PlaylistFetcher.cpp revision daad5b2f4a6bb46a7911661e398278d6a80d7093 
1/*
2 * Copyright (C) 2012 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 "PlaylistFetcher"
19#include <utils/Log.h>
20
21#include "PlaylistFetcher.h"
22
23#include "LiveDataSource.h"
24#include "LiveSession.h"
25#include "M3UParser.h"
26
27#include "include/avc_utils.h"
28#include "include/HTTPBase.h"
29#include "include/ID3.h"
30#include "mpeg2ts/AnotherPacketSource.h"
31
32#include <media/IStreamSource.h>
33#include <media/stagefright/foundation/ABitReader.h>
34#include <media/stagefright/foundation/ABuffer.h>
35#include <media/stagefright/foundation/ADebug.h>
36#include <media/stagefright/foundation/hexdump.h>
37#include <media/stagefright/FileSource.h>
38#include <media/stagefright/MediaDefs.h>
39#include <media/stagefright/MetaData.h>
40#include <media/stagefright/Utils.h>
41
42#include <ctype.h>
43#include <inttypes.h>
44#include <openssl/aes.h>
45#include <openssl/md5.h>
46
47namespace android {
48
49// static
50const int64_t PlaylistFetcher::kMinBufferedDurationUs = 10000000ll;
51const int64_t PlaylistFetcher::kMaxMonitorDelayUs = 3000000ll;
52const int32_t PlaylistFetcher::kDownloadBlockSize = 2048;
53const int32_t PlaylistFetcher::kNumSkipFrames = 10;
54
55PlaylistFetcher::PlaylistFetcher(
56        const sp<AMessage> &notify,
57        const sp<LiveSession> &session,
58        const char *uri,
59        int32_t subtitleGeneration)
60    : mNotify(notify),
61      mStartTimeUsNotify(notify->dup()),
62      mSession(session),
63      mURI(uri),
64      mStreamTypeMask(0),
65      mStartTimeUs(-1ll),
66      mSegmentStartTimeUs(-1ll),
67      mDiscontinuitySeq(-1ll),
68      mStartTimeUsRelative(false),
69      mLastPlaylistFetchTimeUs(-1ll),
70      mSeqNumber(-1),
71      mNumRetries(0),
72      mStartup(true),
73      mAdaptive(false),
74      mPrepared(false),
75      mNextPTSTimeUs(-1ll),
76      mMonitorQueueGeneration(0),
77      mSubtitleGeneration(subtitleGeneration),
78      mRefreshState(INITIAL_MINIMUM_RELOAD_DELAY),
79      mFirstPTSValid(false),
80      mAbsoluteTimeAnchorUs(0ll),
81      mVideoBuffer(new AnotherPacketSource(NULL)) {
82    memset(mPlaylistHash, 0, sizeof(mPlaylistHash));
83    mStartTimeUsNotify->setInt32("what", kWhatStartedAt);
84    mStartTimeUsNotify->setInt32("streamMask", 0);
85}
86
87PlaylistFetcher::~PlaylistFetcher() {
88}
89
90int64_t PlaylistFetcher::getSegmentStartTimeUs(int32_t seqNumber) const {
91    CHECK(mPlaylist != NULL);
92
93    int32_t firstSeqNumberInPlaylist;
94    if (mPlaylist->meta() == NULL || !mPlaylist->meta()->findInt32(
95                "media-sequence", &firstSeqNumberInPlaylist)) {
96        firstSeqNumberInPlaylist = 0;
97    }
98
99    int32_t lastSeqNumberInPlaylist =
100        firstSeqNumberInPlaylist + (int32_t)mPlaylist->size() - 1;
101
102    CHECK_GE(seqNumber, firstSeqNumberInPlaylist);
103    CHECK_LE(seqNumber, lastSeqNumberInPlaylist);
104
105    int64_t segmentStartUs = 0ll;
106    for (int32_t index = 0;
107            index < seqNumber - firstSeqNumberInPlaylist; ++index) {
108        sp<AMessage> itemMeta;
109        CHECK(mPlaylist->itemAt(
110                    index, NULL /* uri */, &itemMeta));
111
112        int64_t itemDurationUs;
113        CHECK(itemMeta->findInt64("durationUs", &itemDurationUs));
114
115        segmentStartUs += itemDurationUs;
116    }
117
118    return segmentStartUs;
119}
120
121int64_t PlaylistFetcher::delayUsToRefreshPlaylist() const {
122    int64_t nowUs = ALooper::GetNowUs();
123
124    if (mPlaylist == NULL || mLastPlaylistFetchTimeUs < 0ll) {
125        CHECK_EQ((int)mRefreshState, (int)INITIAL_MINIMUM_RELOAD_DELAY);
126        return 0ll;
127    }
128
129    if (mPlaylist->isComplete()) {
130        return (~0llu >> 1);
131    }
132
133    int32_t targetDurationSecs;
134    CHECK(mPlaylist->meta()->findInt32("target-duration", &targetDurationSecs));
135
136    int64_t targetDurationUs = targetDurationSecs * 1000000ll;
137
138    int64_t minPlaylistAgeUs;
139
140    switch (mRefreshState) {
141        case INITIAL_MINIMUM_RELOAD_DELAY:
142        {
143            size_t n = mPlaylist->size();
144            if (n > 0) {
145                sp<AMessage> itemMeta;
146                CHECK(mPlaylist->itemAt(n - 1, NULL /* uri */, &itemMeta));
147
148                int64_t itemDurationUs;
149                CHECK(itemMeta->findInt64("durationUs", &itemDurationUs));
150
151                minPlaylistAgeUs = itemDurationUs;
152                break;
153            }
154
155            // fall through
156        }
157
158        case FIRST_UNCHANGED_RELOAD_ATTEMPT:
159        {
160            minPlaylistAgeUs = targetDurationUs / 2;
161            break;
162        }
163
164        case SECOND_UNCHANGED_RELOAD_ATTEMPT:
165        {
166            minPlaylistAgeUs = (targetDurationUs * 3) / 2;
167            break;
168        }
169
170        case THIRD_UNCHANGED_RELOAD_ATTEMPT:
171        {
172            minPlaylistAgeUs = targetDurationUs * 3;
173            break;
174        }
175
176        default:
177            TRESPASS();
178            break;
179    }
180
181    int64_t delayUs = mLastPlaylistFetchTimeUs + minPlaylistAgeUs - nowUs;
182    return delayUs > 0ll ? delayUs : 0ll;
183}
184
185status_t PlaylistFetcher::decryptBuffer(
186        size_t playlistIndex, const sp<ABuffer> &buffer,
187        bool first) {
188    sp<AMessage> itemMeta;
189    bool found = false;
190    AString method;
191
192    for (ssize_t i = playlistIndex; i >= 0; --i) {
193        AString uri;
194        CHECK(mPlaylist->itemAt(i, &uri, &itemMeta));
195
196        if (itemMeta->findString("cipher-method", &method)) {
197            found = true;
198            break;
199        }
200    }
201
202    if (!found) {
203        method = "NONE";
204    }
205    buffer->meta()->setString("cipher-method", method.c_str());
206
207    if (method == "NONE") {
208        return OK;
209    } else if (!(method == "AES-128")) {
210        ALOGE("Unsupported cipher method '%s'", method.c_str());
211        return ERROR_UNSUPPORTED;
212    }
213
214    AString keyURI;
215    if (!itemMeta->findString("cipher-uri", &keyURI)) {
216        ALOGE("Missing key uri");
217        return ERROR_MALFORMED;
218    }
219
220    ssize_t index = mAESKeyForURI.indexOfKey(keyURI);
221
222    sp<ABuffer> key;
223    if (index >= 0) {
224        key = mAESKeyForURI.valueAt(index);
225    } else {
226        ssize_t err = mSession->fetchFile(keyURI.c_str(), &key);
227
228        if (err < 0) {
229            ALOGE("failed to fetch cipher key from '%s'.", keyURI.c_str());
230            return ERROR_IO;
231        } else if (key->size() != 16) {
232            ALOGE("key file '%s' wasn't 16 bytes in size.", keyURI.c_str());
233            return ERROR_MALFORMED;
234        }
235
236        mAESKeyForURI.add(keyURI, key);
237    }
238
239    AES_KEY aes_key;
240    if (AES_set_decrypt_key(key->data(), 128, &aes_key) != 0) {
241        ALOGE("failed to set AES decryption key.");
242        return UNKNOWN_ERROR;
243    }
244
245    size_t n = buffer->size();
246    if (!n) {
247        return OK;
248    }
249    CHECK(n % 16 == 0);
250
251    if (first) {
252        // If decrypting the first block in a file, read the iv from the manifest
253        // or derive the iv from the file's sequence number.
