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1 /*
2  * Copyright (C) 2011 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 //#define LOG_NDEBUG 0
18 #define LOG_TAG "MPEG2PSExtractor"
19 #include <utils/Log.h>
20 
21 #include "include/MPEG2PSExtractor.h"
22 
23 #include "AnotherPacketSource.h"
24 #include "ESQueue.h"
25 
26 #include <media/stagefright/foundation/ABitReader.h>
27 #include <media/stagefright/foundation/ABuffer.h>
28 #include <media/stagefright/foundation/ADebug.h>
29 #include <media/stagefright/foundation/AMessage.h>
30 #include <media/stagefright/foundation/hexdump.h>
31 #include <media/stagefright/DataSource.h>
32 #include <media/stagefright/MediaDefs.h>
33 #include <media/stagefright/MediaErrors.h>
34 #include <media/stagefright/MediaSource.h>
35 #include <media/stagefright/MetaData.h>
36 #include <media/stagefright/Utils.h>
37 #include <utils/String8.h>
38 
39 #include <inttypes.h>
40 
41 namespace android {
42 
43 struct MPEG2PSExtractor::Track : public MediaSource {
44     Track(MPEG2PSExtractor *extractor,
45           unsigned stream_id, unsigned stream_type);
46 
47     virtual status_t start(MetaData *params);
48     virtual status_t stop();
49     virtual sp<MetaData> getFormat();
50 
51     virtual status_t read(
52             MediaBuffer **buffer, const ReadOptions *options);
53 
54 protected:
55     virtual ~Track();
56 
57 private:
58     friend struct MPEG2PSExtractor;
59 
60     MPEG2PSExtractor *mExtractor;
61 
62     unsigned mStreamID;
63     unsigned mStreamType;
64     ElementaryStreamQueue *mQueue;
65     sp<AnotherPacketSource> mSource;
66 
67     status_t appendPESData(
68             unsigned PTS_DTS_flags,
69             uint64_t PTS, uint64_t DTS,
70             const uint8_t *data, size_t size);
71 
72     DISALLOW_EVIL_CONSTRUCTORS(Track);
73 };
74 
75 struct MPEG2PSExtractor::WrappedTrack : public MediaSource {
76     WrappedTrack(const sp<MPEG2PSExtractor> &extractor, const sp<Track> &track);
77 
78     virtual status_t start(MetaData *params);
79     virtual status_t stop();
80     virtual sp<MetaData> getFormat();
81 
82     virtual status_t read(
83             MediaBuffer **buffer, const ReadOptions *options);
84 
85 protected:
86     virtual ~WrappedTrack();
87 
88 private:
89     sp<MPEG2PSExtractor> mExtractor;
90     sp<MPEG2PSExtractor::Track> mTrack;
91 
92     DISALLOW_EVIL_CONSTRUCTORS(WrappedTrack);
93 };
94 
95 ////////////////////////////////////////////////////////////////////////////////
96 
MPEG2PSExtractor(const sp<DataSource> & source)97 MPEG2PSExtractor::MPEG2PSExtractor(const sp<DataSource> &source)
98     : mDataSource(source),
99       mOffset(0),
100       mFinalResult(OK),
101       mBuffer(new ABuffer(0)),
102       mScanning(true),
103       mProgramStreamMapValid(false) {
104     for (size_t i = 0; i < 500; ++i) {
105         if (feedMore() != OK) {
106             break;
107         }
108     }
109 
110     // Remove all tracks that were unable to determine their format.
