PlaylistFetcher.cpp revision 0f9a3cf9962b6859cfee9d4bf4676b5aafca79cb
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> ¬ify, 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 mSegmentStartTimeUs(-1ll), 66 mDiscontinuitySeq(-1ll), 67 mStartTimeUsRelative(false), 68 mLastPlaylistFetchTimeUs(-1ll), 69 mSeqNumber(-1), 70 mNumRetries(0), 71 mStartup(true), 72 mAdaptive(false), 73 mPrepared(false), 74 mNextPTSTimeUs(-1ll), 75 mMonitorQueueGeneration(0), 76 mRefreshState(INITIAL_MINIMUM_RELOAD_DELAY), 77 mFirstPTSValid(false), 78 mAbsoluteTimeAnchorUs(0ll), 79 mVideoBuffer(new AnotherPacketSource(NULL)) { 80 memset(mPlaylistHash, 0, sizeof(mPlaylistHash)); 81 mStartTimeUsNotify->setInt32("what", kWhatStartedAt); 82 mStartTimeUsNotify->setInt32("streamMask", 0); 83} 84 85PlaylistFetcher::~PlaylistFetcher() { 86} 87 88int64_t PlaylistFetcher::getSegmentStartTimeUs(int32_t seqNumber) const { 89 CHECK(mPlaylist != NULL); 90 91 int32_t firstSeqNumberInPlaylist; 92 if (mPlaylist->meta() == NULL || !mPlaylist->meta()->findInt32( 93 "media-sequence", &firstSeqNumberInPlaylist)) { 94 firstSeqNumberInPlaylist = 0; 95 } 96 97 int32_t lastSeqNumberInPlaylist = 98 firstSeqNumberInPlaylist + (int32_t)mPlaylist->size() - 1; 99 100 CHECK_GE(seqNumber, firstSeqNumberInPlaylist); 101 CHECK_LE(seqNumber, lastSeqNumberInPlaylist); 102 103 int64_t segmentStartUs = 0ll; 104 for (int32_t index = 0; 105 index < seqNumber - firstSeqNumberInPlaylist; ++index) { 106 sp<AMessage> itemMeta; 107 CHECK(mPlaylist->itemAt( 108 index, NULL /* uri */, &itemMeta)); 109 110 int64_t itemDurationUs; 111 CHECK(itemMeta->findInt64("durationUs", &itemDurationUs)); 112 113 segmentStartUs += itemDurationUs; 114 } 115 116 return segmentStartUs; 117} 118 119int64_t PlaylistFetcher::delayUsToRefreshPlaylist() const { 120 int64_t nowUs = ALooper::GetNowUs(); 121 122 if (mPlaylist == NULL || mLastPlaylistFetchTimeUs < 0ll) { 123 CHECK_EQ((int)mRefreshState, (int)INITIAL_MINIMUM_RELOAD_DELAY); 124 return 0ll; 125 } 126 127 if (mPlaylist->isComplete()) { 128 return (~0llu >> 1); 129 } 130 131 int32_t targetDurationSecs; 132 CHECK(mPlaylist->meta()->findInt32("target-duration", &targetDurationSecs)); 133 134 int64_t targetDurationUs = targetDurationSecs * 1000000ll; 135 136 int64_t minPlaylistAgeUs; 137 138 switch (mRefreshState) { 139 case INITIAL_MINIMUM_RELOAD_DELAY: 140 { 141 size_t n = mPlaylist->size(); 142 if (n > 0) { 143 sp<AMessage> itemMeta; 144 CHECK(mPlaylist->itemAt(n - 1, NULL /* uri */, &itemMeta)); 145 146 int64_t itemDurationUs; 147 CHECK(itemMeta->findInt64("durationUs", &itemDurationUs)); 148 149 minPlaylistAgeUs = itemDurationUs; 150 break; 151 } 152 153 // fall through 154 } 155 156 case FIRST_UNCHANGED_RELOAD_ATTEMPT: 157 { 158 minPlaylistAgeUs = targetDurationUs / 2; 159 break; 160 } 161 162 case SECOND_UNCHANGED_RELOAD_ATTEMPT: 163 { 164 minPlaylistAgeUs = (targetDurationUs * 3) / 2; 165 break; 166 } 167 168 case THIRD_UNCHANGED_RELOAD_ATTEMPT: 169 { 170 minPlaylistAgeUs = targetDurationUs * 3; 171 break; 172 } 173 174 default: 175 TRESPASS(); 176 break; 177 } 178 179 int64_t delayUs = mLastPlaylistFetchTimeUs + minPlaylistAgeUs - nowUs; 180 return delayUs > 0ll ? delayUs : 0ll; 181} 182 183status_t PlaylistFetcher::decryptBuffer( 184 size_t playlistIndex, const sp<ABuffer> &buffer, 185 bool first) { 186 sp<AMessage> itemMeta; 187 bool found = false; 188 AString method; 189 190 for (ssize_t i = playlistIndex; i >= 0; --i) { 191 AString uri; 192 CHECK(mPlaylist->itemAt(i, &uri, &itemMeta)); 193 194 if (itemMeta->findString("cipher-method", &method)) { 195 found = true; 196 break; 197 } 198 } 199 200 if (!found) { 201 method = "NONE"; 202 } 203 buffer->meta()->setString("cipher-method", method.c_str()); 204 205 if (method == "NONE") { 206 return OK; 207 } else if (!(method == "AES-128")) { 208 ALOGE("Unsupported cipher method '%s'", method.c_str()); 209 return ERROR_UNSUPPORTED; 210 } 211 212 AString keyURI; 213 if (!itemMeta->findString("cipher-uri", &keyURI)) { 214 ALOGE("Missing key uri"); 215 return ERROR_MALFORMED; 216 } 217 218 ssize_t index = mAESKeyForURI.indexOfKey(keyURI); 219 220 sp<ABuffer> key; 221 if (index >= 0) { 222 key = mAESKeyForURI.valueAt(index); 223 } else { 224 ssize_t err = mSession->fetchFile(keyURI.c_str(), &key); 225 226 if (err < 0) { 227 ALOGE("failed to fetch cipher key from '%s'.", keyURI.c_str()); 228 return ERROR_IO; 229 } else if (key->size() != 16) { 230 ALOGE("key file '%s' wasn't 16 bytes in size.", keyURI.c_str()); 231 return ERROR_MALFORMED; 232 } 233 234 mAESKeyForURI.add(keyURI, key); 235 } 236 237 AES_KEY aes_key; 238 if (AES_set_decrypt_key(key->data(), 128, &aes_key) != 0) { 239 ALOGE("failed to set AES decryption key."); 240 return UNKNOWN_ERROR; 241 } 242 243 size_t n = buffer->size(); 244 if (!n) { 245 return OK; 246 } 247 CHECK(n % 16 == 0); 248 249 if (first) { 250 // If decrypting the first block in a file, read the iv from the manifest 251 // or derive the iv from the file's sequence number. 