254
255        AString iv;
256        if (itemMeta->findString("cipher-iv", &iv)) {
257            if ((!iv.startsWith("0x") && !iv.startsWith("0X"))
258                    || iv.size() != 16 * 2 + 2) {
259                ALOGE("malformed cipher IV '%s'.", iv.c_str());
260                return ERROR_MALFORMED;
261            }
262
263            memset(mAESInitVec, 0, sizeof(mAESInitVec));
264            for (size_t i = 0; i < 16; ++i) {
265                char c1 = tolower(iv.c_str()[2 + 2 * i]);
266                char c2 = tolower(iv.c_str()[3 + 2 * i]);
267                if (!isxdigit(c1) || !isxdigit(c2)) {
268                    ALOGE("malformed cipher IV '%s'.", iv.c_str());
269                    return ERROR_MALFORMED;
270                }
271                uint8_t nibble1 = isdigit(c1) ? c1 - '0' : c1 - 'a' + 10;
272                uint8_t nibble2 = isdigit(c2) ? c2 - '0' : c2 - 'a' + 10;
273
274                mAESInitVec[i] = nibble1 << 4 | nibble2;
275            }
276        } else {
277            memset(mAESInitVec, 0, sizeof(mAESInitVec));
278            mAESInitVec[15] = mSeqNumber & 0xff;
279            mAESInitVec[14] = (mSeqNumber >> 8) & 0xff;
280            mAESInitVec[13] = (mSeqNumber >> 16) & 0xff;
281            mAESInitVec[12] = (mSeqNumber >> 24) & 0xff;
282        }
283    }
284
285    AES_cbc_encrypt(
286            buffer->data(), buffer->data(), buffer->size(),
287            &aes_key, mAESInitVec, AES_DECRYPT);
288
289    return OK;
290}
291
292status_t PlaylistFetcher::checkDecryptPadding(const sp<ABuffer> &buffer) {
293    status_t err;
294    AString method;
295    CHECK(buffer->meta()->findString("cipher-method", &method));
296    if (method == "NONE") {
297        return OK;
298    }
299
300    uint8_t padding = 0;
301    if (buffer->size() > 0) {
302        padding = buffer->data()[buffer->size() - 1];
303    }
304
305    if (padding > 16) {
306        return ERROR_MALFORMED;
307    }
308
309    for (size_t i = buffer->size() - padding; i < padding; i++) {
310        if (buffer->data()[i] != padding) {
311            return ERROR_MALFORMED;
312        }
313    }
314
315    buffer->setRange(buffer->offset(), buffer->size() - padding);
316    return OK;
317}
318
319void PlaylistFetcher::postMonitorQueue(int64_t delayUs, int64_t minDelayUs) {
320    int64_t maxDelayUs = delayUsToRefreshPlaylist();
321    if (maxDelayUs < minDelayUs) {
322        maxDelayUs = minDelayUs;
323    }
324    if (delayUs > maxDelayUs) {
325        ALOGV("Need to refresh playlist in %" PRId64 , maxDelayUs);
326        delayUs = maxDelayUs;
327    }
328    sp<AMessage> msg = new AMessage(kWhatMonitorQueue, id());
329    msg->setInt32("generation", mMonitorQueueGeneration);
330    msg->post(delayUs);
331}
332
333void PlaylistFetcher::cancelMonitorQueue() {
334    ++mMonitorQueueGeneration;
335}
336
337void PlaylistFetcher::startAsync(
338        const sp<AnotherPacketSource> &audioSource,
339        const sp<AnotherPacketSource> &videoSource,
340        const sp<AnotherPacketSource> &subtitleSource,
341        int64_t startTimeUs,
342        int64_t segmentStartTimeUs,
343        int32_t startDiscontinuitySeq,
344        bool adaptive) {
345    sp<AMessage> msg = new AMessage(kWhatStart, id());
346
347    uint32_t streamTypeMask = 0ul;
348
349    if (audioSource != NULL) {
350        msg->setPointer("audioSource", audioSource.get());
351        streamTypeMask |= LiveSession::STREAMTYPE_AUDIO;
352    }
353
354    if (videoSource != NULL) {
355        msg->setPointer("videoSource", videoSource.get());
356        streamTypeMask |= LiveSession::STREAMTYPE_VIDEO;
357    }
358
359    if (subtitleSource != NULL) {
360        msg->setPointer("subtitleSource", subtitleSource.get());
361        streamTypeMask |= LiveSession::STREAMTYPE_SUBTITLES;
362    }
363
364    msg->setInt32("streamTypeMask", streamTypeMask);
365    msg->setInt64("startTimeUs", startTimeUs);
366    msg->setInt64("segmentStartTimeUs", segmentStartTimeUs);
367    msg->setInt32("startDiscontinuitySeq", startDiscontinuitySeq);
368    msg->setInt32("adaptive", adaptive);
369    msg->post();
370}
371
372void PlaylistFetcher::pauseAsync() {
373    (new AMessage(kWhatPause, id()))->post();
374}
375
376void PlaylistFetcher::stopAsync(bool clear) {
377    sp<AMessage> msg = new AMessage(kWhatStop, id());
378    msg->setInt32("clear", clear);
379    msg->post();
380}
381
382void PlaylistFetcher::resumeUntilAsync(const sp<AMessage> &params) {
383    AMessage* msg = new AMessage(kWhatResumeUntil, id());
384    msg->setMessage("params", params);
385    msg->post();
386}
387
388void PlaylistFetcher::onMessageReceived(const sp<AMessage> &msg) {
389    switch (msg->what()) {
390        case kWhatStart:
391        {
392            status_t err = onStart(msg);
393
394            sp<AMessage> notify = mNotify->dup();
395            notify->setInt32("what", kWhatStarted);
396            notify->setInt32("err", err);
397            notify->post();
398            break;
399        }
400
401        case kWhatPause:
402        {
403            onPause();
404
405            sp<AMessage> notify = mNotify->dup();
406            notify->setInt32("what", kWhatPaused);
407            notify->post();
408            break;
409        }
410
411        case kWhatStop:
412        {
413            onStop(msg);
414
415            sp<AMessage> notify = mNotify->dup();
416            notify->setInt32("what", kWhatStopped);
417            notify->post();
418            break;
419        }
420
421        case kWhatMonitorQueue:
422        case kWhatDownloadNext:
423        {
424            int32_t generation;
425            CHECK(msg->findInt32("generation", &generation));
426
427            if (generation != mMonitorQueueGeneration) {
428                // Stale event
429                break;
430            }
431
432            if (msg->what() == kWhatMonitorQueue) {
433                onMonitorQueue();
434            } else {
435                onDownloadNext();
436            }
437            break;
438        }
439
440        case kWhatResumeUntil:
441        {
442            onResumeUntil(msg);
443            break;
444        }
445
446        default:
447            TRESPASS();
448    }
449}
450
451status_t PlaylistFetcher::onStart(const sp<AMessage> &msg) {
452    mPacketSources.clear();
453
454    uint32_t streamTypeMask;
455    CHECK(msg->findInt32("streamTypeMask", (int32_t *)&streamTypeMask));
456
457    int64_t startTimeUs;
458    int64_t segmentStartTimeUs;
459    int32_t startDiscontinuitySeq;
460    int32_t adaptive;
461    CHECK(msg->findInt64("startTimeUs", &startTimeUs));
462    CHECK(msg->findInt64("segmentStartTimeUs", &segmentStartTimeUs));
463    CHECK(msg->findInt32("startDiscontinuitySeq", &startDiscontinuitySeq));
464    CHECK(msg->findInt32("adaptive", &adaptive));
465
466    if (streamTypeMask & LiveSession::STREAMTYPE_AUDIO) {
467        void *ptr;
468        CHECK(msg->findPointer("audioSource", &ptr));
469
470        mPacketSources.add(
471                LiveSession::STREAMTYPE_AUDIO,
472                static_cast<AnotherPacketSource *>(ptr));
473    }
474
475    if (streamTypeMask & LiveSession::STREAMTYPE_VIDEO) {
476        void *ptr;
477        CHECK(msg->findPointer("videoSource", &ptr));
478
479        mPacketSources.add(
480                LiveSession::STREAMTYPE_VIDEO,
481                static_cast<AnotherPacketSource *>(ptr));
482    }
483
484    if (streamTypeMask & LiveSession::STREAMTYPE_SUBTITLES) {
485        void *ptr;
486        CHECK(msg->findPointer("subtitleSource", &ptr));
487
488        mPacketSources.add(
489                LiveSession::STREAMTYPE_SUBTITLES,
490                static_cast<AnotherPacketSource *>(ptr));
491    }
492
493    mStreamTypeMask = streamTypeMask;
494
495    mSegmentStartTimeUs = segmentStartTimeUs;
496    mDiscontinuitySeq = startDiscontinuitySeq;
497
498    if (startTimeUs >= 0) {
499        mStartTimeUs = startTimeUs;
500        mSeqNumber = -1;
501        mStartup = true;
502        mPrepared = false;
503        mAdaptive = adaptive;
504    }
505
506    postMonitorQueue();
507
508    return OK;
509}
510
511void PlaylistFetcher::onPause() {
512    cancelMonitorQueue();
513}
514
515void PlaylistFetcher::onStop(const sp<AMessage> &msg) {
516    cancelMonitorQueue();
517
518    int32_t clear;
519    CHECK(msg->findInt32("clear", &clear));
520    if (clear) {
521        for (size_t i = 0; i < mPacketSources.size(); i++) {
522            sp<AnotherPacketSource> packetSource = mPacketSources.valueAt(i);
523            packetSource->clear();
524        }
525    }
526
527    mPacketSources.clear();
528    mStreamTypeMask = 0;
529}
530
531// Resume until we have reached the boundary timestamps listed in `msg`; when
532// the remaining time is too short (within a resume threshold) stop immediately
533// instead.
