(
203                 MediaHTTPService.createHttpServiceBinderIfNecessary(path),
204                 path,
205                 null,
206                 null);
207     }
208 
209     /**
210      * Sets the data source (AssetFileDescriptor) to use. It is the caller's
211      * responsibility to close the file descriptor. It is safe to do so as soon
212      * as this call returns.
213      *
214      * @param afd the AssetFileDescriptor for the file you want to extract from.
215      */
setDataSource(@onNull AssetFileDescriptor afd)216     public final void setDataSource(@NonNull AssetFileDescriptor afd)
217             throws IOException, IllegalArgumentException, IllegalStateException {
218         Preconditions.checkNotNull(afd);
219         // Note: using getDeclaredLength so that our behavior is the same
220         // as previous versions when the content provider is returning
221         // a full file.
222         if (afd.getDeclaredLength() < 0) {
223             setDataSource(afd.getFileDescriptor());
224         } else {
225             setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getDeclaredLength());
226         }
227     }
228 
229     /**
230      * Sets the data source (FileDescriptor) to use. It is the caller's responsibility
231      * to close the file descriptor. It is safe to do so as soon as this call returns.
232      *
233      * @param fd the FileDescriptor for the file you want to extract from.
234      */
setDataSource(@onNull FileDescriptor fd)235     public final void setDataSource(@NonNull FileDescriptor fd) throws IOException {
236         setDataSource(fd, 0, 0x7ffffffffffffffL);
237     }
238 
239     /**
240      * Sets the data source (FileDescriptor) to use.  The FileDescriptor must be
241      * seekable (N.B. a LocalSocket is not seekable). It is the caller's responsibility
242      * to close the file descriptor. It is safe to do so as soon as this call returns.
243      *
244      * @param fd the FileDescriptor for the file you want to extract from.
245      * @param offset the offset into the file where the data to be extracted starts, in bytes
246      * @param length the length in bytes of the data to be extracted
247      */
setDataSource( @onNull FileDescriptor fd, long offset, long length)248     public native final void setDataSource(
249             @NonNull FileDescriptor fd, long offset, long length) throws IOException;
250 
251     /**
252      * Sets the MediaCas instance to use. This should be called after a
253      * successful setDataSource() if at least one track reports mime type
254      * of {@link android.media.MediaFormat#MIMETYPE_AUDIO_SCRAMBLED}
255      * or {@link android.media.MediaFormat#MIMETYPE_VIDEO_SCRAMBLED}.
256      * Stream parsing will not proceed until a valid MediaCas object
257      * is provided.
258      *
259      * @param mediaCas the MediaCas object to use.
260      */
setMediaCas(@onNull MediaCas mediaCas)261     public final void setMediaCas(@NonNull MediaCas mediaCas) {
262         mMediaCas = mediaCas;
263         nativeSetMediaCas(mediaCas.getBinder());
264     }
265 
nativeSetMediaCas(@onNull IBinder casBinder)266     private native final void nativeSetMediaCas(@NonNull IBinder casBinder);
267 
268     /**
269      * Describes the conditional access system used to scramble a track.
270      */
271     public static final class CasInfo {
272         private final int mSystemId;
273         private final MediaCas.Session mSession;
274 
CasInfo(int systemId, @Nullable MediaCas.Session session)275         CasInfo(int systemId, @Nullable MediaCas.Session session) {
276             mSystemId = systemId;
277             mSession = session;
278         }
279 
280         /**
281          * Retrieves the system id of the conditional access system.
282          *
283          * @return CA system id of the CAS used to scramble the track.
284          */
getSystemId()285         public int getSystemId() {
286             return mSystemId;
287         }
288 
289         /**
290          * Retrieves the {@link MediaCas.Session} associated with a track. The
291          * session is needed to initialize a descrambler in order to decode the
292          * scrambled track.
293          * <p>
294          * @see MediaDescrambler#setMediaCasSession
295          * <p>
296          * @return a {@link MediaCas.Session} object associated with a track.
297          */
getSession()298         public MediaCas.Session getSession() {
299             return mSession;
300         }
301     }
302 
303     /**
304      * Retrieves the information about the conditional access system used to scramble
305      * a track.
306      *
307      * @param index of the track.
308      * @return an {@link CasInfo} object describing the conditional access system.