111     for (size_t i = mTracks.size(); i > 0;) {
112         i--;
113         if (mTracks.valueAt(i)->getFormat() == NULL) {
114             mTracks.removeItemsAt(i);
115         }
116     }
117 
118     mScanning = false;
119 }
120 
~MPEG2PSExtractor()121 MPEG2PSExtractor::~MPEG2PSExtractor() {
122 }
123 
countTracks()124 size_t MPEG2PSExtractor::countTracks() {
125     return mTracks.size();
126 }
127 
getTrack(size_t index)128 sp<IMediaSource> MPEG2PSExtractor::getTrack(size_t index) {
129     if (index >= mTracks.size()) {
130         return NULL;
131     }
132 
133     return new WrappedTrack(this, mTracks.valueAt(index));
134 }
135 
getTrackMetaData(size_t index,uint32_t)136 sp<MetaData> MPEG2PSExtractor::getTrackMetaData(
137         size_t index, uint32_t /* flags */) {
138     if (index >= mTracks.size()) {
139         return NULL;
140     }
141 
142     return mTracks.valueAt(index)->getFormat();
143 }
144 
getMetaData()145 sp<MetaData> MPEG2PSExtractor::getMetaData() {
146     sp<MetaData> meta = new MetaData;
147     meta->setCString(kKeyMIMEType, MEDIA_MIMETYPE_CONTAINER_MPEG2PS);
148 
149     return meta;
150 }
151 
flags() const152 uint32_t MPEG2PSExtractor::flags() const {
153     return CAN_PAUSE;
154 }
155 
feedMore()156 status_t MPEG2PSExtractor::feedMore() {
157     Mutex::Autolock autoLock(mLock);
158 
159     // How much data we're reading at a time
160     static const size_t kChunkSize = 8192;
161 
162     for (;;) {
163         status_t err = dequeueChunk();
164 
165         if (err == -EAGAIN && mFinalResult == OK) {
166             memmove(mBuffer->base(), mBuffer->data(), mBuffer->size());
167             mBuffer->setRange(0, mBuffer->size());
168 
169             if (mBuffer->size() + kChunkSize > mBuffer->capacity()) {
170                 size_t newCapacity = mBuffer->capacity() + kChunkSize;
171                 sp<ABuffer> newBuffer = new ABuffer(newCapacity);
172                 memcpy(newBuffer->data(), mBuffer->data(), mBuffer->size());
173                 newBuffer->setRange(0, mBuffer->size());
174                 mBuffer = newBuffer;
175             }
176 
177             ssize_t n = mDataSource->readAt(
178                     mOffset, mBuffer->data() + mBuffer->size(), kChunkSize);
179 
180             if (n < (ssize_t)kChunkSize) {
181                 mFinalResult = (n < 0) ? (status_t)n : ERROR_END_OF_STREAM;
182                 return mFinalResult;
183             }
184 
185             mBuffer->setRange(mBuffer->offset(), mBuffer->size() + n);
186             mOffset += n;
187         } else if (err != OK) {
188             mFinalResult = err;
189             return err;
190         } else {
191             return OK;
192         }
193     }
194 }
195 
dequeueChunk()196 status_t MPEG2PSExtractor::dequeueChunk() {
197     if (mBuffer->size() < 4) {
198         return -EAGAIN;
199     }
200 
201     if (memcmp("\x00\x00\x01", mBuffer->data(), 3)) {
202         return ERROR_MALFORMED;
203     }
204 
205     unsigned chunkType = mBuffer->data()[3];
206 
207     ssize_t res;
208 
209     switch (chunkType) {
210         case 0xba:
211         {
212             res = dequeuePack();
213             break;
214         }
215 
216         case 0xbb:
217         {
218             res = dequeueSystemHeader();
219             break;
220         }
221 
222         default:
223         {
224             res = dequeuePES();
225             break;
226         }
227     }
228 
229     if (res > 0) {
230         if (mBuffer->size() < (size_t)res) {
231             return -EAGAIN;
232         }
233 