252 253 AString iv; 254 if (itemMeta->findString("cipher-iv", &iv)) { 255 if ((!iv.startsWith("0x") && !iv.startsWith("0X")) 256 || iv.size() != 16 * 2 + 2) { 257 ALOGE("malformed cipher IV '%s'.", iv.c_str()); 258 return ERROR_MALFORMED; 259 } 260 261 memset(mAESInitVec, 0, sizeof(mAESInitVec)); 262 for (size_t i = 0; i < 16; ++i) { 263 char c1 = tolower(iv.c_str()[2 + 2 * i]); 264 char c2 = tolower(iv.c_str()[3 + 2 * i]); 265 if (!isxdigit(c1) || !isxdigit(c2)) { 266 ALOGE("malformed cipher IV '%s'.", iv.c_str()); 267 return ERROR_MALFORMED; 268 } 269 uint8_t nibble1 = isdigit(c1) ? c1 - '0' : c1 - 'a' + 10; 270 uint8_t nibble2 = isdigit(c2) ? c2 - '0' : c2 - 'a' + 10; 271 272 mAESInitVec[i] = nibble1 << 4 | nibble2; 273 } 274 } else { 275 memset(mAESInitVec, 0, sizeof(mAESInitVec)); 276 mAESInitVec[15] = mSeqNumber & 0xff; 277 mAESInitVec[14] = (mSeqNumber >> 8) & 0xff; 278 mAESInitVec[13] = (mSeqNumber >> 16) & 0xff; 279 mAESInitVec[12] = (mSeqNumber >> 24) & 0xff; 280 } 281 } 282 283 AES_cbc_encrypt( 284 buffer->data(), buffer->data(), buffer->size(), 285 &aes_key, mAESInitVec, AES_DECRYPT); 286 287 return OK; 288} 289 290status_t PlaylistFetcher::checkDecryptPadding(const sp<ABuffer> &buffer) { 291 status_t err; 292 AString method; 293 CHECK(buffer->meta()->findString("cipher-method", &method)); 294 if (method == "NONE") { 295 return OK; 296 } 297 298 uint8_t padding = 0; 299 if (buffer->size() > 0) { 300 padding = buffer->data()[buffer->size() - 1]; 301 } 302 303 if (padding > 16) { 304 return ERROR_MALFORMED; 305 } 306 307 for (size_t i = buffer->size() - padding; i < padding; i++) { 308 if (buffer->data()[i] != padding) { 309 return ERROR_MALFORMED; 310 } 311 } 312 313 buffer->setRange(buffer->offset(), buffer->size() - padding); 314 return OK; 315} 316 317void PlaylistFetcher::postMonitorQueue(int64_t delayUs, int64_t minDelayUs) { 318 int64_t maxDelayUs = delayUsToRefreshPlaylist(); 319 if (maxDelayUs < minDelayUs) { 320 maxDelayUs = minDelayUs; 321 } 322 if (delayUs > maxDelayUs) { 323 ALOGV("Need to refresh playlist in %" PRId64 , maxDelayUs); 324 delayUs = maxDelayUs; 325 } 326 sp<AMessage> msg = new AMessage(kWhatMonitorQueue, id()); 327 msg->setInt32("generation", mMonitorQueueGeneration); 328 msg->post(delayUs); 329} 330 331void PlaylistFetcher::cancelMonitorQueue() { 332 ++mMonitorQueueGeneration; 333} 334 335void PlaylistFetcher::startAsync( 336 const sp<AnotherPacketSource> &audioSource, 337 const sp<AnotherPacketSource> &videoSource, 338 const sp<AnotherPacketSource> &subtitleSource, 339 int64_t startTimeUs, 340 int64_t segmentStartTimeUs, 341 int32_t startDiscontinuitySeq, 342 bool adaptive) { 343 sp<AMessage> msg = new AMessage(kWhatStart, id()); 344 345 uint32_t streamTypeMask = 0ul; 346 347 if (audioSource != NULL) { 348 msg->setPointer("audioSource", audioSource.get()); 349 streamTypeMask |= LiveSession::STREAMTYPE_AUDIO; 350 } 351 352 if (videoSource != NULL) { 353 msg->setPointer("videoSource", videoSource.get()); 354 streamTypeMask |= LiveSession::STREAMTYPE_VIDEO; 355 } 356 357 if (subtitleSource != NULL) { 358 msg->setPointer("subtitleSource", subtitleSource.get()); 359 streamTypeMask |= LiveSession::STREAMTYPE_SUBTITLES; 360 } 361 362 msg->setInt32("streamTypeMask", streamTypeMask); 363 msg->setInt64("startTimeUs", startTimeUs); 364 msg->setInt64("segmentStartTimeUs", segmentStartTimeUs); 365 msg->setInt32("startDiscontinuitySeq", startDiscontinuitySeq); 366 msg->setInt32("adaptive", adaptive); 367 msg->post(); 368} 369 370void PlaylistFetcher::pauseAsync() { 371 (new AMessage(kWhatPause, id()))->post(); 372} 373 374void PlaylistFetcher::stopAsync(bool clear) { 375 sp<AMessage> msg = new AMessage(kWhatStop, id()); 376 msg->setInt32("clear", clear); 377 msg->post(); 378} 379 380void PlaylistFetcher::resumeUntilAsync(const sp<AMessage> ¶ms) { 381 AMessage* msg = new AMessage(kWhatResumeUntil, id()); 382 msg->setMessage("params", params); 383 msg->post(); 384} 385 386void PlaylistFetcher::onMessageReceived(const sp<AMessage> &msg) { 387 switch (msg->what()) { 388 case kWhatStart: 389 { 390 status_t err = onStart(msg); 391 392 sp<AMessage> notify = mNotify->dup(); 393 notify->setInt32("what", kWhatStarted); 394 notify->setInt32("err", err); 395 notify->post(); 396 break; 397 } 398 399 case kWhatPause: 400 { 401 onPause(); 402 403 sp<AMessage> notify = mNotify->dup(); 404 notify->setInt32("what", kWhatPaused); 405 notify->post(); 406 break; 407 } 408 409 case kWhatStop: 410 { 411 onStop(msg); 412 413 sp<AMessage> notify = mNotify->dup(); 414 notify->setInt32("what", kWhatStopped); 415 notify->post(); 416 break; 417 } 418 419 case kWhatMonitorQueue: 420 case kWhatDownloadNext: 421 { 422 int32_t generation; 423 CHECK(msg->findInt32("generation", &generation)); 424 425 if (generation != mMonitorQueueGeneration) { 426 // Stale event 427 break; 428 } 429 430 if (msg->what() == kWhatMonitorQueue) { 431 onMonitorQueue(); 432 } else { 433 onDownloadNext(); 434 } 435 break; 436 } 437 438 case kWhatResumeUntil: 439 { 440 onResumeUntil(msg); 441 break; 442 } 443 444 default: 445 TRESPASS(); 446 } 447} 448 449status_t PlaylistFetcher::onStart(const sp<AMessage> &msg) { 450 mPacketSources.clear(); 451 452 uint32_t streamTypeMask; 453 CHECK(msg->findInt32("streamTypeMask", (int32_t *)&streamTypeMask)); 454 455 int64_t startTimeUs; 456 int64_t segmentStartTimeUs; 457 int32_t startDiscontinuitySeq; 458 int32_t adaptive; 459 CHECK(msg->findInt64("startTimeUs", &startTimeUs)); 460 CHECK(msg->findInt64("segmentStartTimeUs", &segmentStartTimeUs)); 461 CHECK(msg->findInt32("startDiscontinuitySeq", &startDiscontinuitySeq)); 462 CHECK(msg->findInt32("adaptive", &adaptive)); 463 464 if (streamTypeMask & LiveSession::STREAMTYPE_AUDIO) { 465 void *ptr; 466 CHECK(msg->findPointer("audioSource", &ptr)); 467 468 mPacketSources.add( 469 LiveSession::STREAMTYPE_AUDIO, 470 static_cast<AnotherPacketSource *>(ptr)); 471 } 472 473 if (streamTypeMask & LiveSession::STREAMTYPE_VIDEO) { 