1 /* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 //#define LOG_NDEBUG 0 18 #define LOG_TAG "MPEG2TSWriter" 19 #include <media/stagefright/foundation/ADebug.h> 20 21 #include <media/stagefright/foundation/hexdump.h> 22 #include <media/stagefright/foundation/ABuffer.h> 23 #include <media/stagefright/foundation/AMessage.h> 24 #include <media/stagefright/MPEG2TSWriter.h> 25 #include <media/stagefright/MediaBuffer.h> 26 #include <media/stagefright/MediaDefs.h> 27 #include <media/stagefright/MediaErrors.h> 28 #include <media/stagefright/MediaSource.h> 29 #include <media/stagefright/MetaData.h> 30 #include <media/stagefright/Utils.h> 31 #include <arpa/inet.h> 32 33 #include "include/ESDS.h" 34 35 namespace android { 36 37 struct MPEG2TSWriter::SourceInfo : public AHandler { 38 explicit SourceInfo(const sp<IMediaSource> &source); 39 40 void start(const sp<AMessage> ¬ify, const sp<MetaData> ¶ms); 41 void stop(); 42 43 unsigned streamType() const; 44 unsigned incrementContinuityCounter(); 45 46 void readMore(); 47 48 enum { 49 kNotifyStartFailed, 50 kNotifyBuffer, 51 kNotifyReachedEOS, 52 }; 53 54 sp<ABuffer> lastAccessUnit(); 55 int64_t lastAccessUnitTimeUs(); 56 void setLastAccessUnit(const sp<ABuffer> &accessUnit); 57 58 void setEOSReceived(); 59 bool eosReceived() const; 60 61 protected: 62 virtual void onMessageReceived(const sp<AMessage> &msg); 63 64 virtual ~SourceInfo(); 65 66 private: 67 enum { 68 kWhatStart = 'strt', 69 kWhatRead = 'read', 70 }; 71 72 sp<IMediaSource> mSource; 73 sp<ALooper> mLooper; 74 sp<AMessage> mNotify; 75 76 sp<ABuffer> mAACCodecSpecificData; 77 78 sp<ABuffer> mBuffer; 79 80 sp<ABuffer> mLastAccessUnit; 81 bool mEOSReceived; 82 83 unsigned mStreamType; 84 unsigned mContinuityCounter; 85 86 void extractCodecSpecificData(); 87 88 void appendAACFrames(MediaBuffer *buffer); 89 void appendAVCFrame(MediaBuffer *buffer); 90 91 DISALLOW_EVIL_CONSTRUCTORS(SourceInfo); 92 }; 93 94 MPEG2TSWriter::SourceInfo::SourceInfo(const sp<IMediaSource> &source) 95 : mSource(source), 96 mLooper(new ALooper), 97 mEOSReceived(false), 98 mStreamType(0), 99 mContinuityCounter(0) { 100 mLooper->setName("MPEG2TSWriter source"); 101 102 sp<MetaData> meta = mSource->getFormat(); 103 const char *mime; 104 CHECK(meta->findCString(kKeyMIMEType, &mime)); 105 106 if (!strcasecmp(mime, MEDIA_MIMETYPE_AUDIO_AAC)) { 107 mStreamType = 0x0f; 108 } else if (!strcasecmp(mime, MEDIA_MIMETYPE_VIDEO_AVC)) { 109 mStreamType = 0x1b; 110 } else { 111 TRESPASS(); 112 } 113 } 114 115 MPEG2TSWriter::SourceInfo::~SourceInfo() { 116 } 117 118 unsigned MPEG2TSWriter::SourceInfo::streamType() const { 119 return mStreamType; 120 } 121 122 unsigned MPEG2TSWriter::SourceInfo::incrementContinuityCounter() { 123 if (++mContinuityCounter == 16) { 124 mContinuityCounter = 0; 125 } 126 127 return mContinuityCounter; 128 } 129 130 void MPEG2TSWriter::SourceInfo::start(const sp<AMessage> ¬ify, const sp<MetaData> ¶ms) { 131 mLooper->registerHandler(this); 132 mLooper->start(); 133 mNotify = notify; 134 135 sp<AMessage> msg = new AMessage(kWhatStart, this); 136 msg->setObject("meta", params); 137 msg->post(); 138 } 139 140 void MPEG2TSWriter::SourceInfo::stop() { 141 mLooper->unregisterHandler(id()); 142 mLooper->stop(); 143 144 mSource->stop(); 145 } 146 147 void MPEG2TSWriter::SourceInfo::extractCodecSpecificData() { 148 sp<MetaData> meta = mSource->getFormat(); 149 150 const char *mime; 151 CHECK(meta->findCString(kKeyMIMEType, &mime)); 152 153 if (!strcasecmp(mime, MEDIA_MIMETYPE_AUDIO_AAC)) { 154 uint32_t type; 155 const void *data; 156 size_t size; 157 if (!meta->findData(kKeyESDS, &type, &data, &size)) { 158 // Codec specific data better be in the first data buffer. 