234         mBuffer->setRange(mBuffer->offset() + res, mBuffer->size() - res);
235         res = OK;
236     }
237 
238     return res;
239 }
240 
dequeuePack()241 ssize_t MPEG2PSExtractor::dequeuePack() {
242     // 32 + 2 + 3 + 1 + 15 + 1 + 15+ 1 + 9 + 1 + 22 + 1 + 1 | +5
243 
244     if (mBuffer->size() < 14) {
245         return -EAGAIN;
246     }
247 
248     unsigned pack_stuffing_length = mBuffer->data()[13] & 7;
249 
250     return pack_stuffing_length + 14;
251 }
252 
dequeueSystemHeader()253 ssize_t MPEG2PSExtractor::dequeueSystemHeader() {
254     if (mBuffer->size() < 6) {
255         return -EAGAIN;
256     }
257 
258     unsigned header_length = U16_AT(mBuffer->data() + 4);
259 
260     return header_length + 6;
261 }
262 
dequeuePES()263 ssize_t MPEG2PSExtractor::dequeuePES() {
264     if (mBuffer->size() < 6) {
265         return -EAGAIN;
266     }
267 
268     unsigned PES_packet_length = U16_AT(mBuffer->data() + 4);
269     if (PES_packet_length == 0u) {
270         ALOGE("PES_packet_length is 0");
271         return -EAGAIN;
272     }
273 
274     size_t n = PES_packet_length + 6;
275 
276     if (mBuffer->size() < n) {
277         return -EAGAIN;
278     }
279 
280     ABitReader br(mBuffer->data(), n);
281 
282     unsigned packet_startcode_prefix = br.getBits(24);
283 
284     ALOGV("packet_startcode_prefix = 0x%08x", packet_startcode_prefix);
285 
286     if (packet_startcode_prefix != 1) {
287         ALOGV("Supposedly payload_unit_start=1 unit does not start "
288              "with startcode.");
289 
290         return ERROR_MALFORMED;
291     }
292 
293     if (packet_startcode_prefix != 0x000001u) {
294         ALOGE("Wrong PES prefix");
295         return ERROR_MALFORMED;
296     }
297 
298     unsigned stream_id = br.getBits(8);
299     ALOGV("stream_id = 0x%02x", stream_id);
300 
301     /* unsigned PES_packet_length = */br.getBits(16);
302 
303     if (stream_id == 0xbc) {
304         // program_stream_map
305 
306         if (!mScanning) {
307             return n;
308         }
309 
310         mStreamTypeByESID.clear();
311 
312         /* unsigned current_next_indicator = */br.getBits(1);
313         /* unsigned reserved = */br.getBits(2);
314         /* unsigned program_stream_map_version = */br.getBits(5);
315         /* unsigned reserved = */br.getBits(7);
316         /* unsigned marker_bit = */br.getBits(1);
317         unsigned program_stream_info_length = br.getBits(16);
318 
319         size_t offset = 0;
320         while (offset < program_stream_info_length) {
321             if (offset + 2 > program_stream_info_length) {
322                 return ERROR_MALFORMED;
323             }
324 
325             unsigned descriptor_tag = br.getBits(8);
326             unsigned descriptor_length = br.getBits(8);
327 
328             ALOGI("found descriptor tag 0x%02x of length %u",
329                  descriptor_tag, descriptor_length);
330 
331             if (offset + 2 + descriptor_length > program_stream_info_length) {
332                 return ERROR_MALFORMED;
333             }
334 
335             br.skipBits(8 * descriptor_length);
336 
337             offset += 2 + descriptor_length;
338         }
339 
340         unsigned elementary_stream_map_length = br.getBits(16);
341 
342         offset = 0;
343         while (offset < elementary_stream_map_length) {
344             if (offset + 4 > elementary_stream_map_length) {
345                 return ERROR_MALFORMED;
346             }
347 
348             unsigned stream_type = br.getBits(8);
349             unsigned elementary_stream_id = br.getBits(8);
350 
