PlaylistFetcher.cpp revision 632740c58119a132ce19f6d498e39c5c3773971a 
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 = 192;
53const int32_t PlaylistFetcher::kNumSkipFrames = 10;
54
55PlaylistFetcher::PlaylistFetcher(
56        const sp<AMessage> &notify,
57        const sp<LiveSession> &session,
58        const char *uri)
59    : mNotify(notify),
60      mStartTimeUsNotify(notify->dup()),
61      mSession(session),
62      mURI(uri),
63      mStreamTypeMask(0),
64      mStartTimeUs(-1ll),
65      mMinStartTimeUs(0ll),
66      mStopParams(NULL),
67      mLastPlaylistFetchTimeUs(-1ll),
68      mSeqNumber(-1),
69      mNumRetries(0),
70      mStartup(true),
71      mPrepared(false),
72      mSkipToFirstIDRAfterConnect(false),
73      mNextPTSTimeUs(-1ll),
74      mMonitorQueueGeneration(0),
75      mRefreshState(INITIAL_MINIMUM_RELOAD_DELAY),
76      mFirstPTSValid(false),
77      mAbsoluteTimeAnchorUs(0ll) {
78    memset(mPlaylistHash, 0, sizeof(mPlaylistHash));
79    mStartTimeUsNotify->setInt32("what", kWhatStartedAt);
80    mStartTimeUsNotify->setInt32("streamMask", 0);
81}
82
83PlaylistFetcher::~PlaylistFetcher() {
84}
85
86int64_t PlaylistFetcher::getSegmentStartTimeUs(int32_t seqNumber) const {
87    CHECK(mPlaylist != NULL);
88
89    int32_t firstSeqNumberInPlaylist;
90    if (mPlaylist->meta() == NULL || !mPlaylist->meta()->findInt32(
91                "media-sequence", &firstSeqNumberInPlaylist)) {
92        firstSeqNumberInPlaylist = 0;
93    }
94
95    int32_t lastSeqNumberInPlaylist =
96        firstSeqNumberInPlaylist + (int32_t)mPlaylist->size() - 1;
97
98    CHECK_GE(seqNumber, firstSeqNumberInPlaylist);
99    CHECK_LE(seqNumber, lastSeqNumberInPlaylist);
100
101    int64_t segmentStartUs = 0ll;
102    for (int32_t index = 0;
103            index < seqNumber - firstSeqNumberInPlaylist; ++index) {
104        sp<AMessage> itemMeta;
105        CHECK(mPlaylist->itemAt(
106                    index, NULL /* uri */, &itemMeta));
107
108        int64_t itemDurationUs;
109        CHECK(itemMeta->findInt64("durationUs", &itemDurationUs));
110
111        segmentStartUs += itemDurationUs;
112    }
113
114    return segmentStartUs;
115}
116
117int64_t PlaylistFetcher::delayUsToRefreshPlaylist() const {
118    int64_t nowUs = ALooper::GetNowUs();
119
120    if (mPlaylist == NULL || mLastPlaylistFetchTimeUs < 0ll) {
121        CHECK_EQ((int)mRefreshState, (int)INITIAL_MINIMUM_RELOAD_DELAY);
122        return 0ll;
123    }
124
125    if (mPlaylist->isComplete()) {
126        return (~0llu >> 1);
127    }
128
129    int32_t targetDurationSecs;
130    CHECK(mPlaylist->meta()->findInt32("target-duration", &targetDurationSecs));
131
132    int64_t targetDurationUs = targetDurationSecs * 1000000ll;
133
134    int64_t minPlaylistAgeUs;
135
136    switch (mRefreshState) {
137        case INITIAL_MINIMUM_RELOAD_DELAY:
138        {
139            size_t n = mPlaylist->size();
140            if (n > 0) {
141                sp<AMessage> itemMeta;
142                CHECK(mPlaylist->itemAt(n - 1, NULL /* uri */, &itemMeta));
143
144                int64_t itemDurationUs;
145                CHECK(itemMeta->findInt64("durationUs", &itemDurationUs));
146
147                minPlaylistAgeUs = itemDurationUs;
148                break;
149            }
150
151            // fall through
152        }
153
154        case FIRST_UNCHANGED_RELOAD_ATTEMPT:
155        {
156            minPlaylistAgeUs = targetDurationUs / 2;
157            break;
158        }
159
160        case SECOND_UNCHANGED_RELOAD_ATTEMPT:
161        {
162            minPlaylistAgeUs = (targetDurationUs * 3) / 2;
163            break;
164        }
165
166        case THIRD_UNCHANGED_RELOAD_ATTEMPT:
167        {
168            minPlaylistAgeUs = targetDurationUs * 3;
169            break;
170        }
171
172        default:
173            TRESPASS();
174            break;
175    }
176
177    int64_t delayUs = mLastPlaylistFetchTimeUs + minPlaylistAgeUs - nowUs;
178    return delayUs > 0ll ? delayUs : 0ll;
179}
180
181status_t PlaylistFetcher::decryptBuffer(
182        size_t playlistIndex, const sp<ABuffer> &buffer,
183        bool first) {
184    sp<AMessage> itemMeta;
185    bool found = false;
186    AString method;
187
188    for (ssize_t i = playlistIndex; i >= 0; --i) {
189        AString uri;
190        CHECK(mPlaylist->itemAt(i, &uri, &itemMeta));
191
192        if (itemMeta->findString("cipher-method", &method)) {
193            found = true;
194            break;
195        }
196    }
197
198    if (!found) {
199        method = "NONE";
200    }
201    buffer->meta()->setString("cipher-method", method.c_str());
202
203    if (method == "NONE") {
204        return OK;
205    } else if (!(method == "AES-128")) {
206        ALOGE("Unsupported cipher method '%s'", method.c_str());
207        return ERROR_UNSUPPORTED;
208    }
209
210    AString keyURI;
211    if (!itemMeta->findString("cipher-uri", &keyURI)) {
212        ALOGE("Missing key uri");
213        return ERROR_MALFORMED;
214    }
215
216    ssize_t index = mAESKeyForURI.indexOfKey(keyURI);
217
218    sp<ABuffer> key;
219    if (index >= 0) {
220        key = mAESKeyForURI.valueAt(index);
221    } else {
222        ssize_t err = mSession->fetchFile(keyURI.c_str(), &key);
223
224        if (err < 0) {
225            ALOGE("failed to fetch cipher key from '%s'.", keyURI.c_str());
226            return ERROR_IO;
227        } else if (key->size() != 16) {
228            ALOGE("key file '%s' wasn't 16 bytes in size.", keyURI.c_str());
229            return ERROR_MALFORMED;
230        }
231
232        mAESKeyForURI.add(keyURI, key);
233    }
234
235    AES_KEY aes_key;
236    if (AES_set_decrypt_key(key->data(), 128, &aes_key) != 0) {
237        ALOGE("failed to set AES decryption key.");
238        return UNKNOWN_ERROR;
239    }
240
241    size_t n = buffer->size();
242    if (!n) {
243        return OK;
244    }
245    CHECK(n % 16 == 0);
246
247    if (first) {
248        // If decrypting the first block in a file, read the iv from the manifest
249        // or derive the iv from the file's sequence number.