474 void *ptr; 475 CHECK(msg->findPointer("videoSource", &ptr)); 476 477 mPacketSources.add( 478 LiveSession::STREAMTYPE_VIDEO, 479 static_cast<AnotherPacketSource *>(ptr)); 480 } 481 482 if (streamTypeMask & LiveSession::STREAMTYPE_SUBTITLES) { 483 void *ptr; 484 CHECK(msg->findPointer("subtitleSource", &ptr)); 485 486 mPacketSources.add( 487 LiveSession::STREAMTYPE_SUBTITLES, 488 static_cast<AnotherPacketSource *>(ptr)); 489 } 490 491 mStreamTypeMask = streamTypeMask; 492 493 mSegmentStartTimeUs = segmentStartTimeUs; 494 mDiscontinuitySeq = startDiscontinuitySeq; 495 496 if (startTimeUs >= 0) { 497 mStartTimeUs = startTimeUs; 498 mSeqNumber = -1; 499 mStartup = true; 500 mPrepared = false; 501 mAdaptive = adaptive; 502 } 503 504 postMonitorQueue(); 505 506 return OK; 507} 508 509void PlaylistFetcher::onPause() { 510 cancelMonitorQueue(); 511} 512 513void PlaylistFetcher::onStop(const sp<AMessage> &msg) { 514 cancelMonitorQueue(); 515 516 int32_t clear; 517 CHECK(msg->findInt32("clear", &clear)); 518 if (clear) { 519 for (size_t i = 0; i < mPacketSources.size(); i++) { 520 sp<AnotherPacketSource> packetSource = mPacketSources.valueAt(i); 521 packetSource->clear(); 522 } 523 } 524 525 mPacketSources.clear(); 526 mStreamTypeMask = 0; 527} 528 529// Resume until we have reached the boundary timestamps listed in `msg`; when 530// the remaining time is too short (within a resume threshold) stop immediately 531// instead. 532status_t PlaylistFetcher::onResumeUntil(const sp<AMessage> &msg) { 533 sp<AMessage> params; 534 CHECK(msg->findMessage("params", ¶ms)); 535 536 bool stop = false; 537 for (size_t i = 0; i < mPacketSources.size(); i++) { 538 sp<AnotherPacketSource> packetSource = mPacketSources.valueAt(i); 539 540 const char *stopKey; 541 int streamType = mPacketSources.keyAt(i); 542 switch (streamType) { 543 case LiveSession::STREAMTYPE_VIDEO: 544 stopKey = "timeUsVideo"; 545 break; 546 547 case LiveSession::STREAMTYPE_AUDIO: 548 stopKey = "timeUsAudio"; 549 break; 550 551 case LiveSession::STREAMTYPE_SUBTITLES: 552 stopKey = "timeUsSubtitle"; 553 break; 554 555 default: 556 TRESPASS(); 557 } 558 559 // Don't resume if we would stop within a resume threshold. 560 int32_t discontinuitySeq; 561 int64_t latestTimeUs = 0, stopTimeUs = 0; 562 sp<AMessage> latestMeta = packetSource->getLatestDequeuedMeta(); 563 if (latestMeta != NULL 564 && latestMeta->findInt32("discontinuitySeq", &discontinuitySeq) 565 && discontinuitySeq == mDiscontinuitySeq 566 && latestMeta->findInt64("timeUs", &latestTimeUs) 567 && params->findInt64(stopKey, &stopTimeUs) 568 && stopTimeUs - latestTimeUs < resumeThreshold(latestMeta)) { 569 stop = true; 570 } 571 } 572 573 if (stop) { 574 for (size_t i = 0; i < mPacketSources.size(); i++) { 575 mPacketSources.valueAt(i)->queueAccessUnit(mSession->createFormatChangeBuffer()); 576 } 577 stopAsync(/* clear = */ false); 578 return OK; 579 } 580 581 mStopParams = params; 582 postMonitorQueue(); 583 584 return OK; 585} 586 587void PlaylistFetcher::notifyError(status_t err) { 588 sp<AMessage> notify = mNotify->dup(); 589 notify->setInt32("what", kWhatError); 590 notify->setInt32("err", err); 591 notify->post(); 592} 593 594void PlaylistFetcher::queueDiscontinuity( 595 ATSParser::DiscontinuityType type, const sp<AMessage> &extra) { 596 for (size_t i = 0; i < mPacketSources.size(); ++i) { 597 // do not discard buffer upon #EXT-X-DISCONTINUITY tag 598 // (seek will discard buffer by abandoning old fetchers) 599 mPacketSources.valueAt(i)->queueDiscontinuity( 600 type, extra, false /* discard */); 601 } 602} 603 604void PlaylistFetcher::onMonitorQueue() { 605 bool downloadMore = false; 606 refreshPlaylist(); 607 608 int32_t targetDurationSecs; 609 int64_t targetDurationUs = kMinBufferedDurationUs; 610 if (mPlaylist != NULL) { 611 CHECK(mPlaylist->meta()->findInt32("target-duration", &targetDurationSecs)); 612 targetDurationUs = targetDurationSecs * 1000000ll; 613 } 614 615 // buffer at least 3 times the target duration, or up to 10 seconds 616 int64_t durationToBufferUs = targetDurationUs * 3; 617 if (durationToBufferUs > kMinBufferedDurationUs) { 618 durationToBufferUs = kMinBufferedDurationUs; 619 } 620 621 int64_t bufferedDurationUs = 0ll; 622 status_t finalResult = NOT_ENOUGH_DATA; 623 if (mStreamTypeMask == LiveSession::STREAMTYPE_SUBTITLES) { 624 sp<AnotherPacketSource> packetSource = 625 mPacketSources.valueFor(LiveSession::STREAMTYPE_SUBTITLES); 626 627 bufferedDurationUs = 628 packetSource->getBufferedDurationUs(&finalResult); 629 finalResult = OK; 630 } else { 631 // Use max stream duration to prevent us from waiting on a non-existent stream; 632 // when we cannot make out from the manifest what streams are included in a playlist 633 // we might assume extra streams. 634 for (size_t i = 0; i < mPacketSources.size(); ++i) { 635 if ((mStreamTypeMask & mPacketSources.keyAt(i)) == 0) { 636 continue; 637 } 638 639 int64_t bufferedStreamDurationUs = 640 mPacketSources.valueAt(i)->getBufferedDurationUs(&finalResult); 641 ALOGV("buffered %" PRId64 " for stream %d", 642 bufferedStreamDurationUs, mPacketSources.keyAt(i)); 643 if (bufferedStreamDurationUs > bufferedDurationUs) { 644 bufferedDurationUs = bufferedStreamDurationUs; 645 } 646 } 647 } 648 downloadMore = (bufferedDurationUs < durationToBufferUs); 649 650 // signal start if buffered up at least the target size 651 if (!mPrepared && bufferedDurationUs > targetDurationUs && downloadMore) { 652 mPrepared = true; 653 654 ALOGV("prepared, buffered=%" PRId64 " > %" PRId64 "", 655 bufferedDurationUs, targetDurationUs); 656 sp<AMessage> msg = mNotify->dup(); 657 msg->setInt32("what", kWhatTemporarilyDoneFetching); 658 msg->post(); 659 } 660 661 if (finalResult == OK && downloadMore) { 662 ALOGV("monitoring, buffered=%" PRId64 " < %" PRId64 "", 663 bufferedDurationUs, durationToBufferUs); 664 // delay the next download slightly; hopefully this gives other concurrent fetchers 665 // a better chance to run. 666 // onDownloadNext(); 667 sp<AMessage> msg = new AMessage(kWhatDownloadNext, id()); 668 msg->setInt32("generation", mMonitorQueueGeneration); 669 msg->post(1000l); 670 } else { 671 // Nothing to do yet, try again in a second. 