MPEG2PSExtractor.cpp revision f3ff858fc380fa9d01c6d688a4f594e2a315c095 
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        i--;
113        if (mTracks.valueAt(i)->getFormat() == NULL) {
114            mTracks.removeItemsAt(i);
115        }
116    }
117
118    mScanning = false;
119}
120
121MPEG2PSExtractor::~MPEG2PSExtractor() {
122}
123
124size_t MPEG2PSExtractor::countTracks() {
125    return mTracks.size();
126}
127
128sp<MediaSource> 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
136sp<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
145sp<MetaData> MPEG2PSExtractor::getMetaData() {
146    sp<MetaData> meta = new MetaData;
147    meta->setCString(kKeyMIMEType, MEDIA_MIMETYPE_CONTAINER_MPEG2PS);
148
149    return meta;
150}
151
152uint32_t MPEG2PSExtractor::flags() const {
153    return CAN_PAUSE;
154}
155
156status_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
196status_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
241ssize_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
253ssize_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
263ssize_t MPEG2PSExtractor::dequeuePES() {
264    if (mBuffer->size() < 6) {
265        return -EAGAIN;
266    }
267
268    unsigned PES_packet_length = U16_AT(mBuffer->data() + 4);
269    CHECK_NE(PES_packet_length, 0u);
270
271    size_t n = PES_packet_length + 6;
272
273    if (mBuffer->size() < n) {
274        return -EAGAIN;
275    }
276
277    ABitReader br(mBuffer->data(), n);
278
279    unsigned packet_startcode_prefix = br.getBits(24);
280
281    ALOGV("packet_startcode_prefix = 0x%08x", packet_startcode_prefix);
282
283    if (packet_startcode_prefix != 1) {
284        ALOGV("Supposedly payload_unit_start=1 unit does not start "
285             "with startcode.");
286
287        return ERROR_MALFORMED;
288    }
289
290    CHECK_EQ(packet_startcode_prefix, 0x000001u);
291
292    unsigned stream_id = br.getBits(8);
293    ALOGV("stream_id = 0x%02x", stream_id);
294
295    /* unsigned PES_packet_length = */br.getBits(16);
296
297    if (stream_id == 0xbc) {
298        // program_stream_map
299
300        if (!mScanning) {
301            return n;
302        }
303
304        mStreamTypeByESID.clear();
305
306        /* unsigned current_next_indicator = */br.getBits(1);
307        /* unsigned reserved = */br.getBits(2);
308        /* unsigned program_stream_map_version = */br.getBits(5);
309        /* unsigned reserved = */br.getBits(7);
310        /* unsigned marker_bit = */br.getBits(1);
311        unsigned program_stream_info_length = br.getBits(16);
312
313        size_t offset = 0;
314        while (offset < program_stream_info_length) {
315            if (offset + 2 > program_stream_info_length) {
316                return ERROR_MALFORMED;
317            }
318
319            unsigned descriptor_tag = br.getBits(8);
320            unsigned descriptor_length = br.getBits(8);
321
322            ALOGI("found descriptor tag 0x%02x of length %u",
323                 descriptor_tag, descriptor_length);
324
325            if (offset + 2 + descriptor_length > program_stream_info_length) {
326                return ERROR_MALFORMED;
327            }
328
329            br.skipBits(8 * descriptor_length);
330
331            offset += 2 + descriptor_length;
332        }
333
334        unsigned elementary_stream_map_length = br.getBits(16);
335
336        offset = 0;
337        while (offset < elementary_stream_map_length) {
338            if (offset + 4 > elementary_stream_map_length) {
339                return ERROR_MALFORMED;
340            }
341
342            unsigned stream_type = br.getBits(8);
343            unsigned elementary_stream_id = br.getBits(8);
344
345            ALOGI("elementary stream id 0x%02x has stream type 0x%02x",
346                 elementary_stream_id, stream_type);
347
348            mStreamTypeByESID.add(elementary_stream_id, stream_type);
349
350            unsigned elementary_stream_info_length = br.getBits(16);
351
352            if (offset + 4 + elementary_stream_info_length
353                    > elementary_stream_map_length) {