159 return; 160 } 161 162 ESDS esds((const char *)data, size); 163 CHECK_EQ(esds.InitCheck(), (status_t)OK); 164 165 const uint8_t *codec_specific_data; 166 size_t codec_specific_data_size; 167 esds.getCodecSpecificInfo( 168 (const void **)&codec_specific_data, &codec_specific_data_size); 169 170 CHECK_GE(codec_specific_data_size, 2u); 171 172 mAACCodecSpecificData = new ABuffer(codec_specific_data_size); 173 174 memcpy(mAACCodecSpecificData->data(), codec_specific_data, 175 codec_specific_data_size); 176 177 return; 178 } 179 180 if (strcasecmp(mime, MEDIA_MIMETYPE_VIDEO_AVC)) { 181 return; 182 } 183 184 uint32_t type; 185 const void *data; 186 size_t size; 187 if (!meta->findData(kKeyAVCC, &type, &data, &size)) { 188 // Codec specific data better be part of the data stream then. 189 return; 190 } 191 192 sp<ABuffer> out = new ABuffer(1024); 193 out->setRange(0, 0); 194 195 const uint8_t *ptr = (const uint8_t *)data; 196 197 size_t numSeqParameterSets = ptr[5] & 31; 198 199 ptr += 6; 200 size -= 6; 201 202 for (size_t i = 0; i < numSeqParameterSets; ++i) { 203 CHECK(size >= 2); 204 size_t length = U16_AT(ptr); 205 206 ptr += 2; 207 size -= 2; 208 209 CHECK(size >= length); 210 211 CHECK_LE(out->size() + 4 + length, out->capacity()); 212 memcpy(out->data() + out->size(), "\x00\x00\x00\x01", 4); 213 memcpy(out->data() + out->size() + 4, ptr, length); 214 out->setRange(0, out->size() + length + 4); 215 216 ptr += length; 217 size -= length; 218 } 219 220 CHECK(size >= 1); 221 size_t numPictureParameterSets = *ptr; 222 ++ptr; 223 --size; 224 225 for (size_t i = 0; i < numPictureParameterSets; ++i) { 226 CHECK(size >= 2); 227 size_t length = U16_AT(ptr); 228 229 ptr += 2; 230 size -= 2; 231 232 CHECK(size >= length); 233 234 CHECK_LE(out->size() + 4 + length, out->capacity()); 235 memcpy(out->data() + out->size(), "\x00\x00\x00\x01", 4); 236 memcpy(out->data() + out->size() + 4, ptr, length); 237 out->setRange(0, out->size() + length + 4); 238 239 ptr += length; 240 size -= length; 241 } 242 243 out->meta()->setInt64("timeUs", 0ll); 244 245 sp<AMessage> notify = mNotify->dup(); 246 notify->setInt32("what", kNotifyBuffer); 247 notify->setBuffer("buffer", out); 248 notify->setInt32("oob", true); 249 notify->post(); 250 } 251 252 void MPEG2TSWriter::SourceInfo::appendAVCFrame(MediaBuffer *buffer) { 253 sp<AMessage> notify = mNotify->dup(); 254 notify->setInt32("what", kNotifyBuffer); 255 256 if (mBuffer == NULL || buffer->range_length() > mBuffer->capacity()) { 257 mBuffer = new ABuffer(buffer->range_length()); 258 } 259 mBuffer->setRange(0, 0); 260 261 memcpy(mBuffer->data(), 262 (const uint8_t *)buffer->data() 263 + buffer->range_offset(), 264 buffer->range_length()); 265 266 int64_t timeUs; 267 CHECK(buffer->meta_data()->findInt64(kKeyTime, &timeUs)); 268 mBuffer->meta()->setInt64("timeUs", timeUs); 269 270 int32_t isSync; 271 if (buffer->meta_data()->findInt32(kKeyIsSyncFrame, &isSync) 272 && isSync != 0) { 273 mBuffer->meta()->setInt32("isSync", true); 274 } 275 