534status_t PlaylistFetcher::onResumeUntil(const sp<AMessage> &msg) {
535    sp<AMessage> params;
536    CHECK(msg->findMessage("params", &params));
537
538    bool stop = false;
539    for (size_t i = 0; i < mPacketSources.size(); i++) {
540        sp<AnotherPacketSource> packetSource = mPacketSources.valueAt(i);
541
542        const char *stopKey;
543        int streamType = mPacketSources.keyAt(i);
544        switch (streamType) {
545        case LiveSession::STREAMTYPE_VIDEO:
546            stopKey = "timeUsVideo";
547            break;
548
549        case LiveSession::STREAMTYPE_AUDIO:
550            stopKey = "timeUsAudio";
551            break;
552
553        case LiveSession::STREAMTYPE_SUBTITLES:
554            stopKey = "timeUsSubtitle";
555            break;
556
557        default:
558            TRESPASS();
559        }
560
561        // Don't resume if we would stop within a resume threshold.
562        int32_t discontinuitySeq;
563        int64_t latestTimeUs = 0, stopTimeUs = 0;
564        sp<AMessage> latestMeta = packetSource->getLatestDequeuedMeta();
565        if (latestMeta != NULL
566                && latestMeta->findInt32("discontinuitySeq", &discontinuitySeq)
567                && discontinuitySeq == mDiscontinuitySeq
568                && latestMeta->findInt64("timeUs", &latestTimeUs)
569                && params->findInt64(stopKey, &stopTimeUs)
570                && stopTimeUs - latestTimeUs < resumeThreshold(latestMeta)) {
571            stop = true;
572        }
573    }
574
575    if (stop) {
576        for (size_t i = 0; i < mPacketSources.size(); i++) {
577            mPacketSources.valueAt(i)->queueAccessUnit(mSession->createFormatChangeBuffer());
578        }
579        stopAsync(/* clear = */ false);
580        return OK;
581    }
582
583    mStopParams = params;
584    postMonitorQueue();
585
586    return OK;
587}
588
589void PlaylistFetcher::notifyError(status_t err) {
590    sp<AMessage> notify = mNotify->dup();
591    notify->setInt32("what", kWhatError);
592    notify->setInt32("err", err);
593    notify->post();
594}
595
596void PlaylistFetcher::queueDiscontinuity(
597        ATSParser::DiscontinuityType type, const sp<AMessage> &extra) {
598    for (size_t i = 0; i < mPacketSources.size(); ++i) {
599        // do not discard buffer upon #EXT-X-DISCONTINUITY tag
600        // (seek will discard buffer by abandoning old fetchers)
601        mPacketSources.valueAt(i)->queueDiscontinuity(
602                type, extra, false /* discard */);
603    }
604}
605
606void PlaylistFetcher::onMonitorQueue() {
607    bool downloadMore = false;
608    refreshPlaylist();
609
610    int32_t targetDurationSecs;
611    int64_t targetDurationUs = kMinBufferedDurationUs;
612    if (mPlaylist != NULL) {
613        CHECK(mPlaylist->meta()->findInt32("target-duration", &targetDurationSecs));
614        targetDurationUs = targetDurationSecs * 1000000ll;
615    }
616
617    // buffer at least 3 times the target duration, or up to 10 seconds
618    int64_t durationToBufferUs = targetDurationUs * 3;
619    if (durationToBufferUs > kMinBufferedDurationUs)  {
620        durationToBufferUs = kMinBufferedDurationUs;
621    }
622
623    int64_t bufferedDurationUs = 0ll;
624    status_t finalResult = NOT_ENOUGH_DATA;
625    if (mStreamTypeMask == LiveSession::STREAMTYPE_SUBTITLES) {
626        sp<AnotherPacketSource> packetSource =
627            mPacketSources.valueFor(LiveSession::STREAMTYPE_SUBTITLES);
628
629        bufferedDurationUs =
630                packetSource->getBufferedDurationUs(&finalResult);
631        finalResult = OK;
632    } else {
633        // Use max stream duration to prevent us from waiting on a non-existent stream;
634        // when we cannot make out from the manifest what streams are included in a playlist
635        // we might assume extra streams.
636        for (size_t i = 0; i < mPacketSources.size(); ++i) {
637            if ((mStreamTypeMask & mPacketSources.keyAt(i)) == 0) {
638                continue;
639            }
640
641            int64_t bufferedStreamDurationUs =
642                mPacketSources.valueAt(i)->getBufferedDurationUs(&finalResult);
643            ALOGV("buffered %" PRId64 " for stream %d",
644                    bufferedStreamDurationUs, mPacketSources.keyAt(i));
645            if (bufferedStreamDurationUs > bufferedDurationUs) {
646                bufferedDurationUs = bufferedStreamDurationUs;
647            }
648        }
649    }
650    downloadMore = (bufferedDurationUs < durationToBufferUs);
651
652    // signal start if buffered up at least the target size
653    if (!mPrepared && bufferedDurationUs > targetDurationUs && downloadMore) {
654        mPrepared = true;
655
656        ALOGV("prepared, buffered=%" PRId64 " > %" PRId64 "",
657                bufferedDurationUs, targetDurationUs);
658        sp<AMessage> msg = mNotify->dup();
659        msg->setInt32("what", kWhatTemporarilyDoneFetching);
660        msg->post();
661    }
662
663    if (finalResult == OK && downloadMore) {
664        ALOGV("monitoring, buffered=%" PRId64 " < %" PRId64 "",
665                bufferedDurationUs, durationToBufferUs);
666        // delay the next download slightly; hopefully this gives other concurrent fetchers
667        // a better chance to run.
668        // onDownloadNext();
669        sp<AMessage> msg = new AMessage(kWhatDownloadNext, id());
670        msg->setInt32("generation", mMonitorQueueGeneration);
671        msg->post(1000l);
672    } else {
673        // Nothing to do yet, try again in a second.