354                return ERROR_MALFORMED;
355            }
356
357            offset += 4 + elementary_stream_info_length;
358        }
359
360        /* unsigned CRC32 = */br.getBits(32);
361
362        mProgramStreamMapValid = true;
363    } else if (stream_id != 0xbe  // padding_stream
364            && stream_id != 0xbf  // private_stream_2
365            && stream_id != 0xf0  // ECM
366            && stream_id != 0xf1  // EMM
367            && stream_id != 0xff  // program_stream_directory
368            && stream_id != 0xf2  // DSMCC
369            && stream_id != 0xf8) {  // H.222.1 type E
370        CHECK_EQ(br.getBits(2), 2u);
371
372        /* unsigned PES_scrambling_control = */br.getBits(2);
373        /* unsigned PES_priority = */br.getBits(1);
374        /* unsigned data_alignment_indicator = */br.getBits(1);
375        /* unsigned copyright = */br.getBits(1);
376        /* unsigned original_or_copy = */br.getBits(1);
377
378        unsigned PTS_DTS_flags = br.getBits(2);
379        ALOGV("PTS_DTS_flags = %u", PTS_DTS_flags);
380
381        unsigned ESCR_flag = br.getBits(1);
382        ALOGV("ESCR_flag = %u", ESCR_flag);
383
384        unsigned ES_rate_flag = br.getBits(1);
385        ALOGV("ES_rate_flag = %u", ES_rate_flag);
386
387        unsigned DSM_trick_mode_flag = br.getBits(1);
388        ALOGV("DSM_trick_mode_flag = %u", DSM_trick_mode_flag);
389
390        unsigned additional_copy_info_flag = br.getBits(1);
391        ALOGV("additional_copy_info_flag = %u", additional_copy_info_flag);
392
393        /* unsigned PES_CRC_flag = */br.getBits(1);
394        /* PES_extension_flag = */br.getBits(1);
395
396        unsigned PES_header_data_length = br.getBits(8);
397        ALOGV("PES_header_data_length = %u", PES_header_data_length);
398
399        unsigned optional_bytes_remaining = PES_header_data_length;
400
401        uint64_t PTS = 0, DTS = 0;
402
403        if (PTS_DTS_flags == 2 || PTS_DTS_flags == 3) {
404            CHECK_GE(optional_bytes_remaining, 5u);
405
406            CHECK_EQ(br.getBits(4), PTS_DTS_flags);
407
408            PTS = ((uint64_t)br.getBits(3)) << 30;
409            CHECK_EQ(br.getBits(1), 1u);
410            PTS |= ((uint64_t)br.getBits(15)) << 15;
411            CHECK_EQ(br.getBits(1), 1u);
412            PTS |= br.getBits(15);
413            CHECK_EQ(br.getBits(1), 1u);
414
415            ALOGV("PTS = %" PRIu64, PTS);
416            // ALOGI("PTS = %.2f secs", PTS / 90000.0f);
417
418            optional_bytes_remaining -= 5;
419
420            if (PTS_DTS_flags == 3) {
421                CHECK_GE(optional_bytes_remaining, 5u);
422
423                CHECK_EQ(br.getBits(4), 1u);
424
425                DTS = ((uint64_t)br.getBits(3)) << 30;
426                CHECK_EQ(br.getBits(1), 1u);
427                DTS |= ((uint64_t)br.getBits(15)) << 15;
428                CHECK_EQ(br.getBits(1), 1u);
429                DTS |= br.getBits(15);
430                CHECK_EQ(br.getBits(1), 1u);
431
432                ALOGV("DTS = %" PRIu64, DTS);
433
434                optional_bytes_remaining -= 5;
435            }
436        }
437
438        if (ESCR_flag) {
439            CHECK_GE(optional_bytes_remaining, 6u);
440
441            br.getBits(2);
442
443            uint64_t ESCR = ((uint64_t)br.getBits(3)) << 30;
444            CHECK_EQ(br.getBits(1), 1u);
445            ESCR |= ((uint64_t)br.getBits(15)) << 15;
446            CHECK_EQ(br.getBits(1), 1u);
447            ESCR |= br.getBits(15);
448            CHECK_EQ(br.getBits(1), 1u);
449
450            ALOGV("ESCR = %" PRIu64, ESCR);
451            /* unsigned ESCR_extension = */br.getBits(9);
452
453            CHECK_EQ(br.getBits(1), 1u);
454
455            optional_bytes_remaining -= 6;
456        }
457
458        if (ES_rate_flag) {
459            CHECK_GE(optional_bytes_remaining, 3u);
460
461            CHECK_EQ(br.getBits(1), 1u);
462            /* unsigned ES_rate = */br.getBits(22);
463            CHECK_EQ(br.getBits(1), 1u);
464
465            optional_bytes_remaining -= 3;
466        }
467
468        br.skipBits(optional_bytes_remaining * 8);
469
470        // ES data follows.