276 mBuffer->setRange(0, buffer->range_length()); 277 278 notify->setBuffer("buffer", mBuffer); 279 notify->post(); 280 } 281 282 void MPEG2TSWriter::SourceInfo::appendAACFrames(MediaBuffer *buffer) { 283 sp<AMessage> notify = mNotify->dup(); 284 notify->setInt32("what", kNotifyBuffer); 285 286 if (mBuffer == NULL || 7 + buffer->range_length() > mBuffer->capacity()) { 287 mBuffer = new ABuffer(7 + buffer->range_length()); 288 } 289 290 int64_t timeUs; 291 CHECK(buffer->meta_data()->findInt64(kKeyTime, &timeUs)); 292 293 mBuffer->meta()->setInt64("timeUs", timeUs); 294 mBuffer->meta()->setInt32("isSync", true); 295 296 mBuffer->setRange(0, 0); 297 298 const uint8_t *codec_specific_data = mAACCodecSpecificData->data(); 299 300 unsigned profile = (codec_specific_data[0] >> 3) - 1; 301 302 unsigned sampling_freq_index = 303 ((codec_specific_data[0] & 7) << 1) 304 | (codec_specific_data[1] >> 7); 305 306 unsigned channel_configuration = 307 (codec_specific_data[1] >> 3) & 0x0f; 308 309 uint8_t *ptr = mBuffer->data() + mBuffer->size(); 310 311 const uint32_t aac_frame_length = buffer->range_length() + 7; 312 313 *ptr++ = 0xff; 314 *ptr++ = 0xf1; // b11110001, ID=0, layer=0, protection_absent=1 315 316 *ptr++ = 317 profile << 6 318 | sampling_freq_index << 2 319 | ((channel_configuration >> 2) & 1); // private_bit=0 320 321 // original_copy=0, home=0, copyright_id_bit=0, copyright_id_start=0 322 *ptr++ = 323 (channel_configuration & 3) << 6 324 | aac_frame_length >> 11; 325 *ptr++ = (aac_frame_length >> 3) & 0xff; 326 *ptr++ = (aac_frame_length & 7) << 5; 327 328 // adts_buffer_fullness=0, number_of_raw_data_blocks_in_frame=0 329 *ptr++ = 0; 330 331 memcpy(ptr, 332 (const uint8_t *)buffer->data() + buffer->range_offset(), 333 buffer->range_length()); 334 335 ptr += buffer->range_length(); 336 337 mBuffer->setRange(0, ptr - mBuffer->data()); 338 339 notify->setBuffer("buffer", mBuffer); 340 notify->post(); 341 } 342 343 void MPEG2TSWriter::SourceInfo::readMore() { 344 (new AMessage(kWhatRead, this))->post(); 345 } 346 347 void MPEG2TSWriter::SourceInfo::onMessageReceived(const sp<AMessage> &msg) { 348 switch (msg->what()) { 349 case kWhatStart: 350 { 351 sp<RefBase> obj; 352 CHECK(msg->findObject("meta", &obj)); 353 MetaData *params = static_cast<MetaData *>(obj.get()); 354 status_t err = mSource->start(params); 355 if (err != OK) { 356 sp<AMessage> notify = mNotify->dup(); 357 notify->setInt32("what", kNotifyStartFailed); 358 notify->post(); 359 break; 360 } 361 362 // Extract CSD from config format. 363 extractCodecSpecificData(); 364 365 readMore(); 366 break; 367 } 368 369 case kWhatRead: 370 { 371 MediaBuffer *buffer; 372 status_t err = mSource->read(&buffer); 373 374 if (err != OK && err != INFO_FORMAT_CHANGED) { 375 sp<AMessage> notify = mNotify->dup(); 376 notify->setInt32("what", kNotifyReachedEOS); 377 notify->setInt32("status", err); 378 notify->post(); 379 break; 380 } 381 382 if (err == OK) { 383 if (mStreamType == 0x0f && mAACCodecSpecificData == NULL) { 384 // The first audio buffer must contain CSD if not received yet. 385 CHECK_GE(buffer->range_length(), 2u); 386 mAACCodecSpecificData = new ABuffer(buffer->range_length()); 387 388 memcpy(mAACCodecSpecificData->data(), 389 (const uint8_t *)buffer->data() 390 + buffer->range_offset(), 391 buffer->range_length()); 392 readMore(); 393 } else if (buffer->range_length() > 0) { 394 if (mStreamType == 0x0f) { 395 appendAACFrames(buffer); 396 } else { 397 appendAVCFrame(buffer); 398 } 399 } else { 400 readMore(); 401 } 402 403 buffer->release(); 404 buffer = NULL; 405 } 406 407 // Do not read more data until told to. 408 break; 409 } 410 411 default: 412 TRESPASS(); 413 } 414 } 415 416 sp<ABuffer> MPEG2TSWriter::SourceInfo::lastAccessUnit() { 417 return mLastAccessUnit; 418 } 419 420 void MPEG2TSWriter::SourceInfo::setLastAccessUnit( 421 const sp<ABuffer> &accessUnit) { 422 mLastAccessUnit = accessUnit; 423 } 424 425 int64_t MPEG2TSWriter::SourceInfo::lastAccessUnitTimeUs() { 426 if (mLastAccessUnit == NULL) { 427 return -1; 428 } 429 430 int64_t timeUs; 431 CHECK(mLastAccessUnit->meta()->findInt64("timeUs", &timeUs)); 432 return timeUs; 433 } 434 435 void MPEG2TSWriter::SourceInfo::setEOSReceived() { 436 CHECK(!mEOSReceived); 437 mEOSReceived = true; 438 } 439 440 bool MPEG2TSWriter::SourceInfo::eosReceived() const { 441 return mEOSReceived; 442 } 443 444 //////////////////////////////////////////////////////////////////////////////// 445 446 MPEG2TSWriter::MPEG2TSWriter(int fd) 447 : mFile(fdopen(dup(fd), "wb")), 448 mWriteCookie(NULL), 449 mWriteFunc(NULL), 450 mStarted(false), 451 mNumSourcesDone(0), 452 mNumTSPacketsWritten(0), 453 mNumTSPacketsBeforeMeta(0), 454 mPATContinuityCounter(0), 455 mPMTContinuityCounter(0) { 456 init(); 457 } 458 459 MPEG2TSWriter::MPEG2TSWriter( 460 void *cookie, 461 ssize_t (*write)(void *cookie, const void *data, size_t size)) 462 : mFile(NULL), 463 mWriteCookie(cookie), 464 mWriteFunc(write), 465 mStarted(false), 466 mNumSourcesDone(0), 467 mNumTSPacketsWritten(0), 468 mNumTSPacketsBeforeMeta(0), 469 mPATContinuityCounter(0), 470 mPMTContinuityCounter(0) { 471 init(); 472 } 473 474 void MPEG2TSWriter::init() { 475 CHECK(mFile != NULL || mWriteFunc != NULL); 476 477 initCrcTable(); 478 479 mLooper = new ALooper; 480 mLooper->setName("MPEG2TSWriter"); 481 482 mReflector = new AHandlerReflector<MPEG2TSWriter>(this); 483 484 mLooper->registerHandler(mReflector); 485 mLooper->start(); 486 } 487 488 MPEG2TSWriter::~MPEG2TSWriter() { 489 if (mStarted) { 490 reset(); 491 } 492 493 mLooper->unregisterHandler(mReflector->id()); 494 mLooper->stop(); 495 496 if (mFile != NULL) { 497 fclose(mFile); 498 mFile = NULL; 499 } 500 } 501 502 status_t MPEG2TSWriter::addSource(const sp<IMediaSource> &source) { 503 CHECK(!mStarted); 504 505 sp<MetaData> meta = source->getFormat(); 506 const char *mime; 507 CHECK(meta->findCString(kKeyMIMEType, &mime)); 508 509 if (strcasecmp(mime, MEDIA_MIMETYPE_VIDEO_AVC) 510 && strcasecmp(mime, MEDIA_MIMETYPE_AUDIO_AAC)) { 511 return ERROR_UNSUPPORTED; 512 } 513 514 sp<SourceInfo> info = new SourceInfo(source); 515 516 mSources.push(info); 517 518 return OK; 519 } 520 521 status_t MPEG2TSWriter::start(MetaData *param ) { 522 CHECK(!mStarted); 523 524 mStarted = true; 525 mNumSourcesDone = 0; 526 mNumTSPacketsWritten = 0; 527 mNumTSPacketsBeforeMeta = 0; 528 529 for (size_t i = 0; i < mSources.size(); ++i) { 530 sp<AMessage> notify = 531 new AMessage(kWhatSourceNotify, mReflector); 532 533 notify->setInt32("source-index", i); 534 535 mSources.editItemAt(i)->start(notify, param); 536 } 537 538 return OK; 539 } 540 541 status_t MPEG2TSWriter::reset() { 542 CHECK(mStarted); 543 544 for (size_t i = 