MPEG2TSExtractor.cpp revision d91dc5a0602f54fc0d4d2187f37b5b8169bb62c3 
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/MediaDefs.h>
33#include <media/stagefright/MediaErrors.h>
34#include <media/stagefright/MetaData.h>
35#include <utils/String8.h>
36
37#include "mpeg2ts/AnotherPacketSource.h"
38#include "mpeg2ts/ATSParser.h"
39
40#include <hidl/HybridInterface.h>
41#include <android/hardware/cas/1.0/ICas.h>
42
43namespace android {
44
45using hardware::cas::V1_0::ICas;
46
47static const size_t kTSPacketSize = 188;
48static const int kMaxDurationReadSize = 250000LL;
49static const int kMaxDurationRetry = 6;
50
51struct MPEG2TSSource : public MediaSource {
52    MPEG2TSSource(
53            const sp<MPEG2TSExtractor> &extractor,
54            const sp<AnotherPacketSource> &impl,
55            bool doesSeek);
56
57    virtual status_t start(MetaData *params = NULL);
58    virtual status_t stop();
59    virtual sp<MetaData> getFormat();
60
61    virtual status_t read(
62            MediaBuffer **buffer, const ReadOptions *options = NULL);
63
64private:
65    sp<MPEG2TSExtractor> mExtractor;
66    sp<AnotherPacketSource> mImpl;
67
68    // If there are both audio and video streams, only the video stream
69    // will signal seek on the extractor; otherwise the single stream will seek.
70    bool mDoesSeek;
71
72    DISALLOW_EVIL_CONSTRUCTORS(MPEG2TSSource);
73};
74
75MPEG2TSSource::MPEG2TSSource(
76        const sp<MPEG2TSExtractor> &extractor,
77        const sp<AnotherPacketSource> &impl,
78        bool doesSeek)
79    : mExtractor(extractor),
80      mImpl(impl),
81      mDoesSeek(doesSeek) {
82}
83
84status_t MPEG2TSSource::start(MetaData *params) {
85    return mImpl->start(params);
86}
87
88status_t MPEG2TSSource::stop() {
89    return mImpl->stop();
90}
91
92sp<MetaData> MPEG2TSSource::getFormat() {
93    return mImpl->getFormat();
94}
95
96status_t MPEG2TSSource::read(
97        MediaBuffer **out, const ReadOptions *options) {
98    *out = NULL;
99
100    int64_t seekTimeUs;
101    ReadOptions::SeekMode seekMode;
102    if (mDoesSeek && options && options->getSeekTo(&seekTimeUs, &seekMode)) {
103        // seek is needed
104        status_t err = mExtractor->seek(seekTimeUs, seekMode);
105        if (err != OK) {
106            return err;
107        }
108    }
109
110    if (mExtractor->feedUntilBufferAvailable(mImpl) != OK) {
111        return ERROR_END_OF_STREAM;
112    }
113
114    return mImpl->read(out, options);
115}
116
117////////////////////////////////////////////////////////////////////////////////
118
119MPEG2TSExtractor::MPEG2TSExtractor(const sp<DataSource> &source)
120    : mDataSource(source),
121      mParser(new ATSParser),
122      mLastSyncEvent(0),
123      mOffset(0) {
124    init();
125}
126
127size_t MPEG2TSExtractor::countTracks() {
128    return mSourceImpls.size();
129}
130
131sp<MediaSource> MPEG2TSExtractor::getTrack(size_t index) {
132    if (index >= mSourceImpls.size()) {
133        return NULL;
134    }
135
136    // The seek reference track (video if present; audio otherwise) performs
137    // seek requests, while other tracks ignore requests.