351             ALOGI("elementary stream id 0x%02x has stream type 0x%02x",
352                  elementary_stream_id, stream_type);
353 
354             mStreamTypeByESID.add(elementary_stream_id, stream_type);
355 
356             unsigned elementary_stream_info_length = br.getBits(16);
357 
358             if (offset + 4 + elementary_stream_info_length
359                     > elementary_stream_map_length) {
360                 return ERROR_MALFORMED;
361             }
362 
363             offset += 4 + elementary_stream_info_length;
364         }
365 
366         /* unsigned CRC32 = */br.getBits(32);
367 
368         mProgramStreamMapValid = true;
369     } else if (stream_id != 0xbe  // padding_stream
370             && stream_id != 0xbf  // private_stream_2
371             && stream_id != 0xf0  // ECM
372             && stream_id != 0xf1  // EMM
373             && stream_id != 0xff  // program_stream_directory
374             && stream_id != 0xf2  // DSMCC
375             && stream_id != 0xf8) {  // H.222.1 type E
376         /* unsigned PES_marker_bits = */br.getBits(2);  // should be 0x2(hex)
377         /* unsigned PES_scrambling_control = */br.getBits(2);
378         /* unsigned PES_priority = */br.getBits(1);
379         /* unsigned data_alignment_indicator = */br.getBits(1);
380         /* unsigned copyright = */br.getBits(1);
381         /* unsigned original_or_copy = */br.getBits(1);
382 
383         unsigned PTS_DTS_flags = br.getBits(2);
384         ALOGV("PTS_DTS_flags = %u", PTS_DTS_flags);
385 
386         unsigned ESCR_flag = br.getBits(1);
387         ALOGV("ESCR_flag = %u", ESCR_flag);
388 
389         unsigned ES_rate_flag = br.getBits(1);
390         ALOGV("ES_rate_flag = %u", ES_rate_flag);
391 
392         unsigned DSM_trick_mode_flag = br.getBits(1);
393         ALOGV("DSM_trick_mode_flag = %u", DSM_trick_mode_flag);
394 
395         unsigned additional_copy_info_flag = br.getBits(1);
396         ALOGV("additional_copy_info_flag = %u", additional_copy_info_flag);
397 
398         /* unsigned PES_CRC_flag = */br.getBits(1);
399         /* PES_extension_flag = */br.getBits(1);
400 
401         unsigned PES_header_data_length = br.getBits(8);
402         ALOGV("PES_header_data_length = %u", PES_header_data_length);
403 
404         unsigned optional_bytes_remaining = PES_header_data_length;
405 
406         uint64_t PTS = 0, DTS = 0;
407 
408         if (PTS_DTS_flags == 2 || PTS_DTS_flags == 3) {
409             if (optional_bytes_remaining < 5u) {
410                 return ERROR_MALFORMED;
411             }
412 
413             if (br.getBits(4) != PTS_DTS_flags) {
414                 return ERROR_MALFORMED;
415             }
416 
417             PTS = ((uint64_t)br.getBits(3)) << 30;
418             if (br.getBits(1) != 1u) {
419                 return ERROR_MALFORMED;
420             }
421             PTS |= ((uint64_t)br.getBits(15)) << 15;
422             if (br.getBits(1) != 1u) {
423                 return ERROR_MALFORMED;
424             }
425             PTS |= br.getBits(15);
426             if (br.getBits(1) != 1u) {
427                 return ERROR_MALFORMED;
428             }
429 
430             ALOGV("PTS = %" PRIu64, PTS);
431             // ALOGI("PTS = %.2f secs", PTS / 90000.0f);
432 
433             optional_bytes_remaining -= 5;
434 
435             if (PTS_DTS_flags == 3) {
436                 if (optional_bytes_remaining < 5u) {
437                     return ERROR_MALFORMED;
438                 }
439 
440                 if (br.getBits(4) != 1u) {
441                     return ERROR_MALFORMED;
442                 }
443 
