ATSParser.cpp revision bff07d0b22a5ee2d9f044f6cb5e4be1532017ab0 
1/*
2 * Copyright (C) 2010 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 "ATSParser"
19#include <utils/Log.h>
20
21#include "ATSParser.h"
22
23#include "AnotherPacketSource.h"
24#include "ESQueue.h"
25#include "include/avc_utils.h"
26
27#include <media/stagefright/foundation/ABitReader.h>
28#include <media/stagefright/foundation/ABuffer.h>
29#include <media/stagefright/foundation/ADebug.h>
30#include <media/stagefright/foundation/AMessage.h>
31#include <media/stagefright/foundation/hexdump.h>
32#include <media/stagefright/MediaDefs.h>
33#include <media/stagefright/MediaErrors.h>
34#include <media/stagefright/MetaData.h>
35#include <utils/KeyedVector.h>
36
37namespace android {
38
39// I want the expression "y" evaluated even if verbose logging is off.
40#define MY_LOGV(x, y) \
41    do { unsigned tmp = y; LOGV(x, tmp); } while (0)
42
43static const size_t kTSPacketSize = 188;
44
45struct ATSParser::Program : public RefBase {
46    Program(unsigned programMapPID);
47
48    bool parsePID(
49            unsigned pid, unsigned payload_unit_start_indicator,
50            ABitReader *br);
51
52    void signalDiscontinuity(bool isASeek);
53
54    sp<MediaSource> getSource(SourceType type);
55
56    int64_t convertPTSToTimestamp(uint64_t PTS);
57
58private:
59    unsigned mProgramMapPID;
60    KeyedVector<unsigned, sp<Stream> > mStreams;
61    bool mFirstPTSValid;
62    uint64_t mFirstPTS;
63
64    void parseProgramMap(ABitReader *br);
65
66    DISALLOW_EVIL_CONSTRUCTORS(Program);
67};
68
69struct ATSParser::Stream : public RefBase {
70    Stream(Program *program, unsigned elementaryPID, unsigned streamType);
71
72    void parse(
73            unsigned payload_unit_start_indicator,
74            ABitReader *br);
75
76    void signalDiscontinuity(bool isASeek);
77
78    sp<MediaSource> getSource(SourceType type);
79
80protected:
81    virtual ~Stream();
82
83private:
84    Program *mProgram;
85    unsigned mElementaryPID;
86    unsigned mStreamType;
87
88    sp<ABuffer> mBuffer;
89    sp<AnotherPacketSource> mSource;
90    bool mPayloadStarted;
91
92    ElementaryStreamQueue mQueue;
93
94    void flush();
95    void parsePES(ABitReader *br);
96
97    void onPayloadData(
98            unsigned PTS_DTS_flags, uint64_t PTS, uint64_t DTS,
99            const uint8_t *data, size_t size);
100
101    void extractAACFrames(const sp<ABuffer> &buffer);
102
103    DISALLOW_EVIL_CONSTRUCTORS(Stream);
104};
105
106////////////////////////////////////////////////////////////////////////////////
107
108ATSParser::Program::Program(unsigned programMapPID)
109    : mProgramMapPID(programMapPID),
110      mFirstPTSValid(false),
111      mFirstPTS(0) {
112}
113
114bool ATSParser::Program::parsePID(
115        unsigned pid, unsigned payload_unit_start_indicator,
116        ABitReader *br) {
117    if (pid == mProgramMapPID) {
118        if (payload_unit_start_indicator) {
119            unsigned skip = br->getBits(8);
120            br->skipBits(skip * 8);
121        }
122
123        parseProgramMap(br);
124        return true;
125    }
126
127    ssize_t index = mStreams.indexOfKey(pid);
128    if (index < 0) {
129        return false;
130    }
131
132    mStreams.editValueAt(index)->parse(
133            payload_unit_start_indicator, br);
134
135    return true;
136}
137
138void ATSParser::Program::signalDiscontinuity(bool isASeek) {
139    for (size_t i = 0; i < mStreams.size(); ++i) {
140        mStreams.editValueAt(i)->signalDiscontinuity(isASeek);