138    return new MPEG2TSSource(this, mSourceImpls.editItemAt(index),
139            (mSeekSyncPoints == &mSyncPoints.editItemAt(index)));
140}
141
142sp<MetaData> MPEG2TSExtractor::getTrackMetaData(
143        size_t index, uint32_t /* flags */) {
144    return index < mSourceImpls.size()
145        ? mSourceImpls.editItemAt(index)->getFormat() : NULL;
146}
147
148sp<MetaData> MPEG2TSExtractor::getMetaData() {
149    sp<MetaData> meta = new MetaData;
150    meta->setCString(kKeyMIMEType, MEDIA_MIMETYPE_CONTAINER_MPEG2TS);
151
152    return meta;
153}
154
155//static
156bool MPEG2TSExtractor::isScrambledFormat(const sp<MetaData> &format) {
157    const char *mime;
158    return format->findCString(kKeyMIMEType, &mime)
159            && (!strcasecmp(MEDIA_MIMETYPE_VIDEO_SCRAMBLED, mime)
160                    || !strcasecmp(MEDIA_MIMETYPE_AUDIO_SCRAMBLED, mime));
161}
162
163status_t MPEG2TSExtractor::setMediaCas(const HInterfaceToken &casToken) {
164    HalToken halToken;
165    halToken.setToExternal((uint8_t*)casToken.data(), casToken.size());
166    sp<ICas> cas = ICas::castFrom(retrieveHalInterface(halToken));
167    ALOGD("setMediaCas: %p", cas.get());
168
169    status_t err = mParser->setMediaCas(cas);
170    if (err == OK) {
171        ALOGI("All tracks now have descramblers");
172        init();
173    }
174    return err;
175}
176
177void MPEG2TSExtractor::addSource(const sp<AnotherPacketSource> &impl) {
178    bool found = false;
179    for (size_t i = 0; i < mSourceImpls.size(); i++) {
180        if (mSourceImpls[i] == impl) {
181            found = true;
182            break;
183        }
184    }
185    if (!found) {
186        mSourceImpls.push(impl);
187    }
188}
189
190void MPEG2TSExtractor::init() {
191    bool haveAudio = false;
192    bool haveVideo = false;
193    int64_t startTime = ALooper::GetNowUs();
194
195    status_t err;
196    while ((err = feedMore(true /* isInit */)) == OK
197            || err == ERROR_DRM_DECRYPT_UNIT_NOT_INITIALIZED) {
198        if (haveAudio && haveVideo) {
199            addSyncPoint_l(mLastSyncEvent);
200            mLastSyncEvent.reset();
201            break;
202        }
203        if (!haveVideo) {
204            sp<AnotherPacketSource> impl =
205                (AnotherPacketSource *)mParser->getSource(
206                        ATSParser::VIDEO).get();
207
208            if (impl != NULL) {
209                sp<MetaData> format = impl->getFormat();
210                if (format != NULL) {
211                    haveVideo = true;
212                    addSource(impl);
213                    if (!isScrambledFormat(format)) {
214                        mSyncPoints.push();
215                        mSeekSyncPoints = &mSyncPoints.editTop();
216                    }
217                }
218            }
219        }
220
221        if (!haveAudio) {
222            sp<AnotherPacketSource> impl =
223                (AnotherPacketSource *)mParser->getSource(
224                        ATSParser::AUDIO).get();
225
226            if (impl != NULL) {
227                sp<MetaData> format = impl->getFormat();
228                if (format != NULL) {
229                    haveAudio = true;
230                    addSource(impl);
231                    if (!isScrambledFormat(format)) {
232                        mSyncPoints.push();
233                        if (!haveVideo) {
234                            mSeekSyncPoints = &mSyncPoints.editTop();
235                        }
236                    }
237                }
238            }
239        }
240
241        addSyncPoint_l(mLastSyncEvent);
242        mLastSyncEvent.reset();
243
244        // ERROR_DRM_DECRYPT_UNIT_NOT_INITIALIZED is returned when the mpeg2ts
245        // is scrambled but we don't have a MediaCas object set. The extraction
246        // will only continue when setMediaCas() is called successfully.
247        if (err == ERROR_DRM_DECRYPT_UNIT_NOT_INITIALIZED) {
248            ALOGI("stopped parsing scrambled content, "
249                  "haveAudio=%d, haveVideo=%d, elaspedTime=%" PRId64,
250                    haveAudio, haveVideo, ALooper::GetNowUs() - startTime);
251            return;
252        }
253
254        // Wait only for 2 seconds to detect audio/video streams.