674
675        sp<AMessage> msg = mNotify->dup();
676        msg->setInt32("what", kWhatTemporarilyDoneFetching);
677        msg->post();
678
679        int64_t delayUs = mPrepared ? kMaxMonitorDelayUs : targetDurationUs / 2;
680        ALOGV("pausing for %" PRId64 ", buffered=%" PRId64 " > %" PRId64 "",
681                delayUs, bufferedDurationUs, durationToBufferUs);
682        // :TRICKY: need to enforce minimum delay because the delay to
683        // refresh the playlist will become 0
684        postMonitorQueue(delayUs, mPrepared ? targetDurationUs * 2 : 0);
685    }
686}
687
688status_t PlaylistFetcher::refreshPlaylist() {
689    if (delayUsToRefreshPlaylist() <= 0) {
690        bool unchanged;
691        sp<M3UParser> playlist = mSession->fetchPlaylist(
692                mURI.c_str(), mPlaylistHash, &unchanged);
693
694        if (playlist == NULL) {
695            if (unchanged) {
696                // We succeeded in fetching the playlist, but it was
697                // unchanged from the last time we tried.
698
699                if (mRefreshState != THIRD_UNCHANGED_RELOAD_ATTEMPT) {
700                    mRefreshState = (RefreshState)(mRefreshState + 1);
701                }
702            } else {
703                ALOGE("failed to load playlist at url '%s'", uriDebugString(mURI).c_str());
704                return ERROR_IO;
705            }
706        } else {
707            mRefreshState = INITIAL_MINIMUM_RELOAD_DELAY;
708            mPlaylist = playlist;
709
710            if (mPlaylist->isComplete() || mPlaylist->isEvent()) {
711                updateDuration();
712            }
713        }
714
715        mLastPlaylistFetchTimeUs = ALooper::GetNowUs();
716    }
717    return OK;
718}
719
720// static
721bool PlaylistFetcher::bufferStartsWithTsSyncByte(const sp<ABuffer>& buffer) {
722    return buffer->size() > 0 && buffer->data()[0] == 0x47;
723}
724
725void PlaylistFetcher::onDownloadNext() {
726    status_t err = refreshPlaylist();
727    int32_t firstSeqNumberInPlaylist = 0;
728    int32_t lastSeqNumberInPlaylist = 0;
729    bool discontinuity = false;
730
731    if (mPlaylist != NULL) {
732        if (mPlaylist->meta() != NULL) {
733            mPlaylist->meta()->findInt32("media-sequence", &firstSeqNumberInPlaylist);
734        }
735
736        lastSeqNumberInPlaylist =
737                firstSeqNumberInPlaylist + (int32_t)mPlaylist->size() - 1;
738
739        if (mDiscontinuitySeq < 0) {
740            mDiscontinuitySeq = mPlaylist->getDiscontinuitySeq();
741        }
742    }
743
744    if (mPlaylist != NULL && mSeqNumber < 0) {
745        CHECK_GE(mStartTimeUs, 0ll);
746
747        if (mSegmentStartTimeUs < 0) {
748            if (!mPlaylist->isComplete() && !mPlaylist->isEvent()) {
749                // If this is a live session, start 3 segments from the end on connect
750                mSeqNumber = lastSeqNumberInPlaylist - 3;
751                if (mSeqNumber < firstSeqNumberInPlaylist) {
752                    mSeqNumber = firstSeqNumberInPlaylist;
753                }
754            } else {
755                mSeqNumber = getSeqNumberForTime(mStartTimeUs);
756                mStartTimeUs -= getSegmentStartTimeUs(mSeqNumber);
757            }
758            mStartTimeUsRelative = true;
759            ALOGV("Initial sequence number for time %" PRId64 " is %d from (%d .. %d)",
760                    mStartTimeUs, mSeqNumber, firstSeqNumberInPlaylist,
761                    lastSeqNumberInPlaylist);
762        } else {
763            mSeqNumber = getSeqNumberForTime(mSegmentStartTimeUs);
764            if (mAdaptive) {
765                // avoid double fetch/decode
766                mSeqNumber += 1;
767            }
768            ssize_t minSeq = getSeqNumberForDiscontinuity(mDiscontinuitySeq);
769            if (mSeqNumber < minSeq) {
770                mSeqNumber = minSeq;
771            }
772
773            if (mSeqNumber < firstSeqNumberInPlaylist) {
774                mSeqNumber = firstSeqNumberInPlaylist;
775            }
776
777            if (mSeqNumber > lastSeqNumberInPlaylist) {
778                mSeqNumber = lastSeqNumberInPlaylist;
779            }
780            ALOGV("Initial sequence number for live event %d from (%d .. %d)",
781                    mSeqNumber, firstSeqNumberInPlaylist,
782                    lastSeqNumberInPlaylist);
783        }
784    }
785
786    // if mPlaylist is NULL then err must be non-OK; but the other way around might not be true
787    if (mSeqNumber < firstSeqNumberInPlaylist
788            || mSeqNumber > lastSeqNumberInPlaylist
789            || err != OK) {
790        if ((err != OK || !mPlaylist->isComplete()) && mNumRetries < kMaxNumRetries) {
791            ++mNumRetries;
792
793            if (mSeqNumber > lastSeqNumberInPlaylist || err != OK) {
794                // make sure we reach this retry logic on refresh failures
795                // by adding an err != OK clause to all enclosing if's.
796
797                // refresh in increasing fraction (1/2, 1/3, ...) of the
798                // playlist's target duration or 3 seconds, whichever is less
799                int64_t delayUs = kMaxMonitorDelayUs;
800                if (mPlaylist != NULL && mPlaylist->meta() != NULL) {
801                    int32_t targetDurationSecs;
802                    CHECK(mPlaylist->meta()->findInt32("target-duration", &targetDurationSecs));
803                    delayUs = mPlaylist->size() * targetDurationSecs *
804                            1000000ll / (1 + mNumRetries);
805                }
806                if (delayUs > kMaxMonitorDelayUs) {
807                    delayUs = kMaxMonitorDelayUs;
808                }
809                ALOGV("sequence number high: %d from (%d .. %d), "
810                      "monitor in %" PRId64 " (retry=%d)",
811                        mSeqNumber, firstSeqNumberInPlaylist,
812                        lastSeqNumberInPlaylist, delayUs, mNumRetries);
813                postMonitorQueue(delayUs);
814                return;
815            }
816
817            if (err != OK) {
818                notifyError(err);
819                return;
820            }
821
822            // we've missed the boat, let's start 3 segments prior to the latest sequence
823            // number available and signal a discontinuity.
824
825            ALOGI("We've missed the boat, restarting playback."
826                  "  mStartup=%d, was  looking for %d in %d-%d",
827                    mStartup, mSeqNumber, firstSeqNumberInPlaylist,
828                    lastSeqNumberInPlaylist);
829            mSeqNumber = lastSeqNumberInPlaylist - 3;
830            if (mSeqNumber < firstSeqNumberInPlaylist) {
831                mSeqNumber = firstSeqNumberInPlaylist;
832            }
833            discontinuity = true;
834
835            // fall through
836        } else {
837            ALOGE("Cannot find sequence number %d in playlist "
838                 "(contains %d - %d)",
839                 mSeqNumber, firstSeqNumberInPlaylist,
840                  firstSeqNumberInPlaylist + (int32_t)mPlaylist->size() - 1);
841
842            notifyError(ERROR_END_OF_STREAM);
843            return;
844        }
845    }
846
847    mNumRetries = 0;
848
849    AString uri;
850    sp<AMessage> itemMeta;
851    CHECK(mPlaylist->itemAt(
852                mSeqNumber - firstSeqNumberInPlaylist,
853                &uri,
854                &itemMeta));
855
856    int32_t val;
857    if (itemMeta->findInt32("discontinuity", &val) && val != 0) {
858        mDiscontinuitySeq++;
859        discontinuity = true;
860    }
861
862    int64_t range_offset, range_length;
863    if (!itemMeta->findInt64("range-offset", &range_offset)
864            || !itemMeta->findInt64("range-length", &range_length)) {
865        range_offset = 0;
866        range_length = -1;
867    }
868
869    ALOGV("fetching segment %d from (%d .. %d)",
870          mSeqNumber, firstSeqNumberInPlaylist, lastSeqNumberInPlaylist);
871
872    ALOGV("fetching '%s'", uri.c_str());
873
874    sp<DataSource> source;
875    sp<ABuffer> buffer, tsBuffer;
876    // decrypt a junk buffer to prefetch key; since a session uses only one http connection,
877    // this avoids interleaved connections to the key and segment file.
