MPEG2PSExtractor.cpp revision f6d0c1fd6d9e697bb3a891fae14c7e9d4b685de6 
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
41namespace android {
42
43struct 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
54protected:
55    virtual ~Track();
56
57private:
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
75struct 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
85protected:
86    virtual ~WrappedTrack();
87
88private:
89    sp<MPEG2PSExtractor> mExtractor;
90    sp<MPEG2PSExtractor::Track> mTrack;
91
92    DISALLOW_EVIL_CONSTRUCTORS(WrappedTrack);
93};
94
95////////////////////////////////////////////////////////////////////////////////
96
97MPEG2PSExtractor::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        if (mTracks.valueAt(i)->getFormat() == NULL) {
113            mTracks.removeItemsAt(i);
114        }
115    }
116
117    mScanning = false;
118}
119
120MPEG2PSExtractor::~MPEG2PSExtractor() {
121}
122
123size_t MPEG2PSExtractor::countTracks() {
124    return mTracks.size();
125}
126
127sp<MediaSource> MPEG2PSExtractor::getTrack(size_t index) {
128    if (index >= mTracks.size()) {
129        return NULL;
130    }
131
132    return new WrappedTrack(this, mTracks.valueAt(index));
133}
134
135sp<MetaData> MPEG2PSExtractor::getTrackMetaData(
136        size_t index, uint32_t /* flags */) {
137    if (index >= mTracks.size()) {
138        return NULL;
139    }
140
141    return mTracks.valueAt(index)->getFormat();
142}
143
144sp<MetaData> MPEG2PSExtractor::getMetaData() {
145    sp<MetaData> meta = new MetaData;
146    meta->setCString(kKeyMIMEType, MEDIA_MIMETYPE_CONTAINER_MPEG2PS);
147
148    return meta;
149}
150
151uint32_t MPEG2PSExtractor::flags() const {
152    return CAN_PAUSE;
153}
154
155status_t MPEG2PSExtractor::feedMore() {
156    Mutex::Autolock autoLock(mLock);
157
158    // How much data we're reading at a time
159    static const size_t kChunkSize = 8192;
160
161    for (;;) {
162        status_t err = dequeueChunk();
163
164        if (err == -EAGAIN && mFinalResult == OK) {
165            memmove(mBuffer->base(), mBuffer->data(), mBuffer->size());
166            mBuffer->setRange(0, mBuffer->size());
167
168            if (mBuffer->size() + kChunkSize > mBuffer->capacity()) {
169                size_t newCapacity = mBuffer->capacity() + kChunkSize;
170                sp<ABuffer> newBuffer = new ABuffer(newCapacity);
171                memcpy(newBuffer->data(), mBuffer->data(), mBuffer->size());
172                newBuffer->setRange(0, mBuffer->size());
173                mBuffer = newBuffer;
174            }
175
176            ssize_t n = mDataSource->readAt(
177                    mOffset, mBuffer->data() + mBuffer->size(), kChunkSize);
178
179            if (n < (ssize_t)kChunkSize) {
180                mFinalResult = (n < 0) ? (status_t)n : ERROR_END_OF_STREAM;
181                return mFinalResult;
182            }
183
184            mBuffer->setRange(mBuffer->offset(), mBuffer->size() + n);
185            mOffset += n;
186        } else if (err != OK) {
187            mFinalResult = err;
188            return err;
189        } else {
190            return OK;
191        }
192    }
193}
194
195status_t MPEG2PSExtractor::dequeueChunk() {
196    if (mBuffer->size() < 4) {
197        return -EAGAIN;
198    }
199
200    if (memcmp("\x00\x00\x01", mBuffer->data(), 3)) {
201        return ERROR_MALFORMED;
202    }
203
204    unsigned chunkType = mBuffer->data()[3];
205
206    ssize_t res;
207
208    switch (chunkType) {
209        case 0xba:
210        {
211            res = dequeuePack();
212            break;
213        }
214
215        case 0xbb:
216        {
217            res = dequeueSystemHeader();
218            break;
219        }
220
221        default:
222        {
223            res = dequeuePES();
224            break;
225        }
226    }
227
228    if (res > 0) {
229        if (mBuffer->size() < (size_t)res) {