309      */
getCasInfo(int index)310     public CasInfo getCasInfo(int index) {
311         Map<String, Object> formatMap = getTrackFormatNative(index);
312         if (formatMap.containsKey(MediaFormat.KEY_CA_SYSTEM_ID)) {
313             int systemId = ((Integer)formatMap.get(MediaFormat.KEY_CA_SYSTEM_ID)).intValue();
314             MediaCas.Session session = null;
315             if (mMediaCas != null && formatMap.containsKey(MediaFormat.KEY_CA_SESSION_ID)) {
316                 ByteBuffer buf = (ByteBuffer) formatMap.get(MediaFormat.KEY_CA_SESSION_ID);
317                 buf.rewind();
318                 final byte[] sessionId = new byte[buf.remaining()];
319                 buf.get(sessionId);
320                 session = mMediaCas.createFromSessionId(sessionId);
321             }
322             return new CasInfo(systemId, session);
323         }
324         return null;
325     }
326 
327     @Override
finalize()328     protected void finalize() {
329         native_finalize();
330     }
331 
332     /**
333      * Make sure you call this when you're done to free up any resources
334      * instead of relying on the garbage collector to do this for you at
335      * some point in the future.
336      */
release()337     public native final void release();
338 
339     /**
340      * Count the number of tracks found in the data source.
341      */
getTrackCount()342     public native final int getTrackCount();
343 
344     /**
345      * Extract DRM initialization data if it exists
346      *
347      * @return DRM initialization data in the content, or {@code null}
348      * if no recognizable DRM format is found;
349      * @see DrmInitData
350      */
getDrmInitData()351     public DrmInitData getDrmInitData() {
352         Map<String, Object> formatMap = getFileFormatNative();
353         if (formatMap == null) {
354             return null;
355         }
356         if (formatMap.containsKey("pssh")) {
357             Map<UUID, byte[]> psshMap = getPsshInfo();
358             final Map<UUID, DrmInitData.SchemeInitData> initDataMap =
359                 new HashMap<UUID, DrmInitData.SchemeInitData>();
360             for (Map.Entry<UUID, byte[]> e: psshMap.entrySet()) {
361                 UUID uuid = e.getKey();
362                 byte[] data = e.getValue();
363                 initDataMap.put(uuid, new DrmInitData.SchemeInitData("cenc", data));
364             }
365             return new DrmInitData() {
366                 public SchemeInitData get(UUID schemeUuid) {
367                     return initDataMap.get(schemeUuid);
368                 }
369             };
370         } else {
371             int numTracks = getTrackCount();
372             for (int i = 0; i < numTracks; ++i) {
373                 Map<String, Object> trackFormatMap = getTrackFormatNative(i);
374                 if (!trackFormatMap.containsKey("crypto-key")) {
375                     continue;
376                 }
377                 ByteBuffer buf = (ByteBuffer) trackFormatMap.get("crypto-key");
378                 buf.rewind();
379                 final byte[] data = new byte[buf.remaining()];
380                 buf.get(data);
381                 return new DrmInitData() {
382                     public SchemeInitData get(UUID schemeUuid) {
383                         return new DrmInitData.SchemeInitData("webm", data);
384                     }
385                 };
386             }
387         }
388         return null;
389     }
390 
391     /**
392      * Get the PSSH info if present.
393      * @return a map of uuid-to-bytes, with the uuid specifying
394      * the crypto scheme, and the bytes being the data specific to that scheme.
395      * This can be {@code null} if the source does not contain PSSH info.
396      */
397     @Nullable
398     public Map<UUID, byte[]> getPsshInfo() {
399         Map<UUID, byte[]> psshMap = null;
400         Map<String, Object> formatMap = getFileFormatNative();
401         if (formatMap != null && formatMap.containsKey("pssh")) {
402             ByteBuffer rawpssh = (ByteBuffer) formatMap.get("pssh");
403             rawpssh.order(ByteOrder.nativeOrder());
404             rawpssh.rewind();
405             formatMap.remove("pssh");
406             // parse the flat pssh bytebuffer into something more manageable
407             psshMap = new HashMap<UUID, byte[]>();
408             while (rawpssh.remaining() > 0) {
409                 rawpssh.order(ByteOrder.BIG_ENDIAN);
410                 long msb = rawpssh.getLong();
411                 long lsb = rawpssh.getLong();
412                 UUID uuid = new UUID(msb, lsb);
413                 rawpssh.order(ByteOrder.nativeOrder());
414                 int datalen = rawpssh.getInt();
415                 byte [] psshdata = new byte[datalen];
416                 rawpssh.get(psshdata);
417                 psshMap.put(uuid, psshdata);
418             }
419         }
420         return psshMap;
421     }
422 
423     @NonNull
424     private native Map<String, Object> getFileFormatNative();
425 
426     /**
427      * Get the track format at the specified index.