255        if (ALooper::GetNowUs() - startTime > 2000000ll) {
256            break;
257        }
258    }
259
260    off64_t size;
261    if (mDataSource->getSize(&size) == OK && (haveAudio || haveVideo)) {
262        sp<AnotherPacketSource> impl = haveVideo
263                ? (AnotherPacketSource *)mParser->getSource(
264                        ATSParser::VIDEO).get()
265                : (AnotherPacketSource *)mParser->getSource(
266                        ATSParser::AUDIO).get();
267        size_t prevSyncSize = 1;
268        int64_t durationUs = -1;
269        List<int64_t> durations;
270        // Estimate duration --- stabilize until you get <500ms deviation.
271        while (feedMore() == OK
272                && ALooper::GetNowUs() - startTime <= 2000000ll) {
273            if (mSeekSyncPoints->size() > prevSyncSize) {
274                prevSyncSize = mSeekSyncPoints->size();
275                int64_t diffUs = mSeekSyncPoints->keyAt(prevSyncSize - 1)
276                        - mSeekSyncPoints->keyAt(0);
277                off64_t diffOffset = mSeekSyncPoints->valueAt(prevSyncSize - 1)
278                        - mSeekSyncPoints->valueAt(0);
279                int64_t currentDurationUs = size * diffUs / diffOffset;
280                durations.push_back(currentDurationUs);
281                if (durations.size() > 5) {
282                    durations.erase(durations.begin());
283                    int64_t min = *durations.begin();
284                    int64_t max = *durations.begin();
285                    for (auto duration : durations) {
286                        if (min > duration) {
287                            min = duration;
288                        }
289                        if (max < duration) {
290                            max = duration;
291                        }
292                    }
293                    if (max - min < 500 * 1000) {
294                        durationUs = currentDurationUs;
295                        break;
296                    }
297                }
298            }
299        }
300        status_t err;
301        int64_t bufferedDurationUs;
302        bufferedDurationUs = impl->getBufferedDurationUs(&err);
303        if (err == ERROR_END_OF_STREAM) {
304            durationUs = bufferedDurationUs;
305        }
306        if (durationUs > 0) {
307            const sp<MetaData> meta = impl->getFormat();
308            meta->setInt64(kKeyDuration, durationUs);
309            impl->setFormat(meta);
310        } else {
311            estimateDurationsFromTimesUsAtEnd();
312        }
313    }
314
315    ALOGI("haveAudio=%d, haveVideo=%d, elaspedTime=%" PRId64,
316            haveAudio, haveVideo, ALooper::GetNowUs() - startTime);
317}
318
319status_t MPEG2TSExtractor::feedMore(bool isInit) {
320    Mutex::Autolock autoLock(mLock);
321
322    uint8_t packet[kTSPacketSize];
323    ssize_t n = mDataSource->readAt(mOffset, packet, kTSPacketSize);
324
325    if (n < (ssize_t)kTSPacketSize) {
326        if (n >= 0) {
327            mParser->signalEOS(ERROR_END_OF_STREAM);
328        }
329        return (n < 0) ? (status_t)n : ERROR_END_OF_STREAM;
330    }
331
332    ATSParser::SyncEvent event(mOffset);
333    mOffset += n;
334    status_t err = mParser->feedTSPacket(packet, kTSPacketSize, &event);
335    if (event.hasReturnedData()) {
336        if (isInit) {
337            mLastSyncEvent = event;
338        } else {
339            addSyncPoint_l(event);
340        }
341    }
342    return err;
343}
344
345void MPEG2TSExtractor::addSyncPoint_l(const ATSParser::SyncEvent &event) {
346    if (!event.hasReturnedData()) {
347        return;
348    }
349
350    for (size_t i = 0; i < mSourceImpls.size(); ++i) {
351        if (mSourceImpls[i].get() == event.getMediaSource().get()) {
352            KeyedVector<int64_t, off64_t> *syncPoints = &mSyncPoints.editItemAt(i);
353            syncPoints->add(event.getTimeUs(), event.getOffset());
354            // We're keeping the size of the sync points at most 5mb per a track.