250
251        AString iv;
252        if (itemMeta->findString("cipher-iv", &iv)) {
253            if ((!iv.startsWith("0x") && !iv.startsWith("0X"))
254                    || iv.size() != 16 * 2 + 2) {
255                ALOGE("malformed cipher IV '%s'.", iv.c_str());
256                return ERROR_MALFORMED;
257            }
258
259            memset(mAESInitVec, 0, sizeof(mAESInitVec));
260            for (size_t i = 0; i < 16; ++i) {
261                char c1 = tolower(iv.c_str()[2 + 2 * i]);
262                char c2 = tolower(iv.c_str()[3 + 2 * i]);
263                if (!isxdigit(c1) || !isxdigit(c2)) {
264                    ALOGE("malformed cipher IV '%s'.", iv.c_str());
265                    return ERROR_MALFORMED;
266                }
267                uint8_t nibble1 = isdigit(c1) ? c1 - '0' : c1 - 'a' + 10;
268                uint8_t nibble2 = isdigit(c2) ? c2 - '0' : c2 - 'a' + 10;
269
270                mAESInitVec[i] = nibble1 << 4 | nibble2;
271            }
272        } else {
273            memset(mAESInitVec, 0, sizeof(mAESInitVec));
274            mAESInitVec[15] = mSeqNumber & 0xff;
275            mAESInitVec[14] = (mSeqNumber >> 8) & 0xff;
276            mAESInitVec[13] = (mSeqNumber >> 16) & 0xff;
277            mAESInitVec[12] = (mSeqNumber >> 24) & 0xff;
278        }
279    }
280
281    AES_cbc_encrypt(
282            buffer->data(), buffer->data(), buffer->size(),
283            &aes_key, mAESInitVec, AES_DECRYPT);
284
285    return OK;
286}
287
288status_t PlaylistFetcher::checkDecryptPadding(const sp<ABuffer> &buffer) {
289    status_t err;
290    AString method;
291    CHECK(buffer->meta()->findString("cipher-method", &method));
292    if (method == "NONE") {
293        return OK;
294    }
295
296    uint8_t padding = 0;
297    if (buffer->size() > 0) {
298        padding = buffer->data()[buffer->size() - 1];
299    }
300
301    if (padding > 16) {
302        return ERROR_MALFORMED;
303    }
304
305    for (size_t i = buffer->size() - padding; i < padding; i++) {
306        if (buffer->data()[i] != padding) {
307            return ERROR_MALFORMED;
308        }
309    }
310
311    buffer->setRange(buffer->offset(), buffer->size() - padding);
312    return OK;
313}
314
315void PlaylistFetcher::postMonitorQueue(int64_t delayUs, int64_t minDelayUs) {
316    int64_t maxDelayUs = delayUsToRefreshPlaylist();
317    if (maxDelayUs < minDelayUs) {
318        maxDelayUs = minDelayUs;
319    }
320    if (delayUs > maxDelayUs) {
321        ALOGV("Need to refresh playlist in %" PRId64 , maxDelayUs);
322        delayUs = maxDelayUs;
323    }
324    sp<AMessage> msg = new AMessage(kWhatMonitorQueue, id());
325    msg->setInt32("generation", mMonitorQueueGeneration);
326    msg->post(delayUs);
327}
328
329void PlaylistFetcher::cancelMonitorQueue() {
330    ++mMonitorQueueGeneration;
331}
332
333void PlaylistFetcher::startAsync(
334        const sp<AnotherPacketSource> &audioSource,
335        const sp<AnotherPacketSource> &videoSource,
336        const sp<AnotherPacketSource> &subtitleSource,
337        int64_t startTimeUs,
338        int64_t minStartTimeUs,
339        int32_t startSeqNumberHint) {
340    sp<AMessage> msg = new AMessage(kWhatStart, id());
341
342    uint32_t streamTypeMask = 0ul;
343
344    if (audioSource != NULL) {
345        msg->setPointer("audioSource", audioSource.get());
346        streamTypeMask |= LiveSession::STREAMTYPE_AUDIO;
347    }
348
349    if (videoSource != NULL) {
350        msg->setPointer("videoSource", videoSource.get());
351        streamTypeMask |= LiveSession::STREAMTYPE_VIDEO;
352    }
353
354    if (subtitleSource != NULL) {
355        msg->setPointer("subtitleSource", subtitleSource.get());
356        streamTypeMask |= LiveSession::STREAMTYPE_SUBTITLES;
357    }
358
359    msg->setInt32("streamTypeMask", streamTypeMask);
360    msg->setInt64("startTimeUs", startTimeUs);
361    msg->setInt64("minStartTimeUs", minStartTimeUs);
362    msg->setInt32("startSeqNumberHint", startSeqNumberHint);
363    msg->post();
364}
365
366void PlaylistFetcher::pauseAsync() {
367    (new AMessage(kWhatPause, id()))->post();
368}
369
370void PlaylistFetcher::stopAsync(bool selfTriggered) {
371    sp<AMessage> msg = new AMessage(kWhatStop, id());
372    msg->setInt32("selfTriggered", selfTriggered);
373    msg->post();
374}
375
376void PlaylistFetcher::resumeUntilAsync(const sp<AMessage> &params) {
377    AMessage* msg = new AMessage(kWhatResumeUntil, id());
378    msg->setMessage("params", params);
379    msg->post();
380}
381
382void PlaylistFetcher::onMessageReceived(const sp<AMessage> &msg) {
383    switch (msg->what()) {
384        case kWhatStart:
385        {
386            status_t err = onStart(msg);
387
388            sp<AMessage> notify = mNotify->dup();
389            notify->setInt32("what", kWhatStarted);
390            notify->setInt32("err", err);
391            notify->post();
392            break;
393        }
394
395        case kWhatPause:
396        {
397            onPause();
398
399            sp<AMessage> notify = mNotify->dup();
400            notify->setInt32("what", kWhatPaused);
401            notify->post();
402            break;
403        }
404
405        case kWhatStop:
406        {
407            onStop(msg);
408
409            sp<AMessage> notify = mNotify->dup();
410            notify->setInt32("what", kWhatStopped);
411            notify->post();
412            break;
413        }
414
415        case kWhatMonitorQueue:
416        case kWhatDownloadNext:
417        {
418            int32_t generation;
419            CHECK(msg->findInt32("generation", &generation));
420
421            if (generation != mMonitorQueueGeneration) {
422                // Stale event
423                break;
424            }
425
426            if (msg->what() == kWhatMonitorQueue) {
427                onMonitorQueue();
428            } else {
429                onDownloadNext();
430            }
431            break;
432        }
433
434        case kWhatResumeUntil:
435        {
436            onResumeUntil(msg);
437            break;
438        }
439
440        default:
441            TRESPASS();
442    }
443}
444
445status_t PlaylistFetcher::onStart(const sp<AMessage> &msg) {
446    mPacketSources.clear();
447
448    uint32_t streamTypeMask;