0; i < mSources.size(); ++i) { 545 mSources.editItemAt(i)->stop(); 546 } 547 mStarted = false; 548 549 return OK; 550 } 551 552 status_t MPEG2TSWriter::pause() { 553 CHECK(mStarted); 554 555 return OK; 556 } 557 558 bool MPEG2TSWriter::reachedEOS() { 559 return !mStarted || (mNumSourcesDone == mSources.size() ? true : false); 560 } 561 562 status_t MPEG2TSWriter::dump( 563 int /* fd */, const Vector<String16> & /* args */) { 564 return OK; 565 } 566 567 void MPEG2TSWriter::onMessageReceived(const sp<AMessage> &msg) { 568 switch (msg->what()) { 569 case kWhatSourceNotify: 570 { 571 int32_t sourceIndex; 572 CHECK(msg->findInt32("source-index", &sourceIndex)); 573 sp<SourceInfo> source = mSources.editItemAt(sourceIndex); 574 575 int32_t what; 576 CHECK(msg->findInt32("what", &what)); 577 578 if (what == SourceInfo::kNotifyReachedEOS 579 || what == SourceInfo::kNotifyStartFailed) { 580 source->setEOSReceived(); 581 582 sp<ABuffer> buffer = source->lastAccessUnit(); 583 source->setLastAccessUnit(NULL); 584 585 if (buffer != NULL) { 586 writeTS(); 587 writeAccessUnit(sourceIndex, buffer); 588 } 589 590 ++mNumSourcesDone; 591 } else if (what == SourceInfo::kNotifyBuffer) { 592 sp<ABuffer> buffer; 593 CHECK(msg->findBuffer("buffer", &buffer)); 594 CHECK(source->lastAccessUnit() == NULL); 595 596 int32_t oob; 597 if (msg->findInt32("oob", &oob) && oob) { 598 // This is codec specific data delivered out of band. 599 // It can be written out immediately. 600 writeTS(); 601 writeAccessUnit(sourceIndex, buffer); 602 break; 603 } 604 605 // We don't just write out data as we receive it from 606 // the various sources. That would essentially write them 607 // out in random order (as the thread scheduler determines 608 // how the messages are dispatched). 609 // Instead we gather an access unit for all tracks and 610 // write out the one with the smallest timestamp, then 611 // request more data for the written out track. 612 // Rinse, repeat. 613 // If we don't have data on any track we don't write 614 // anything just yet. 615 source->setLastAccessUnit(buffer); 616 617 ALOGV("lastAccessUnitTimeUs[%d] = %.2f secs", 618 sourceIndex, source->lastAccessUnitTimeUs() / 1E6); 619 int64_t minTimeUs = -1; 620 size_t minIndex = 0; 621 622 for (size_t i = 0; i < mSources.size(); ++i) { 623 const sp<SourceInfo> &source = mSources.editItemAt(i); 624 625 if (source->eosReceived()) { 626 continue; 627 } 628 629 int64_t timeUs = source->lastAccessUnitTimeUs(); 630 if (timeUs < 0) { 631 minTimeUs = -1; 632 break; 633 } else if (minTimeUs < 0 || timeUs < minTimeUs) { 634 minTimeUs = timeUs; 635 minIndex = i; 636 } 637 } 638 639 if (minTimeUs < 0) { 640 ALOGV("not all tracks have valid data."); 641 break; 642 } 643 644 ALOGV("writing access unit at time %.2f secs (index %zu)", 645 minTimeUs / 1E6, minIndex); 646 647 source = mSources.editItemAt(minIndex); 648 buffer = source->lastAccessUnit(); 649 source->setLastAccessUnit(NULL); 650 651 writeTS(); 652 writeAccessUnit(minIndex, buffer); 653 654 source->readMore(); 655 } 656 break; 657 } 658 659 default: 660 TRESPASS(); 661 } 662 } 663 664 void MPEG2TSWriter::writeProgramAssociationTable() { 665 // 0x47 666 // transport_error_indicator = b0 667 // payload_unit_start_indicator = b1 668 // transport_priority = b0 669 // PID = b0000000000000 (13 bits) 670 // transport_scrambling_control = b00 671 // adaptation_field_control = b01 (no adaptation field, payload only) 672 // continuity_counter = b???? 673 // skip = 0x00 674 // --- payload follows 675 // table_id = 0x00 676 // section_syntax_indicator = b1 677 // must_be_zero = b0 678 // reserved = b11 679 // section_length = 0x00d 680 // transport_stream_id = 0x0000 681 // reserved = b11 682 // version_number = b00001 683 // current_next_indicator = b1 684 // section_number = 0x00 685 // last_section_number = 0x00 686 // one program follows: 687 // program_number = 0x0001 688 // reserved = b111 689 // program_map_PID = 0x01e0 (13 bits!) 690 // CRC = 0x???????? 691 692 static const uint8_t kData[] = { 693 0x47, 694 0x40, 0x00, 0x10, 0x00, // b0100 0000 0000 0000 0001 ???? 0000 0000 695 0x00, 0xb0, 0x0d, 0x00, // b0000 0000 1011 0000 0000 1101 0000 0000 696 0x00, 0xc3, 0x00, 0x00, // b0000 0000 1100 0011 0000 0000 0000 0000 697 0x00, 0x01, 0xe1, 0xe0, // b0000 0000 0000 0001 1110 0001 1110 0000 698 0x00, 0x00, 0x00, 0x00 // b???? ???? ???? ???? ???? ???? ???? ???? 699 }; 700 701 sp<ABuffer> buffer = new ABuffer(188); 702 memset(buffer->data(), 0xff, buffer->size()); 703 memcpy(buffer->data(), kData, sizeof(kData)); 704 705 if (++mPATContinuityCounter == 16) { 706 mPATContinuityCounter = 0; 707 } 708 buffer->data()[3] |= mPATContinuityCounter; 709 710 uint32_t crc = htonl(crc32(&buffer->data()[5], 12)); 711 memcpy(&buffer->data()[17], &crc, sizeof(crc)); 712 713 CHECK_EQ(internalWrite(buffer->data(), buffer->size()), (ssize_t)buffer->size()); 714 } 715 716 void MPEG2TSWriter::writeProgramMap() { 717 // 0x47 718 // transport_error_indicator = b0 719 // payload_unit_start_indicator = b1 720 // transport_priority = b0 721 // PID = b0 0001 1110 0000 (13 bits) [0x1e0] 722 // transport_scrambling_control = b00 723 // adaptation_field_control = b01 (no adaptation field, payload only) 724 // continuity_counter = b???? 725 // skip = 0x00 726 // -- payload follows 727 // table_id = 0x02 728 // section_syntax_indicator = b1 729 // must_be_zero = b0 730 // reserved = b11 731 // section_length = 0x??? 732 // program_number = 0x0001 733 // reserved = b11 734 // version_number = b00001 735 // current_next_indicator = b1 736 // section_number = 0x00 737 // last_section_number = 0x00 738 // reserved = b111 739 // PCR_PID = b? ???? ???? ???? (13 bits) 740 // reserved = b1111 741 // program_info_length = 0x000 742 // one or more elementary stream descriptions follow: 743 // stream_type = 0x?? 744 // reserved = b111 745 // elementary_PID = b? ???? ???? ???? (13 bits) 746 // reserved = b1111 747 // ES_info_length = 0x000 748 // CRC = 0x???????? 749 750 static const uint8_t kData[] = { 751 0x47, 752 0x41, 0xe0, 0x10, 0x00, // b0100 0001 1110 0000 0001 ???? 0000 0000 753 0x02, 0xb0, 0x00, 0x00, // b0000 0010 1011 ???? ???? ???? 0000 0000 754 0x01, 0xc3, 0x00, 0x00, // b0000 0001 1100 0011 0000 0000 0000 0000 755 0xe0, 0x00, 0xf0, 0x00 // b111? ???? ???? ???? 