355            size_t size = syncPoints->size();
356            if (size >= 327680) {
357                int64_t firstTimeUs = syncPoints->keyAt(0);
358                int64_t lastTimeUs = syncPoints->keyAt(size - 1);
359                if (event.getTimeUs() - firstTimeUs > lastTimeUs - event.getTimeUs()) {
360                    syncPoints->removeItemsAt(0, 4096);
361                } else {
362                    syncPoints->removeItemsAt(size - 4096, 4096);
363                }
364            }
365            break;
366        }
367    }
368}
369
370status_t MPEG2TSExtractor::estimateDurationsFromTimesUsAtEnd()  {
371    if (!(mDataSource->flags() & DataSource::kIsLocalFileSource)) {
372        return ERROR_UNSUPPORTED;
373    }
374
375    off64_t size = 0;
376    status_t err = mDataSource->getSize(&size);
377    if (err != OK) {
378        return err;
379    }
380
381    uint8_t packet[kTSPacketSize];
382    const off64_t zero = 0;
383    off64_t offset = max(zero, size - kMaxDurationReadSize);
384    if (mDataSource->readAt(offset, &packet, 0) < 0) {
385        return ERROR_IO;
386    }
387
388    int retry = 0;
389    bool allDurationsFound = false;
390    int64_t timeAnchorUs = mParser->getFirstPTSTimeUs();
391    do {
392        int bytesRead = 0;
393        sp<ATSParser> parser = new ATSParser(ATSParser::TS_TIMESTAMPS_ARE_ABSOLUTE);
394        ATSParser::SyncEvent ev(0);
395        offset = max(zero, size - (kMaxDurationReadSize << retry));
396        offset = (offset / kTSPacketSize) * kTSPacketSize;
397        for (;;) {
398            if (bytesRead >= kMaxDurationReadSize << max(0, retry - 1)) {
399                break;
400            }
401
402            ssize_t n = mDataSource->readAt(offset, packet, kTSPacketSize);
403            if (n < 0) {
404                return n;
405            } else if (n < (ssize_t)kTSPacketSize) {
406                break;
407            }
408
409            offset += kTSPacketSize;
410            bytesRead += kTSPacketSize;
411            err = parser->feedTSPacket(packet, kTSPacketSize, &ev);
412            if (err != OK) {
413                return err;
414            }
415
416            if (ev.hasReturnedData()) {
417                int64_t durationUs = ev.getTimeUs();
418                ATSParser::SourceType type = ev.getType();
419                ev.reset();
420
421                int64_t firstTimeUs;
422                sp<AnotherPacketSource> src =
423                    (AnotherPacketSource *)mParser->getSource(type).get();
424                if (src == NULL || src->nextBufferTime(&firstTimeUs) != OK) {
425                    continue;
426                }
427                durationUs += src->getEstimatedBufferDurationUs();
428                durationUs -= timeAnchorUs;
429                durationUs -= firstTimeUs;
430                if (durationUs > 0) {
431                    int64_t origDurationUs, lastDurationUs;
432                    const sp<MetaData> meta = src->getFormat();
433                    const uint32_t kKeyLastDuration = 'ldur';
434                    // Require two consecutive duration calculations to be within 1 sec before
435                    // updating; use MetaData to store previous duration estimate in per-stream
436                    // context.