878    {
879        sp<ABuffer> junk = new ABuffer(16);
880        junk->setRange(0, 16);
881        status_t err = decryptBuffer(mSeqNumber - firstSeqNumberInPlaylist, junk,
882                true /* first */);
883        if (err != OK) {
884            notifyError(err);
885            return;
886        }
887    }
888
889    // block-wise download
890    bool startup = mStartup;
891    ssize_t bytesRead;
892    do {
893        bytesRead = mSession->fetchFile(
894                uri.c_str(), &buffer, range_offset, range_length, kDownloadBlockSize, &source);
895
896        if (bytesRead < 0) {
897            status_t err = bytesRead;
898            ALOGE("failed to fetch .ts segment at url '%s'", uri.c_str());
899            notifyError(err);
900            return;
901        }
902
903        CHECK(buffer != NULL);
904
905        size_t size = buffer->size();
906        // Set decryption range.
907        buffer->setRange(size - bytesRead, bytesRead);
908        status_t err = decryptBuffer(mSeqNumber - firstSeqNumberInPlaylist, buffer,
909                buffer->offset() == 0 /* first */);
910        // Unset decryption range.
911        buffer->setRange(0, size);
912
913        if (err != OK) {
914            ALOGE("decryptBuffer failed w/ error %d", err);
915
916            notifyError(err);
917            return;
918        }
919
920        if (startup || discontinuity) {
921            // Signal discontinuity.
922
923            if (mPlaylist->isComplete() || mPlaylist->isEvent()) {
924                // If this was a live event this made no sense since
925                // we don't have access to all the segment before the current
926                // one.
927                mNextPTSTimeUs = getSegmentStartTimeUs(mSeqNumber);
928            }
929
930            if (discontinuity) {
931                ALOGI("queueing discontinuity (explicit=%d)", discontinuity);
932
933                queueDiscontinuity(
934                        ATSParser::DISCONTINUITY_FORMATCHANGE,
935                        NULL /* extra */);
936
937                discontinuity = false;
938            }
939
940            startup = false;
941        }
942
943        err = OK;
944        if (bufferStartsWithTsSyncByte(buffer)) {
945            // Incremental extraction is only supported for MPEG2 transport streams.
946            if (tsBuffer == NULL) {
947                tsBuffer = new ABuffer(buffer->data(), buffer->capacity());
948                tsBuffer->setRange(0, 0);
949            } else if (tsBuffer->capacity() != buffer->capacity()) {
950                size_t tsOff = tsBuffer->offset(), tsSize = tsBuffer->size();
951                tsBuffer = new ABuffer(buffer->data(), buffer->capacity());
952                tsBuffer->setRange(tsOff, tsSize);
953            }
954            tsBuffer->setRange(tsBuffer->offset(), tsBuffer->size() + bytesRead);
955
956            err = extractAndQueueAccessUnitsFromTs(tsBuffer);
957        }
958
959        if (err == -EAGAIN) {
960            // starting sequence number too low/high
961            mTSParser.clear();
962            postMonitorQueue();
963            return;
964        } else if (err == ERROR_OUT_OF_RANGE) {
965            // reached stopping point
966            stopAsync(/* clear = */ false);
967            return;
968        } else if (err != OK) {
969            notifyError(err);
970            return;
971        }
972
973    } while (bytesRead != 0);
974
975    if (bufferStartsWithTsSyncByte(buffer)) {
976        // If we still don't see a stream after fetching a full ts segment mark it as
977        // nonexistent.
978        const size_t kNumTypes = ATSParser::NUM_SOURCE_TYPES;
979        ATSParser::SourceType srcTypes[kNumTypes] =
980                { ATSParser::VIDEO, ATSParser::AUDIO };
981        LiveSession::StreamType streamTypes[kNumTypes] =
982                { LiveSession::STREAMTYPE_VIDEO, LiveSession::STREAMTYPE_AUDIO };
983
984        for (size_t i = 0; i < kNumTypes; i++) {
985            ATSParser::SourceType srcType = srcTypes[i];
986            LiveSession::StreamType streamType = streamTypes[i];
987
988            sp<AnotherPacketSource> source =
989                static_cast<AnotherPacketSource *>(
990                    mTSParser->getSource(srcType).get());
991
992            if (source == NULL) {
993                ALOGW("MPEG2 Transport stream does not contain %s data.",
994                      srcType == ATSParser::VIDEO ? "video" : "audio");
995
996                mStreamTypeMask &= ~streamType;
997                mPacketSources.removeItem(streamType);
998            }
999        }
1000
1001    }
1002
1003    if (checkDecryptPadding(buffer) != OK) {
1004        ALOGE("Incorrect padding bytes after decryption.");
1005        notifyError(ERROR_MALFORMED);
1006        return;
1007    }
1008
1009    err = OK;
1010    if (tsBuffer != NULL) {
1011        AString method;
1012        CHECK(buffer->meta()->findString("cipher-method", &method));
1013        if ((tsBuffer->size() > 0 && method == "NONE")
1014                || tsBuffer->size() > 16) {
1015            ALOGE("MPEG2 transport stream is not an even multiple of 188 "
1016                    "bytes in length.");
1017            notifyError(ERROR_MALFORMED);
1018            return;
1019        }
1020    }
1021
1022    // bulk extract non-ts files
1023    if (tsBuffer == NULL) {
1024        err = extractAndQueueAccessUnits(buffer, itemMeta);
1025        if (err == -EAGAIN) {
1026            // starting sequence number too low/high
1027            postMonitorQueue();
1028            return;
1029        } else if (err == ERROR_OUT_OF_RANGE) {
1030            // reached stopping point
1031            stopAsync(/* clear = */false);
1032            return;
1033        }
1034    }
1035
1036    if (err != OK) {
1037        notifyError(err);
1038        return;
1039    }
1040
1041    ++mSeqNumber;
1042
1043    postMonitorQueue();
1044}
1045
1046int32_t PlaylistFetcher::getSeqNumberWithAnchorTime(int64_t anchorTimeUs) const {
1047    int32_t firstSeqNumberInPlaylist, lastSeqNumberInPlaylist;
1048    if (mPlaylist->meta() == NULL
1049            || !mPlaylist->meta()->findInt32("media-sequence", &firstSeqNumberInPlaylist)) {
1050        firstSeqNumberInPlaylist = 0;
1051    }
1052    lastSeqNumberInPlaylist = firstSeqNumberInPlaylist + mPlaylist->size() - 1;
1053
1054    int32_t index = mSeqNumber - firstSeqNumberInPlaylist - 1;
1055    while (index >= 0 && anchorTimeUs > mStartTimeUs) {
1056        sp<AMessage> itemMeta;
1057        CHECK(mPlaylist->itemAt(index, NULL /* uri */, &itemMeta));
1058
1059        int64_t itemDurationUs;
1060        CHECK(itemMeta->findInt64("durationUs", &itemDurationUs));
1061
1062        anchorTimeUs -= itemDurationUs;
1063        --index;
1064    }
1065
1066    int32_t newSeqNumber = firstSeqNumberInPlaylist + index + 1;
1067    if (newSeqNumber <= lastSeqNumberInPlaylist) {
1068        return newSeqNumber;
1069    } else {
1070        return lastSeqNumberInPlaylist;
1071    }
1072}
1073
1074int32_t PlaylistFetcher::getSeqNumberForDiscontinuity(size_t discontinuitySeq) const {
1075    int32_t firstSeqNumberInPlaylist;
1076    if (mPlaylist->meta() == NULL
1077            || !mPlaylist->meta()->findInt32("media-sequence", &firstSeqNumberInPlaylist)) {
1078        firstSeqNumberInPlaylist = 0;
1079    }
1080
1081    size_t curDiscontinuitySeq = mPlaylist->getDiscontinuitySeq();
1082    if (discontinuitySeq < curDiscontinuitySeq) {
1083        return firstSeqNumberInPlaylist <= 0 ? 0 : (firstSeqNumberInPlaylist - 1);
1084    }
1085
1086    size_t index = 0;
1087    while (index < mPlaylist->size()) {
1088        sp<AMessage> itemMeta;
1089        CHECK(mPlaylist->itemAt( index, NULL /* uri */, &itemMeta));
1090
1091        int64_t discontinuity;
