MPEG2TSExtractor.cpp revision 15d02f84351eaca14099bde11cfbf6f124bea71f 
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 "MPEG2TSExtractor"
19
20#include <inttypes.h>
21#include <utils/Log.h>
22
23#include "MPEG2TSExtractor.h"
24
25#include <media/DataSource.h>
26#include <media/IStreamSource.h>
27#include <media/MediaSource.h>
28#include <media/stagefright/foundation/ABuffer.h>
29#include <media/stagefright/foundation/ADebug.h>
30#include <media/stagefright/foundation/ALooper.h>
31#include <media/stagefright/foundation/AUtils.h>
32#include <media/stagefright/foundation/MediaKeys.h>
33#include <media/stagefright/MediaDefs.h>
34#include <media/stagefright/MediaErrors.h>
35#include <media/stagefright/MetaData.h>
36#include <utils/String8.h>
37
38#include "mpeg2ts/AnotherPacketSource.h"
39#include "mpeg2ts/ATSParser.h"
40
41#include <hidl/HybridInterface.h>
42#include <android/hardware/cas/1.0/ICas.h>
43
44namespace android {
45
46using hardware::cas::V1_0::ICas;
47
48static const size_t kTSPacketSize = 188;
49static const int kMaxDurationReadSize = 250000LL;
50static const int kMaxDurationRetry = 6;
51
52struct MPEG2TSSource : public MediaSource {
53    MPEG2TSSource(
54            const sp<MPEG2TSExtractor> &extractor,
55            const sp<AnotherPacketSource> &impl,
56            bool doesSeek);
57
58    virtual status_t start(MetaData *params = NULL);
59    virtual status_t stop();
60    virtual sp<MetaData> getFormat();
61
62    virtual status_t read(
63            MediaBuffer **buffer, const ReadOptions *options = NULL);
64
65private:
66    sp<MPEG2TSExtractor> mExtractor;
67    sp<AnotherPacketSource> mImpl;
68
69    // If there are both audio and video streams, only the video stream
70    // will signal seek on the extractor; otherwise the single stream will seek.
71    bool mDoesSeek;
72
73    DISALLOW_EVIL_CONSTRUCTORS(MPEG2TSSource);
74};
75
76MPEG2TSSource::MPEG2TSSource(
77        const sp<MPEG2TSExtractor> &extractor,
78        const sp<AnotherPacketSource> &impl,
79        bool doesSeek)
80    : mExtractor(extractor),
81      mImpl(impl),
82      mDoesSeek(doesSeek) {
83}
84
85status_t MPEG2TSSource::start(MetaData *params) {
86    return mImpl->start(params);
87}
88
89status_t MPEG2TSSource::stop() {
90    return mImpl->stop();
91}
92
93sp<MetaData> MPEG2TSSource::getFormat() {
94    return mImpl->getFormat();
95}
96
97status_t MPEG2TSSource::read(
98        MediaBuffer **out, const ReadOptions *options) {
99    *out = NULL;
100
101    int64_t seekTimeUs;
102    ReadOptions::SeekMode seekMode;
103    if (mDoesSeek && options && options->getSeekTo(&seekTimeUs, &seekMode)) {
104        // seek is needed
105        status_t err = mExtractor->seek(seekTimeUs, seekMode);
106        if (err != OK) {
107            return err;
108        }
109    }
110
111    if (mExtractor->feedUntilBufferAvailable(mImpl) != OK) {
112        return ERROR_END_OF_STREAM;
113    }
114
115    return mImpl->read(out, options);
116}
117
118////////////////////////////////////////////////////////////////////////////////
119
120MPEG2TSExtractor::MPEG2TSExtractor(const sp<DataSource> &source)
121    : mDataSource(source),
122      mParser(new ATSParser),
123      mLastSyncEvent(0),
124      mOffset(0) {
125    init();
126}
127
128size_t MPEG2TSExtractor::countTracks() {
129    return mSourceImpls.size();
130}
131
132sp<MediaSource> MPEG2TSExtractor::getTrack(size_t index) {
133    if (index >= mSourceImpls.size()) {
134        return NULL;
135    }
136
137    // The seek reference track (video if present; audio otherwise) performs
138    // seek requests, while other tracks ignore requests.