449    CHECK(msg->findInt32("streamTypeMask", (int32_t *)&streamTypeMask));
450
451    int64_t startTimeUs;
452    int32_t startSeqNumberHint;
453    CHECK(msg->findInt64("startTimeUs", &startTimeUs));
454    CHECK(msg->findInt64("minStartTimeUs", (int64_t *) &mMinStartTimeUs));
455    CHECK(msg->findInt32("startSeqNumberHint", &startSeqNumberHint));
456
457    if (streamTypeMask & LiveSession::STREAMTYPE_AUDIO) {
458        void *ptr;
459        CHECK(msg->findPointer("audioSource", &ptr));
460
461        mPacketSources.add(
462                LiveSession::STREAMTYPE_AUDIO,
463                static_cast<AnotherPacketSource *>(ptr));
464    }
465
466    if (streamTypeMask & LiveSession::STREAMTYPE_VIDEO) {
467        void *ptr;
468        CHECK(msg->findPointer("videoSource", &ptr));
469
470        mPacketSources.add(
471                LiveSession::STREAMTYPE_VIDEO,
472                static_cast<AnotherPacketSource *>(ptr));
473    }
474
475    if (streamTypeMask & LiveSession::STREAMTYPE_SUBTITLES) {
476        void *ptr;
477        CHECK(msg->findPointer("subtitleSource", &ptr));
478
479        mPacketSources.add(
480                LiveSession::STREAMTYPE_SUBTITLES,
481                static_cast<AnotherPacketSource *>(ptr));
482    }
483
484    mStreamTypeMask = streamTypeMask;
485    mStartTimeUs = startTimeUs;
486
487    if (mStartTimeUs >= 0ll) {
488        mSeqNumber = -1;
489        mStartup = true;
490        mPrepared = false;
491    }
492
493    if (startSeqNumberHint >= 0) {
494        mSeqNumber = startSeqNumberHint;
495    }
496
497    postMonitorQueue();
498
499    return OK;
500}
501
502void PlaylistFetcher::onPause() {
503    cancelMonitorQueue();
504}
505
506void PlaylistFetcher::onStop(const sp<AMessage> &msg) {
507    cancelMonitorQueue();
508
509    int32_t selfTriggered;
510    CHECK(msg->findInt32("selfTriggered", &selfTriggered));
511    if (!selfTriggered) {
512        // Self triggered stops only happen during switching, in which case we do not want
513        // to clear the discontinuities queued at the end of packet sources.
514        for (size_t i = 0; i < mPacketSources.size(); i++) {
515            sp<AnotherPacketSource> packetSource = mPacketSources.valueAt(i);
516            packetSource->clear();
517        }
518    }
519
520    mPacketSources.clear();
521    mStreamTypeMask = 0;
522}
523
524// Resume until we have reached the boundary timestamps listed in `msg`; when
525// the remaining time is too short (within a resume threshold) stop immediately
526// instead.
527status_t PlaylistFetcher::onResumeUntil(const sp<AMessage> &msg) {
528    sp<AMessage> params;
529    CHECK(msg->findMessage("params", &params));
530
531    bool stop = false;
532    for (size_t i = 0; i < mPacketSources.size(); i++) {
533        sp<AnotherPacketSource> packetSource = mPacketSources.valueAt(i);
534
535        const char *stopKey;
536        int streamType = mPacketSources.keyAt(i);
537        switch (streamType) {
538        case LiveSession::STREAMTYPE_VIDEO:
539            stopKey = "timeUsVideo";
540            break;
541
542        case LiveSession::STREAMTYPE_AUDIO:
543            stopKey = "timeUsAudio";
544            break;
545
546        case LiveSession::STREAMTYPE_SUBTITLES:
547            stopKey = "timeUsSubtitle";
548            break;
549
550        default:
551            TRESPASS();
552        }
553
554        // Don't resume if we would stop within a resume threshold.
555        int64_t latestTimeUs = 0, stopTimeUs = 0;
556        sp<AMessage> latestMeta = packetSource->getLatestMeta();
557        if (latestMeta != NULL
558                && (latestMeta->findInt64("timeUs", &latestTimeUs)
559                && params->findInt64(stopKey, &stopTimeUs))) {
560            int64_t diffUs = stopTimeUs - latestTimeUs;
561            if (diffUs < resumeThreshold(latestMeta)) {
562                stop = true;
563            }
564        }
565    }
566
567    if (stop) {
568        for (size_t i = 0; i < mPacketSources.size(); i++) {
569            mPacketSources.valueAt(i)->queueAccessUnit(mSession->createFormatChangeBuffer());
570        }
571        stopAsync(/* selfTriggered = */ true);
572        return OK;
573    }
574
575    mStopParams = params;
576    postMonitorQueue();
577
578    return OK;
579}
580
581void PlaylistFetcher::notifyError(status_t err) {
582    sp<AMessage> notify = mNotify->dup();
583    notify->setInt32("what", kWhatError);
584    notify->setInt32("err", err);
585    notify->post();
586}
587
588void PlaylistFetcher::queueDiscontinuity(
589        ATSParser::DiscontinuityType type, const sp<AMessage> &extra) {
590    for (size_t i = 0; i < mPacketSources.size(); ++i) {
591        // do not discard buffer upon #EXT-X-DISCONTINUITY tag
592        // (seek will discard buffer by abandoning old fetchers)
593        mPacketSources.valueAt(i)->queueDiscontinuity(
594                type, extra, false /* discard */);
595    }
596}
597
598void PlaylistFetcher::onMonitorQueue() {
599    bool downloadMore = false;
600    refreshPlaylist();
601
602    int32_t targetDurationSecs;
603    int64_t targetDurationUs = kMinBufferedDurationUs;
604    if (mPlaylist != NULL) {
605        CHECK(mPlaylist->meta()->findInt32("target-duration", &targetDurationSecs));
606        targetDurationUs = targetDurationSecs * 1000000ll;
607    }
608
609    // buffer at least 3 times the target duration, or up to 10 seconds
610    int64_t durationToBufferUs = targetDurationUs * 3;
611    if (durationToBufferUs > kMinBufferedDurationUs)  {
612        durationToBufferUs = kMinBufferedDurationUs;
613    }
614
615    int64_t bufferedDurationUs = 0ll;
616    status_t finalResult = NOT_ENOUGH_DATA;
617    if (mStreamTypeMask == LiveSession::STREAMTYPE_SUBTITLES) {
618        sp<AnotherPacketSource> packetSource =
619            mPacketSources.valueFor(LiveSession::STREAMTYPE_SUBTITLES);
620
621        bufferedDurationUs =
622                packetSource->getBufferedDurationUs(&finalResult);
623        finalResult = OK;
624    } else {
625        // Use max stream duration to prevent us from waiting on a non-existent stream;
626        // when we cannot make out from the manifest what streams are included in a playlist
627        // we might assume extra streams.