1092        if (itemMeta->findInt64("discontinuity", &discontinuity)) {
1093            curDiscontinuitySeq++;
1094        }
1095
1096        if (curDiscontinuitySeq == discontinuitySeq) {
1097            return firstSeqNumberInPlaylist + index;
1098        }
1099
1100        ++index;
1101    }
1102
1103    return firstSeqNumberInPlaylist + mPlaylist->size();
1104}
1105
1106int32_t PlaylistFetcher::getSeqNumberForTime(int64_t timeUs) const {
1107    int32_t firstSeqNumberInPlaylist;
1108    if (mPlaylist->meta() == NULL || !mPlaylist->meta()->findInt32(
1109                "media-sequence", &firstSeqNumberInPlaylist)) {
1110        firstSeqNumberInPlaylist = 0;
1111    }
1112
1113    size_t index = 0;
1114    int64_t segmentStartUs = 0;
1115    while (index < mPlaylist->size()) {
1116        sp<AMessage> itemMeta;
1117        CHECK(mPlaylist->itemAt(
1118                    index, NULL /* uri */, &itemMeta));
1119
1120        int64_t itemDurationUs;
1121        CHECK(itemMeta->findInt64("durationUs", &itemDurationUs));
1122
1123        if (timeUs < segmentStartUs + itemDurationUs) {
1124            break;
1125        }
1126
1127        segmentStartUs += itemDurationUs;
1128        ++index;
1129    }
1130
1131    if (index >= mPlaylist->size()) {
1132        index = mPlaylist->size() - 1;
1133    }
1134
1135    return firstSeqNumberInPlaylist + index;
1136}
1137
1138const sp<ABuffer> &PlaylistFetcher::setAccessUnitProperties(
1139        const sp<ABuffer> &accessUnit, const sp<AnotherPacketSource> &source, bool discard) {
1140    sp<MetaData> format = source->getFormat();
1141    if (format != NULL) {
1142        // for simplicity, store a reference to the format in each unit
1143        accessUnit->meta()->setObject("format", format);
1144    }
1145
1146    if (discard) {
1147        accessUnit->meta()->setInt32("discard", discard);
1148    }
1149
1150    accessUnit->meta()->setInt32("discontinuitySeq", mDiscontinuitySeq);
1151    accessUnit->meta()->setInt64("segmentStartTimeUs", getSegmentStartTimeUs(mSeqNumber));
1152    return accessUnit;
1153}
1154
1155status_t PlaylistFetcher::extractAndQueueAccessUnitsFromTs(const sp<ABuffer> &buffer) {
1156    if (mTSParser == NULL) {
1157        // Use TS_TIMESTAMPS_ARE_ABSOLUTE so pts carry over between fetchers.
1158        mTSParser = new ATSParser(ATSParser::TS_TIMESTAMPS_ARE_ABSOLUTE);
1159    }
1160
1161    if (mNextPTSTimeUs >= 0ll) {
1162        sp<AMessage> extra = new AMessage;
1163        // Since we are using absolute timestamps, signal an offset of 0 to prevent
1164        // ATSParser from skewing the timestamps of access units.
1165        extra->setInt64(IStreamListener::kKeyMediaTimeUs, 0);
1166
1167        mTSParser->signalDiscontinuity(
1168                ATSParser::DISCONTINUITY_TIME, extra);
1169
1170        mAbsoluteTimeAnchorUs = mNextPTSTimeUs;
1171        mNextPTSTimeUs = -1ll;
1172        mFirstPTSValid = false;
1173    }
1174
1175    size_t offset = 0;
1176    while (offset + 188 <= buffer->size()) {
1177        status_t err = mTSParser->feedTSPacket(buffer->data() + offset, 188);
1178
1179        if (err != OK) {
1180            return err;
1181        }
1182
1183        offset += 188;
1184    }
1185    // setRange to indicate consumed bytes.
1186    buffer->setRange(buffer->offset() + offset, buffer->size() - offset);
1187
1188    status_t err = OK;
1189    for (size_t i = mPacketSources.size(); i-- > 0;) {
1190        sp<AnotherPacketSource> packetSource = mPacketSources.valueAt(i);
1191
1192        const char *key;
1193        ATSParser::SourceType type;
1194        const LiveSession::StreamType stream = mPacketSources.keyAt(i);
1195        switch (stream) {
1196            case LiveSession::STREAMTYPE_VIDEO:
1197                type = ATSParser::VIDEO;
1198                key = "timeUsVideo";
1199                break;
1200
1201            case LiveSession::STREAMTYPE_AUDIO:
1202                type = ATSParser::AUDIO;
1203                key = "timeUsAudio";
1204                break;
1205
1206            case LiveSession::STREAMTYPE_SUBTITLES:
1207            {
1208                ALOGE("MPEG2 Transport streams do not contain subtitles.");
1209                return ERROR_MALFORMED;
1210                break;
1211            }
1212
1213            default:
1214                TRESPASS();
1215        }
1216
1217        sp<AnotherPacketSource> source =
1218            static_cast<AnotherPacketSource *>(
1219                    mTSParser->getSource(type).get());
1220
1221        if (source == NULL) {
1222            continue;
1223        }
1224
1225        int64_t timeUs;
1226        sp<ABuffer> accessUnit;
1227        status_t finalResult;
1228        while (source->hasBufferAvailable(&finalResult)
1229                && source->dequeueAccessUnit(&accessUnit) == OK) {
1230
1231            CHECK(accessUnit->meta()->findInt64("timeUs", &timeUs));
1232
1233            if (mStartup) {
1234                if (!mFirstPTSValid) {
1235                    mFirstTimeUs = timeUs;
1236                    mFirstPTSValid = true;
1237                }
1238                if (mStartTimeUsRelative) {
1239                    timeUs -= mFirstTimeUs;
1240                    if (timeUs < 0) {
1241                        timeUs = 0;
1242                    }
1243                }
1244
1245                if (timeUs < mStartTimeUs) {
1246                    // buffer up to the closest preceding IDR frame
1247                    ALOGV("timeUs %" PRId64 " us < mStartTimeUs %" PRId64 " us",
1248                            timeUs, mStartTimeUs);
1249                    const char *mime;
1250                    sp<MetaData> format  = source->getFormat();
1251                    bool isAvc = false;
1252                    if (format != NULL && format->findCString(kKeyMIMEType, &mime)
1253                            && !strcasecmp(mime, MEDIA_MIMETYPE_VIDEO_AVC)) {
1254                        isAvc = true;
1255                    }
1256                    if (isAvc && IsIDR(accessUnit)) {
1257                        mVideoBuffer->clear();
1258                    }
1259                    if (isAvc) {
1260                        mVideoBuffer->queueAccessUnit(accessUnit);
1261                    }
1262
1263                    continue;
1264                }
1265            }
1266
1267            CHECK(accessUnit->meta()->findInt64("timeUs", &timeUs));
1268            if (mStartTimeUsNotify != NULL && timeUs > mStartTimeUs) {
1269
1270                int32_t targetDurationSecs;
1271                CHECK(mPlaylist->meta()->findInt32("target-duration", &targetDurationSecs));
1272                int64_t targetDurationUs = targetDurationSecs * 1000000ll;
1273                // mStartup
1274                //   mStartup is true until we have queued a packet for all the streams
1275                //   we are fetching. We queue packets whose timestamps are greater than
1276                //   mStartTimeUs.
1277                // mSegmentStartTimeUs >= 0
1278                //   mSegmentStartTimeUs is non-negative when adapting or switching tracks
1279                // timeUs - mStartTimeUs > targetDurationUs:
1280                //   This and the 2 above conditions should only happen when adapting in a live
1281                //   stream; the old fetcher has already fetched to mStartTimeUs; the new fetcher
1282                //   would start fetching after timeUs, which should be greater than mStartTimeUs;
1283                //   the old fetcher would then continue fetching data until timeUs. We don't want
1284                //   timeUs to be too far ahead of mStartTimeUs because we want the old fetcher to
1285                //   stop as early as possible. The definition of being "too far ahead" is
1286                //   arbitrary; here we use targetDurationUs as threshold.