230            return -EAGAIN;
231        }
232
233        mBuffer->setRange(mBuffer->offset() + res, mBuffer->size() - res);
234        res = OK;
235    }
236
237    return res;
238}
239
240ssize_t MPEG2PSExtractor::dequeuePack() {
241    // 32 + 2 + 3 + 1 + 15 + 1 + 15+ 1 + 9 + 1 + 22 + 1 + 1 | +5
242
243    if (mBuffer->size() < 14) {
244        return -EAGAIN;
245    }
246
247    unsigned pack_stuffing_length = mBuffer->data()[13] & 7;
248
249    return pack_stuffing_length + 14;
250}
251
252ssize_t MPEG2PSExtractor::dequeueSystemHeader() {
253    if (mBuffer->size() < 6) {
254        return -EAGAIN;
255    }
256
257    unsigned header_length = U16_AT(mBuffer->data() + 4);
258
259    return header_length + 6;
260}
261
262ssize_t MPEG2PSExtractor::dequeuePES() {
263    if (mBuffer->size() < 6) {
264        return -EAGAIN;
265    }
266
267    unsigned PES_packet_length = U16_AT(mBuffer->data() + 4);
268    CHECK_NE(PES_packet_length, 0u);
269
270    size_t n = PES_packet_length + 6;
271
272    if (mBuffer->size() < n) {
273        return -EAGAIN;
274    }
275
276    ABitReader br(mBuffer->data(), n);
277
278    unsigned packet_startcode_prefix = br.getBits(24);
279
280    ALOGV("packet_startcode_prefix = 0x%08x", packet_startcode_prefix);
281
282    if (packet_startcode_prefix != 1) {
283        ALOGV("Supposedly payload_unit_start=1 unit does not start "
284             "with startcode.");
285
286        return ERROR_MALFORMED;
287    }
288
289    CHECK_EQ(packet_startcode_prefix, 0x000001u);
290
291    unsigned stream_id = br.getBits(8);
292    ALOGV("stream_id = 0x%02x", stream_id);
293
294    /* unsigned PES_packet_length = */br.getBits(16);
295
296    if (stream_id == 0xbc) {
297        // program_stream_map
298
299        if (!mScanning) {
300            return n;
301        }
302
303        mStreamTypeByESID.clear();
304
305        /* unsigned current_next_indicator = */br.getBits(1);
306        /* unsigned reserved = */br.getBits(2);
307        /* unsigned program_stream_map_version = */br.getBits(5);
308        /* unsigned reserved = */br.getBits(7);
309        /* unsigned marker_bit = */br.getBits(1);
310        unsigned program_stream_info_length = br.getBits(16);
311
312        size_t offset = 0;
313        while (offset < program_stream_info_length) {
314            if (offset + 2 > program_stream_info_length) {
315                return ERROR_MALFORMED;
316            }
317
318            unsigned descriptor_tag = br.getBits(8);
319            unsigned descriptor_length = br.getBits(8);
320
321            ALOGI("found descriptor tag 0x%02x of length %u",
322                 descriptor_tag, descriptor_length);
323
324            if (offset + 2 + descriptor_length > program_stream_info_length) {
325                return ERROR_MALFORMED;
326            }
327
328            br.skipBits(8 * descriptor_length);
329
330            offset += 2 + descriptor_length;
331        }
332
333        unsigned elementary_stream_map_length = br.getBits(16);
334
335        offset = 0;
336        while (offset < elementary_stream_map_length) {
337            if (offset + 4 > elementary_stream_map_length) {
338                return ERROR_MALFORMED;
339            }
340
341            unsigned stream_type = br.getBits(8);
342            unsigned elementary_stream_id = br.getBits(8);
343
344            ALOGI("elementary stream id 0x%02x has stream type 0x%02x",
345                 elementary_stream_id, stream_type);
346
347            mStreamTypeByESID.add(elementary_stream_id, stream_type);
348
349            unsigned elementary_stream_info_length = br.getBits(16);
350
351            if (offset + 4 + elementary_stream_info_length
352                    > elementary_stream_map_length) {
353                return ERROR_MALFORMED;
354            }
355
356            offset += 4 + elementary_stream_info_length;
357        }
358
359        /* unsigned CRC32 = */br.getBits(32);
360