628        for (size_t i = 0; i < mPacketSources.size(); ++i) {
629            if ((mStreamTypeMask & mPacketSources.keyAt(i)) == 0) {
630                continue;
631            }
632
633            int64_t bufferedStreamDurationUs =
634                mPacketSources.valueAt(i)->getBufferedDurationUs(&finalResult);
635            ALOGV("buffered %" PRId64 " for stream %d",
636                    bufferedStreamDurationUs, mPacketSources.keyAt(i));
637            if (bufferedStreamDurationUs > bufferedDurationUs) {
638                bufferedDurationUs = bufferedStreamDurationUs;
639            }
640        }
641    }
642    downloadMore = (bufferedDurationUs < durationToBufferUs);
643
644    // signal start if buffered up at least the target size
645    if (!mPrepared && bufferedDurationUs > targetDurationUs && downloadMore) {
646        mPrepared = true;
647
648        ALOGV("prepared, buffered=%" PRId64 " > %" PRId64 "",
649                bufferedDurationUs, targetDurationUs);
650        sp<AMessage> msg = mNotify->dup();
651        msg->setInt32("what", kWhatTemporarilyDoneFetching);
652        msg->post();
653    }
654
655    if (finalResult == OK && downloadMore) {
656        ALOGV("monitoring, buffered=%" PRId64 " < %" PRId64 "",
657                bufferedDurationUs, durationToBufferUs);
658        // delay the next download slightly; hopefully this gives other concurrent fetchers
659        // a better chance to run.
660        // onDownloadNext();
661        sp<AMessage> msg = new AMessage(kWhatDownloadNext, id());
662        msg->setInt32("generation", mMonitorQueueGeneration);
663        msg->post(1000l);
664    } else {
665        // Nothing to do yet, try again in a second.
666
667        sp<AMessage> msg = mNotify->dup();
668        msg->setInt32("what", kWhatTemporarilyDoneFetching);
669        msg->post();
670
671        int64_t delayUs = mPrepared ? kMaxMonitorDelayUs : targetDurationUs / 2;
672        ALOGV("pausing for %" PRId64 ", buffered=%" PRId64 " > %" PRId64 "",
673                delayUs, bufferedDurationUs, durationToBufferUs);
674        // :TRICKY: need to enforce minimum delay because the delay to
675        // refresh the playlist will become 0
676        postMonitorQueue(delayUs, mPrepared ? targetDurationUs * 2 : 0);
677    }
678}
679
680status_t PlaylistFetcher::refreshPlaylist() {
681    if (delayUsToRefreshPlaylist() <= 0) {
682        bool unchanged;
683        sp<M3UParser> playlist = mSession->fetchPlaylist(
684                mURI.c_str(), mPlaylistHash, &unchanged);
685
686        if (playlist == NULL) {
687            if (unchanged) {
688                // We succeeded in fetching the playlist, but it was
689                // unchanged from the last time we tried.
690
691                if (mRefreshState != THIRD_UNCHANGED_RELOAD_ATTEMPT) {
692                    mRefreshState = (RefreshState)(mRefreshState + 1);
693                }
694            } else {
695                ALOGE("failed to load playlist at url '%s'", mURI.c_str());
696                notifyError(ERROR_IO);
697                return ERROR_IO;
698            }
699        } else {
700            mRefreshState = INITIAL_MINIMUM_RELOAD_DELAY;
701            mPlaylist = playlist;
702
703            if (mPlaylist->isComplete() || mPlaylist->isEvent()) {
704                updateDuration();
705            }
706        }
707
708        mLastPlaylistFetchTimeUs = ALooper::GetNowUs();
709    }
710    return OK;
711}
712
713// static
714bool PlaylistFetcher::bufferStartsWithTsSyncByte(const sp<ABuffer>& buffer) {
715    return buffer->size() > 0 && buffer->data()[0] == 0x47;
716}
717
718void PlaylistFetcher::onDownloadNext() {
719    if (refreshPlaylist() != OK) {
720        return;
721    }
722
723    int32_t firstSeqNumberInPlaylist;
724    if (mPlaylist->meta() == NULL || !mPlaylist->meta()->findInt32(
725                "media-sequence", &firstSeqNumberInPlaylist)) {
726        firstSeqNumberInPlaylist = 0;
727    }
728
729    bool discontinuity = false;
730
731    const int32_t lastSeqNumberInPlaylist =
732        firstSeqNumberInPlaylist + (int32_t)mPlaylist->size() - 1;
733
734    if (mStartup && mSeqNumber >= 0
735            && (mSeqNumber < firstSeqNumberInPlaylist || mSeqNumber > lastSeqNumberInPlaylist)) {
736        // in case we guessed wrong during reconfiguration, try fetching the latest content.
737        mSeqNumber = lastSeqNumberInPlaylist;
738    }
739
740    if (mSeqNumber < 0) {
741        CHECK_GE(mStartTimeUs, 0ll);
742
743        if (mPlaylist->isComplete() || mPlaylist->isEvent()) {
744            mSeqNumber = getSeqNumberForTime(mStartTimeUs);
745            ALOGV("Initial sequence number for time %" PRId64 " is %d from (%d .. %d)",
746                    mStartTimeUs, mSeqNumber, firstSeqNumberInPlaylist,
747                    lastSeqNumberInPlaylist);
748        } else {
749            // If this is a live session, start 3 segments from the end.