672 673 sp<AMessage> msg = mNotify->dup(); 674 msg->setInt32("what", kWhatTemporarilyDoneFetching); 675 msg->post(); 676 677 int64_t delayUs = mPrepared ? kMaxMonitorDelayUs : targetDurationUs / 2; 678 ALOGV("pausing for %" PRId64 ", buffered=%" PRId64 " > %" PRId64 "", 679 delayUs, bufferedDurationUs, durationToBufferUs); 680 // :TRICKY: need to enforce minimum delay because the delay to 681 // refresh the playlist will become 0 682 postMonitorQueue(delayUs, mPrepared ? targetDurationUs * 2 : 0); 683 } 684} 685 686status_t PlaylistFetcher::refreshPlaylist() { 687 if (delayUsToRefreshPlaylist() <= 0) { 688 bool unchanged; 689 sp<M3UParser> playlist = mSession->fetchPlaylist( 690 mURI.c_str(), mPlaylistHash, &unchanged); 691 692 if (playlist == NULL) { 693 if (unchanged) { 694 // We succeeded in fetching the playlist, but it was 695 // unchanged from the last time we tried. 696 697 if (mRefreshState != THIRD_UNCHANGED_RELOAD_ATTEMPT) { 698 mRefreshState = (RefreshState)(mRefreshState + 1); 699 } 700 } else { 701 ALOGE("failed to load playlist at url '%s'", mURI.c_str()); 702 notifyError(ERROR_IO); 703 return ERROR_IO; 704 } 705 } else { 706 mRefreshState = INITIAL_MINIMUM_RELOAD_DELAY; 707 mPlaylist = playlist; 708 709 if (mPlaylist->isComplete() || mPlaylist->isEvent()) { 710 updateDuration(); 711 } 712 } 713 714 mLastPlaylistFetchTimeUs = ALooper::GetNowUs(); 715 } 716 return OK; 717} 718 719// static 720bool PlaylistFetcher::bufferStartsWithTsSyncByte(const sp<ABuffer>& buffer) { 721 return buffer->size() > 0 && buffer->data()[0] == 0x47; 722} 723 724void PlaylistFetcher::onDownloadNext() { 725 if (refreshPlaylist() != OK) { 726 return; 727 } 728 729 int32_t firstSeqNumberInPlaylist; 730 if (mPlaylist->meta() == NULL || !mPlaylist->meta()->findInt32( 731 "media-sequence", &firstSeqNumberInPlaylist)) { 732 firstSeqNumberInPlaylist = 0; 733 } 734 735 bool discontinuity = false; 736 737 const int32_t lastSeqNumberInPlaylist = 738 firstSeqNumberInPlaylist + (int32_t)mPlaylist->size() - 1; 739 740 if (mStartup && mSeqNumber >= 0 741 && (mSeqNumber < firstSeqNumberInPlaylist || mSeqNumber > lastSeqNumberInPlaylist)) { 742 // in case we guessed wrong during reconfiguration, try fetching the latest content. 743 mSeqNumber = lastSeqNumberInPlaylist; 744 } 745 746 if (mDiscontinuitySeq < 0) { 747 mDiscontinuitySeq = mPlaylist->getDiscontinuitySeq(); 748 } 749 750 if (mSeqNumber < 0) { 751 CHECK_GE(mStartTimeUs, 0ll); 752 753 if (mSegmentStartTimeUs < 0) { 754 if (!mPlaylist->isComplete() && !mPlaylist->isEvent()) { 755 // If this is a live session, start 3 segments from the end on connect 756 mSeqNumber = lastSeqNumberInPlaylist - 3; 757 if (mSeqNumber < firstSeqNumberInPlaylist) { 758 mSeqNumber = firstSeqNumberInPlaylist; 759 } 760 } else { 761 mSeqNumber = getSeqNumberForTime(mStartTimeUs); 762 mStartTimeUs -= getSegmentStartTimeUs(mSeqNumber); 763 } 764 mStartTimeUsRelative = true; 765 ALOGV("Initial sequence number for time %" PRId64 " is %d from (%d .. %d)", 766 mStartTimeUs, mSeqNumber, firstSeqNumberInPlaylist, 767 lastSeqNumberInPlaylist); 768 } else { 769 mSeqNumber = getSeqNumberForTime(mSegmentStartTimeUs); 770 if (mAdaptive) { 771 // avoid double fetch/decode 772 mSeqNumber += 1; 773 } 774 ssize_t minSeq = getSeqNumberForDiscontinuity(mDiscontinuitySeq); 775 if (mSeqNumber < minSeq) { 776 mSeqNumber = minSeq; 777 } 778 779 if (mSeqNumber < firstSeqNumberInPlaylist) { 780 mSeqNumber = firstSeqNumberInPlaylist; 781 } 782 783 if (mSeqNumber > lastSeqNumberInPlaylist) { 784 mSeqNumber = lastSeqNumberInPlaylist; 785 } 786 ALOGV("Initial sequence number for live event %d from (%d .. %d)", 787 mSeqNumber, firstSeqNumberInPlaylist, 788 lastSeqNumberInPlaylist); 789 } 790 } 791 792 if (mSeqNumber < firstSeqNumberInPlaylist 793 || mSeqNumber > lastSeqNumberInPlaylist) { 794 if (!mPlaylist->isComplete() && mNumRetries < kMaxNumRetries) { 795 ++mNumRetries; 796 797 if (mSeqNumber > lastSeqNumberInPlaylist) { 798 // refresh in increasing fraction (1/2, 1/3, ...) of the 799 // playlist's target duration or 3 seconds, whichever is less 800 int32_t targetDurationSecs; 801 CHECK(mPlaylist->meta()->findInt32( 802 "target-duration", &targetDurationSecs)); 803 int64_t delayUs = mPlaylist->size() * targetDurationSecs * 804 1000000ll / (1 + mNumRetries); 805 if (delayUs > kMaxMonitorDelayUs) { 806 delayUs = kMaxMonitorDelayUs; 807 } 808 ALOGV("sequence number high: %d from (%d .. %d), " 809 "monitor in %" PRId64 " (retry=%d)", 810 mSeqNumber, firstSeqNumberInPlaylist, 811 lastSeqNumberInPlaylist, delayUs, mNumRetries); 812 postMonitorQueue(delayUs); 813 return; 814 } 815 816 // we've missed the boat, let's start from the lowest sequence 817 // number available and signal a discontinuity. 818 819 ALOGI("We've missed the boat, restarting playback." 