139    return new MPEG2TSSource(this, mSourceImpls.editItemAt(index),
140            (mSeekSyncPoints == &mSyncPoints.editItemAt(index)));
141}
142
143sp<MetaData> MPEG2TSExtractor::getTrackMetaData(
144        size_t index, uint32_t /* flags */) {
145    return index < mSourceImpls.size()
146        ? mSourceImpls.editItemAt(index)->getFormat() : NULL;
147}
148
149sp<MetaData> MPEG2TSExtractor::getMetaData() {
150    sp<MetaData> meta = new MetaData;
151    meta->setCString(kKeyMIMEType, MEDIA_MIMETYPE_CONTAINER_MPEG2TS);
152
153    return meta;
154}
155
156//static
157bool MPEG2TSExtractor::isScrambledFormat(const sp<MetaData> &format) {
158    const char *mime;
159    return format->findCString(kKeyMIMEType, &mime)
160            && (!strcasecmp(MEDIA_MIMETYPE_VIDEO_SCRAMBLED, mime)
161                    || !strcasecmp(MEDIA_MIMETYPE_AUDIO_SCRAMBLED, mime));
162}
163
164status_t MPEG2TSExtractor::setMediaCas(const HInterfaceToken &casToken) {
165    HalToken halToken;
166    halToken.setToExternal((uint8_t*)casToken.data(), casToken.size());
167    sp<ICas> cas = ICas::castFrom(retrieveHalInterface(halToken));
168    ALOGD("setMediaCas: %p", cas.get());
169
170    status_t err = mParser->setMediaCas(cas);
171    if (err == OK) {
172        ALOGI("All tracks now have descramblers");
173        init();
174    }
175    return err;
176}
177
178void MPEG2TSExtractor::addSource(const sp<AnotherPacketSource> &impl) {
179    bool found = false;
180    for (size_t i = 0; i < mSourceImpls.size(); i++) {
181        if (mSourceImpls[i] == impl) {
182            found = true;
183            break;
184        }
185    }
186    if (!found) {
187        mSourceImpls.push(impl);
188    }
189}
190
191void MPEG2TSExtractor::init() {
192    bool haveAudio = false;
193    bool haveVideo = false;
194    int64_t startTime = ALooper::GetNowUs();
195
196    status_t err;
197    while ((err = feedMore(true /* isInit */)) == OK
198            || err == ERROR_DRM_DECRYPT_UNIT_NOT_INITIALIZED) {
199        if (haveAudio && haveVideo) {
200            addSyncPoint_l(mLastSyncEvent);
201            mLastSyncEvent.reset();
202            break;
203        }
204        if (!haveVideo) {
205            sp<AnotherPacketSource> impl =
206                (AnotherPacketSource *)mParser->getSource(
207                        ATSParser::VIDEO).get();
208
209            if (impl != NULL) {
210                sp<MetaData> format = impl->getFormat();
211                if (format != NULL) {
212                    haveVideo = true;
213                    addSource(impl);
214                    if (!isScrambledFormat(format)) {
215                        mSyncPoints.push();
216                        mSeekSyncPoints = &mSyncPoints.editTop();
217                    }
218                }
219            }
220        }
221
222        if (!haveAudio) {
223            sp<AnotherPacketSource> impl =
224                (AnotherPacketSource *)mParser->getSource(
225                        ATSParser::AUDIO).get();
226
227            if (impl != NULL) {
228                sp<MetaData> format = impl->getFormat();
229                if (format != NULL) {
230                    haveAudio = true;
231                    addSource(impl);
232                    if (!isScrambledFormat(format)) {
233                        mSyncPoints.push();
234                        if (!haveVideo) {
235                            mSeekSyncPoints = &mSyncPoints.editTop();
236                        }
237                    }
238                }
239            }
240        }
241
242        addSyncPoint_l(mLastSyncEvent);
243        mLastSyncEvent.reset();
244
245        // ERROR_DRM_DECRYPT_UNIT_NOT_INITIALIZED is returned when the mpeg2ts
246        // is scrambled but we don't have a MediaCas object set. The extraction
247        // will only continue when setMediaCas() is called successfully.