750            mSeqNumber = lastSeqNumberInPlaylist - 3;
751            if (mSeqNumber < firstSeqNumberInPlaylist) {
752                mSeqNumber = firstSeqNumberInPlaylist;
753            }
754            ALOGV("Initial sequence number for live event %d from (%d .. %d)",
755                    mSeqNumber, firstSeqNumberInPlaylist,
756                    lastSeqNumberInPlaylist);
757        }
758
759        mStartTimeUs = -1ll;
760    }
761
762    if (mSeqNumber < firstSeqNumberInPlaylist
763            || mSeqNumber > lastSeqNumberInPlaylist) {
764        if (!mPlaylist->isComplete() && mNumRetries < kMaxNumRetries) {
765            ++mNumRetries;
766
767            if (mSeqNumber > lastSeqNumberInPlaylist) {
768                // refresh in increasing fraction (1/2, 1/3, ...) of the
769                // playlist's target duration or 3 seconds, whichever is less
770                int32_t targetDurationSecs;
771                CHECK(mPlaylist->meta()->findInt32(
772                        "target-duration", &targetDurationSecs));
773                int64_t delayUs = mPlaylist->size() * targetDurationSecs *
774                        1000000ll / (1 + mNumRetries);
775                if (delayUs > kMaxMonitorDelayUs) {
776                    delayUs = kMaxMonitorDelayUs;
777                }
778                ALOGV("sequence number high: %d from (%d .. %d), "
779                      "monitor in %" PRId64 " (retry=%d)",
780                        mSeqNumber, firstSeqNumberInPlaylist,
781                        lastSeqNumberInPlaylist, delayUs, mNumRetries);
782                postMonitorQueue(delayUs);
783                return;
784            }
785
786            // we've missed the boat, let's start from the lowest sequence
787            // number available and signal a discontinuity.
788
789            ALOGI("We've missed the boat, restarting playback."
790                  "  mStartup=%d, was  looking for %d in %d-%d",
791                    mStartup, mSeqNumber, firstSeqNumberInPlaylist,
792                    lastSeqNumberInPlaylist);
793            mSeqNumber = lastSeqNumberInPlaylist - 3;
794            if (mSeqNumber < firstSeqNumberInPlaylist) {
795                mSeqNumber = firstSeqNumberInPlaylist;
796            }
797            discontinuity = true;
798
799            // fall through
800        } else {
801            ALOGE("Cannot find sequence number %d in playlist "
802                 "(contains %d - %d)",
803                 mSeqNumber, firstSeqNumberInPlaylist,
804                  firstSeqNumberInPlaylist + (int32_t)mPlaylist->size() - 1);
805
806            notifyError(ERROR_END_OF_STREAM);
807            return;
808        }
809    }
810
811    mNumRetries = 0;
812
813    AString uri;
814    sp<AMessage> itemMeta;
815    CHECK(mPlaylist->itemAt(
816                mSeqNumber - firstSeqNumberInPlaylist,
817                &uri,
818                &itemMeta));
819
820    int32_t val;
821    if (itemMeta->findInt32("discontinuity", &val) && val != 0) {
822        discontinuity = true;
823    }
824
825    int64_t range_offset, range_length;
826    if (!itemMeta->findInt64("range-offset", &range_offset)
827            || !itemMeta->findInt64("range-length", &range_length)) {
828        range_offset = 0;
829        range_length = -1;
830    }
831
832    ALOGV("fetching segment %d from (%d .. %d)",
833          mSeqNumber, firstSeqNumberInPlaylist, lastSeqNumberInPlaylist);
834
835    ALOGV("fetching '%s'", uri.c_str());
836
837    sp<DataSource> source;
838    sp<ABuffer> buffer, tsBuffer;
839    // decrypt a junk buffer to prefetch key; since a session uses only one http connection,
840    // this avoids interleaved connections to the key and segment file.
841    {
842        sp<ABuffer> junk = new ABuffer(16);
843        junk->setRange(0, 16);
844        status_t err = decryptBuffer(mSeqNumber - firstSeqNumberInPlaylist, junk,
845                true /* first */);
846        if (err != OK) {
847            notifyError(err);
848            return;
849        }
850    }
851
852    // block-wise download
853    ssize_t bytesRead;
854    do {
855        bytesRead = mSession->fetchFile(
856                uri.c_str(), &buffer, range_offset, range_length, kDownloadBlockSize, &source);
857
858        if (bytesRead < 0) {
859            status_t err = bytesRead;
860            ALOGE("failed to fetch .ts segment at url '%s'", uri.c_str());
861            notifyError(err);
862            return;
863        }
864
865        CHECK(buffer != NULL);
866
867        size_t size = buffer->size();
868        // Set decryption range.
869        buffer->setRange(size - bytesRead, bytesRead);
870        status_t err = decryptBuffer(mSeqNumber - firstSeqNumberInPlaylist, buffer,
871                buffer->offset() == 0 /* first */);
872        // Unset decryption range.
873        buffer->setRange(0, size);
874
875        if (err != OK) {
876            ALOGE("decryptBuffer failed w/ error %d", err);
877
878            notifyError(err);
879            return;
880        }
881
882        if (mStartup || discontinuity) {
883            // Signal discontinuity.
884
885            if (mPlaylist->isComplete() || mPlaylist->isEvent()) {
886                // If this was a live event this made no sense since
887                // we don't have access to all the segment before the current
888                // one.
889                mNextPTSTimeUs = getSegmentStartTimeUs(mSeqNumber);
890            }
891
892            if (discontinuity) {
893                ALOGI("queueing discontinuity (explicit=%d)", discontinuity);
894
895                queueDiscontinuity(
896                        ATSParser::DISCONTINUITY_FORMATCHANGE,
897                        NULL /* extra */);
898
899                discontinuity = false;
900            }
901        }
902
903        err = OK;
904        if (bufferStartsWithTsSyncByte(buffer)) {
905            // Incremental extraction is only supported for MPEG2 transport streams.
906            if (tsBuffer == NULL) {
907                tsBuffer = new ABuffer(buffer->data(), buffer->capacity());
908                tsBuffer->setRange(0, 0);
909            } else if (tsBuffer->capacity() != buffer->capacity()) {
910                size_t tsOff = tsBuffer->offset(), tsSize = tsBuffer->size();
911                tsBuffer = new ABuffer(buffer->data(), buffer->capacity());
912                tsBuffer->setRange(tsOff, tsSize);
913            }
914            tsBuffer->setRange(tsBuffer->offset(), tsBuffer->size() + bytesRead);
915
916            err = extractAndQueueAccessUnitsFromTs(tsBuffer);
917        }
918
919        if (err == -EAGAIN) {
920            // bad starting sequence number hint
921            mTSParser.clear();
922            postMonitorQueue();
923            return;
924        }
925
926        if (err == ERROR_OUT_OF_RANGE) {
927            // reached stopping point
928            stopAsync(/* selfTriggered = */ true);
929            return;
930        }
931
932        if (err != OK) {
933            notifyError(err);
934            return;
935        }
936
937        mStartup = false;
938    } while (bytesRead != 0);
939
940    if (bufferStartsWithTsSyncByte(buffer)) {
941        // If we still don't see a stream after fetching a full ts segment mark it as
942        // nonexistent.