820 " mStartup=%d, was looking for %d in %d-%d", 821 mStartup, mSeqNumber, firstSeqNumberInPlaylist, 822 lastSeqNumberInPlaylist); 823 mSeqNumber = lastSeqNumberInPlaylist - 3; 824 if (mSeqNumber < firstSeqNumberInPlaylist) { 825 mSeqNumber = firstSeqNumberInPlaylist; 826 } 827 discontinuity = true; 828 829 // fall through 830 } else { 831 ALOGE("Cannot find sequence number %d in playlist " 832 "(contains %d - %d)", 833 mSeqNumber, firstSeqNumberInPlaylist, 834 firstSeqNumberInPlaylist + (int32_t)mPlaylist->size() - 1); 835 836 notifyError(ERROR_END_OF_STREAM); 837 return; 838 } 839 } 840 841 mNumRetries = 0; 842 843 AString uri; 844 sp<AMessage> itemMeta; 845 CHECK(mPlaylist->itemAt( 846 mSeqNumber - firstSeqNumberInPlaylist, 847 &uri, 848 &itemMeta)); 849 850 int32_t val; 851 if (itemMeta->findInt32("discontinuity", &val) && val != 0) { 852 mDiscontinuitySeq++; 853 discontinuity = true; 854 } 855 856 int64_t range_offset, range_length; 857 if (!itemMeta->findInt64("range-offset", &range_offset) 858 || !itemMeta->findInt64("range-length", &range_length)) { 859 range_offset = 0; 860 range_length = -1; 861 } 862 863 ALOGV("fetching segment %d from (%d .. %d)", 864 mSeqNumber, firstSeqNumberInPlaylist, lastSeqNumberInPlaylist); 865 866 ALOGV("fetching '%s'", uri.c_str()); 867 868 sp<DataSource> source; 869 sp<ABuffer> buffer, tsBuffer; 870 // decrypt a junk buffer to prefetch key; since a session uses only one http connection, 871 // this avoids interleaved connections to the key and segment file. 872 { 873 sp<ABuffer> junk = new ABuffer(16); 874 junk->setRange(0, 16); 875 status_t err = decryptBuffer(mSeqNumber - firstSeqNumberInPlaylist, junk, 876 true /* first */); 877 if (err != OK) { 878 notifyError(err); 879 return; 880 } 881 } 882 883 // block-wise download 884 bool startup = mStartup; 885 ssize_t bytesRead; 886 do { 887 bytesRead = mSession->fetchFile( 888 uri.c_str(), &buffer, range_offset, range_length, kDownloadBlockSize, &source); 889 890 if (bytesRead < 0) { 891 status_t err = bytesRead; 892 ALOGE("failed to fetch .ts segment at url '%s'", uri.c_str()); 893 notifyError(err); 894 return; 895 } 896 897 CHECK(buffer != NULL); 898 899 size_t size = buffer->size(); 900 // Set decryption range. 901 buffer->setRange(size - bytesRead, bytesRead); 902 status_t err = decryptBuffer(mSeqNumber - firstSeqNumberInPlaylist, buffer, 903 buffer->offset() == 0 /* first */); 904 // Unset decryption range. 905 buffer->setRange(0, size); 906 907 if (err != OK) { 908 ALOGE("decryptBuffer failed w/ error %d", err); 909 910 notifyError(err); 911 return; 912 } 913 914 if (startup || discontinuity) { 915 // Signal discontinuity. 916 917 if (mPlaylist->isComplete() || mPlaylist->isEvent()) { 918 // If this was a live event this made no sense since 919 // we don't have access to all the segment before the current 920 // one. 921 mNextPTSTimeUs = getSegmentStartTimeUs(mSeqNumber); 922 } 923 924 if (discontinuity) { 925 ALOGI("queueing discontinuity (explicit=%d)", discontinuity); 926 927 queueDiscontinuity( 928 ATSParser::DISCONTINUITY_FORMATCHANGE, 929 NULL /* extra */); 930 931 discontinuity = false; 932 } 933 934 startup = false; 935 } 936 937 err = OK; 938 if (bufferStartsWithTsSyncByte(buffer)) { 939 // Incremental extraction is only supported for MPEG2 transport streams. 940 if (tsBuffer == NULL) { 941 tsBuffer = new ABuffer(buffer->data(), buffer->capacity()); 942 tsBuffer->setRange(0, 0); 943 } else if (tsBuffer->capacity() != buffer->capacity()) { 944 size_t tsOff = tsBuffer->offset(), tsSize = tsBuffer->size(); 945 tsBuffer = new ABuffer(buffer->data(), buffer->capacity()); 946 tsBuffer->setRange(tsOff, tsSize); 947 } 948 tsBuffer->setRange(tsBuffer->offset(), tsBuffer->size() + bytesRead); 949 950 err = extractAndQueueAccessUnitsFromTs(tsBuffer); 951 } 952 953 if (err == -EAGAIN) { 954 // starting sequence number too low 955 mTSParser.clear(); 956 postMonitorQueue(); 957 return; 958 } else if (err == ERROR_OUT_OF_RANGE) { 959 // reached stopping point 960 stopAsync(/* clear = */ false); 961 return; 962 } else if (err != OK) { 963 notifyError(err); 964 return; 965 } 966 967 } while (bytesRead != 0); 968 969 if (bufferStartsWithTsSyncByte(buffer)) { 970 // If we still don't see a stream after fetching a full ts segment mark it as 971 // nonexistent. 972 const size_t kNumTypes = ATSParser::NUM_SOURCE_TYPES; 973 ATSParser::SourceType srcTypes[kNumTypes] = 974 { ATSParser::VIDEO, ATSParser::AUDIO }; 975 LiveSession::StreamType streamTypes[kNumTypes] = 976 { LiveSession::STREAMTYPE_VIDEO, LiveSession::STREAMTYPE_AUDIO }; 977 978 for (size_t i = 0; i < kNumTypes; i++) { 979 ATSParser::SourceType srcType = srcTypes[i]; 980 LiveSession::StreamType streamType = streamTypes[i]; 981 982 sp<AnotherPacketSource> source = 983 static_cast<AnotherPacketSource *>( 984 mTSParser->getSource(srcType).get()); 985 986 if (source == NULL) { 987 ALOGW("MPEG2 Transport stream does not contain %s data.", 988 srcType == ATSParser::VIDEO ? "video" : "audio"); 989 990 mStreamTypeMask &= ~streamType; 991 mPacketSources.removeItem(streamType); 992 } 993 } 994 995 } 996 997 if (checkDecryptPadding(buffer) != OK) { 998 ALOGE("Incorrect padding bytes after decryption."); 999 notifyError(ERROR_MALFORMED); 1000 return; 1001 } 1002 1003 status_t err = OK; 1004 if (tsBuffer != NULL) { 1005 AString method; 1006 CHECK(buffer->meta()->findString("cipher-method", &method)); 1007 if ((tsBuffer->size() > 0 && method == "NONE") 