141    }
142}
143
144void ATSParser::Program::parseProgramMap(ABitReader *br) {
145    unsigned table_id = br->getBits(8);
146    LOGV("  table_id = %u", table_id);
147    CHECK_EQ(table_id, 0x02u);
148
149    unsigned section_syntax_indicator = br->getBits(1);
150    LOGV("  section_syntax_indicator = %u", section_syntax_indicator);
151    CHECK_EQ(section_syntax_indicator, 1u);
152
153    CHECK_EQ(br->getBits(1), 0u);
154    MY_LOGV("  reserved = %u", br->getBits(2));
155
156    unsigned section_length = br->getBits(12);
157    LOGV("  section_length = %u", section_length);
158    CHECK((section_length & 0xc00) == 0);
159    CHECK_LE(section_length, 1021u);
160
161    MY_LOGV("  program_number = %u", br->getBits(16));
162    MY_LOGV("  reserved = %u", br->getBits(2));
163    MY_LOGV("  version_number = %u", br->getBits(5));
164    MY_LOGV("  current_next_indicator = %u", br->getBits(1));
165    MY_LOGV("  section_number = %u", br->getBits(8));
166    MY_LOGV("  last_section_number = %u", br->getBits(8));
167    MY_LOGV("  reserved = %u", br->getBits(3));
168    MY_LOGV("  PCR_PID = 0x%04x", br->getBits(13));
169    MY_LOGV("  reserved = %u", br->getBits(4));
170
171    unsigned program_info_length = br->getBits(12);
172    LOGV("  program_info_length = %u", program_info_length);
173    CHECK((program_info_length & 0xc00) == 0);
174
175    br->skipBits(program_info_length * 8);  // skip descriptors
176
177    // infoBytesRemaining is the number of bytes that make up the
178    // variable length section of ES_infos. It does not include the
179    // final CRC.
180    size_t infoBytesRemaining = section_length - 9 - program_info_length - 4;
181
182    while (infoBytesRemaining > 0) {
183        CHECK_GE(infoBytesRemaining, 5u);
184
185        unsigned streamType = br->getBits(8);
186        LOGV("    stream_type = 0x%02x", streamType);
187
188        MY_LOGV("    reserved = %u", br->getBits(3));
189
190        unsigned elementaryPID = br->getBits(13);
191        LOGV("    elementary_PID = 0x%04x", elementaryPID);
192
193        MY_LOGV("    reserved = %u", br->getBits(4));
194
195        unsigned ES_info_length = br->getBits(12);
196        LOGV("    ES_info_length = %u", ES_info_length);
197        CHECK((ES_info_length & 0xc00) == 0);
198
199        CHECK_GE(infoBytesRemaining - 5, ES_info_length);
200
201#if 0
202        br->skipBits(ES_info_length * 8);  // skip descriptors
203#else
204        unsigned info_bytes_remaining = ES_info_length;
205        while (info_bytes_remaining >= 2) {
206            MY_LOGV("      tag = 0x%02x", br->getBits(8));
207
208            unsigned descLength = br->getBits(8);
209            LOGV("      len = %u", descLength);
210
211            CHECK_GE(info_bytes_remaining, 2 + descLength);
212
213            br->skipBits(descLength * 8);
214
215            info_bytes_remaining -= descLength + 2;
216        }
217        CHECK_EQ(info_bytes_remaining, 0u);
218#endif
219
220        ssize_t index = mStreams.indexOfKey(elementaryPID);
221#if 0  // XXX revisit
222        CHECK_LT(index, 0);
223        mStreams.add(elementaryPID,
224                     new Stream(this, elementaryPID, streamType));
225#else
226        if (index < 0) {
227            mStreams.add(elementaryPID,
228                         new Stream(this, elementaryPID, streamType));
229        }
230#endif
231
232        infoBytesRemaining -= 5 + ES_info_length;
233    }
234
235    CHECK_EQ(infoBytesRemaining, 0u);
236
237    MY_LOGV("  CRC = 0x%08x", br->getBits(32));
238}
239