437                    if (!meta->findInt64(kKeyDuration, &origDurationUs)
438                            || !meta->findInt64(kKeyLastDuration, &lastDurationUs)
439                            || (origDurationUs < durationUs
440                             && abs(durationUs - lastDurationUs) < 60000000)) {
441                        meta->setInt64(kKeyDuration, durationUs);
442                    }
443                    meta->setInt64(kKeyLastDuration, durationUs);
444                }
445            }
446        }
447
448        if (!allDurationsFound) {
449            allDurationsFound = true;
450            for (auto t: {ATSParser::VIDEO, ATSParser::AUDIO}) {
451                sp<AnotherPacketSource> src = (AnotherPacketSource *)mParser->getSource(t).get();
452                if (src == NULL) {
453                    continue;
454                }
455                int64_t durationUs;
456                const sp<MetaData> meta = src->getFormat();
457                if (!meta->findInt64(kKeyDuration, &durationUs)) {
458                    allDurationsFound = false;
459                    break;
460                }
461            }
462        }
463
464        ++retry;
465    } while(!allDurationsFound && offset > 0 && retry <= kMaxDurationRetry);
466
467    return allDurationsFound? OK : ERROR_UNSUPPORTED;
468}
469
470uint32_t MPEG2TSExtractor::flags() const {
471    return CAN_PAUSE | CAN_SEEK_BACKWARD | CAN_SEEK_FORWARD;
472}
473
474status_t MPEG2TSExtractor::seek(int64_t seekTimeUs,
475        const MediaSource::ReadOptions::SeekMode &seekMode) {
476    if (mSeekSyncPoints == NULL || mSeekSyncPoints->isEmpty()) {
477        ALOGW("No sync point to seek to.");
478        // ... and therefore we have nothing useful to do here.
479        return OK;
480    }
481
482    // Determine whether we're seeking beyond the known area.
483    bool shouldSeekBeyond =
484            (seekTimeUs > mSeekSyncPoints->keyAt(mSeekSyncPoints->size() - 1));
485
486    // Determine the sync point to seek.
487    size_t index = 0;
488    for (; index < mSeekSyncPoints->size(); ++index) {
489        int64_t timeUs = mSeekSyncPoints->keyAt(index);
490        if (timeUs > seekTimeUs) {
491            break;
492        }
493    }
494
495    switch (seekMode) {
496        case MediaSource::ReadOptions::SEEK_NEXT_SYNC:
497            if (index == mSeekSyncPoints->size()) {
498                ALOGW("Next sync not found; starting from the latest sync.");
499                --index;
500            }
501            break;
502        case MediaSource::ReadOptions::SEEK_CLOSEST_SYNC:
503        case MediaSource::ReadOptions::SEEK_CLOSEST:
504            ALOGW("seekMode not supported: %d; falling back to PREVIOUS_SYNC",
505                    seekMode);
506            // fall-through
507        case MediaSource::ReadOptions::SEEK_PREVIOUS_SYNC:
508            if (index == 0) {
509                ALOGW("Previous sync not found; starting from the earliest "
510                        "sync.");
511            } else {
512                --index;
513            }
514            break;
515    }
516    if (!shouldSeekBeyond || mOffset <= mSeekSyncPoints->valueAt(index)) {
517        int64_t actualSeekTimeUs = mSeekSyncPoints->keyAt(index);
518        mOffset = mSeekSyncPoints->valueAt(index);
519        status_t err = queueDiscontinuityForSeek(actualSeekTimeUs);
520        if (err != OK) {
521            return err;
522        }
523    }
524
525    if (shouldSeekBeyond) {
526        status_t err = seekBeyond(seekTimeUs);
527        if (err != OK) {
528            return err;
529        }
530    }
531
532    // Fast-forward to sync frame.
533    for (size_t i = 0; i < mSourceImpls.size(); ++i) {
534        const sp<AnotherPacketSource> &impl = mSourceImpls[i];
535        status_t err;
536        feedUntilBufferAvailable(impl);
537        while (impl->hasBufferAvailable(&err)) {
538            sp<AMessage> meta = impl->getMetaAfterLastDequeued(0);
539            sp<ABuffer> buffer;
540            if (meta == NULL) {
541                return UNKNOWN_ERROR;
542            }
543            int32_t sync;
544            if (meta->findInt32("isSync", &sync) && sync) {
545                break;
546            }
547            err = impl->dequeueAccessUnit(&buffer);
548            if (err != OK) {
549                return err;
550            }
551            feedUntilBufferAvailable(impl);
552        }
553    }
554
555    return OK;
556}
557
558status_t MPEG2TSExtractor::queueDiscontinuityForSeek(int64_t actualSeekTimeUs) {
559    // Signal discontinuity
560    sp<AMessage> extra(new AMessage);
561    extra->setInt64(IStreamListener::kKeyMediaTimeUs, actualSeekTimeUs);
562    mParser->signalDiscontinuity(ATSParser::DISCONTINUITY_TIME, extra);
563
564    // After discontinuity, impl should only have discontinuities
565    // with the last being what we queued. Dequeue them all here.