1008 || tsBuffer->size() > 16) { 1009 ALOGE("MPEG2 transport stream is not an even multiple of 188 " 1010 "bytes in length."); 1011 notifyError(ERROR_MALFORMED); 1012 return; 1013 } 1014 } 1015 1016 // bulk extract non-ts files 1017 if (tsBuffer == NULL) { 1018 err = extractAndQueueAccessUnits(buffer, itemMeta); 1019 } 1020 1021 if (err != OK) { 1022 notifyError(err); 1023 return; 1024 } 1025 1026 mStartup = false; 1027 ++mSeqNumber; 1028 1029 postMonitorQueue(); 1030} 1031 1032int32_t PlaylistFetcher::getSeqNumberForDiscontinuity(size_t discontinuitySeq) const { 1033 int32_t firstSeqNumberInPlaylist; 1034 if (mPlaylist->meta() == NULL 1035 || !mPlaylist->meta()->findInt32("media-sequence", &firstSeqNumberInPlaylist)) { 1036 firstSeqNumberInPlaylist = 0; 1037 } 1038 1039 size_t curDiscontinuitySeq = mPlaylist->getDiscontinuitySeq(); 1040 if (discontinuitySeq < curDiscontinuitySeq) { 1041 return firstSeqNumberInPlaylist <= 0 ? 0 : (firstSeqNumberInPlaylist - 1); 1042 } 1043 1044 size_t index = 0; 1045 while (index < mPlaylist->size()) { 1046 sp<AMessage> itemMeta; 1047 CHECK(mPlaylist->itemAt( index, NULL /* uri */, &itemMeta)); 1048 1049 int64_t discontinuity; 1050 if (itemMeta->findInt64("discontinuity", &discontinuity)) { 1051 curDiscontinuitySeq++; 1052 } 1053 1054 if (curDiscontinuitySeq == discontinuitySeq) { 1055 return firstSeqNumberInPlaylist + index; 1056 } 1057 1058 ++index; 1059 } 1060 1061 return firstSeqNumberInPlaylist + mPlaylist->size(); 1062} 1063 1064int32_t PlaylistFetcher::getSeqNumberForTime(int64_t timeUs) const { 1065 int32_t firstSeqNumberInPlaylist; 1066 if (mPlaylist->meta() == NULL || !mPlaylist->meta()->findInt32( 1067 "media-sequence", &firstSeqNumberInPlaylist)) { 1068 firstSeqNumberInPlaylist = 0; 1069 } 1070 1071 size_t index = 0; 1072 int64_t segmentStartUs = 0; 1073 while (index < mPlaylist->size()) { 1074 sp<AMessage> itemMeta; 1075 CHECK(mPlaylist->itemAt( 1076 index, NULL /* uri */, &itemMeta)); 1077 1078 int64_t itemDurationUs; 1079 CHECK(itemMeta->findInt64("durationUs", &itemDurationUs)); 1080 1081 if (timeUs < segmentStartUs + itemDurationUs) { 1082 break; 1083 } 1084 1085 segmentStartUs += itemDurationUs; 1086 ++index; 1087 } 1088 1089 if (index >= mPlaylist->size()) { 1090 index = mPlaylist->size() - 1; 1091 } 1092 1093 return firstSeqNumberInPlaylist + index; 1094} 1095 1096const sp<ABuffer> &PlaylistFetcher::setAccessUnitProperties( 1097 const sp<ABuffer> &accessUnit, const sp<AnotherPacketSource> &source, bool discard) { 1098 sp<MetaData> format = source->getFormat(); 1099 if (format != NULL) { 1100 // for simplicity, store a reference to the format in each unit 1101 accessUnit->meta()->setObject("format", format); 1102 } 1103 1104 if (discard) { 1105 accessUnit->meta()->setInt32("discard", discard); 1106 } 1107 1108 accessUnit->meta()->setInt32("discontinuitySeq", mDiscontinuitySeq); 1109 accessUnit->meta()->setInt64("segmentStartTimeUs", getSegmentStartTimeUs(mSeqNumber)); 1110 return accessUnit; 1111} 1112 1113status_t PlaylistFetcher::extractAndQueueAccessUnitsFromTs(const sp<ABuffer> &buffer) { 1114 if (mTSParser == NULL) { 1115 // Use TS_TIMESTAMPS_ARE_ABSOLUTE so pts carry over between fetchers. 1116 mTSParser = new ATSParser(ATSParser::TS_TIMESTAMPS_ARE_ABSOLUTE); 1117 } 1118 1119 if (mNextPTSTimeUs >= 0ll) { 1120 sp<AMessage> extra = new AMessage; 1121 // Since we are using absolute timestamps, signal an offset of 0 to prevent 1122 // ATSParser from skewing the timestamps of access units. 1123 extra->setInt64(IStreamListener::kKeyMediaTimeUs, 0); 1124 1125 mTSParser->signalDiscontinuity( 1126 ATSParser::DISCONTINUITY_SEEK, extra); 1127 1128 mAbsoluteTimeAnchorUs = mNextPTSTimeUs; 1129 mNextPTSTimeUs = -1ll; 1130 mFirstPTSValid = false; 1131 } 1132 1133 size_t offset = 0; 1134 while (offset + 188 <= buffer->size()) { 1135 status_t err = mTSParser->feedTSPacket(buffer->data() + offset, 188); 1136 1137 if (err != OK) { 1138 return err; 1139 } 1140 1141 offset += 188; 1142 } 1143 // setRange to indicate consumed bytes. 1144 buffer->setRange(buffer->offset() + offset, buffer->size() - offset); 1145 1146 status_t err = OK; 1147 for (size_t i = mPacketSources.size(); i-- > 0;) { 1148 sp<AnotherPacketSource> packetSource = mPacketSources.valueAt(i); 1149 1150 const char *key; 1151 ATSParser::SourceType type; 1152 const LiveSession::StreamType stream = mPacketSources.keyAt(i); 1153 switch (stream) { 1154 case LiveSession::STREAMTYPE_VIDEO: 1155 type = ATSParser::VIDEO; 1156 key = "timeUsVideo"; 1157 break; 1158 1159 case LiveSession::STREAMTYPE_AUDIO: 1160 type = ATSParser::AUDIO; 1161 key = "timeUsAudio"; 1162 break; 1163 1164 case LiveSession::STREAMTYPE_SUBTITLES: 1165 { 1166 ALOGE("MPEG2 Transport streams do not contain subtitles."); 1167 return ERROR_MALFORMED; 1168 break; 1169 } 1170 1171 default: 1172 TRESPASS(); 1173 } 1174 1175 sp<AnotherPacketSource> source = 1176 static_cast<AnotherPacketSource *>( 1177 mTSParser->getSource(type).get()); 1178 1179 if (source == NULL) { 1180 continue; 1181 } 1182 1183 int64_t timeUs; 1184 sp<ABuffer> accessUnit; 1185 status_t finalResult; 1186 while (source->hasBufferAvailable(&finalResult) 1187 && source->dequeueAccessUnit(&accessUnit) == OK) { 1188 1189 CHECK(accessUnit->meta()->findInt64("timeUs", &timeUs)); 1190 1191 if (mStartup) { 1192 if (!mFirstPTSValid) { 1193 mFirstTimeUs = timeUs; 1194 mFirstPTSValid = true; 1195 } 1196 if (mStartTimeUsRelative) { 1197 timeUs -= mFirstTimeUs; 1198 if (timeUs < 0) { 1199 timeUs = 0; 1200 } 1201 } else if (mAdaptive && timeUs > mStartTimeUs) { 1202 int32_t seq; 1203 if (mStartTimeUsNotify != NULL 1204 && !mStartTimeUsNotify->findInt32("discontinuitySeq", &seq)) { 1205 mStartTimeUsNotify->setInt32("discontinuitySeq", mDiscontinuitySeq); 1206 } 1207 int64_t startTimeUs; 1208 if (mStartTimeUsNotify != NULL 1209 && !mStartTimeUsNotify->findInt64(key, &startTimeUs)) { 1210 mStartTimeUsNotify->setInt64(key, timeUs); 1211 1212 uint32_t streamMask = 0; 1213 mStartTimeUsNotify->findInt32("streamMask", (int32_t *) &streamMask); 1214 streamMask |= mPacketSources.keyAt(i); 1215 mStartTimeUsNotify->setInt32("streamMask", streamMask); 1216 1217 if (streamMask == mStreamTypeMask) { 1218 mStartTimeUsNotify->post(); 1219 mStartTimeUsNotify.clear(); 1220 } 1221 } 1222 } 1223 1224 if (timeUs < mStartTimeUs) { 1225 if (mAdaptive) { 1226 int32_t targetDuration; 1227 mPlaylist->meta()->findInt32("target-duration", &targetDuration); 1228 int32_t incr = (mStartTimeUs - timeUs) / 1000000 / targetDuration; 1229 if (incr == 0) { 1230 // increment mSeqNumber by at least one 1231 incr = 1; 1232 } 1233 mSeqNumber += incr; 1234 err = -EAGAIN; 1235 break; 1236 } else { 1237 // buffer up to the closest preceding IDR frame 1238 ALOGV("timeUs %" PRId64 " us < mStartTimeUs %" PRId64 " us", 1239 timeUs, mStartTimeUs); 1240 const char *mime; 1241 sp<MetaData> format = source->getFormat(); 1242 bool isAvc = false; 1243 if (format != NULL && format->findCString(kKeyMIMEType, &mime) 1244 && !strcasecmp(mime, MEDIA_MIMETYPE_VIDEO_AVC)) { 1245 isAvc = true; 1246 } 1247 if (isAvc && IsIDR(accessUnit)) { 1248 mVideoBuffer->clear(); 1249 } 1250 if (isAvc) { 1251 mVideoBuffer->queueAccessUnit(accessUnit); 1252 } 1253 1254 continue; 1255 } 1256 } 1257 } 1258 1259 if (mStopParams != NULL) { 1260 // Queue discontinuity in original stream. 1261 int32_t discontinuitySeq; 1262 int64_t stopTimeUs; 1263 if (!mStopParams->findInt32("discontinuitySeq", &discontinuitySeq) 1264 || discontinuitySeq > mDiscontinuitySeq 1265 || !mStopParams->findInt64(key, &stopTimeUs) 1266 || (discontinuitySeq == mDiscontinuitySeq 1267 && timeUs >= stopTimeUs)) { 1268 packetSource->queueAccessUnit(mSession->createFormatChangeBuffer()); 1269 mStreamTypeMask &= ~stream; 1270 mPacketSources.removeItemsAt(i); 1271 break; 1272 } 1273 } 1274 1275 // Note that we do NOT dequeue any discontinuities except for format change. 1276 if (stream == LiveSession::STREAMTYPE_VIDEO) { 1277 const bool discard = true; 1278 status_t status; 1279 while (mVideoBuffer->hasBufferAvailable(&status)) { 1280 sp<ABuffer> videoBuffer; 1281 mVideoBuffer->dequeueAccessUnit(&videoBuffer); 1282 setAccessUnitProperties(videoBuffer, source, discard); 1283 packetSource->queueAccessUnit(videoBuffer); 1284 } 1285 } 1286 1287 setAccessUnitProperties(accessUnit, source); 1288 packetSource->queueAccessUnit(accessUnit); 1289 } 1290 1291 if (err != OK) { 1292 break; 1293 } 1294 } 1295 1296 if (err != OK) { 1297 for (size_t i = mPacketSources.size(); i-- > 0;) { 1298 sp<AnotherPacketSource> packetSource = mPacketSources.valueAt(i); 1299 packetSource->clear(); 1300 } 1301 return err; 1302 } 1303 1304 if (!mStreamTypeMask) { 1305 // Signal gap is filled between original and new stream. 1306 ALOGV("ERROR OUT OF RANGE"); 1307 return ERROR_OUT_OF_RANGE; 1308 } 1309 1310 return OK; 1311} 1312 1313/* static */ 1314bool PlaylistFetcher::bufferStartsWithWebVTTMagicSequence( 1315 const sp<ABuffer> &buffer) { 1316 size_t pos = 0; 1317 1318 // skip possible BOM 1319 if (buffer->size() >= pos + 3 && 1320 !memcmp("\xef\xbb\xbf", buffer->data() + pos, 3)) { 1321 pos += 3; 1322 } 1323 1324 // accept WEBVTT followed by SPACE, TAB or (CR) LF 1325 if (buffer->size() < pos + 6 || 1326 memcmp("WEBVTT", buffer->data() + pos, 6)) { 1327 return false; 1328 } 1329 pos += 6; 1330 1331 if (buffer->size() == pos) { 1332 return true; 1333 } 1334 1335 uint8_t sep = buffer->data()[pos]; 1336 return sep == ' ' || sep == '\t' || sep == '\n' || sep == '\r'; 1337} 1338 1339status_t PlaylistFetcher::extractAndQueueAccessUnits( 1340 const sp<ABuffer> &buffer, const sp<AMessage> &itemMeta) { 1341 if (bufferStartsWithWebVTTMagicSequence(buffer)) { 1342 if (mStreamTypeMask != LiveSession::STREAMTYPE_SUBTITLES) { 1343 ALOGE("This stream only contains subtitles."); 1344 return ERROR_MALFORMED; 1345 } 1346 1347 const sp<AnotherPacketSource> packetSource = 1348 mPacketSources.valueFor(LiveSession::STREAMTYPE_SUBTITLES); 1349 1350 int64_t durationUs; 1351 CHECK(itemMeta->findInt64("durationUs", &durationUs)); 1352 buffer->meta()->setInt64("timeUs", getSegmentStartTimeUs(mSeqNumber)); 1353 buffer->meta()->setInt64("durationUs", durationUs); 1354 buffer->meta()->setInt64("segmentStartTimeUs", getSegmentStartTimeUs(mSeqNumber)); 1355 buffer->meta()->setInt32("discontinuitySeq", mDiscontinuitySeq); 1356 1357 packetSource->queueAccessUnit(buffer); 1358 return OK; 1359 } 1360 1361 if (mNextPTSTimeUs >= 0ll) { 1362 mFirstPTSValid = false; 1363 mAbsoluteTimeAnchorUs = mNextPTSTimeUs; 1364 mNextPTSTimeUs = -1ll; 1365 } 1366 1367 // This better be an ISO 13818-7 (AAC) or ISO 13818-1 (MPEG) audio 1368 // stream prefixed by an ID3 tag. 1369 1370 bool firstID3Tag = true; 1371 uint64_t PTS = 0; 1372 1373 for (;;) { 1374 // Make sure to skip all ID3 tags preceding the audio data. 1375 // At least one must be present to provide the PTS timestamp. 