1287                if (mStartup && mSegmentStartTimeUs >= 0
1288                        && timeUs - mStartTimeUs > targetDurationUs) {
1289                    // we just guessed a starting timestamp that is too high when adapting in a
1290                    // live stream; re-adjust based on the actual timestamp extracted from the
1291                    // media segment; if we didn't move backward after the re-adjustment
1292                    // (newSeqNumber), start at least 1 segment prior.
1293                    int32_t newSeqNumber = getSeqNumberWithAnchorTime(timeUs);
1294                    if (newSeqNumber >= mSeqNumber) {
1295                        --mSeqNumber;
1296                    } else {
1297                        mSeqNumber = newSeqNumber;
1298                    }
1299                    mStartTimeUsNotify = mNotify->dup();
1300                    mStartTimeUsNotify->setInt32("what", kWhatStartedAt);
1301                    return -EAGAIN;
1302                }
1303
1304                int32_t seq;
1305                if (!mStartTimeUsNotify->findInt32("discontinuitySeq", &seq)) {
1306                    mStartTimeUsNotify->setInt32("discontinuitySeq", mDiscontinuitySeq);
1307                }
1308                int64_t startTimeUs;
1309                if (!mStartTimeUsNotify->findInt64(key, &startTimeUs)) {
1310                    mStartTimeUsNotify->setInt64(key, timeUs);
1311
1312                    uint32_t streamMask = 0;
1313                    mStartTimeUsNotify->findInt32("streamMask", (int32_t *) &streamMask);
1314                    streamMask |= mPacketSources.keyAt(i);
1315                    mStartTimeUsNotify->setInt32("streamMask", streamMask);
1316
1317                    if (streamMask == mStreamTypeMask) {
1318                        mStartup = false;
1319                        mStartTimeUsNotify->post();
1320                        mStartTimeUsNotify.clear();
1321                    }
1322                }
1323            }
1324
1325            if (mStopParams != NULL) {
1326                // Queue discontinuity in original stream.
1327                int32_t discontinuitySeq;
1328                int64_t stopTimeUs;
1329                if (!mStopParams->findInt32("discontinuitySeq", &discontinuitySeq)
1330                        || discontinuitySeq > mDiscontinuitySeq
1331                        || !mStopParams->findInt64(key, &stopTimeUs)
1332                        || (discontinuitySeq == mDiscontinuitySeq
1333                                && timeUs >= stopTimeUs)) {
1334                    packetSource->queueAccessUnit(mSession->createFormatChangeBuffer());
1335                    mStreamTypeMask &= ~stream;
1336                    mPacketSources.removeItemsAt(i);
1337                    break;
1338                }
1339            }
1340
1341            // Note that we do NOT dequeue any discontinuities except for format change.
1342            if (stream == LiveSession::STREAMTYPE_VIDEO) {
1343                const bool discard = true;
1344                status_t status;
1345                while (mVideoBuffer->hasBufferAvailable(&status)) {
1346                    sp<ABuffer> videoBuffer;
1347                    mVideoBuffer->dequeueAccessUnit(&videoBuffer);
1348                    setAccessUnitProperties(videoBuffer, source, discard);
1349                    packetSource->queueAccessUnit(videoBuffer);
1350                }
1351            }
1352
1353            setAccessUnitProperties(accessUnit, source);
1354            packetSource->queueAccessUnit(accessUnit);
1355        }
1356
1357        if (err != OK) {
1358            break;
1359        }
1360    }
1361
1362    if (err != OK) {
1363        for (size_t i = mPacketSources.size(); i-- > 0;) {
1364            sp<AnotherPacketSource> packetSource = mPacketSources.valueAt(i);
1365            packetSource->clear();
1366        }
1367        return err;
1368    }
1369
1370    if (!mStreamTypeMask) {
1371        // Signal gap is filled between original and new stream.
1372        ALOGV("ERROR OUT OF RANGE");
1373        return ERROR_OUT_OF_RANGE;
1374    }
1375
1376    return OK;
1377}
1378
1379/* static */
1380bool PlaylistFetcher::bufferStartsWithWebVTTMagicSequence(
1381        const sp<ABuffer> &buffer) {
1382    size_t pos = 0;
1383
1384    // skip possible BOM
1385    if (buffer->size() >= pos + 3 &&
1386            !memcmp("\xef\xbb\xbf", buffer->data() + pos, 3)) {
1387        pos += 3;
1388    }
1389
1390    // accept WEBVTT followed by SPACE, TAB or (CR) LF
1391    if (buffer->size() < pos + 6 ||
1392            memcmp("WEBVTT", buffer->data() + pos, 6)) {
1393        return false;
1394    }
1395    pos += 6;
1396
1397    if (buffer->size() == pos) {
1398        return true;
1399    }
1400
1401    uint8_t sep = buffer->data()[pos];
1402    return sep == ' ' || sep == '\t' || sep == '\n' || sep == '\r';
1403}
1404
1405status_t PlaylistFetcher::extractAndQueueAccessUnits(
1406        const sp<ABuffer> &buffer, const sp<AMessage> &itemMeta) {
1407    if (bufferStartsWithWebVTTMagicSequence(buffer)) {
1408        if (mStreamTypeMask != LiveSession::STREAMTYPE_SUBTITLES) {
1409            ALOGE("This stream only contains subtitles.");
1410            return ERROR_MALFORMED;
1411        }
1412
1413        const sp<AnotherPacketSource> packetSource =
1414            mPacketSources.valueFor(LiveSession::STREAMTYPE_SUBTITLES);
1415
1416        int64_t durationUs;
1417        CHECK(itemMeta->findInt64("durationUs", &durationUs));
1418        buffer->meta()->setInt64("timeUs", getSegmentStartTimeUs(mSeqNumber));
1419        buffer->meta()->setInt64("durationUs", durationUs);
1420        buffer->meta()->setInt64("segmentStartTimeUs", getSegmentStartTimeUs(mSeqNumber));
1421        buffer->meta()->setInt32("discontinuitySeq", mDiscontinuitySeq);
1422        buffer->meta()->setInt32("subtitleGeneration", mSubtitleGeneration);
1423
1424        packetSource->queueAccessUnit(buffer);
1425        return OK;
1426    }
1427
1428    if (mNextPTSTimeUs >= 0ll) {
1429        mFirstPTSValid = false;
1430        mAbsoluteTimeAnchorUs = mNextPTSTimeUs;
1431        mNextPTSTimeUs = -1ll;
1432    }
1433
1434    // This better be an ISO 13818-7 (AAC) or ISO 13818-1 (MPEG) audio
1435    // stream prefixed by an ID3 tag.
1436
1437    bool firstID3Tag = true;
1438    uint64_t PTS = 0;
1439
1440    for (;;) {
1441        // Make sure to skip all ID3 tags preceding the audio data.
1442        // At least one must be present to provide the PTS timestamp.