240sp<MediaSource> ATSParser::Program::getSource(SourceType type) {
241    for (size_t i = 0; i < mStreams.size(); ++i) {
242        sp<MediaSource> source = mStreams.editValueAt(i)->getSource(type);
243        if (source != NULL) {
244            return source;
245        }
246    }
247
248    return NULL;
249}
250
251int64_t ATSParser::Program::convertPTSToTimestamp(uint64_t PTS) {
252    if (!mFirstPTSValid) {
253        mFirstPTSValid = true;
254        mFirstPTS = PTS;
255        PTS = 0;
256    } else if (PTS < mFirstPTS) {
257        PTS = 0;
258    } else {
259        PTS -= mFirstPTS;
260    }
261
262    return (PTS * 100) / 9;
263}
264
265////////////////////////////////////////////////////////////////////////////////
266
267ATSParser::Stream::Stream(
268        Program *program, unsigned elementaryPID, unsigned streamType)
269    : mProgram(program),
270      mElementaryPID(elementaryPID),
271      mStreamType(streamType),
272      mBuffer(new ABuffer(128 * 1024)),
273      mPayloadStarted(false),
274      mQueue(streamType == 0x1b
275              ? ElementaryStreamQueue::H264 : ElementaryStreamQueue::AAC) {
276    mBuffer->setRange(0, 0);
277}
278
279ATSParser::Stream::~Stream() {
280}
281
282void ATSParser::Stream::parse(
283        unsigned payload_unit_start_indicator, ABitReader *br) {
284    if (payload_unit_start_indicator) {
285        if (mPayloadStarted) {
286            // Otherwise we run the danger of receiving the trailing bytes
287            // of a PES packet that we never saw the start of and assuming
288            // we have a a complete PES packet.
289
290            flush();
291        }
292
293        mPayloadStarted = true;
294    }
295
296    if (!mPayloadStarted) {
297        return;
298    }
299
300    size_t payloadSizeBits = br->numBitsLeft();
301    CHECK((payloadSizeBits % 8) == 0);
302
303    CHECK_LE(mBuffer->size() + payloadSizeBits / 8, mBuffer->capacity());
304
305    memcpy(mBuffer->data() + mBuffer->size(), br->data(), payloadSizeBits / 8);
306    mBuffer->setRange(0, mBuffer->size() + payloadSizeBits / 8);
307}
308
309void ATSParser::Stream::signalDiscontinuity(bool isASeek) {
310    LOGV("Stream discontinuity");
311    mPayloadStarted = false;
312    mBuffer->setRange(0, 0);
313
314    mQueue.clear();
315
316    if (isASeek) {
317        // This is only a "minor" discontinuity, we stay within the same
318        // bitstream.
319
320        mSource->clear();
321        return;
322    }
323
324    if (mStreamType == 0x1b && mSource != NULL) {
325        // Don't signal discontinuities on audio streams.
326        mSource->queueDiscontinuity();
327    }
328}
329
330void ATSParser::Stream::parsePES(ABitReader *br) {
331    unsigned packet_startcode_prefix = br->getBits(24);
332
333    LOGV("packet_startcode_prefix = 0x%08x", packet_startcode_prefix);
334
335    CHECK_EQ(packet_startcode_prefix, 0x000001u);
336
337    unsigned stream_id = br->getBits(8);
338    LOGV("stream_id = 0x%02x", stream_id);
339
340    unsigned PES_packet_length = br->getBits(16);
341    LOGV("PES_packet_length = %u", PES_packet_length);
342
343    if (stream_id != 0xbc  // program_stream_map
344            && stream_id != 0xbe  // padding_stream
345            && stream_id != 0xbf  // private_stream_2
346            && stream_id != 0xf0  // ECM
347            && stream_id != 0xf1  // EMM
348            && stream_id != 0xff  // program_stream_directory
349            && stream_id != 0xf2  // DSMCC
350            && stream_id != 0xf8) {  // H.222.1 type E
351        CHECK_EQ(br->getBits(2), 2u);