361        mProgramStreamMapValid = true;
362    } else if (stream_id != 0xbe  // padding_stream
363            && stream_id != 0xbf  // private_stream_2
364            && stream_id != 0xf0  // ECM
365            && stream_id != 0xf1  // EMM
366            && stream_id != 0xff  // program_stream_directory
367            && stream_id != 0xf2  // DSMCC
368            && stream_id != 0xf8) {  // H.222.1 type E
369        CHECK_EQ(br.getBits(2), 2u);
370
371        /* unsigned PES_scrambling_control = */br.getBits(2);
372        /* unsigned PES_priority = */br.getBits(1);
373        /* unsigned data_alignment_indicator = */br.getBits(1);
374        /* unsigned copyright = */br.getBits(1);
375        /* unsigned original_or_copy = */br.getBits(1);
376
377        unsigned PTS_DTS_flags = br.getBits(2);
378        ALOGV("PTS_DTS_flags = %u", PTS_DTS_flags);
379
380        unsigned ESCR_flag = br.getBits(1);
381        ALOGV("ESCR_flag = %u", ESCR_flag);
382
383        unsigned ES_rate_flag = br.getBits(1);
384        ALOGV("ES_rate_flag = %u", ES_rate_flag);
385
386        unsigned DSM_trick_mode_flag = br.getBits(1);
387        ALOGV("DSM_trick_mode_flag = %u", DSM_trick_mode_flag);
388
389        unsigned additional_copy_info_flag = br.getBits(1);
390        ALOGV("additional_copy_info_flag = %u", additional_copy_info_flag);
391
392        /* unsigned PES_CRC_flag = */br.getBits(1);
393        /* PES_extension_flag = */br.getBits(1);
394
395        unsigned PES_header_data_length = br.getBits(8);
396        ALOGV("PES_header_data_length = %u", PES_header_data_length);
397
398        unsigned optional_bytes_remaining = PES_header_data_length;
399
400        uint64_t PTS = 0, DTS = 0;
401
402        if (PTS_DTS_flags == 2 || PTS_DTS_flags == 3) {
403            CHECK_GE(optional_bytes_remaining, 5u);
404
405            CHECK_EQ(br.getBits(4), PTS_DTS_flags);
406
407            PTS = ((uint64_t)br.getBits(3)) << 30;
408            CHECK_EQ(br.getBits(1), 1u);
409            PTS |= ((uint64_t)br.getBits(15)) << 15;
410            CHECK_EQ(br.getBits(1), 1u);
411            PTS |= br.getBits(15);
412            CHECK_EQ(br.getBits(1), 1u);
413
414            ALOGV("PTS = %" PRIu64, PTS);
415            // ALOGI("PTS = %.2f secs", PTS / 90000.0f);
416
417            optional_bytes_remaining -= 5;
418
419            if (PTS_DTS_flags == 3) {
420                CHECK_GE(optional_bytes_remaining, 5u);
421
422                CHECK_EQ(br.getBits(4), 1u);
423
424                DTS = ((uint64_t)br.getBits(3)) << 30;
425                CHECK_EQ(br.getBits(1), 1u);
426                DTS |= ((uint64_t)br.getBits(15)) << 15;
427                CHECK_EQ(br.getBits(1), 1u);
428                DTS |= br.getBits(15);
429                CHECK_EQ(br.getBits(1), 1u);
430
431                ALOGV("DTS = %" PRIu64, DTS);
432
433                optional_bytes_remaining -= 5;
434            }
435        }
436
437        if (ESCR_flag) {
438            CHECK_GE(optional_bytes_remaining, 6u);
439
440            br.getBits(2);
441
442            uint64_t ESCR = ((uint64_t)br.getBits(3)) << 30;
443            CHECK_EQ(br.getBits(1), 1u);
444            ESCR |= ((uint64_t)br.getBits(15)) << 15;
445            CHECK_EQ(br.getBits(1), 1u);
446            ESCR |= br.getBits(15);
447            CHECK_EQ(br.getBits(1), 1u);
448
449            ALOGV("ESCR = %" PRIu64, ESCR);
450            /* unsigned ESCR_extension = */br.getBits(9);
451
452            CHECK_EQ(br.getBits(1), 1u);
453
454            optional_bytes_remaining -= 6;
455        }
456
457        if (ES_rate_flag) {
458            CHECK_GE(optional_bytes_remaining, 3u);
459
460            CHECK_EQ(br.getBits(1), 1u);
461            /* unsigned ES_rate = */br.getBits(22);
462            CHECK_EQ(br.getBits(1), 1u);
463
464            optional_bytes_remaining -= 3;
465        }
466
467        br.skipBits(optional_bytes_remaining * 8);
468
469        // ES data follows.