444                 DTS = ((uint64_t)br.getBits(3)) << 30;
445                 if (br.getBits(1) != 1u) {
446                     return ERROR_MALFORMED;
447                 }
448                 DTS |= ((uint64_t)br.getBits(15)) << 15;
449                 if (br.getBits(1) != 1u) {
450                     return ERROR_MALFORMED;
451                 }
452                 DTS |= br.getBits(15);
453                 if (br.getBits(1) != 1u) {
454                     return ERROR_MALFORMED;
455                 }
456 
457                 ALOGV("DTS = %" PRIu64, DTS);
458 
459                 optional_bytes_remaining -= 5;
460             }
461         }
462 
463         if (ESCR_flag) {
464             if (optional_bytes_remaining < 6u) {
465                 return ERROR_MALFORMED;
466             }
467 
468             br.getBits(2);
469 
470             uint64_t ESCR = ((uint64_t)br.getBits(3)) << 30;
471             if (br.getBits(1) != 1u) {
472                 return ERROR_MALFORMED;
473             }
474             ESCR |= ((uint64_t)br.getBits(15)) << 15;
475             if (br.getBits(1) != 1u) {
476                 return ERROR_MALFORMED;
477             }
478             ESCR |= br.getBits(15);
479             if (br.getBits(1) != 1u) {
480                 return ERROR_MALFORMED;
481             }
482 
483             ALOGV("ESCR = %" PRIu64, ESCR);
484             /* unsigned ESCR_extension = */br.getBits(9);
485 
486             if (br.getBits(1) != 1u) {
487                 return ERROR_MALFORMED;
488             }
489 
490             optional_bytes_remaining -= 6;
491         }
492 
493         if (ES_rate_flag) {
494             if (optional_bytes_remaining < 3u) {
495                 return ERROR_MALFORMED;
496             }
497 
498             if (br.getBits(1) != 1u) {
499                 return ERROR_MALFORMED;
500             }
501             /* unsigned ES_rate = */br.getBits(22);
502             if (br.getBits(1) != 1u) {
503                 return ERROR_MALFORMED;
504             }
505 
506             optional_bytes_remaining -= 3;
507         }
508 
509         if (br.numBitsLeft() < optional_bytes_remaining * 8) {
510             return ERROR_MALFORMED;
511         }
512 
513         br.skipBits(optional_bytes_remaining * 8);
514 
515         // ES data follows.
516 
517         if (PES_packet_length < PES_header_data_length + 3) {
518             return ERROR_MALFORMED;
519         }
520 
521         unsigned dataLength =
522             PES_packet_length - 3 - PES_header_data_length;
523 
524         if (br.numBitsLeft() < dataLength * 8) {
525             ALOGE("PES packet does not carry enough data to contain "
526                  "payload. (numBitsLeft = %zu, required = %u)",
527                  br.numBitsLeft(), dataLength * 8);
528 
529             return ERROR_MALFORMED;
530         }
531 
532         if (br.numBitsLeft() < dataLength * 8) {
533             return ERROR_MALFORMED;
534         }
535 
536         ssize_t index = mTracks.indexOfKey(stream_id);
537         if (index < 0 && mScanning) {
538             unsigned streamType;
539 
540             ssize_t streamTypeIndex;
541             if (mProgramStreamMapValid
542                     && (streamTypeIndex =
543                             mStreamTypeByESID.indexOfKey(stream_id)) >= 0) {
544                 streamType = mStreamTypeByESID.valueAt(streamTypeIndex);
545             } else if ((stream_id & ~0x1f) == 0xc0) {
546                 // ISO/IEC 13818-3 or ISO/IEC 11172-3 or ISO/IEC 13818-7
547                 // or ISO/IEC 14496-3 audio