1443
1444        ID3 id3(buffer->data(), buffer->size(), true /* ignoreV1 */);
1445        if (!id3.isValid()) {
1446            if (firstID3Tag) {
1447                ALOGE("Unable to parse ID3 tag.");
1448                return ERROR_MALFORMED;
1449            } else {
1450                break;
1451            }
1452        }
1453
1454        if (firstID3Tag) {
1455            bool found = false;
1456
1457            ID3::Iterator it(id3, "PRIV");
1458            while (!it.done()) {
1459                size_t length;
1460                const uint8_t *data = it.getData(&length);
1461
1462                static const char *kMatchName =
1463                    "com.apple.streaming.transportStreamTimestamp";
1464                static const size_t kMatchNameLen = strlen(kMatchName);
1465
1466                if (length == kMatchNameLen + 1 + 8
1467                        && !strncmp((const char *)data, kMatchName, kMatchNameLen)) {
1468                    found = true;
1469                    PTS = U64_AT(&data[kMatchNameLen + 1]);
1470                }
1471
1472                it.next();
1473            }
1474
1475            if (!found) {
1476                ALOGE("Unable to extract transportStreamTimestamp from ID3 tag.");
1477                return ERROR_MALFORMED;
1478            }
1479        }
1480
1481        // skip the ID3 tag
1482        buffer->setRange(
1483                buffer->offset() + id3.rawSize(), buffer->size() - id3.rawSize());
1484
1485        firstID3Tag = false;
1486    }
1487
1488    if (mStreamTypeMask != LiveSession::STREAMTYPE_AUDIO) {
1489        ALOGW("This stream only contains audio data!");
1490
1491        mStreamTypeMask &= LiveSession::STREAMTYPE_AUDIO;
1492
1493        if (mStreamTypeMask == 0) {
1494            return OK;
1495        }
1496    }
1497
1498    sp<AnotherPacketSource> packetSource =
1499        mPacketSources.valueFor(LiveSession::STREAMTYPE_AUDIO);
1500
1501    if (packetSource->getFormat() == NULL && buffer->size() >= 7) {
1502        ABitReader bits(buffer->data(), buffer->size());
1503
1504        // adts_fixed_header
1505
1506        CHECK_EQ(bits.getBits(12), 0xfffu);
1507        bits.skipBits(3);  // ID, layer
1508        bool protection_absent = bits.getBits(1) != 0;
1509
1510        unsigned profile = bits.getBits(2);
1511        CHECK_NE(profile, 3u);
1512        unsigned sampling_freq_index = bits.getBits(4);
1513        bits.getBits(1);  // private_bit
1514        unsigned channel_configuration = bits.getBits(3);
1515        CHECK_NE(channel_configuration, 0u);
1516        bits.skipBits(2);  // original_copy, home
1517
1518        sp<MetaData> meta = MakeAACCodecSpecificData(
1519                profile, sampling_freq_index, channel_configuration);
1520
1521        meta->setInt32(kKeyIsADTS, true);
1522
1523        packetSource->setFormat(meta);
1524    }
1525
1526    int64_t numSamples = 0ll;
1527    int32_t sampleRate;
1528    CHECK(packetSource->getFormat()->findInt32(kKeySampleRate, &sampleRate));
1529
1530    int64_t timeUs = (PTS * 100ll) / 9ll;
1531    if (!mFirstPTSValid) {
1532        mFirstPTSValid = true;
1533        mFirstTimeUs = timeUs;
1534    }
1535
1536    size_t offset = 0;
1537    while (offset < buffer->size()) {
1538        const uint8_t *adtsHeader = buffer->data() + offset;
1539        CHECK_LT(offset + 5, buffer->size());
1540
1541        unsigned aac_frame_length =
1542            ((adtsHeader[3] & 3) << 11)
1543            | (adtsHeader[4] << 3)
1544            | (adtsHeader[5] >> 5);
1545
1546        if (aac_frame_length == 0) {
1547            const uint8_t *id3Header = adtsHeader;
1548            if (!memcmp(id3Header, "ID3", 3)) {
1549                ID3 id3(id3Header, buffer->size() - offset, true);
1550                if (id3.isValid()) {
1551                    offset += id3.rawSize();
1552                    continue;
1553                };
1554            }
1555            return ERROR_MALFORMED;
1556        }
1557
1558        CHECK_LE(offset + aac_frame_length, buffer->size());
1559
1560        int64_t unitTimeUs = timeUs + numSamples * 1000000ll / sampleRate;
1561        offset += aac_frame_length;
1562
1563        // Each AAC frame encodes 1024 samples.
1564        numSamples += 1024;
1565
1566        if (mStartup) {
1567            int64_t startTimeUs = unitTimeUs;
1568            if (mStartTimeUsRelative) {
1569                startTimeUs -= mFirstTimeUs;
1570                if (startTimeUs  < 0) {
1571                    startTimeUs = 0;
1572                }
1573            }
1574            if (startTimeUs < mStartTimeUs) {
1575                continue;
1576            }
1577
1578            if (mStartTimeUsNotify != NULL) {
1579                int32_t targetDurationSecs;
1580                CHECK(mPlaylist->meta()->findInt32("target-duration", &targetDurationSecs));
1581                int64_t targetDurationUs = targetDurationSecs * 1000000ll;
1582
1583                // Duplicated logic from how we handle .ts playlists.
1584                if (mStartup && mSegmentStartTimeUs >= 0
1585                        && timeUs - mStartTimeUs > targetDurationUs) {
1586                    int32_t newSeqNumber = getSeqNumberWithAnchorTime(timeUs);
1587                    if (newSeqNumber >= mSeqNumber) {
1588                        --mSeqNumber;
1589                    } else {
1590                        mSeqNumber = newSeqNumber;
1591                    }
1592                    return -EAGAIN;
1593                }
1594
1595                mStartTimeUsNotify->setInt64("timeUsAudio", timeUs);
1596                mStartTimeUsNotify->setInt32("discontinuitySeq", mDiscontinuitySeq);
1597                mStartTimeUsNotify->setInt32("streamMask", LiveSession::STREAMTYPE_AUDIO);
1598                mStartTimeUsNotify->post();
1599                mStartTimeUsNotify.clear();
1600            }
1601        }
1602
1603        if (mStopParams != NULL) {
1604            // Queue discontinuity in original stream.
1605            int32_t discontinuitySeq;
1606            int64_t stopTimeUs;
1607            if (!mStopParams->findInt32("discontinuitySeq", &discontinuitySeq)
1608                    || discontinuitySeq > mDiscontinuitySeq
1609                    || !mStopParams->findInt64("timeUsAudio", &stopTimeUs)
1610                    || (discontinuitySeq == mDiscontinuitySeq && unitTimeUs >= stopTimeUs)) {
1611                packetSource->queueAccessUnit(mSession->createFormatChangeBuffer());
1612                mStreamTypeMask = 0;
1613                mPacketSources.clear();
1614                return ERROR_OUT_OF_RANGE;
1615            }
1616        }
1617
1618        sp<ABuffer> unit = new ABuffer(aac_frame_length);
1619        memcpy(unit->data(), adtsHeader, aac_frame_length);
1620
1621        unit->meta()->setInt64("timeUs", unitTimeUs);
1622        setAccessUnitProperties(unit, packetSource);
1623        packetSource->queueAccessUnit(unit);
1624    }
1625
1626    return OK;
1627}
1628
1629void PlaylistFetcher::updateDuration() {
1630    int64_t durationUs = 0ll;
1631    for (size_t index = 0; index < mPlaylist->size(); ++index) {
1632        sp<AMessage> itemMeta;
1633        CHECK(mPlaylist->itemAt(
1634                    index, NULL /* uri */, &itemMeta));
1635
1636        int64_t itemDurationUs;
1637        CHECK(itemMeta->findInt64("durationUs", &itemDurationUs));
1638
1639        durationUs += itemDurationUs;
1640    }
1641
1642    sp<AMessage> msg = mNotify->dup();
1643    msg->setInt32("what", kWhatDurationUpdate);
1644    msg->setInt64("durationUs", durationUs);
1645    msg->post();
1646}
1647
1648int64_t PlaylistFetcher::resumeThreshold(const sp<AMessage> &msg) {
1649    int64_t durationUs, threshold;
1650    if (msg->findInt64("durationUs", &durationUs)) {
1651        return kNumSkipFrames * durationUs;
1652    }
1653
1654    sp<RefBase> obj;
1655    msg->findObject("format", &obj);
1656    MetaData *format = static_cast<MetaData *>(obj.get());
1657
1658    const char *mime;
1659    CHECK(format->findCString(kKeyMIMEType, &mime));
1660    bool audio = !strncasecmp(mime, "audio/", 6);
1661    if (audio) {
1662        // Assumes 1000 samples per frame.
1663        int32_t sampleRate;
1664        CHECK(format->findInt32(kKeySampleRate, &sampleRate));
1665        return kNumSkipFrames  /* frames */ * 1000 /* samples */
1666                * (1000000 / sampleRate) /* sample duration (us) */;
1667    } else {
1668        int32_t frameRate;
1669        if (format->findInt32(kKeyFrameRate, &frameRate) && frameRate > 0) {
1670            return kNumSkipFrames * (1000000 / frameRate);
1671        }
1672    }
1673
1674    return 500000ll;
1675}
1676
1677}  // namespace android
1678