248        if (err == ERROR_DRM_DECRYPT_UNIT_NOT_INITIALIZED) {
249            ALOGI("stopped parsing scrambled content, "
250                  "haveAudio=%d, haveVideo=%d, elaspedTime=%" PRId64,
251                    haveAudio, haveVideo, ALooper::GetNowUs() - startTime);
252            return;
253        }
254
255        // Wait only for 2 seconds to detect audio/video streams.
256        if (ALooper::GetNowUs() - startTime > 2000000ll) {
257            break;
258        }
259    }
260
261    off64_t size;
262    if (mDataSource->getSize(&size) == OK && (haveAudio || haveVideo)) {
263        sp<AnotherPacketSource> impl = haveVideo
264                ? (AnotherPacketSource *)mParser->getSource(
265                        ATSParser::VIDEO).get()
266                : (AnotherPacketSource *)mParser->getSource(
267                        ATSParser::AUDIO).get();
268        size_t prevSyncSize = 1;
269        int64_t durationUs = -1;
270        List<int64_t> durations;
271        // Estimate duration --- stabilize until you get <500ms deviation.
272        while (feedMore() == OK
273                && ALooper::GetNowUs() - startTime <= 2000000ll) {
274            if (mSeekSyncPoints->size() > prevSyncSize) {
275                prevSyncSize = mSeekSyncPoints->size();
276                int64_t diffUs = mSeekSyncPoints->keyAt(prevSyncSize - 1)
277                        - mSeekSyncPoints->keyAt(0);
278                off64_t diffOffset = mSeekSyncPoints->valueAt(prevSyncSize - 1)
279                        - mSeekSyncPoints->valueAt(0);
280                int64_t currentDurationUs = size * diffUs / diffOffset;
281                durations.push_back(currentDurationUs);
282                if (durations.size() > 5) {
283                    durations.erase(durations.begin());
284                    int64_t min = *durations.begin();
285                    int64_t max = *durations.begin();
286                    for (auto duration : durations) {
287                        if (min > duration) {
288                            min = duration;
289                        }
290                        if (max < duration) {
291                            max = duration;
292                        }
293                    }
294                    if (max - min < 500 * 1000) {
295                        durationUs = currentDurationUs;
296                        break;
297                    }
298                }
299            }
300        }
301        status_t err;
302        int64_t bufferedDurationUs;
303        bufferedDurationUs = impl->getBufferedDurationUs(&err);
304        if (err == ERROR_END_OF_STREAM) {
305            durationUs = bufferedDurationUs;
306        }
307        if (durationUs > 0) {
308            const sp<MetaData> meta = impl->getFormat();
309            meta->setInt64(kKeyDuration, durationUs);
310            impl->setFormat(meta);
311        } else {
312            estimateDurationsFromTimesUsAtEnd();
313        }
314    }
315
316    ALOGI("haveAudio=%d, haveVideo=%d, elaspedTime=%" PRId64,
317            haveAudio, haveVideo, ALooper::GetNowUs() - startTime);
318}
319
320status_t MPEG2TSExtractor::feedMore(bool isInit) {
321    Mutex::Autolock autoLock(mLock);
322
323    uint8_t packet[kTSPacketSize];
324    ssize_t n = mDataSource->readAt(mOffset, packet, kTSPacketSize);
325
326    if (n < (ssize_t)kTSPacketSize) {
327        if (n >= 0) {
328            mParser->signalEOS(ERROR_END_OF_STREAM);
329        }
330        return (n < 0) ? (status_t)n : ERROR_END_OF_STREAM;
331    }
332
333    ATSParser::SyncEvent event(mOffset);
334    mOffset += n;
335    status_t err = mParser->feedTSPacket(packet, kTSPacketSize, &event);
336    if (event.hasReturnedData()) {
337        if (isInit) {
338            mLastSyncEvent = event;
339        } else {
340            addSyncPoint_l(event);
341        }
342    }
343    return err;
344}
345
346void MPEG2TSExtractor::addSyncPoint_l(const ATSParser::SyncEvent &event) {
347    if (!event.hasReturnedData()) {
348        return;
349    }
350
351    for (size_t i = 0; i < mSourceImpls.size(); ++i) {
352        if (mSourceImpls[i].get() == event.getMediaSource().get()) {
353            KeyedVector<int64_t, off64_t> *syncPoints = &mSyncPoints.editItemAt(i);
354            syncPoints->add(event.getTimeUs(), event.getOffset());
355            // We're keeping the size of the sync points at most 5mb per a track.
