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 SourceInfo(const sp<MediaSource> &source); 39 40 void start(const sp<AMessage> ¬ify); 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<MediaSource> mSource; 73 sp<ALooper> mLooper; 74 sp<AMessage> mNotify; 75 76 sp<ABuffer> mAACCodecSpecificData; 77 78 sp<ABuffer> mAACBuffer; 79 80 sp<ABuffer> mLastAccessUnit; 81 bool mEOSReceived; 82 83 unsigned mStreamType; 84 unsigned mContinuityCounter; 85 86 void extractCodecSpecificData(); 87 88 bool appendAACFrames(MediaBuffer *buffer); 89 bool flushAACFrames(); 90 91 void postAVCFrame(MediaBuffer *buffer); 92 93 DISALLOW_EVIL_CONSTRUCTORS(SourceInfo); 94 }; 95 96 MPEG2TSWriter::SourceInfo::SourceInfo(const sp<MediaSource> &source) 97 : mSource(source), 98 mLooper(new ALooper), 99 mEOSReceived(false), 100 mStreamType(0), 101 mContinuityCounter(0) { 102 mLooper->setName("MPEG2TSWriter source"); 103 104 sp<MetaData> meta = mSource->getFormat(); 105 const char *mime; 106 CHECK(meta->findCString(kKeyMIMEType, &mime)); 107 108 if (!strcasecmp(mime, MEDIA_MIMETYPE_AUDIO_AAC)) { 109 mStreamType = 0x0f; 110 } else if (!strcasecmp(mime, MEDIA_MIMETYPE_VIDEO_AVC)) { 111 mStreamType = 0x1b; 112 } else { 113 TRESPASS(); 114 } 115 } 116 117 MPEG2TSWriter::SourceInfo::~SourceInfo() { 118 } 119 120 unsigned MPEG2TSWriter::SourceInfo::streamType() const { 121 return mStreamType; 122 } 123 124 unsigned MPEG2TSWriter::SourceInfo::incrementContinuityCounter() { 125 if (++mContinuityCounter == 16) { 126 mContinuityCounter = 0; 127 } 128 129 return mContinuityCounter; 130 } 131 132 void MPEG2TSWriter::SourceInfo::start(const sp<AMessage> ¬ify) { 133 mLooper->registerHandler(this); 134 mLooper->start(); 135 136 mNotify = notify; 137 138 (new AMessage(kWhatStart, id()))->post(); 139 } 140 141 void MPEG2TSWriter::SourceInfo::stop() { 142 mLooper->unregisterHandler(id()); 143 mLooper->stop(); 144 145 mSource->stop(); 146 } 147 148 void MPEG2TSWriter::SourceInfo::extractCodecSpecificData() { 149 sp<MetaData> meta = mSource->getFormat(); 150 151 const char *mime; 152 CHECK(meta->findCString(kKeyMIMEType, &mime)); 153 154 if (!strcasecmp(mime, MEDIA_MIMETYPE_AUDIO_AAC)) { 155 uint32_t type; 156 const void *data; 157 size_t size; 158 if (!meta->findData(kKeyESDS, &type, &data, &size)) { 159 // Codec specific data better be in the first data buffer. 160 return; 161 } 162 163 ESDS esds((const char *)data, size); 164 CHECK_EQ(esds.InitCheck(), (status_t)OK); 165 166 const uint8_t *codec_specific_data; 167 size_t codec_specific_data_size; 168 esds.getCodecSpecificInfo( 169 (const void **)&codec_specific_data, &codec_specific_data_size); 170 171 CHECK_GE(codec_specific_data_size, 2u); 172 173 mAACCodecSpecificData = new ABuffer(codec_specific_data_size); 174 175 memcpy(mAACCodecSpecificData->data(), codec_specific_data, 176 codec_specific_data_size); 177 178 return; 179 } 180 181 if (strcasecmp(mime, MEDIA_MIMETYPE_VIDEO_AVC)) { 182 return; 183 } 184 185 uint32_t type; 186 const void *data; 187 size_t size; 188 if (!meta->findData(kKeyAVCC, &type, &data, &size)) { 189 // Codec specific data better be part of the data stream then. 190 return; 191 } 192 193 sp<ABuffer> out = new ABuffer(1024); 194 out->setRange(0, 0); 195 196 const uint8_t *ptr = (const uint8_t *)data; 197 198 size_t numSeqParameterSets = ptr[5] & 31; 199 200 ptr += 6; 201 size -= 6; 202 