943        const size_t kNumTypes = ATSParser::NUM_SOURCE_TYPES;
944        ATSParser::SourceType srcTypes[kNumTypes] =
945                { ATSParser::VIDEO, ATSParser::AUDIO };
946        LiveSession::StreamType streamTypes[kNumTypes] =
947                { LiveSession::STREAMTYPE_VIDEO, LiveSession::STREAMTYPE_AUDIO };
948
949        for (size_t i = 0; i < kNumTypes; i++) {
950            ATSParser::SourceType srcType = srcTypes[i];
951            LiveSession::StreamType streamType = streamTypes[i];
952
953            sp<AnotherPacketSource> source =
954                static_cast<AnotherPacketSource *>(
955                    mTSParser->getSource(srcType).get());
956
957            if (source == NULL) {
958                ALOGW("MPEG2 Transport stream does not contain %s data.",
959                      srcType == ATSParser::VIDEO ? "video" : "audio");
960
961                mStreamTypeMask &= ~streamType;
962                mPacketSources.removeItem(streamType);
963            }
964        }
965
966    }
967
968    if (checkDecryptPadding(buffer) != OK) {
969        ALOGE("Incorrect padding bytes after decryption.");
970        notifyError(ERROR_MALFORMED);
971        return;
972    }
973
974    status_t err = OK;
975    if (tsBuffer != NULL) {
976        AString method;
977        CHECK(buffer->meta()->findString("cipher-method", &method));
978        if ((tsBuffer->size() > 0 && method == "NONE")
979                || tsBuffer->size() > 16) {
980            ALOGE("MPEG2 transport stream is not an even multiple of 188 "
981                    "bytes in length.");
982            notifyError(ERROR_MALFORMED);
983            return;
984        }
985    }
986
987    // bulk extract non-ts files
988    if (tsBuffer == NULL) {
989      err = extractAndQueueAccessUnits(buffer, itemMeta);
990    }
991
992    if (err != OK) {
993        notifyError(err);
994        return;
995    }
996
997    ++mSeqNumber;
998
999    postMonitorQueue();
1000}
1001
1002int32_t PlaylistFetcher::getSeqNumberForTime(int64_t timeUs) const {
1003    int32_t firstSeqNumberInPlaylist;
1004    if (mPlaylist->meta() == NULL || !mPlaylist->meta()->findInt32(
1005                "media-sequence", &firstSeqNumberInPlaylist)) {
1006        firstSeqNumberInPlaylist = 0;
1007    }
1008
1009    size_t index = 0;
1010    int64_t segmentStartUs = 0;
1011    while (index < mPlaylist->size()) {
1012        sp<AMessage> itemMeta;
1013        CHECK(mPlaylist->itemAt(
1014                    index, NULL /* uri */, &itemMeta));
1015
1016        int64_t itemDurationUs;
1017        CHECK(itemMeta->findInt64("durationUs", &itemDurationUs));
1018
1019        if (timeUs < segmentStartUs + itemDurationUs) {
1020            break;
1021        }
1022
1023        segmentStartUs += itemDurationUs;
1024        ++index;
1025    }
1026
1027    if (index >= mPlaylist->size()) {
1028        index = mPlaylist->size() - 1;
1029    }
1030
1031    return firstSeqNumberInPlaylist + index;
1032}
1033
1034status_t PlaylistFetcher::extractAndQueueAccessUnitsFromTs(const sp<ABuffer> &buffer) {
1035    if (mTSParser == NULL) {
1036        // Use TS_TIMESTAMPS_ARE_ABSOLUTE so pts carry over between fetchers.
1037        mTSParser = new ATSParser(ATSParser::TS_TIMESTAMPS_ARE_ABSOLUTE);
1038    }
1039
1040    if (mNextPTSTimeUs >= 0ll) {
1041        sp<AMessage> extra = new AMessage;
1042        // Since we are using absolute timestamps, signal an offset of 0 to prevent
1043        // ATSParser from skewing the timestamps of access units.
1044        extra->setInt64(IStreamListener::kKeyMediaTimeUs, 0);
1045
1046        mTSParser->signalDiscontinuity(
1047                ATSParser::DISCONTINUITY_SEEK, extra);
1048
1049        mNextPTSTimeUs = -1ll;
1050    }
1051
1052    size_t offset = 0;
1053    while (offset + 188 <= buffer->size()) {
1054        status_t err = mTSParser->feedTSPacket(buffer->data() + offset, 188);
1055
1056        if (err != OK) {
1057            return err;
1058        }
1059
1060        offset += 188;
1061    }
1062    // setRange to indicate consumed bytes.