356            size_t size = syncPoints->size();
357            if (size >= 327680) {
358                int64_t firstTimeUs = syncPoints->keyAt(0);
359                int64_t lastTimeUs = syncPoints->keyAt(size - 1);
360                if (event.getTimeUs() - firstTimeUs > lastTimeUs - event.getTimeUs()) {
361                    syncPoints->removeItemsAt(0, 4096);
362                } else {
363                    syncPoints->removeItemsAt(size - 4096, 4096);
364                }
365            }
366            break;
367        }
368    }
369}
370
371status_t MPEG2TSExtractor::estimateDurationsFromTimesUsAtEnd()  {
372    if (!(mDataSource->flags() & DataSource::kIsLocalFileSource)) {
373        return ERROR_UNSUPPORTED;
374    }
375
376    off64_t size = 0;
377    status_t err = mDataSource->getSize(&size);
378    if (err != OK) {
379        return err;
380    }
381
382    uint8_t packet[kTSPacketSize];
383    const off64_t zero = 0;
384    off64_t offset = max(zero, size - kMaxDurationReadSize);
385    if (mDataSource->readAt(offset, &packet, 0) < 0) {
386        return ERROR_IO;
387    }
388
389    int retry = 0;
390    bool allDurationsFound = false;
391    int64_t timeAnchorUs = mParser->getFirstPTSTimeUs();
392    do {
393        int bytesRead = 0;
394        sp<ATSParser> parser = new ATSParser(ATSParser::TS_TIMESTAMPS_ARE_ABSOLUTE);
395        ATSParser::SyncEvent ev(0);
396        offset = max(zero, size - (kMaxDurationReadSize << retry));
397        offset = (offset / kTSPacketSize) * kTSPacketSize;
398        for (;;) {
399            if (bytesRead >= kMaxDurationReadSize << max(0, retry - 1)) {
400                break;
401            }
402
403            ssize_t n = mDataSource->readAt(offset, packet, kTSPacketSize);
404            if (n < 0) {
405                return n;
406            } else if (n < (ssize_t)kTSPacketSize) {
407                break;
408            }
409
410            offset += kTSPacketSize;
411            bytesRead += kTSPacketSize;
412            err = parser->feedTSPacket(packet, kTSPacketSize, &ev);
413            if (err != OK) {
414                return err;
415            }
416
417            if (ev.hasReturnedData()) {
418                int64_t durationUs = ev.getTimeUs();
419                ATSParser::SourceType type = ev.getType();
420                ev.reset();
421
422                int64_t firstTimeUs;
423                sp<AnotherPacketSource> src =
424                    (AnotherPacketSource *)mParser->getSource(type).get();
425                if (src == NULL || src->nextBufferTime(&firstTimeUs) != OK) {
426                    continue;
427                }
428                durationUs += src->getEstimatedBufferDurationUs();
429                durationUs -= timeAnchorUs;
430                durationUs -= firstTimeUs;
431                if (durationUs > 0) {
432                    int64_t origDurationUs, lastDurationUs;
433                    const sp<MetaData> meta = src->getFormat();
434                    const uint32_t kKeyLastDuration = 'ldur';
435                    // Require two consecutive duration calculations to be within 1 sec before
436                    // updating; use MetaData to store previous duration estimate in per-stream
437                    // context.