566    for (size_t i = 0; i < mSourceImpls.size(); ++i) {
567        const sp<AnotherPacketSource> &impl = mSourceImpls.itemAt(i);
568        sp<ABuffer> buffer;
569        status_t err;
570        while (impl->hasBufferAvailable(&err)) {
571            if (err != OK) {
572                return err;
573            }
574            err = impl->dequeueAccessUnit(&buffer);
575            // If the source contains anything but discontinuity, that's
576            // a programming mistake.
577            CHECK(err == INFO_DISCONTINUITY);
578        }
579    }
580
581    // Feed until we have a buffer for each source.
582    for (size_t i = 0; i < mSourceImpls.size(); ++i) {
583        const sp<AnotherPacketSource> &impl = mSourceImpls.itemAt(i);
584        sp<ABuffer> buffer;
585        status_t err = feedUntilBufferAvailable(impl);
586        if (err != OK) {
587            return err;
588        }
589    }
590
591    return OK;
592}
593
594status_t MPEG2TSExtractor::seekBeyond(int64_t seekTimeUs) {
595    // If we're seeking beyond where we know --- read until we reach there.
596    size_t syncPointsSize = mSeekSyncPoints->size();
597
598    while (seekTimeUs > mSeekSyncPoints->keyAt(
599            mSeekSyncPoints->size() - 1)) {
600        status_t err;
601        if (syncPointsSize < mSeekSyncPoints->size()) {
602            syncPointsSize = mSeekSyncPoints->size();
603            int64_t syncTimeUs = mSeekSyncPoints->keyAt(syncPointsSize - 1);
604            // Dequeue buffers before sync point in order to avoid too much
605            // cache building up.
606            sp<ABuffer> buffer;
607            for (size_t i = 0; i < mSourceImpls.size(); ++i) {
608                const sp<AnotherPacketSource> &impl = mSourceImpls[i];
609                int64_t timeUs;
610                while ((err = impl->nextBufferTime(&timeUs)) == OK) {
611                    if (timeUs < syncTimeUs) {
612                        impl->dequeueAccessUnit(&buffer);
613                    } else {
614                        break;
615                    }
616                }
617                if (err != OK && err != -EWOULDBLOCK) {
618                    return err;
619                }
620            }
621        }
622        if (feedMore() != OK) {
623            return ERROR_END_OF_STREAM;
624        }
625    }
626
627    return OK;
628}
629
630status_t MPEG2TSExtractor::feedUntilBufferAvailable(
631        const sp<AnotherPacketSource> &impl) {
632    status_t finalResult;
633    while (!impl->hasBufferAvailable(&finalResult)) {
634        if (finalResult != OK) {
635            return finalResult;
636        }
637
638        status_t err = feedMore();
639        if (err != OK) {
640            impl->signalEOS(err);
641        }
642    }
643    return OK;
644}
645
646////////////////////////////////////////////////////////////////////////////////
647
648bool SniffMPEG2TS(
649        const sp<DataSource> &source, String8 *mimeType, float *confidence,
650        sp<AMessage> *) {
651    for (int i = 0; i < 5; ++i) {
652        char header;
653        if (source->readAt(kTSPacketSize * i, &header, 1) != 1
654                || header != 0x47) {
655            return false;
656        }
657    }
658
659    *confidence = 0.1f;
660    mimeType->setTo(MEDIA_MIMETYPE_CONTAINER_MPEG2TS);
661
662    return true;
663}
664
665}  // namespace android
666