470
471        CHECK_GE(PES_packet_length, PES_header_data_length + 3);
472
473        unsigned dataLength =
474            PES_packet_length - 3 - PES_header_data_length;
475
476        if (br.numBitsLeft() < dataLength * 8) {
477            ALOGE("PES packet does not carry enough data to contain "
478                 "payload. (numBitsLeft = %zu, required = %u)",
479                 br.numBitsLeft(), dataLength * 8);
480
481            return ERROR_MALFORMED;
482        }
483
484        CHECK_GE(br.numBitsLeft(), dataLength * 8);
485
486        ssize_t index = mTracks.indexOfKey(stream_id);
487        if (index < 0 && mScanning) {
488            unsigned streamType;
489
490            ssize_t streamTypeIndex;
491            if (mProgramStreamMapValid
492                    && (streamTypeIndex =
493                            mStreamTypeByESID.indexOfKey(stream_id)) >= 0) {
494                streamType = mStreamTypeByESID.valueAt(streamTypeIndex);
495            } else if ((stream_id & ~0x1f) == 0xc0) {
496                // ISO/IEC 13818-3 or ISO/IEC 11172-3 or ISO/IEC 13818-7
497                // or ISO/IEC 14496-3 audio
498                streamType = ATSParser::STREAMTYPE_MPEG2_AUDIO;
499            } else if ((stream_id & ~0x0f) == 0xe0) {
500                // ISO/IEC 13818-2 or ISO/IEC 11172-2 or ISO/IEC 14496-2 video
501                streamType = ATSParser::STREAMTYPE_MPEG2_VIDEO;
502            } else {
503                streamType = ATSParser::STREAMTYPE_RESERVED;
504            }
505
506            index = mTracks.add(
507                    stream_id, new Track(this, stream_id, streamType));
508        }
509
510        status_t err = OK;
511
512        if (index >= 0) {
513            err =
514                mTracks.editValueAt(index)->appendPESData(
515                    PTS_DTS_flags, PTS, DTS, br.data(), dataLength);
516        }
517
518        br.skipBits(dataLength * 8);
519
520        if (err != OK) {
521            return err;
522        }
523    } else if (stream_id == 0xbe) {  // padding_stream
524        CHECK_NE(PES_packet_length, 0u);
525        br.skipBits(PES_packet_length * 8);
526    } else {
527        CHECK_NE(PES_packet_length, 0u);
528        br.skipBits(PES_packet_length * 8);
529    }
530
531    return n;
532}
533
534////////////////////////////////////////////////////////////////////////////////
535
536MPEG2PSExtractor::Track::Track(
537        MPEG2PSExtractor *extractor, unsigned stream_id, unsigned stream_type)
538    : mExtractor(extractor),
539      mStreamID(stream_id),
540      mStreamType(stream_type),
541      mQueue(NULL) {
542    bool supported = true;
543    ElementaryStreamQueue::Mode mode;
544
545    switch (mStreamType) {
546        case ATSParser::STREAMTYPE_H264:
547            mode = ElementaryStreamQueue::H264;
548            break;
549        case ATSParser::STREAMTYPE_MPEG2_AUDIO_ADTS:
550            mode = ElementaryStreamQueue::AAC;
551            break;
552        case ATSParser::STREAMTYPE_MPEG1_AUDIO:
553        case ATSParser::STREAMTYPE_MPEG2_AUDIO:
554            mode = ElementaryStreamQueue::MPEG_AUDIO;
555            break;
556
557        case ATSParser::STREAMTYPE_MPEG1_VIDEO:
558        case ATSParser::STREAMTYPE_MPEG2_VIDEO:
559            mode = ElementaryStreamQueue::MPEG_VIDEO;
560            break;
561
562        case ATSParser::STREAMTYPE_MPEG4_VIDEO:
563            mode = ElementaryStreamQueue::MPEG4_VIDEO;
564            break;
565
566        default:
567            supported = false;
568            break;
569    }
570
571    if (supported) {
572        mQueue = new ElementaryStreamQueue(mode);
573    } else {
574        ALOGI("unsupported stream ID 0x%02x", stream_id);
575    }
576}
577
578MPEG2PSExtractor::Track::~Track() {