1111 0000 0000 0000 756 }; 757 758 sp<ABuffer> buffer = new ABuffer(188); 759 memset(buffer->data(), 0xff, buffer->size()); 760 memcpy(buffer->data(), kData, sizeof(kData)); 761 762 if (++mPMTContinuityCounter == 16) { 763 mPMTContinuityCounter = 0; 764 } 765 buffer->data()[3] |= mPMTContinuityCounter; 766 767 size_t section_length = 5 * mSources.size() + 4 + 9; 768 buffer->data()[6] |= section_length >> 8; 769 buffer->data()[7] = section_length & 0xff; 770 771 static const unsigned kPCR_PID = 0x1e1; 772 buffer->data()[13] |= (kPCR_PID >> 8) & 0x1f; 773 buffer->data()[14] = kPCR_PID & 0xff; 774 775 uint8_t *ptr = &buffer->data()[sizeof(kData)]; 776 for (size_t i = 0; i < mSources.size(); ++i) { 777 *ptr++ = mSources.editItemAt(i)->streamType(); 778 779 const unsigned ES_PID = 0x1e0 + i + 1; 780 *ptr++ = 0xe0 | (ES_PID >> 8); 781 *ptr++ = ES_PID & 0xff; 782 *ptr++ = 0xf0; 783 *ptr++ = 0x00; 784 } 785 786 uint32_t crc = htonl(crc32(&buffer->data()[5], 12+mSources.size()*5)); 787 memcpy(&buffer->data()[17+mSources.size()*5], &crc, sizeof(crc)); 788 789 CHECK_EQ(internalWrite(buffer->data(), buffer->size()), (ssize_t)buffer->size()); 790 } 791 792 void MPEG2TSWriter::writeAccessUnit( 793 int32_t sourceIndex, const sp<ABuffer> &accessUnit) { 794 // 0x47 795 // transport_error_indicator = b0 796 // payload_unit_start_indicator = b1 797 // transport_priority = b0 798 // PID = b0 0001 1110 ???? (13 bits) [0x1e0 + 1 + sourceIndex] 799 // transport_scrambling_control = b00 800 // adaptation_field_control = b?? 801 // continuity_counter = b???? 802 // -- payload follows 803 // packet_startcode_prefix = 0x000001 804 // stream_id = 0x?? (0xe0 for avc video, 0xc0 for aac audio) 805 // PES_packet_length = 0x???? 806 // reserved = b10 807 // PES_scrambling_control = b00 808 // PES_priority = b0 809 // data_alignment_indicator = b1 810 // copyright = b0 811 // original_or_copy = b0 812 // PTS_DTS_flags = b10 (PTS only) 813 // ESCR_flag = b0 814 // ES_rate_flag = b0 815 // DSM_trick_mode_flag = b0 816 // additional_copy_info_flag = b0 817 // PES_CRC_flag = b0 818 // PES_extension_flag = b0 819 // PES_header_data_length = 0x05 820 // reserved = b0010 (PTS) 821 // PTS[32..30] = b??? 822 // reserved = b1 823 // PTS[29..15] = b??? ???? ???? ???? (15 bits) 824 // reserved = b1 825 // PTS[14..0] = b??? ???? ???? ???? (15 bits) 826 // reserved = b1 827 // the first fragment of "buffer" follows 828 829 sp<ABuffer> buffer = new ABuffer(188); 830 memset(buffer->data(), 0xff, buffer->size()); 831 832 const unsigned PID = 0x1e0 + sourceIndex + 1; 833 834 const unsigned continuity_counter = 835 mSources.editItemAt(sourceIndex)->incrementContinuityCounter(); 836 837 // XXX if there are multiple streams of a kind (more than 1 audio or 838 // more than 1 video) they need distinct stream_ids. 839 const unsigned stream_id = 840 mSources.editItemAt(sourceIndex)->streamType() == 0x0f ? 0xc0 : 0xe0; 841 842 int64_t timeUs; 843 CHECK(accessUnit->meta()->findInt64("timeUs", &timeUs)); 844 845 uint32_t PTS = (timeUs * 9ll) / 100ll; 846 847 size_t PES_packet_length = accessUnit->size() + 8; 848 bool padding = (accessUnit->size() < (188 - 18)); 849 850 if (PES_packet_length >= 65536) { 851 // This really should only happen for video. 852 CHECK_EQ(stream_id, 0xe0u); 853 854 // It's valid to set this to 0 for video according to the specs. 855 PES_packet_length = 0; 856 } 857 858 uint8_t *ptr = buffer->data(); 859 *ptr++ = 0x47; 860 *ptr++ = 0x40 | (PID >> 8); 861 *ptr++ = PID & 0xff; 862 *ptr++ = (padding ? 