1376 1377 ID3 id3(buffer->data(), buffer->size(), true /* ignoreV1 */); 1378 if (!id3.isValid()) { 1379 if (firstID3Tag) { 1380 ALOGE("Unable to parse ID3 tag."); 1381 return ERROR_MALFORMED; 1382 } else { 1383 break; 1384 } 1385 } 1386 1387 if (firstID3Tag) { 1388 bool found = false; 1389 1390 ID3::Iterator it(id3, "PRIV"); 1391 while (!it.done()) { 1392 size_t length; 1393 const uint8_t *data = it.getData(&length); 1394 1395 static const char *kMatchName = 1396 "com.apple.streaming.transportStreamTimestamp"; 1397 static const size_t kMatchNameLen = strlen(kMatchName); 1398 1399 if (length == kMatchNameLen + 1 + 8 1400 && !strncmp((const char *)data, kMatchName, kMatchNameLen)) { 1401 found = true; 1402 PTS = U64_AT(&data[kMatchNameLen + 1]); 1403 } 1404 1405 it.next(); 1406 } 1407 1408 if (!found) { 1409 ALOGE("Unable to extract transportStreamTimestamp from ID3 tag."); 1410 return ERROR_MALFORMED; 1411 } 1412 } 1413 1414 // skip the ID3 tag 1415 buffer->setRange( 1416 buffer->offset() + id3.rawSize(), buffer->size() - id3.rawSize()); 1417 1418 firstID3Tag = false; 1419 } 1420 1421 if (mStreamTypeMask != LiveSession::STREAMTYPE_AUDIO) { 1422 ALOGW("This stream only contains audio data!"); 1423 1424 mStreamTypeMask &= LiveSession::STREAMTYPE_AUDIO; 1425 1426 if (mStreamTypeMask == 0) { 1427 return OK; 1428 } 1429 } 1430 1431 sp<AnotherPacketSource> packetSource = 1432 mPacketSources.valueFor(LiveSession::STREAMTYPE_AUDIO); 1433 1434 if (packetSource->getFormat() == NULL && buffer->size() >= 7) { 1435 ABitReader bits(buffer->data(), buffer->size()); 1436 1437 // adts_fixed_header 1438 1439 CHECK_EQ(bits.getBits(12), 0xfffu); 1440 bits.skipBits(3); // ID, layer 1441 bool protection_absent = bits.getBits(1) != 0; 1442 1443 unsigned profile = bits.getBits(2); 1444 CHECK_NE(profile, 3u); 1445 unsigned sampling_freq_index = bits.getBits(4); 1446 bits.getBits(1); // private_bit 1447 unsigned channel_configuration = bits.getBits(3); 1448 CHECK_NE(channel_configuration, 0u); 1449 bits.skipBits(2); // original_copy, home 1450 1451 sp<MetaData> meta = MakeAACCodecSpecificData( 1452 profile, sampling_freq_index, channel_configuration); 1453 1454 meta->setInt32(kKeyIsADTS, true); 1455 1456 packetSource->setFormat(meta); 1457 } 1458 1459 int64_t numSamples = 0ll; 1460 int32_t sampleRate; 1461 CHECK(packetSource->getFormat()->findInt32(kKeySampleRate, &sampleRate)); 1462 1463 int64_t timeUs = (PTS * 100ll) / 9ll; 1464 if (!mFirstPTSValid) { 1465 mFirstPTSValid = true; 1466 mFirstTimeUs = timeUs; 1467 } 1468 1469 size_t offset = 0; 1470 while (offset < buffer->size()) { 1471 const uint8_t *adtsHeader = buffer->data() + offset; 1472 CHECK_LT(offset + 5, buffer->size()); 1473 1474 unsigned aac_frame_length = 1475 ((adtsHeader[3] & 3) << 11) 1476 | (adtsHeader[4] << 3) 1477 | (adtsHeader[5] >> 5); 1478 1479 if (aac_frame_length == 0) { 1480 const uint8_t *id3Header = adtsHeader; 1481 if (!memcmp(id3Header, "ID3", 3)) { 1482 ID3 id3(id3Header, buffer->size() - offset, true); 1483 if (id3.isValid()) { 1484 offset += id3.rawSize(); 1485 continue; 1486 }; 1487 } 1488 return ERROR_MALFORMED; 1489 } 1490 1491 CHECK_LE(offset + aac_frame_length, buffer->size()); 1492 1493 int64_t unitTimeUs = timeUs + numSamples * 1000000ll / sampleRate; 1494 offset += aac_frame_length; 1495 1496 // Each AAC frame encodes 1024 samples. 1497 numSamples += 1024; 1498 1499 if (mStartup) { 1500 int64_t startTimeUs = unitTimeUs; 1501 if (mStartTimeUsRelative) { 1502 startTimeUs -= mFirstTimeUs; 1503 if (startTimeUs < 0) { 1504 startTimeUs = 0; 1505 } 1506 } 1507 if (startTimeUs < mStartTimeUs) { 1508 continue; 1509 } 1510 } 1511 1512 sp<ABuffer> unit = new ABuffer(aac_frame_length); 1513 memcpy(unit->data(), adtsHeader, aac_frame_length); 1514 1515 unit->meta()->setInt64("timeUs", unitTimeUs); 1516 unit->meta()->setInt64("segmentStartTimeUs", getSegmentStartTimeUs(mSeqNumber)); 1517 unit->meta()->setInt32("discontinuitySeq", mDiscontinuitySeq); 1518 packetSource->queueAccessUnit(unit); 1519 } 1520 1521 return OK; 1522} 1523 1524void PlaylistFetcher::updateDuration() { 1525 int64_t durationUs = 0ll; 1526 for (size_t index = 0; index < mPlaylist->size(); ++index) { 1527 sp<AMessage> itemMeta; 1528 CHECK(mPlaylist->itemAt( 1529 index, NULL /* uri */, &itemMeta)); 1530 1531 int64_t itemDurationUs; 1532 CHECK(itemMeta->findInt64("durationUs", &itemDurationUs)); 1533 1534 durationUs += itemDurationUs; 1535 } 1536 1537 sp<AMessage> msg = mNotify->dup(); 1538 msg->setInt32("what", kWhatDurationUpdate); 1539 msg->setInt64("durationUs", durationUs); 1540 msg->post(); 1541} 1542 1543int64_t PlaylistFetcher::resumeThreshold(const sp<AMessage> &msg) { 1544 int64_t durationUs, threshold; 1545 if (msg->findInt64("durationUs", &durationUs)) { 1546 return kNumSkipFrames * durationUs; 1547 } 1548 1549 sp<RefBase> obj; 1550 msg->findObject("format", &obj); 1551 MetaData *format = static_cast<MetaData *>(obj.get()); 1552 1553 const char *mime; 1554 CHECK(format->findCString(kKeyMIMEType, &mime)); 1555 bool audio = !strncasecmp(mime, "audio/", 6); 1556 if (audio) { 1557 // Assumes 1000 samples per frame. 1558 int32_t sampleRate; 1559 CHECK(format->findInt32(kKeySampleRate, &sampleRate)); 1560 return kNumSkipFrames /* frames */ * 1000 /* samples */ 1561 * (1000000 / sampleRate) /* sample duration (us) */; 1562 } else { 1563 int32_t frameRate; 1564 if (format->findInt32(kKeyFrameRate, &frameRate) && frameRate > 0) { 1565 return kNumSkipFrames * (1000000 / frameRate); 1566 } 1567 } 1568 1569 return 500000ll; 1570} 1571 1572} // namespace android 1573