428      *
429      * More detail on the representation can be found at {@link android.media.MediaCodec}
430      * <p>
431      * The following table summarizes support for format keys across android releases:
432      *
433      * <table style="width: 0%">
434      *  <thead>
435      *   <tr>
436      *    <th rowspan=2>OS Version(s)</th>
437      *    <td colspan=3>{@code MediaFormat} keys used for</th>
438      *   </tr><tr>
439      *    <th>All Tracks</th>
440      *    <th>Audio Tracks</th>
441      *    <th>Video Tracks</th>
442      *   </tr>
443      *  </thead>
444      *  <tbody>
445      *   <tr>
446      *    <td>{@link android.os.Build.VERSION_CODES#JELLY_BEAN}</td>
447      *    <td rowspan=8>{@link MediaFormat#KEY_MIME},<br>
448      *        {@link MediaFormat#KEY_DURATION},<br>
449      *        {@link MediaFormat#KEY_MAX_INPUT_SIZE}</td>
450      *    <td rowspan=5>{@link MediaFormat#KEY_SAMPLE_RATE},<br>
451      *        {@link MediaFormat#KEY_CHANNEL_COUNT},<br>
452      *        {@link MediaFormat#KEY_CHANNEL_MASK},<br>
453      *        gapless playback information<sup>.mp3, .mp4</sup>,<br>
454      *        {@link MediaFormat#KEY_IS_ADTS}<sup>AAC if streaming</sup>,<br>
455      *        codec-specific data<sup>AAC, Vorbis</sup></td>
456      *    <td rowspan=2>{@link MediaFormat#KEY_WIDTH},<br>
457      *        {@link MediaFormat#KEY_HEIGHT},<br>
458      *        codec-specific data<sup>AVC, MPEG4</sup></td>
459      *   </tr><tr>
460      *    <td>{@link android.os.Build.VERSION_CODES#JELLY_BEAN_MR1}</td>
461      *   </tr><tr>
462      *    <td>{@link android.os.Build.VERSION_CODES#JELLY_BEAN_MR2}</td>
463      *    <td rowspan=3>as above, plus<br>
464      *        Pixel aspect ratio information<sup>AVC, *</sup></td>
465      *   </tr><tr>
466      *    <td>{@link android.os.Build.VERSION_CODES#KITKAT}</td>
467      *   </tr><tr>
468      *    <td>{@link android.os.Build.VERSION_CODES#KITKAT_WATCH}</td>
469      *   </tr><tr>
470      *    <td>{@link android.os.Build.VERSION_CODES#LOLLIPOP}</td>
471      *    <td rowspan=2>as above, plus<br>
472      *        {@link MediaFormat#KEY_BIT_RATE}<sup>AAC</sup>,<br>
473      *        codec-specific data<sup>Opus</sup></td>
474      *    <td rowspan=2>as above, plus<br>
475      *        {@link MediaFormat#KEY_ROTATION}<sup>.mp4</sup>,<br>
476      *        {@link MediaFormat#KEY_BIT_RATE}<sup>MPEG4</sup>,<br>
477      *        codec-specific data<sup>HEVC</sup></td>
478      *   </tr><tr>
479      *    <td>{@link android.os.Build.VERSION_CODES#LOLLIPOP_MR1}</td>
480      *   </tr><tr>
481      *    <td>{@link android.os.Build.VERSION_CODES#M}</td>
482      *    <td>as above, plus<br>
483      *        gapless playback information<sup>Opus</sup></td>
484      *    <td>as above, plus<br>
485      *        {@link MediaFormat#KEY_FRAME_RATE} (integer)</td>
486      *   </tr><tr>
487      *    <td>{@link android.os.Build.VERSION_CODES#N}</td>
488      *    <td>as above, plus<br>
489      *        {@link MediaFormat#KEY_TRACK_ID},<br>
490      *        <!-- {link MediaFormat#KEY_MAX_BIT_RATE}<sup>#, .mp4</sup>,<br> -->
491      *        {@link MediaFormat#KEY_BIT_RATE}<sup>#, .mp4</sup></td>
492      *    <td>as above, plus<br>
493      *        {@link MediaFormat#KEY_PCM_ENCODING},<br>
494      *        {@link MediaFormat#KEY_PROFILE}<sup>AAC</sup></td>
495      *    <td>as above, plus<br>
496      *        {@link MediaFormat#KEY_HDR_STATIC_INFO}<sup>#, .webm</sup>,<br>
497      *        {@link MediaFormat#KEY_COLOR_STANDARD}<sup>#</sup>,<br>
498      *        {@link MediaFormat#KEY_COLOR_TRANSFER}<sup>#</sup>,<br>
499      *        {@link MediaFormat#KEY_COLOR_RANGE}<sup>#</sup>,<br>
500      *        {@link MediaFormat#KEY_PROFILE}<sup>MPEG2, H.263, MPEG4, AVC, HEVC, VP9</sup>,<br>
501      *        {@link MediaFormat#KEY_LEVEL}<sup>H.263, MPEG4, AVC, HEVC, VP9</sup>,<br>
502      *        codec-specific data<sup>VP9</sup></td>
503      *   </tr>
504      *   <tr>
505      *    <td colspan=4>
506      *     <p class=note><strong>Notes:</strong><br>
507      *      #: container-specified value only.<br>
508      *      .mp4, .webm&hellip;: for listed containers<br>
509      *      MPEG4, AAC&hellip;: for listed codecs
510      *    </td>
511      *   </tr><tr>
512      *    <td colspan=4>
513      *     <p class=note>Note that that level information contained in the container many times
514      *     does not match the level of the actual bitstream. You may want to clear the level using
515      *     {@code MediaFormat.setString(KEY_LEVEL, null)} before using the track format to find a
516      *     decoder that can play back a particular track.