548                 streamType = ATSParser::STREAMTYPE_MPEG2_AUDIO;
549             } else if ((stream_id & ~0x0f) == 0xe0) {
550                 // ISO/IEC 13818-2 or ISO/IEC 11172-2 or ISO/IEC 14496-2 video
551                 streamType = ATSParser::STREAMTYPE_MPEG2_VIDEO;
552             } else {
553                 streamType = ATSParser::STREAMTYPE_RESERVED;
554             }
555 
556             index = mTracks.add(
557                     stream_id, new Track(this, stream_id, streamType));
558         }
559 
560         status_t err = OK;
561 
562         if (index >= 0) {
563             err =
564                 mTracks.editValueAt(index)->appendPESData(
565                     PTS_DTS_flags, PTS, DTS, br.data(), dataLength);
566         }
567 
568         br.skipBits(dataLength * 8);
569 
570         if (err != OK) {
571             return err;
572         }
573     } else if (stream_id == 0xbe) {  // padding_stream
574         if (PES_packet_length == 0u) {
575             return ERROR_MALFORMED;
576         }
577         br.skipBits(PES_packet_length * 8);
578     } else {
579         if (PES_packet_length == 0u) {
580             return ERROR_MALFORMED;
581         }
582         br.skipBits(PES_packet_length * 8);
583     }
584 
585     return n;
586 }
587 
588 ////////////////////////////////////////////////////////////////////////////////
589 
Track(MPEG2PSExtractor * extractor,unsigned stream_id,unsigned stream_type)590 MPEG2PSExtractor::Track::Track(
591         MPEG2PSExtractor *extractor, unsigned stream_id, unsigned stream_type)
592     : mExtractor(extractor),
593       mStreamID(stream_id),
594       mStreamType(stream_type),
595       mQueue(NULL) {
596     bool supported = true;
597     ElementaryStreamQueue::Mode mode;
598 
599     switch (mStreamType) {
600         case ATSParser::STREAMTYPE_H264:
601             mode = ElementaryStreamQueue::H264;
602             break;
603         case ATSParser::STREAMTYPE_MPEG2_AUDIO_ADTS:
604             mode = ElementaryStreamQueue::AAC;
605             break;
606         case ATSParser::STREAMTYPE_MPEG1_AUDIO:
607         case ATSParser::STREAMTYPE_MPEG2_AUDIO:
608             mode = ElementaryStreamQueue::MPEG_AUDIO;
609             break;
610 
611         case ATSParser::STREAMTYPE_MPEG1_VIDEO:
612         case ATSParser::STREAMTYPE_MPEG2_VIDEO:
613             mode = ElementaryStreamQueue::MPEG_VIDEO;
614             break;
615 
616         case ATSParser::STREAMTYPE_MPEG4_VIDEO:
617             mode = ElementaryStreamQueue::MPEG4_VIDEO;
618             break;
619 
620         default:
621             supported = false;
622             break;
623     }
624 
625     if (supported) {
626         mQueue = new ElementaryStreamQueue(mode);
627     } else {
628         ALOGI("unsupported stream ID 0x%02x", stream_id);
629     }
630 }
631 
~Track()632 MPEG2PSExtractor::Track::~Track() {
633     delete mQueue;
634     mQueue = NULL;
635 }
636 
start(MetaData * params)637 status_t MPEG2PSExtractor::Track::start(MetaData *params) {
638     if (mSource == NULL) {
639         return NO_INIT;
640     }
641 
642     return mSource->start(params);
643 }
644 
stop()645 status_t MPEG2PSExtractor::Track::stop() {
646     if (mSource == NULL) {
647         return NO_INIT;
648     }
649 
650     return mSource->stop();
651 }
652 
getFormat()653 sp<MetaData> MPEG2PSExtractor::Track::getFormat() {
654     if (mSource == NULL) {
655         return NULL;
656     }
657 
658     return mSource->getFormat();
659 }
660 
read(MediaBuffer ** buffer,const ReadOptions * options)661 status_t MPEG2PSExtractor::Track::read(