352
353        MY_LOGV("PES_scrambling_control = %u", br->getBits(2));
354        MY_LOGV("PES_priority = %u", br->getBits(1));
355        MY_LOGV("data_alignment_indicator = %u", br->getBits(1));
356        MY_LOGV("copyright = %u", br->getBits(1));
357        MY_LOGV("original_or_copy = %u", br->getBits(1));
358
359        unsigned PTS_DTS_flags = br->getBits(2);
360        LOGV("PTS_DTS_flags = %u", PTS_DTS_flags);
361
362        unsigned ESCR_flag = br->getBits(1);
363        LOGV("ESCR_flag = %u", ESCR_flag);
364
365        unsigned ES_rate_flag = br->getBits(1);
366        LOGV("ES_rate_flag = %u", ES_rate_flag);
367
368        unsigned DSM_trick_mode_flag = br->getBits(1);
369        LOGV("DSM_trick_mode_flag = %u", DSM_trick_mode_flag);
370
371        unsigned additional_copy_info_flag = br->getBits(1);
372        LOGV("additional_copy_info_flag = %u", additional_copy_info_flag);
373
374        MY_LOGV("PES_CRC_flag = %u", br->getBits(1));
375        MY_LOGV("PES_extension_flag = %u", br->getBits(1));
376
377        unsigned PES_header_data_length = br->getBits(8);
378        LOGV("PES_header_data_length = %u", PES_header_data_length);
379
380        unsigned optional_bytes_remaining = PES_header_data_length;
381
382        uint64_t PTS = 0, DTS = 0;
383
384        if (PTS_DTS_flags == 2 || PTS_DTS_flags == 3) {
385            CHECK_GE(optional_bytes_remaining, 5u);
386
387            CHECK_EQ(br->getBits(4), PTS_DTS_flags);
388
389            PTS = ((uint64_t)br->getBits(3)) << 30;
390            CHECK_EQ(br->getBits(1), 1u);
391            PTS |= ((uint64_t)br->getBits(15)) << 15;
392            CHECK_EQ(br->getBits(1), 1u);
393            PTS |= br->getBits(15);
394            CHECK_EQ(br->getBits(1), 1u);
395
396            LOGV("PTS = %llu", PTS);
397            // LOGI("PTS = %.2f secs", PTS / 90000.0f);
398
399            optional_bytes_remaining -= 5;
400
401            if (PTS_DTS_flags == 3) {
402                CHECK_GE(optional_bytes_remaining, 5u);
403
404                CHECK_EQ(br->getBits(4), 1u);
405
406                DTS = ((uint64_t)br->getBits(3)) << 30;
407                CHECK_EQ(br->getBits(1), 1u);
408                DTS |= ((uint64_t)br->getBits(15)) << 15;
409                CHECK_EQ(br->getBits(1), 1u);
410                DTS |= br->getBits(15);
411                CHECK_EQ(br->getBits(1), 1u);
412
413                LOGV("DTS = %llu", DTS);
414
415                optional_bytes_remaining -= 5;
416            }
417        }
418
419        if (ESCR_flag) {
420            CHECK_GE(optional_bytes_remaining, 6u);
421
422            br->getBits(2);
423
424            uint64_t ESCR = ((uint64_t)br->getBits(3)) << 30;
425            CHECK_EQ(br->getBits(1), 1u);
426            ESCR |= ((uint64_t)br->getBits(15)) << 15;
427            CHECK_EQ(br->getBits(1), 1u);
428            ESCR |= br->getBits(15);
429            CHECK_EQ(br->getBits(1), 1u);
430
431            LOGV("ESCR = %llu", ESCR);
432            MY_LOGV("ESCR_extension = %u", br->getBits(9));
433
434            CHECK_EQ(br->getBits(1), 1u);
435
436            optional_bytes_remaining -= 6;
437        }
438
439        if (ES_rate_flag) {
440            CHECK_GE(optional_bytes_remaining, 3u);
441
442            CHECK_EQ(br->getBits(1), 1u);
443            MY_LOGV("ES_rate = %u", br->getBits(22));
444            CHECK_EQ(br->getBits(1), 1u);
445
446            optional_bytes_remaining -= 3;
447        }
448
449        br->skipBits(optional_bytes_remaining * 8);
450
451        // ES data follows.