517      *    </td>
518      *   </tr><tr>
519      *    <td colspan=4>
520      *     <p class=note><strong>*Pixel (sample) aspect ratio</strong> is returned in the following
521      *     keys. The display width can be calculated for example as:
522      *     <p align=center>
523      *     display-width = display-height * crop-width / crop-height * sar-width / sar-height
524      *    </td>
525      *   </tr><tr>
526      *    <th>Format Key</th><th>Value Type</th><th colspan=2>Description</th>
527      *   </tr><tr>
528      *    <td>{@code "sar-width"}</td><td>Integer</td><td colspan=2>Pixel aspect ratio width</td>
529      *   </tr><tr>
530      *    <td>{@code "sar-height"}</td><td>Integer</td><td colspan=2>Pixel aspect ratio height</td>
531      *   </tr>
532      *  </tbody>
533      * </table>
534      *
535      */
536     @NonNull
537     public MediaFormat getTrackFormat(int index) {
538         return new MediaFormat(getTrackFormatNative(index));
539     }
540 
541     @NonNull
542     private native Map<String, Object> getTrackFormatNative(int index);
543 
544     /**
545      * Subsequent calls to {@link #readSampleData}, {@link #getSampleTrackIndex} and
546      * {@link #getSampleTime} only retrieve information for the subset of tracks
547      * selected.
548      * Selecting the same track multiple times has no effect, the track is
549      * only selected once.
550      */
551     public native void selectTrack(int index);
552 
553     /**
554      * Subsequent calls to {@link #readSampleData}, {@link #getSampleTrackIndex} and
555      * {@link #getSampleTime} only retrieve information for the subset of tracks
556      * selected.
557      */
558     public native void unselectTrack(int index);
559 
560     /**
561      * If possible, seek to a sync sample at or before the specified time
562      */
563     public static final int SEEK_TO_PREVIOUS_SYNC       = 0;
564     /**
565      * If possible, seek to a sync sample at or after the specified time
566      */
567     public static final int SEEK_TO_NEXT_SYNC           = 1;
568     /**
569      * If possible, seek to the sync sample closest to the specified time
570      */
571     public static final int SEEK_TO_CLOSEST_SYNC        = 2;
572 
573     /** @hide */
574     @IntDef({
575         SEEK_TO_PREVIOUS_SYNC,
576         SEEK_TO_NEXT_SYNC,
577         SEEK_TO_CLOSEST_SYNC,
578     })
579     @Retention(RetentionPolicy.SOURCE)
580     public @interface SeekMode {}
581 
582     /**
583      * All selected tracks seek near the requested time according to the
584      * specified mode.
585      */
586     public native void seekTo(long timeUs, @SeekMode int mode);
587 
588     /**
589      * Advance to the next sample. Returns false if no more sample data
590      * is available (end of stream).
591      *
592      * When extracting a local file, the behaviors of {@link #advance} and
593      * {@link #readSampleData} are undefined in presence of concurrent
594      * writes to the same local file; more specifically, end of stream
595      * could be signalled earlier than expected.
596      */
597     public native boolean advance();
598 
599     /**
600      * Retrieve the current encoded sample and store it in the byte buffer
601      * starting at the given offset.
602      * <p>
603      * <b>Note:</b>As of API 21, on success the position and limit of
604      * {@code byteBuf} is updated to point to the data just read.
605      * @param byteBuf the destination byte buffer
606      * @return the sample size (or -1 if no more samples are available).