579    delete mQueue;
580    mQueue = NULL;
581}
582
583status_t MPEG2PSExtractor::Track::start(MetaData *params) {
584    if (mSource == NULL) {
585        return NO_INIT;
586    }
587
588    return mSource->start(params);
589}
590
591status_t MPEG2PSExtractor::Track::stop() {
592    if (mSource == NULL) {
593        return NO_INIT;
594    }
595
596    return mSource->stop();
597}
598
599sp<MetaData> MPEG2PSExtractor::Track::getFormat() {
600    if (mSource == NULL) {
601        return NULL;
602    }
603
604    return mSource->getFormat();
605}
606
607status_t MPEG2PSExtractor::Track::read(
608        MediaBuffer **buffer, const ReadOptions *options) {
609    if (mSource == NULL) {
610        return NO_INIT;
611    }
612
613    status_t finalResult;
614    while (!mSource->hasBufferAvailable(&finalResult)) {
615        if (finalResult != OK) {
616            return ERROR_END_OF_STREAM;
617        }
618
619        status_t err = mExtractor->feedMore();
620
621        if (err != OK) {
622            mSource->signalEOS(err);
623        }
624    }
625
626    return mSource->read(buffer, options);
627}
628
629status_t MPEG2PSExtractor::Track::appendPESData(
630        unsigned PTS_DTS_flags,
631        uint64_t PTS, uint64_t /* DTS */,
632        const uint8_t *data, size_t size) {
633    if (mQueue == NULL) {
634        return OK;
635    }
636
637    int64_t timeUs;
638    if (PTS_DTS_flags == 2 || PTS_DTS_flags == 3) {
639        timeUs = (PTS * 100) / 9;
640    } else {
641        timeUs = 0;
642    }
643
644    status_t err = mQueue->appendData(data, size, timeUs);
645
646    if (err != OK) {
647        return err;
648    }
649
650    sp<ABuffer> accessUnit;
651    while ((accessUnit = mQueue->dequeueAccessUnit()) != NULL) {
652        if (mSource == NULL) {
653            sp<MetaData> meta = mQueue->getFormat();
654
655            if (meta != NULL) {
656                ALOGV("Stream ID 0x%02x now has data.", mStreamID);
657
658                mSource = new AnotherPacketSource(meta);
659                mSource->queueAccessUnit(accessUnit);
660            }
661        } else if (mQueue->getFormat() != NULL) {
662            mSource->queueAccessUnit(accessUnit);
663        }
664    }
665
666    return OK;
667}
668
669////////////////////////////////////////////////////////////////////////////////
670
671MPEG2PSExtractor::WrappedTrack::WrappedTrack(
672        const sp<MPEG2PSExtractor> &extractor, const sp<Track> &track)
673    : mExtractor(extractor),
674      mTrack(track) {
675}
676
677MPEG2PSExtractor::WrappedTrack::~WrappedTrack() {
678}
679
680status_t MPEG2PSExtractor::WrappedTrack::start(MetaData *params) {
681    return mTrack->start(params);
682}
683
684status_t MPEG2PSExtractor::WrappedTrack::stop() {
685    return mTrack->stop();
686}
687
688sp<MetaData> MPEG2PSExtractor::WrappedTrack::getFormat() {
689    return mTrack->getFormat();
690}
691
692status_t MPEG2PSExtractor::WrappedTrack::read(
693        MediaBuffer **buffer, const ReadOptions *options) {
694    return mTrack->read(buffer, options);
695}
696
697////////////////////////////////////////////////////////////////////////////////
698
699bool SniffMPEG2PS(
700        const sp<DataSource> &source, String8 *mimeType, float *confidence,
701        sp<AMessage> *) {
702    uint8_t header[5];
703    if (source->readAt(0, header, sizeof(header)) < (ssize_t)sizeof(header)) {
704        return false;
705    }
706
707    if (memcmp("\x00\x00\x01\xba", header, 4) || (header[4] >> 6) != 1) {
708        return false;
709    }
710
711    *confidence = 0.25f;  // Slightly larger than .mp3 extractor's confidence
712
713    mimeType->setTo(MEDIA_MIMETYPE_CONTAINER_MPEG2PS);
714
715    return true;
716}
717
718}  // namespace android
719