0x30 : 0x10) | continuity_counter; 863 if (padding) { 864 int paddingSize = 188 - accessUnit->size() - 18; 865 *ptr++ = paddingSize - 1; 866 if (paddingSize >= 2) { 867 *ptr++ = 0x00; 868 ptr += paddingSize - 2; 869 } 870 } 871 *ptr++ = 0x00; 872 *ptr++ = 0x00; 873 *ptr++ = 0x01; 874 *ptr++ = stream_id; 875 *ptr++ = PES_packet_length >> 8; 876 *ptr++ = PES_packet_length & 0xff; 877 *ptr++ = 0x84; 878 *ptr++ = 0x80; 879 *ptr++ = 0x05; 880 *ptr++ = 0x20 | (((PTS >> 30) & 7) << 1) | 1; 881 *ptr++ = (PTS >> 22) & 0xff; 882 *ptr++ = (((PTS >> 15) & 0x7f) << 1) | 1; 883 *ptr++ = (PTS >> 7) & 0xff; 884 *ptr++ = ((PTS & 0x7f) << 1) | 1; 885 886 size_t sizeLeft = buffer->data() + buffer->size() - ptr; 887 size_t copy = accessUnit->size(); 888 if (copy > sizeLeft) { 889 copy = sizeLeft; 890 } 891 892 memcpy(ptr, accessUnit->data(), copy); 893 894 CHECK_EQ(internalWrite(buffer->data(), buffer->size()), (ssize_t)buffer->size()); 895 896 size_t offset = copy; 897 while (offset < accessUnit->size()) { 898 bool lastAccessUnit = ((accessUnit->size() - offset) < 184); 899 // for subsequent fragments of "buffer": 900 // 0x47 901 // transport_error_indicator = b0 902 // payload_unit_start_indicator = b0 903 // transport_priority = b0 904 // PID = b0 0001 1110 ???? (13 bits) [0x1e0 + 1 + sourceIndex] 905 // transport_scrambling_control = b00 906 // adaptation_field_control = b?? 907 // continuity_counter = b???? 908 // the fragment of "buffer" follows. 909 910 memset(buffer->data(), 0xff, buffer->size()); 911 912 const unsigned continuity_counter = 913 mSources.editItemAt(sourceIndex)->incrementContinuityCounter(); 914 915 ptr = buffer->data(); 916 *ptr++ = 0x47; 917 *ptr++ = 0x00 | (PID >> 8); 918 *ptr++ = PID & 0xff; 919 *ptr++ = (lastAccessUnit ? 0x30 : 0x10) | continuity_counter; 920 921 if (lastAccessUnit) { 922 // Pad packet using an adaptation field 923 // Adaptation header all to 0 execpt size 924 uint8_t paddingSize = (uint8_t)184 - (accessUnit->size() - offset); 925 *ptr++ = paddingSize - 1; 926 if (paddingSize >= 2) { 927 *ptr++ = 0x00; 928 ptr += paddingSize - 2; 929 } 930 } 931 932 size_t sizeLeft = buffer->data() + buffer->size() - ptr; 933 size_t copy = accessUnit->size() - offset; 934 if (copy > sizeLeft) { 935 copy = sizeLeft; 936 } 937 938 memcpy(ptr, accessUnit->data() + offset, copy); 939 CHECK_EQ(internalWrite(buffer->data(), buffer->size()), 940 (ssize_t)buffer->size()); 941 942 offset += copy; 943 } 944 } 945 946 void MPEG2TSWriter::writeTS() { 947 if (mNumTSPacketsWritten >= mNumTSPacketsBeforeMeta) { 948 writeProgramAssociationTable(); 949 writeProgramMap(); 950 951 mNumTSPacketsBeforeMeta = mNumTSPacketsWritten + 2500; 952 } 953 } 954 955 void MPEG2TSWriter::initCrcTable() { 956 uint32_t poly = 0x04C11DB7; 957 958 for (int i = 0; i < 256; i++) { 959 uint32_t crc = i << 24; 960 for (int j = 0; j < 8; j++) { 961 crc = (crc << 1) ^ ((crc & 0x80000000) ? (poly) : 0); 962 } 963 mCrcTable[i] = crc; 964 } 965 } 966 967 /** 968 * Compute CRC32 checksum for buffer starting at offset start and for length 969 * bytes. 970 */ 971 uint32_t MPEG2TSWriter::crc32(const uint8_t *p_start, size_t length) { 972 uint32_t crc = 0xFFFFFFFF; 973 const uint8_t *p; 974 975 for (p = p_start; p < p_start + length; p++) { 976 crc = (crc << 8) ^ mCrcTable[((crc >> 24) ^ *p) & 0xFF]; 977 } 978 979 return crc; 980 } 981 982 ssize_t MPEG2TSWriter::internalWrite(const void *data, size_t size) { 983 if (mFile != NULL) { 984 return fwrite(data, 1, size, mFile); 985 } 986 987 return (*mWriteFunc)(mWriteCookie, data, size); 988 } 989 990 } // namespace android 991 992