471
472        CHECK_GE(PES_packet_length, PES_header_data_length + 3);
473
474        unsigned dataLength =
475            PES_packet_length - 3 - PES_header_data_length;
476
477        if (br.numBitsLeft() < dataLength * 8) {
478            ALOGE("PES packet does not carry enough data to contain "
479                 "payload. (numBitsLeft = %zu, required = %u)",
480                 br.numBitsLeft(), dataLength * 8);
481
482            return ERROR_MALFORMED;
483        }
484
485        CHECK_GE(br.numBitsLeft(), dataLength * 8);
486
487        ssize_t index = mTracks.indexOfKey(stream_id);
488        if (index < 0 && mScanning) {
489            unsigned streamType;
490
491            ssize_t streamTypeIndex;
492            if (mProgramStreamMapValid
493                    && (streamTypeIndex =
494                            mStreamTypeByESID.indexOfKey(stream_id)) >= 0) {
495                streamType = mStreamTypeByESID.valueAt(streamTypeIndex);
496            } else if ((stream_id & ~0x1f) == 0xc0) {
497                // ISO/IEC 13818-3 or ISO/IEC 11172-3 or ISO/IEC 13818-7
498                // or ISO/IEC 14496-3 audio
499                streamType = ATSParser::STREAMTYPE_MPEG2_AUDIO;
500            } else if ((stream_id & ~0x0f) == 0xe0) {
501                // ISO/IEC 13818-2 or ISO/IEC 11172-2 or ISO/IEC 14496-2 video
502                streamType = ATSParser::STREAMTYPE_MPEG2_VIDEO;
503            } else {
504                streamType = ATSParser::STREAMTYPE_RESERVED;
505            }
506
507            index = mTracks.add(
508                    stream_id, new Track(this, stream_id, streamType));
509        }
510
511        status_t err = OK;
512
513        if (index >= 0) {
514            err =
515                mTracks.editValueAt(index)->appendPESData(
516                    PTS_DTS_flags, PTS, DTS, br.data(), dataLength);
517        }
518
519        br.skipBits(dataLength * 8);
520
521        if (err != OK) {
522            return err;
523        }
524    } else if (stream_id == 0xbe) {  // padding_stream
525        CHECK_NE(PES_packet_length, 0u);
526        br.skipBits(PES_packet_length * 8);
527    } else {
528        CHECK_NE(PES_packet_length, 0u);
529        br.skipBits(PES_packet_length * 8);
530    }
531
532    return n;
533}
534
535////////////////////////////////////////////////////////////////////////////////
536
537MPEG2PSExtractor::Track::Track(
538        MPEG2PSExtractor *extractor, unsigned stream_id, unsigned stream_type)
539    : mExtractor(extractor),
540      mStreamID(stream_id),
541      mStreamType(stream_type),
542      mQueue(NULL) {
543    bool supported = true;
544    ElementaryStreamQueue::Mode mode;
545
546    switch (mStreamType) {
547        case ATSParser::STREAMTYPE_H264:
548            mode = ElementaryStreamQueue::H264;
549            break;
550        case ATSParser::STREAMTYPE_MPEG2_AUDIO_ADTS:
551            mode = ElementaryStreamQueue::AAC;
552            break;
553        case ATSParser::STREAMTYPE_MPEG1_AUDIO:
554        case ATSParser::STREAMTYPE_MPEG2_AUDIO:
555            mode = ElementaryStreamQueue::MPEG_AUDIO;
556            break;
557
558        case ATSParser::STREAMTYPE_MPEG1_VIDEO:
559        case ATSParser::STREAMTYPE_MPEG2_VIDEO:
560            mode = ElementaryStreamQueue::MPEG_VIDEO;
561            break;
562
563        case ATSParser::STREAMTYPE_MPEG4_VIDEO:
564            mode = ElementaryStreamQueue::MPEG4_VIDEO;
565            break;
566
567        default:
568            supported = false;
569            break;
570    }
571
572    if (supported) {
573        mQueue = new ElementaryStreamQueue(mode);
574    } else {
575        ALOGI("unsupported stream ID 0x%02x", stream_id);
576    }
577}
578
579MPEG2PSExtractor::Track::~Track() {