662         MediaBuffer **buffer, const ReadOptions *options) {
663     if (mSource == NULL) {
664         return NO_INIT;
665     }
666 
667     status_t finalResult;
668     while (!mSource->hasBufferAvailable(&finalResult)) {
669         if (finalResult != OK) {
670             return ERROR_END_OF_STREAM;
671         }
672 
673         status_t err = mExtractor->feedMore();
674 
675         if (err != OK) {
676             mSource->signalEOS(err);
677         }
678     }
679 
680     return mSource->read(buffer, options);
681 }
682 
appendPESData(unsigned PTS_DTS_flags,uint64_t PTS,uint64_t,const uint8_t * data,size_t size)683 status_t MPEG2PSExtractor::Track::appendPESData(
684         unsigned PTS_DTS_flags,
685         uint64_t PTS, uint64_t /* DTS */,
686         const uint8_t *data, size_t size) {
687     if (mQueue == NULL) {
688         return OK;
689     }
690 
691     int64_t timeUs;
692     if (PTS_DTS_flags == 2 || PTS_DTS_flags == 3) {
693         timeUs = (PTS * 100) / 9;
694     } else {
695         timeUs = 0;
696     }
697 
698     status_t err = mQueue->appendData(data, size, timeUs);
699 
700     if (err != OK) {
701         return err;
702     }
703 
704     sp<ABuffer> accessUnit;
705     while ((accessUnit = mQueue->dequeueAccessUnit()) != NULL) {
706         if (mSource == NULL) {
707             sp<MetaData> meta = mQueue->getFormat();
708 
709             if (meta != NULL) {
710                 ALOGV("Stream ID 0x%02x now has data.", mStreamID);
711 
712                 mSource = new AnotherPacketSource(meta);
713                 mSource->queueAccessUnit(accessUnit);
714             }
715         } else if (mQueue->getFormat() != NULL) {
716             mSource->queueAccessUnit(accessUnit);
717         }
718     }
719 
720     return OK;
721 }
722 
723 ////////////////////////////////////////////////////////////////////////////////
724 
WrappedTrack(const sp<MPEG2PSExtractor> & extractor,const sp<Track> & track)725 MPEG2PSExtractor::WrappedTrack::WrappedTrack(
726         const sp<MPEG2PSExtractor> &extractor, const sp<Track> &track)
727     : mExtractor(extractor),
728       mTrack(track) {
729 }
730 
~WrappedTrack()731 MPEG2PSExtractor::WrappedTrack::~WrappedTrack() {
732 }
733 
start(MetaData * params)734 status_t MPEG2PSExtractor::WrappedTrack::start(MetaData *params) {
735     return mTrack->start(params);
736 }
737 
stop()738 status_t MPEG2PSExtractor::WrappedTrack::stop() {
739     return mTrack->stop();
740 }
741 
getFormat()742 sp<MetaData> MPEG2PSExtractor::WrappedTrack::getFormat() {
743     return mTrack->getFormat();
744 }
745 
read(MediaBuffer ** buffer,const ReadOptions * options)746 status_t MPEG2PSExtractor::WrappedTrack::read(
747         MediaBuffer **buffer, const ReadOptions *options) {
748     return mTrack->read(buffer, options);
749 }
750 
751 ////////////////////////////////////////////////////////////////////////////////
752 
SniffMPEG2PS(const sp<DataSource> & source,String8 * mimeType,float * confidence,sp<AMessage> *)753 bool SniffMPEG2PS(
754         const sp<DataSource> &source, String8 *mimeType, float *confidence,
755         sp<AMessage> *) {
756     uint8_t header[5];
757     if (source->readAt(0, header, sizeof(header)) < (ssize_t)sizeof(header)) {
758         return false;
759     }
760 
761     if (memcmp("\x00\x00\x01\xba", header, 4) || (header[4] >> 6) != 1) {
762         return false;
763     }
764 
765     *confidence = 0.25f;  // Slightly larger than .mp3 extractor's confidence
766 
767     mimeType->setTo(MEDIA_MIMETYPE_CONTAINER_MPEG2PS);
768 
769     return true;
770 }
771 
772 }  // namespace android
773