438                    if (!meta->findInt64(kKeyDuration, &origDurationUs)
439                            || !meta->findInt64(kKeyLastDuration, &lastDurationUs)
440                            || (origDurationUs < durationUs
441                             && abs(durationUs - lastDurationUs) < 60000000)) {
442                        meta->setInt64(kKeyDuration, durationUs);
443                    }
444                    meta->setInt64(kKeyLastDuration, durationUs);
445                }
446            }
447        }
448
449        if (!allDurationsFound) {
450            allDurationsFound = true;
451            for (auto t: {ATSParser::VIDEO, ATSParser::AUDIO}) {
452                sp<AnotherPacketSource> src = (AnotherPacketSource *)mParser->getSource(t).get();
453                if (src == NULL) {
454                    continue;
455                }
456                int64_t durationUs;
457                const sp<MetaData> meta = src->getFormat();
458                if (!meta->findInt64(kKeyDuration, &durationUs)) {
459                    allDurationsFound = false;
460                    break;
461                }
462            }
463        }
464
465        ++retry;
466    } while(!allDurationsFound && offset > 0 && retry <= kMaxDurationRetry);
467
468    return allDurationsFound? OK : ERROR_UNSUPPORTED;
469}
470
471uint32_t MPEG2TSExtractor::flags() const {
472    return CAN_PAUSE | CAN_SEEK_BACKWARD | CAN_SEEK_FORWARD;
473}
474
475status_t MPEG2TSExtractor::seek(int64_t seekTimeUs,
476        const MediaSource::ReadOptions::SeekMode &seekMode) {
477    if (mSeekSyncPoints == NULL || mSeekSyncPoints->isEmpty()) {
478        ALOGW("No sync point to seek to.");
479        // ... and therefore we have nothing useful to do here.
480        return OK;
481    }
482
483    // Determine whether we're seeking beyond the known area.
484    bool shouldSeekBeyond =
485            (seekTimeUs > mSeekSyncPoints->keyAt(mSeekSyncPoints->size() - 1));
486
487    // Determine the sync point to seek.
488    size_t index = 0;
489    for (; index < mSeekSyncPoints->size(); ++index) {
490        int64_t timeUs = mSeekSyncPoints->keyAt(index);
491        if (timeUs > seekTimeUs) {
492            break;
493        }
494    }
495
496    switch (seekMode) {
497        case MediaSource::ReadOptions::SEEK_NEXT_SYNC:
498            if (index == mSeekSyncPoints->size()) {
499                ALOGW("Next sync not found; starting from the latest sync.");
500                --index;
501            }
502            break;
503        case MediaSource::ReadOptions::SEEK_CLOSEST_SYNC:
504        case MediaSource::ReadOptions::SEEK_CLOSEST:
505            ALOGW("seekMode not supported: %d; falling back to PREVIOUS_SYNC",
506                    seekMode);
507            // fall-through
508        case MediaSource::ReadOptions::SEEK_PREVIOUS_SYNC:
509            if (index == 0) {
510                ALOGW("Previous sync not found; starting from the earliest "
511                        "sync.");
512            } else {
513                --index;
514            }
515            break;
516        default:
517            return ERROR_UNSUPPORTED;
518    }
519    if (!shouldSeekBeyond || mOffset <= mSeekSyncPoints->valueAt(index)) {
520        int64_t actualSeekTimeUs = mSeekSyncPoints->keyAt(index);
521        mOffset = mSeekSyncPoints->valueAt(index);
522        status_t err = queueDiscontinuityForSeek(actualSeekTimeUs);
523        if (err != OK) {
524            return err;
525        }
526    }
527
528    if (shouldSeekBeyond) {
529        status_t err = seekBeyond(seekTimeUs);
530        if (err != OK) {
531            return err;
532        }
533    }
534
535    // Fast-forward to sync frame.