1063    buffer->setRange(buffer->offset() + offset, buffer->size() - offset);
1064
1065    status_t err = OK;
1066    for (size_t i = mPacketSources.size(); i-- > 0;) {
1067        sp<AnotherPacketSource> packetSource = mPacketSources.valueAt(i);
1068
1069        const char *key;
1070        ATSParser::SourceType type;
1071        const LiveSession::StreamType stream = mPacketSources.keyAt(i);
1072        switch (stream) {
1073            case LiveSession::STREAMTYPE_VIDEO:
1074                type = ATSParser::VIDEO;
1075                key = "timeUsVideo";
1076                break;
1077
1078            case LiveSession::STREAMTYPE_AUDIO:
1079                type = ATSParser::AUDIO;
1080                key = "timeUsAudio";
1081                break;
1082
1083            case LiveSession::STREAMTYPE_SUBTITLES:
1084            {
1085                ALOGE("MPEG2 Transport streams do not contain subtitles.");
1086                return ERROR_MALFORMED;
1087                break;
1088            }
1089
1090            default:
1091                TRESPASS();
1092        }
1093
1094        sp<AnotherPacketSource> source =
1095            static_cast<AnotherPacketSource *>(
1096                    mTSParser->getSource(type).get());
1097
1098        if (source == NULL) {
1099            continue;
1100        }
1101
1102        if (stream == LiveSession::STREAMTYPE_VIDEO && mVideoMime.empty()) {
1103            const char *mime;
1104            if (source->getFormat()->findCString(kKeyMIMEType, &mime)) {
1105                mVideoMime.setTo(mime);
1106                if (!strcasecmp(mime, MEDIA_MIMETYPE_VIDEO_AVC)) {
1107                    mSkipToFirstIDRAfterConnect = true;
1108                }
1109            }
1110        }
1111
1112        int64_t timeUs;
1113        sp<ABuffer> accessUnit;
1114        status_t finalResult;
1115        while (source->hasBufferAvailable(&finalResult)
1116                && source->dequeueAccessUnit(&accessUnit) == OK) {
1117
1118            if (stream == LiveSession::STREAMTYPE_VIDEO && mSkipToFirstIDRAfterConnect) {
1119                if (!IsIDR(accessUnit)) {
1120                    continue;
1121                } else {
1122                    mSkipToFirstIDRAfterConnect = false;
1123                }
1124            }
1125
1126            CHECK(accessUnit->meta()->findInt64("timeUs", &timeUs));
1127            if (mMinStartTimeUs > 0) {
1128                if (timeUs < mMinStartTimeUs) {
1129                    // TODO untested path
1130                    // try a later ts
1131                    int32_t targetDuration;
1132                    mPlaylist->meta()->findInt32("target-duration", &targetDuration);
1133                    int32_t incr = (mMinStartTimeUs - timeUs) / 1000000 / targetDuration;
1134                    if (incr == 0) {
1135                        // increment mSeqNumber by at least one
1136                        incr = 1;
1137                    }
1138                    mSeqNumber += incr;
1139                    err = -EAGAIN;
1140                    break;
1141                } else {
1142                    int64_t startTimeUs;
1143                    if (mStartTimeUsNotify != NULL
1144                            && !mStartTimeUsNotify->findInt64(key, &startTimeUs)) {
1145                        mStartTimeUsNotify->setInt64(key, timeUs);
1146
1147                        uint32_t streamMask = 0;
1148                        mStartTimeUsNotify->findInt32("streamMask", (int32_t *) &streamMask);
1149                        streamMask |= mPacketSources.keyAt(i);
1150                        mStartTimeUsNotify->setInt32("streamMask", streamMask);
1151
1152                        if (streamMask == mStreamTypeMask) {
1153                            mStartTimeUsNotify->post();
1154                            mStartTimeUsNotify.clear();
1155                        }
1156                    }
1157                }
1158            }
1159
1160            if (mStopParams != NULL) {
1161                // Queue discontinuity in original stream.
1162                int64_t stopTimeUs;
1163                if (!mStopParams->findInt64(key, &stopTimeUs) || timeUs >= stopTimeUs) {
1164                    packetSource->queueAccessUnit(mSession->createFormatChangeBuffer());
1165                    mStreamTypeMask &= ~stream;
1166                    mPacketSources.removeItemsAt(i);
1167                    break;
1168                }
1169            }
1170
1171            // Note that we do NOT dequeue any discontinuities except for format change.
1172
1173            // for simplicity, store a reference to the format in each unit
1174            sp<MetaData> format = source->getFormat();
1175            if (format != NULL) {
1176                accessUnit->meta()->setObject("format", format);
1177            }
1178
1179            // Stash the sequence number so we can hint future playlist where to start at.
1180            accessUnit->meta()->setInt32("seq", mSeqNumber);
1181            packetSource->queueAccessUnit(accessUnit);
1182        }
1183
1184        if (err != OK) {
1185            break;
1186        }
1187    }
1188
1189    if (err != OK) {
1190        for (size_t i = mPacketSources.size(); i-- > 0;) {
1191            sp<AnotherPacketSource> packetSource = mPacketSources.valueAt(i);
1192            packetSource->clear();
1193        }
1194        return err;
1195    }
1196
1197    if (!mStreamTypeMask) {
1198        // Signal gap is filled between original and new stream.
1199        ALOGV("ERROR OUT OF RANGE");
1200        return ERROR_OUT_OF_RANGE;
1201    }
1202
1203    return OK;
1204}
1205
1206/* static */
1207bool PlaylistFetcher::bufferStartsWithWebVTTMagicSequence(
1208        const sp<ABuffer> &buffer) {
1209    size_t pos = 0;
1210
1211    // skip possible BOM
1212    if (buffer->size() >= pos + 3 &&
1213            !memcmp("\xef\xbb\xbf", buffer->data() + pos, 3)) {
1214        pos += 3;
1215    }
1216
1217    // accept WEBVTT followed by SPACE, TAB or (CR) LF
1218    if (buffer->size() < pos + 6 ||
1219            memcmp("WEBVTT", buffer->data() + pos, 6)) {
1220        return false;
1221    }
1222    pos += 6;
1223
1224    if (buffer->size() == pos) {
1225        return true;
1226    }
1227
1228    uint8_t sep = buffer->data()[pos];
1229    return sep == ' ' || sep == '\t' || sep == '\n' || sep == '\r';
1230}
1231
1232status_t PlaylistFetcher::extractAndQueueAccessUnits(
1233        const sp<ABuffer> &buffer, const sp<AMessage> &itemMeta) {
1234    if (bufferStartsWithWebVTTMagicSequence(buffer)) {
1235        if (mStreamTypeMask != LiveSession::STREAMTYPE_SUBTITLES) {
1236            ALOGE("This stream only contains subtitles.");
1237            return ERROR_MALFORMED;
1238        }
1239
1240        const sp<AnotherPacketSource> packetSource =
1241            mPacketSources.valueFor(LiveSession::STREAMTYPE_SUBTITLES);
1242
1243        int64_t durationUs;
1244        CHECK(itemMeta->findInt64("durationUs", &durationUs));
1245        buffer->meta()->setInt64("timeUs", getSegmentStartTimeUs(mSeqNumber));
1246        buffer->meta()->setInt64("durationUs", durationUs);
1247        buffer->meta()->setInt32("seq", mSeqNumber);
1248
1249        packetSource->queueAccessUnit(buffer);
1250        return OK;
1251    }
1252
1253    if (mNextPTSTimeUs >= 0ll) {
1254        mFirstPTSValid = false;
1255        mAbsoluteTimeAnchorUs = mNextPTSTimeUs;
1256        mNextPTSTimeUs = -1ll;
1257    }
1258
1259    // This better be an ISO 13818-7 (AAC) or ISO 13818-1 (MPEG) audio
1260    // stream prefixed by an ID3 tag.
1261
1262    bool firstID3Tag = true;
1263    uint64_t PTS = 0;
1264
1265    for (;;) {
1266        // Make sure to skip all ID3 tags preceding the audio data.
1267        // At least one must be present to provide the PTS timestamp.