452
453        if (PES_packet_length != 0) {
454            CHECK_GE(PES_packet_length, PES_header_data_length + 3);
455
456            unsigned dataLength =
457                PES_packet_length - 3 - PES_header_data_length;
458
459            CHECK_GE(br->numBitsLeft(), dataLength * 8);
460
461            onPayloadData(
462                    PTS_DTS_flags, PTS, DTS, br->data(), dataLength);
463
464            br->skipBits(dataLength * 8);
465        } else {
466            onPayloadData(
467                    PTS_DTS_flags, PTS, DTS,
468                    br->data(), br->numBitsLeft() / 8);
469
470            size_t payloadSizeBits = br->numBitsLeft();
471            CHECK((payloadSizeBits % 8) == 0);
472
473            LOGV("There's %d bytes of payload.", payloadSizeBits / 8);
474        }
475    } else if (stream_id == 0xbe) {  // padding_stream
476        CHECK_NE(PES_packet_length, 0u);
477        br->skipBits(PES_packet_length * 8);
478    } else {
479        CHECK_NE(PES_packet_length, 0u);
480        br->skipBits(PES_packet_length * 8);
481    }
482}
483
484void ATSParser::Stream::flush() {
485    if (mBuffer->size() == 0) {
486        return;
487    }
488
489    LOGV("flushing stream 0x%04x size = %d", mElementaryPID, mBuffer->size());
490
491    ABitReader br(mBuffer->data(), mBuffer->size());
492    parsePES(&br);
493
494    mBuffer->setRange(0, 0);
495}
496
497void ATSParser::Stream::onPayloadData(
498        unsigned PTS_DTS_flags, uint64_t PTS, uint64_t DTS,
499        const uint8_t *data, size_t size) {
500    LOGV("onPayloadData mStreamType=0x%02x", mStreamType);
501
502    CHECK(PTS_DTS_flags == 2 || PTS_DTS_flags == 3);
503    int64_t timeUs = mProgram->convertPTSToTimestamp(PTS);
504
505    status_t err = mQueue.appendData(data, size, timeUs);
506    CHECK_EQ(err, (status_t)OK);
507
508    sp<ABuffer> accessUnit;
509    while ((accessUnit = mQueue.dequeueAccessUnit()) != NULL) {
510        if (mSource == NULL) {
511            sp<MetaData> meta = mQueue.getFormat();
512
513            if (meta != NULL) {
514                LOGV("created source!");
515                mSource = new AnotherPacketSource(meta);
516                mSource->queueAccessUnit(accessUnit);
517            }
518        } else if (mQueue.getFormat() != NULL) {
519            // After a discontinuity we invalidate the queue's format
520            // and won't enqueue any access units to the source until
521            // the queue has reestablished the new format.
522            mSource->queueAccessUnit(accessUnit);
523        }
524    }
525}
526
527sp<MediaSource> ATSParser::Stream::getSource(SourceType type) {
528    if ((type == AVC_VIDEO && mStreamType == 0x1b)
529        || (type == MPEG2ADTS_AUDIO && mStreamType == 0x0f)) {
530        return mSource;
531    }
532
533    return NULL;
534}
535
536////////////////////////////////////////////////////////////////////////////////
537
538ATSParser::ATSParser() {
539}
540
541ATSParser::~ATSParser() {
542}
543
544void ATSParser::feedTSPacket(const void *data, size_t size) {
545    CHECK_EQ(size, kTSPacketSize);
546
547    ABitReader br((const uint8_t *)data, kTSPacketSize);
548    parseTS(&br);
549}
550
551void ATSParser::signalDiscontinuity(bool isASeek) {
552    for (size_t i = 0; i < mPrograms.size(); ++i) {
553        mPrograms.editItemAt(i)->signalDiscontinuity(isASeek);
554    }
555}
556
557void ATSParser::parseProgramAssociationTable(ABitReader *br) {
558    unsigned table_id = br->getBits(8);
559    LOGV("  table_id = %u", table_id);
560    CHECK_EQ(table_id, 0x00u);
561
562    unsigned section_syntax_indictor = br->getBits(1);
563    LOGV("  section_syntax_indictor = %u", section_syntax_indictor);
564    CHECK_EQ(section_syntax_indictor, 1u);
565
566    CHECK_EQ(br->getBits(1), 0u);
567    MY_LOGV("  reserved = %u", br->getBits(2));