536    for (size_t i = 0; i < mSourceImpls.size(); ++i) {
537        const sp<AnotherPacketSource> &impl = mSourceImpls[i];
538        status_t err;
539        feedUntilBufferAvailable(impl);
540        while (impl->hasBufferAvailable(&err)) {
541            sp<AMessage> meta = impl->getMetaAfterLastDequeued(0);
542            sp<ABuffer> buffer;
543            if (meta == NULL) {
544                return UNKNOWN_ERROR;
545            }
546            int32_t sync;
547            if (meta->findInt32("isSync", &sync) && sync) {
548                break;
549            }
550            err = impl->dequeueAccessUnit(&buffer);
551            if (err != OK) {
552                return err;
553            }
554            feedUntilBufferAvailable(impl);
555        }
556    }
557
558    return OK;
559}
560
561status_t MPEG2TSExtractor::queueDiscontinuityForSeek(int64_t actualSeekTimeUs) {
562    // Signal discontinuity
563    sp<AMessage> extra(new AMessage);
564    extra->setInt64(kATSParserKeyMediaTimeUs, actualSeekTimeUs);
565    mParser->signalDiscontinuity(ATSParser::DISCONTINUITY_TIME, extra);
566
567    // After discontinuity, impl should only have discontinuities
568    // with the last being what we queued. Dequeue them all here.
569    for (size_t i = 0; i < mSourceImpls.size(); ++i) {
570        const sp<AnotherPacketSource> &impl = mSourceImpls.itemAt(i);
571        sp<ABuffer> buffer;
572        status_t err;
573        while (impl->hasBufferAvailable(&err)) {
574            if (err != OK) {
575                return err;
576            }
577            err = impl->dequeueAccessUnit(&buffer);
578            // If the source contains anything but discontinuity, that's
579            // a programming mistake.
580            CHECK(err == INFO_DISCONTINUITY);
581        }
582    }
583
584    // Feed until we have a buffer for each source.
585    for (size_t i = 0; i < mSourceImpls.size(); ++i) {
586        const sp<AnotherPacketSource> &impl = mSourceImpls.itemAt(i);
587        sp<ABuffer> buffer;
588        status_t err = feedUntilBufferAvailable(impl);
589        if (err != OK) {
590            return err;
591        }
592    }
593
594    return OK;
595}
596
597status_t MPEG2TSExtractor::seekBeyond(int64_t seekTimeUs) {
598    // If we're seeking beyond where we know --- read until we reach there.
599    size_t syncPointsSize = mSeekSyncPoints->size();
600
601    while (seekTimeUs > mSeekSyncPoints->keyAt(
602            mSeekSyncPoints->size() - 1)) {
603        status_t err;
604        if (syncPointsSize < mSeekSyncPoints->size()) {
605            syncPointsSize = mSeekSyncPoints->size();
606            int64_t syncTimeUs = mSeekSyncPoints->keyAt(syncPointsSize - 1);
607            // Dequeue buffers before sync point in order to avoid too much
608            // cache building up.
609            sp<ABuffer> buffer;
610            for (size_t i = 0; i < mSourceImpls.size(); ++i) {
611                const sp<AnotherPacketSource> &impl = mSourceImpls[i];
612                int64_t timeUs;
613                while ((err = impl->nextBufferTime(&timeUs)) == OK) {
614                    if (timeUs < syncTimeUs) {
615                        impl->dequeueAccessUnit(&buffer);
616                    } else {
617                        break;
618                    }
619                }
620                if (err != OK && err != -EWOULDBLOCK) {
621                    return err;
622                }
623            }
624        }
625        if (feedMore() != OK) {
626            return ERROR_END_OF_STREAM;
627        }
628    }
629
630    return OK;
631}
632
633status_t MPEG2TSExtractor::feedUntilBufferAvailable(
634        const sp<AnotherPacketSource> &impl) {
635    status_t finalResult;
636    while (!impl->hasBufferAvailable(&finalResult)) {
637        if (finalResult != OK) {
638            return finalResult;
639        }
640
641        status_t err = feedMore();
642        if (err != OK) {
643            impl->signalEOS(err);
644        }
645    }
646    return OK;
647}
648
649////////////////////////////////////////////////////////////////////////////////
650
651bool SniffMPEG2TS(
652        const sp<DataSource> &source, String8 *mimeType, float *confidence,
653        sp<AMessage> *) {
654    for (int i = 0; i < 5; ++i) {
655        char header;
656        if (source->readAt(kTSPacketSize * i, &header, 1) != 1
657                || header != 0x47) {
658            return false;
659        }
660    }
661
662    *confidence = 0.1f;
663    mimeType->setTo(MEDIA_MIMETYPE_CONTAINER_MPEG2TS);
664
665    return true;
666}
667
668}  // namespace android
669