203 for (size_t i = 0; i < numSeqParameterSets; ++i) { 204 CHECK(size >= 2); 205 size_t length = U16_AT(ptr); 206 207 ptr += 2; 208 size -= 2; 209 210 CHECK(size >= length); 211 212 CHECK_LE(out->size() + 4 + length, out->capacity()); 213 memcpy(out->data() + out->size(), "\x00\x00\x00\x01", 4); 214 memcpy(out->data() + out->size() + 4, ptr, length); 215 out->setRange(0, out->size() + length + 4); 216 217 ptr += length; 218 size -= length; 219 } 220 221 CHECK(size >= 1); 222 size_t numPictureParameterSets = *ptr; 223 ++ptr; 224 --size; 225 226 for (size_t i = 0; i < numPictureParameterSets; ++i) { 227 CHECK(size >= 2); 228 size_t length = U16_AT(ptr); 229 230 ptr += 2; 231 size -= 2; 232 233 CHECK(size >= length); 234 235 CHECK_LE(out->size() + 4 + length, out->capacity()); 236 memcpy(out->data() + out->size(), "\x00\x00\x00\x01", 4); 237 memcpy(out->data() + out->size() + 4, ptr, length); 238 out->setRange(0, out->size() + length + 4); 239 240 ptr += length; 241 size -= length; 242 } 243 244 out->meta()->setInt64("timeUs", 0ll); 245 246 sp<AMessage> notify = mNotify->dup(); 247 notify->setInt32("what", kNotifyBuffer); 248 notify->setBuffer("buffer", out); 249 notify->setInt32("oob", true); 250 notify->post(); 251 } 252 253 void MPEG2TSWriter::SourceInfo::postAVCFrame(MediaBuffer *buffer) { 254 sp<AMessage> notify = mNotify->dup(); 255 notify->setInt32("what", kNotifyBuffer); 256 257 sp<ABuffer> copy = 258 new ABuffer(buffer->range_length()); 259 memcpy(copy->data(), 260 (const uint8_t *)buffer->data() 261 + buffer->range_offset(), 262 buffer->range_length()); 263 264 int64_t timeUs; 265 CHECK(buffer->meta_data()->findInt64(kKeyTime, &timeUs)); 266 copy->meta()->setInt64("timeUs", timeUs); 267 268 int32_t isSync; 269 if (buffer->meta_data()->findInt32(kKeyIsSyncFrame, &isSync) 270 && isSync != 0) { 271 copy->meta()->setInt32("isSync", true); 272 } 273 274 notify->setBuffer("buffer", copy); 275 notify->post(); 276 } 277 278 bool MPEG2TSWriter::SourceInfo::appendAACFrames(MediaBuffer *buffer) { 279 bool accessUnitPosted = false; 280 281 if (mAACBuffer != NULL 282 && mAACBuffer->size() + 7 + buffer->range_length() 283 > mAACBuffer->capacity()) { 284 accessUnitPosted = flushAACFrames(); 285 } 286 287 if (mAACBuffer == NULL) { 288 size_t alloc = 4096; 289 if (buffer->range_length() + 7 > alloc) { 290 alloc = 7 + buffer->range_length(); 291 } 292 293 mAACBuffer = new ABuffer(alloc); 294 295 int64_t timeUs; 296 CHECK(buffer->meta_data()->findInt64(kKeyTime, &timeUs)); 297 298 mAACBuffer->meta()->setInt64("timeUs", timeUs); 299 mAACBuffer->meta()->setInt32("isSync", true); 300 301 mAACBuffer->setRange(0, 0); 302 } 303 304 const uint8_t *codec_specific_data = mAACCodecSpecificData->data(); 305 306 unsigned profile = (codec_specific_data[0] >> 3) - 1; 307 308 unsigned sampling_freq_index = 309 ((codec_specific_data[0] & 7) << 1) 310 | (codec_specific_data[1] >> 7); 311 312 unsigned channel_configuration = 313 (codec_specific_data[1] >> 3) & 0x0f; 314 315 uint8_t *ptr = mAACBuffer->data() + mAACBuffer->size(); 316 317 const uint32_t aac_frame_length = buffer->range_length() + 7; 318 319 *ptr++ = 0xff; 320 *ptr++ = 0xf1; // b11110001, ID=0, layer=0, protection_absent=1 321 322 *ptr++ = 323 profile << 6 324 | sampling_freq_index << 2 325 | ((channel_configuration >> 2) & 1); // private_bit=0 326 327 // original_copy=0, home=0, copyright_id_bit=0, copyright_id_start=0 328 *ptr++ = 329 (channel_configuration & 3) << 6 330 | aac_frame_length >> 11; 331 *ptr++ = (aac_frame_length >> 3) & 0xff; 332 *ptr++ = (aac_frame_length & 7) << 5; 333 334 // adts_buffer_fullness=0, number_of_raw_data_blocks_in_frame=0 335 *ptr++ = 0; 336 337 memcpy(ptr, 338 (const uint8_t *)buffer->data() + buffer->range_offset(), 339 buffer->range_length()); 340 341 ptr += buffer->range_length(); 342 343 mAACBuffer->setRange(0, ptr - mAACBuffer->data()); 344 345 return accessUnitPosted; 346 } 347 348 bool MPEG2TSWriter::SourceInfo::flushAACFrames() { 349 if (mAACBuffer == NULL) { 350 return false; 351 } 352 353 sp<AMessage> notify = mNotify->dup(); 354 notify->setInt32("what", kNotifyBuffer); 355 notify->setBuffer("buffer", mAACBuffer); 356 notify->post(); 357 358 mAACBuffer.clear(); 359 360 return true; 361 } 362 363 void MPEG2TSWriter::SourceInfo::readMore() { 364 (new AMessage(kWhatRead, id()))->post(); 365 } 366 367 void MPEG2TSWriter::SourceInfo::onMessageReceived(const sp<AMessage> &msg) { 368 switch (msg->what()) { 369 case kWhatStart: 370 { 371 status_t err = mSource->start(); 372 if (err != OK) { 373 sp<AMessage> notify = mNotify->dup(); 374 notify->setInt32("what", kNotifyStartFailed); 375 notify->post(); 376 break; 377 } 378 379 extractCodecSpecificData(); 380 381 readMore(); 382 break; 383 } 384 385 case kWhatRead: 386 { 387 MediaBuffer *buffer; 388 status_t err = mSource->read(&buffer); 389 390 if (err != OK && err != INFO_FORMAT_CHANGED) { 391 if (mStreamType == 0x0f) { 392 flushAACFrames(); 393 } 394 395 sp<AMessage> notify = mNotify->dup(); 396 notify->setInt32("what", kNotifyReachedEOS); 397 notify->setInt32("status", err); 398 notify->post(); 399 break; 400 } 401 402 if (err == OK) { 403 if (mStreamType == 0x0f && mAACCodecSpecificData == NULL) { 404 // The first buffer contains codec specific data. 405 406 CHECK_GE(buffer->range_length(), 2u); 407 408 mAACCodecSpecificData = new ABuffer(buffer->range_length()); 409 410 memcpy(mAACCodecSpecificData->data(), 411 (const uint8_t *)buffer->data() 412 + buffer->range_offset(), 413 buffer->range_length()); 414 } else if (buffer->range_length() > 0) { 415 if (mStreamType == 0x0f) { 416 if (!appendAACFrames(buffer)) { 417 msg->post(); 418 } 419 } else { 420 postAVCFrame(buffer); 421 } 422 } else { 423 readMore(); 424 } 425 426 buffer->release(); 427 buffer = NULL; 428 } 429 430 // Do not read more data until told to. 431 break; 432 } 433 434 default: 435 TRESPASS(); 436 } 437 } 438 439 sp<ABuffer> MPEG2TSWriter::SourceInfo::lastAccessUnit() { 440 return mLastAccessUnit; 441 } 442 443 void MPEG2TSWriter::SourceInfo::setLastAccessUnit( 444 const sp<ABuffer> &accessUnit) { 445 mLastAccessUnit = accessUnit; 446 } 447 448 int64_t MPEG2TSWriter::SourceInfo::lastAccessUnitTimeUs() { 449 if (mLastAccessUnit == NULL) { 450 return -1; 451 } 452 453 int64_t timeUs; 454 CHECK(mLastAccessUnit->meta()->findInt64("timeUs", &timeUs)); 455 456 return timeUs; 457 } 458 459 void MPEG2TSWriter::SourceInfo::setEOSReceived() { 460 CHECK(!mEOSReceived); 461 mEOSReceived = true; 462 } 463 464 bool MPEG2TSWriter::SourceInfo::eosReceived() const { 465 return mEOSReceived; 466 } 467 468 //////////////////////////////////////////////////////////////////////////////// 469 470 MPEG2TSWriter::MPEG2TSWriter(int fd) 471 : mFile(fdopen(dup(fd), "wb")), 