580    delete mQueue;
581    mQueue = NULL;
582}
583
584status_t MPEG2PSExtractor::Track::start(MetaData *params) {
585    if (mSource == NULL) {
586        return NO_INIT;
587    }
588
589    return mSource->start(params);
590}
591
592status_t MPEG2PSExtractor::Track::stop() {
593    if (mSource == NULL) {
594        return NO_INIT;
595    }
596
597    return mSource->stop();
598}
599
600sp<MetaData> MPEG2PSExtractor::Track::getFormat() {
601    if (mSource == NULL) {
602        return NULL;
603    }
604
605    return mSource->getFormat();
606}
607
608status_t MPEG2PSExtractor::Track::read(
609        MediaBuffer **buffer, const ReadOptions *options) {
610    if (mSource == NULL) {
611        return NO_INIT;
612    }
613
614    status_t finalResult;
615    while (!mSource->hasBufferAvailable(&finalResult)) {
616        if (finalResult != OK) {
617            return ERROR_END_OF_STREAM;
618        }
619
620        status_t err = mExtractor->feedMore();
621
622        if (err != OK) {
623            mSource->signalEOS(err);
624        }
625    }
626
627    return mSource->read(buffer, options);
628}
629
630status_t MPEG2PSExtractor::Track::appendPESData(
631        unsigned PTS_DTS_flags,
632        uint64_t PTS, uint64_t /* DTS */,
633        const uint8_t *data, size_t size) {
634    if (mQueue == NULL) {
635        return OK;
636    }
637
638    int64_t timeUs;
639    if (PTS_DTS_flags == 2 || PTS_DTS_flags == 3) {
640        timeUs = (PTS * 100) / 9;
641    } else {
642        timeUs = 0;
643    }
644
645    status_t err = mQueue->appendData(data, size, timeUs);
646
647    if (err != OK) {
648        return err;
649    }
650
651    sp<ABuffer> accessUnit;
652    while ((accessUnit = mQueue->dequeueAccessUnit()) != NULL) {
653        if (mSource == NULL) {
654            sp<MetaData> meta = mQueue->getFormat();
655
656            if (meta != NULL) {
657                ALOGV("Stream ID 0x%02x now has data.", mStreamID);
658
659                mSource = new AnotherPacketSource(meta);
660                mSource->queueAccessUnit(accessUnit);
661            }
662        } else if (mQueue->getFormat() != NULL) {
663            mSource->queueAccessUnit(accessUnit);
664        }
665    }
666
667    return OK;
668}
669
670////////////////////////////////////////////////////////////////////////////////
671
672MPEG2PSExtractor::WrappedTrack::WrappedTrack(
673        const sp<MPEG2PSExtractor> &extractor, const sp<Track> &track)
674    : mExtractor(extractor),
675      mTrack(track) {
676}
677
678MPEG2PSExtractor::WrappedTrack::~WrappedTrack() {
679}
680
681status_t MPEG2PSExtractor::WrappedTrack::start(MetaData *params) {
682    return mTrack->start(params);
683}
684
685status_t MPEG2PSExtractor::WrappedTrack::stop() {
686    return mTrack->stop();
687}
688
689sp<MetaData> MPEG2PSExtractor::WrappedTrack::getFormat() {
690    return mTrack->getFormat();
691}
692
693status_t MPEG2PSExtractor::WrappedTrack::read(
694        MediaBuffer **buffer, const ReadOptions *options) {
695    return mTrack->read(buffer, options);
696}
697
698////////////////////////////////////////////////////////////////////////////////
699
700bool SniffMPEG2PS(
701        const sp<DataSource> &source, String8 *mimeType, float *confidence,
702        sp<AMessage> *) {
703    uint8_t header[5];
704    if (source->readAt(0, header, sizeof(header)) < (ssize_t)sizeof(header)) {
705        return false;
706    }
707
708    if (memcmp("\x00\x00\x01\xba", header, 4) || (header[4] >> 6) != 1) {
709        return false;
710    }
711
712    *confidence = 0.25f;  // Slightly larger than .mp3 extractor's confidence
713
714    mimeType->setTo(MEDIA_MIMETYPE_CONTAINER_MPEG2PS);
715
716    return true;
717}
718
719}  // namespace android
720