607      */
608     public native int readSampleData(@NonNull ByteBuffer byteBuf, int offset);
609 
610     /**
611      * Returns the track index the current sample originates from (or -1
612      * if no more samples are available)
613      */
614     public native int getSampleTrackIndex();
615 
616     /**
617      * Returns the current sample's presentation time in microseconds.
618      * or -1 if no more samples are available.
619      */
620     public native long getSampleTime();
621 
622     // Keep these in sync with their equivalents in NuMediaExtractor.h
623     /**
624      * The sample is a sync sample (or in {@link MediaCodec}'s terminology
625      * it is a key frame.)
626      *
627      * @see MediaCodec#BUFFER_FLAG_KEY_FRAME
628      */
629     public static final int SAMPLE_FLAG_SYNC      = 1;
630 
631     /**
632      * The sample is (at least partially) encrypted, see also the documentation
633      * for {@link android.media.MediaCodec#queueSecureInputBuffer}
634      */
635     public static final int SAMPLE_FLAG_ENCRYPTED = 2;
636 
637     /**
638      * This indicates that the buffer only contains part of a frame,
639      * and the decoder should batch the data until a buffer without
640      * this flag appears before decoding the frame.
641      *
642      * @see MediaCodec#BUFFER_FLAG_PARTIAL_FRAME
643      */
644     public static final int SAMPLE_FLAG_PARTIAL_FRAME = 4;
645 
646     /** @hide */
647     @IntDef(
648         flag = true,
649         value = {
650             SAMPLE_FLAG_SYNC,
651             SAMPLE_FLAG_ENCRYPTED,
652             SAMPLE_FLAG_PARTIAL_FRAME,
653     })
654     @Retention(RetentionPolicy.SOURCE)
655     public @interface SampleFlag {}
656 
657     /**
658      * Returns the current sample's flags.
659      */
660     @SampleFlag
661     public native int getSampleFlags();
662 
663     /**
664      * If the sample flags indicate that the current sample is at least
665      * partially encrypted, this call returns relevant information about
666      * the structure of the sample data required for decryption.
667      * @param info The android.media.MediaCodec.CryptoInfo structure
668      *             to be filled in.
669      * @return true iff the sample flags contain {@link #SAMPLE_FLAG_ENCRYPTED}
670      */
671     public native boolean getSampleCryptoInfo(@NonNull MediaCodec.CryptoInfo info);
672 
673     /**
674      * Returns an estimate of how much data is presently cached in memory
675      * expressed in microseconds. Returns -1 if that information is unavailable
676      * or not applicable (no cache).
677      */
678     public native long getCachedDuration();
679 
680     /**
681      * Returns true iff we are caching data and the cache has reached the
682      * end of the data stream (for now, a future seek may of course restart
683      * the fetching of data).
684      * This API only returns a meaningful result if {@link #getCachedDuration}
685      * indicates the presence of a cache, i.e. does NOT return -1.
686      */
687     public native boolean hasCacheReachedEndOfStream();
688 
689     /**
690      *  Return Metrics data about the current media container.
691      *
692      * @return a {@link PersistableBundle} containing the set of attributes and values
693      * available for the media container being handled by this instance
694      * of MediaExtractor.
695      * The attributes are descibed in {@link MetricsConstants}.
696      *
697      *  Additional vendor-specific fields may also be present in
698      *  the return value.
699      */
700 
701     public PersistableBundle getMetrics() {
702         PersistableBundle bundle = native_getMetrics();
703         return bundle;
704     }
705 
706     private native PersistableBundle native_getMetrics();
707 
708     private static native final void native_init();
709     private native final void native_setup();
710     private native final void native_finalize();
711 
712     static {
713         System.loadLibrary("media_jni");
714         native_init();
715     }
716 
717     private MediaCas mMediaCas;
718 
719     private long mNativeContext;
720 
721     public final static class MetricsConstants
722     {
723         private MetricsConstants() {}
724 
725         /**
726          * Key to extract the container format
727          * from the {@link MediaExtractor#getMetrics} return value.
728          * The value is a String.
729          */
730         public static final String FORMAT = "android.media.mediaextractor.fmt";
731 
732         /**
733          * Key to extract the container MIME type
734          * from the {@link MediaExtractor#getMetrics} return value.
735          * The value is a String.
736          */
737         public static final String MIME_TYPE = "android.media.mediaextractor.mime";
738 
739         /**
740          * Key to extract the number of tracks in the container
741          * from the {@link MediaExtractor#getMetrics} return value.
742          * The value is an integer.
743          */
744         public static final String TRACKS = "android.media.mediaextractor.ntrk";
745 
746     }
747 
748 }
749