568
569    unsigned section_length = br->getBits(12);
570    LOGV("  section_length = %u", section_length);
571    CHECK((section_length & 0xc00) == 0);
572
573    MY_LOGV("  transport_stream_id = %u", br->getBits(16));
574    MY_LOGV("  reserved = %u", br->getBits(2));
575    MY_LOGV("  version_number = %u", br->getBits(5));
576    MY_LOGV("  current_next_indicator = %u", br->getBits(1));
577    MY_LOGV("  section_number = %u", br->getBits(8));
578    MY_LOGV("  last_section_number = %u", br->getBits(8));
579
580    size_t numProgramBytes = (section_length - 5 /* header */ - 4 /* crc */);
581    CHECK_EQ((numProgramBytes % 4), 0u);
582
583    for (size_t i = 0; i < numProgramBytes / 4; ++i) {
584        unsigned program_number = br->getBits(16);
585        LOGV("    program_number = %u", program_number);
586
587        MY_LOGV("    reserved = %u", br->getBits(3));
588
589        if (program_number == 0) {
590            MY_LOGV("    network_PID = 0x%04x", br->getBits(13));
591        } else {
592            unsigned programMapPID = br->getBits(13);
593
594            LOGV("    program_map_PID = 0x%04x", programMapPID);
595
596            mPrograms.push(new Program(programMapPID));
597        }
598    }
599
600    MY_LOGV("  CRC = 0x%08x", br->getBits(32));
601}
602
603void ATSParser::parsePID(
604        ABitReader *br, unsigned PID,
605        unsigned payload_unit_start_indicator) {
606    if (PID == 0) {
607        if (payload_unit_start_indicator) {
608            unsigned skip = br->getBits(8);
609            br->skipBits(skip * 8);
610        }
611        parseProgramAssociationTable(br);
612        return;
613    }
614
615    bool handled = false;
616    for (size_t i = 0; i < mPrograms.size(); ++i) {
617        if (mPrograms.editItemAt(i)->parsePID(
618                    PID, payload_unit_start_indicator, br)) {
619            handled = true;
620            break;
621        }
622    }
623
624    if (!handled) {
625        LOGV("PID 0x%04x not handled.", PID);
626    }
627}
628
629void ATSParser::parseAdaptationField(ABitReader *br) {
630    unsigned adaptation_field_length = br->getBits(8);
631    if (adaptation_field_length > 0) {
632        br->skipBits(adaptation_field_length * 8);  // XXX
633    }
634}
635
636void ATSParser::parseTS(ABitReader *br) {
637    LOGV("---");
638
639    unsigned sync_byte = br->getBits(8);
640    CHECK_EQ(sync_byte, 0x47u);
641
642    MY_LOGV("transport_error_indicator = %u", br->getBits(1));
643
644    unsigned payload_unit_start_indicator = br->getBits(1);
645    LOGV("payload_unit_start_indicator = %u", payload_unit_start_indicator);
646
647    MY_LOGV("transport_priority = %u", br->getBits(1));
648
649    unsigned PID = br->getBits(13);
650    LOGV("PID = 0x%04x", PID);
651
652    MY_LOGV("transport_scrambling_control = %u", br->getBits(2));
653
654    unsigned adaptation_field_control = br->getBits(2);
655    LOGV("adaptation_field_control = %u", adaptation_field_control);
656
657    unsigned continuity_counter = br->getBits(4);
658    LOGV("continuity_counter = %u", continuity_counter);
659
660    // LOGI("PID = 0x%04x, continuity_counter = %u", PID, continuity_counter);
661
662    if (adaptation_field_control == 2 || adaptation_field_control == 3) {
663        parseAdaptationField(br);
664    }
665
666    if (adaptation_field_control == 1 || adaptation_field_control == 3) {
667        parsePID(br, PID, payload_unit_start_indicator);
668    }
669}
670
671sp<MediaSource> ATSParser::getSource(SourceType type) {
672    for (size_t i = 0; i < mPrograms.size(); ++i) {
673        sp<MediaSource> source = mPrograms.editItemAt(i)->getSource(type);
674
675        if (source != NULL) {
676            return source;
677        }
678    }
679
680    return NULL;
681}
682
683}  // namespace android
684