1268
1269        ID3 id3(buffer->data(), buffer->size(), true /* ignoreV1 */);
1270        if (!id3.isValid()) {
1271            if (firstID3Tag) {
1272                ALOGE("Unable to parse ID3 tag.");
1273                return ERROR_MALFORMED;
1274            } else {
1275                break;
1276            }
1277        }
1278
1279        if (firstID3Tag) {
1280            bool found = false;
1281
1282            ID3::Iterator it(id3, "PRIV");
1283            while (!it.done()) {
1284                size_t length;
1285                const uint8_t *data = it.getData(&length);
1286
1287                static const char *kMatchName =
1288                    "com.apple.streaming.transportStreamTimestamp";
1289                static const size_t kMatchNameLen = strlen(kMatchName);
1290
1291                if (length == kMatchNameLen + 1 + 8
1292                        && !strncmp((const char *)data, kMatchName, kMatchNameLen)) {
1293                    found = true;
1294                    PTS = U64_AT(&data[kMatchNameLen + 1]);
1295                }
1296
1297                it.next();
1298            }
1299
1300            if (!found) {
1301                ALOGE("Unable to extract transportStreamTimestamp from ID3 tag.");
1302                return ERROR_MALFORMED;
1303            }
1304        }
1305
1306        // skip the ID3 tag
1307        buffer->setRange(
1308                buffer->offset() + id3.rawSize(), buffer->size() - id3.rawSize());
1309
1310        firstID3Tag = false;
1311    }
1312
1313    if (!mFirstPTSValid) {
1314        mFirstPTSValid = true;
1315        mFirstPTS = PTS;
1316    }
1317    PTS -= mFirstPTS;
1318
1319    int64_t timeUs = (PTS * 100ll) / 9ll + mAbsoluteTimeAnchorUs;
1320
1321    if (mStreamTypeMask != LiveSession::STREAMTYPE_AUDIO) {
1322        ALOGW("This stream only contains audio data!");
1323
1324        mStreamTypeMask &= LiveSession::STREAMTYPE_AUDIO;
1325
1326        if (mStreamTypeMask == 0) {
1327            return OK;
1328        }
1329    }
1330
1331    sp<AnotherPacketSource> packetSource =
1332        mPacketSources.valueFor(LiveSession::STREAMTYPE_AUDIO);
1333
1334    if (packetSource->getFormat() == NULL && buffer->size() >= 7) {
1335        ABitReader bits(buffer->data(), buffer->size());
1336
1337        // adts_fixed_header
1338
1339        CHECK_EQ(bits.getBits(12), 0xfffu);
1340        bits.skipBits(3);  // ID, layer
1341        bool protection_absent = bits.getBits(1) != 0;
1342
1343        unsigned profile = bits.getBits(2);
1344        CHECK_NE(profile, 3u);
1345        unsigned sampling_freq_index = bits.getBits(4);
1346        bits.getBits(1);  // private_bit
1347        unsigned channel_configuration = bits.getBits(3);
1348        CHECK_NE(channel_configuration, 0u);
1349        bits.skipBits(2);  // original_copy, home
1350
1351        sp<MetaData> meta = MakeAACCodecSpecificData(
1352                profile, sampling_freq_index, channel_configuration);
1353
1354        meta->setInt32(kKeyIsADTS, true);
1355
1356        packetSource->setFormat(meta);
1357    }
1358
1359    int64_t numSamples = 0ll;
1360    int32_t sampleRate;
1361    CHECK(packetSource->getFormat()->findInt32(kKeySampleRate, &sampleRate));
1362
1363    size_t offset = 0;
1364    while (offset < buffer->size()) {
1365        const uint8_t *adtsHeader = buffer->data() + offset;
1366        CHECK_LT(offset + 5, buffer->size());
1367
1368        unsigned aac_frame_length =
1369            ((adtsHeader[3] & 3) << 11)
1370            | (adtsHeader[4] << 3)
1371            | (adtsHeader[5] >> 5);
1372
1373        if (aac_frame_length == 0) {
1374            const uint8_t *id3Header = adtsHeader;
1375            if (!memcmp(id3Header, "ID3", 3)) {
1376                ID3 id3(id3Header, buffer->size() - offset, true);
1377                if (id3.isValid()) {
1378                    offset += id3.rawSize();
1379                    continue;
1380                };
1381            }
1382            return ERROR_MALFORMED;
1383        }
1384
1385        CHECK_LE(offset + aac_frame_length, buffer->size());
1386
1387        sp<ABuffer> unit = new ABuffer(aac_frame_length);
1388        memcpy(unit->data(), adtsHeader, aac_frame_length);
1389
1390        int64_t unitTimeUs = timeUs + numSamples * 1000000ll / sampleRate;
1391        unit->meta()->setInt64("timeUs", unitTimeUs);
1392
1393        // Each AAC frame encodes 1024 samples.
1394        numSamples += 1024;
1395
1396        unit->meta()->setInt32("seq", mSeqNumber);
1397        packetSource->queueAccessUnit(unit);
1398
1399        offset += aac_frame_length;
1400    }
1401
1402    return OK;
1403}
1404
1405void PlaylistFetcher::updateDuration() {
1406    int64_t durationUs = 0ll;
1407    for (size_t index = 0; index < mPlaylist->size(); ++index) {
1408        sp<AMessage> itemMeta;
1409        CHECK(mPlaylist->itemAt(
1410                    index, NULL /* uri */, &itemMeta));
1411
1412        int64_t itemDurationUs;
1413        CHECK(itemMeta->findInt64("durationUs", &itemDurationUs));
1414
1415        durationUs += itemDurationUs;
1416    }
1417
1418    sp<AMessage> msg = mNotify->dup();
1419    msg->setInt32("what", kWhatDurationUpdate);
1420    msg->setInt64("durationUs", durationUs);
1421    msg->post();
1422}
1423
1424int64_t PlaylistFetcher::resumeThreshold(const sp<AMessage> &msg) {
1425    int64_t durationUs, threshold;
1426    if (msg->findInt64("durationUs", &durationUs)) {
1427        return kNumSkipFrames * durationUs;
1428    }
1429
1430    sp<RefBase> obj;
1431    msg->findObject("format", &obj);
1432    MetaData *format = static_cast<MetaData *>(obj.get());
1433
1434    const char *mime;
1435    CHECK(format->findCString(kKeyMIMEType, &mime));
1436    bool audio = !strncasecmp(mime, "audio/", 6);
1437    if (audio) {
1438        // Assumes 1000 samples per frame.
1439        int32_t sampleRate;
1440        CHECK(format->findInt32(kKeySampleRate, &sampleRate));
1441        return kNumSkipFrames  /* frames */ * 1000 /* samples */
1442                * (1000000 / sampleRate) /* sample duration (us) */;
1443    } else {
1444        int32_t frameRate;
1445        if (format->findInt32(kKeyFrameRate, &frameRate) && frameRate > 0) {
1446            return kNumSkipFrames * (1000000 / frameRate);
1447        }
1448    }
1449
1450    return 500000ll;
1451}
1452
1453}  // namespace android
1454