472 mWriteCookie(NULL), 473 mWriteFunc(NULL), 474 mStarted(false), 475 mNumSourcesDone(0), 476 mNumTSPacketsWritten(0), 477 mNumTSPacketsBeforeMeta(0), 478 mPATContinuityCounter(0), 479 mPMTContinuityCounter(0) { 480 init(); 481 } 482 483 MPEG2TSWriter::MPEG2TSWriter(const char *filename) 484 : mFile(fopen(filename, "wb")), 485 mWriteCookie(NULL), 486 mWriteFunc(NULL), 487 mStarted(false), 488 mNumSourcesDone(0), 489 mNumTSPacketsWritten(0), 490 mNumTSPacketsBeforeMeta(0), 491 mPATContinuityCounter(0), 492 mPMTContinuityCounter(0) { 493 init(); 494 } 495 496 MPEG2TSWriter::MPEG2TSWriter( 497 void *cookie, 498 ssize_t (*write)(void *cookie, const void *data, size_t size)) 499 : mFile(NULL), 500 mWriteCookie(cookie), 501 mWriteFunc(write), 502 mStarted(false), 503 mNumSourcesDone(0), 504 mNumTSPacketsWritten(0), 505 mNumTSPacketsBeforeMeta(0), 506 mPATContinuityCounter(0), 507 mPMTContinuityCounter(0) { 508 init(); 509 } 510 511 void MPEG2TSWriter::init() { 512 CHECK(mFile != NULL || mWriteFunc != NULL); 513 514 initCrcTable(); 515 516 mLooper = new ALooper; 517 mLooper->setName("MPEG2TSWriter"); 518 519 mReflector = new AHandlerReflector<MPEG2TSWriter>(this); 520 521 mLooper->registerHandler(mReflector); 522 mLooper->start(); 523 } 524 525 MPEG2TSWriter::~MPEG2TSWriter() { 526 if (mStarted) { 527 reset(); 528 } 529 530 mLooper->unregisterHandler(mReflector->id()); 531 mLooper->stop(); 532 533 if (mFile != NULL) { 534 fclose(mFile); 535 mFile = NULL; 536 } 537 } 538 539 status_t MPEG2TSWriter::addSource(const sp<MediaSource> &source) { 540 CHECK(!mStarted); 541 542 sp<MetaData> meta = source->getFormat(); 543 const char *mime; 544 CHECK(meta->findCString(kKeyMIMEType, &mime)); 545 546 if (strcasecmp(mime, MEDIA_MIMETYPE_VIDEO_AVC) 547 && strcasecmp(mime, MEDIA_MIMETYPE_AUDIO_AAC)) { 548 return ERROR_UNSUPPORTED; 549 } 550 551 sp<SourceInfo> info = new SourceInfo(source); 552 553 mSources.push(info); 554 555 return OK; 556 } 557 558 status_t MPEG2TSWriter::start(MetaData *param) { 559 CHECK(!mStarted); 560 561 mStarted = true; 562 mNumSourcesDone = 0; 563 mNumTSPacketsWritten = 0; 564 mNumTSPacketsBeforeMeta = 0; 565 566 for (size_t i = 0; i < mSources.size(); ++i) { 567 sp<AMessage> notify = 568 new AMessage(kWhatSourceNotify, mReflector->id()); 569 570 notify->setInt32("source-index", i); 571 572 mSources.editItemAt(i)->start(notify); 573 } 574 575 return OK; 576 } 577 578 status_t MPEG2TSWriter::reset() { 579 CHECK(mStarted); 580 581 for (size_t i = 0; i < mSources.size(); ++i) { 582 mSources.editItemAt(i)->stop(); 583 } 584 mStarted = false; 585 586 return OK; 587 } 588 589 status_t MPEG2TSWriter::pause() { 590 CHECK(mStarted); 591 592 return OK; 593 } 594 595 bool MPEG2TSWriter::reachedEOS() { 596 return !mStarted || (mNumSourcesDone == mSources.size() ? true : false); 597 } 598 599 status_t MPEG2TSWriter::dump(int fd, const Vector<String16> &args) { 600 return OK; 601 } 602 603 void MPEG2TSWriter::onMessageReceived(const sp<AMessage> &msg) { 604 switch (msg->what()) { 605 case kWhatSourceNotify: 606 { 607 int32_t sourceIndex; 608 CHECK(msg->findInt32("source-index", &sourceIndex)); 609 610 int32_t what; 611 CHECK(msg->findInt32("what", &what)); 612 613 if (what == SourceInfo::kNotifyReachedEOS 614 || what == SourceInfo::kNotifyStartFailed) { 615 sp<SourceInfo> source = mSources.editItemAt(sourceIndex); 616 source->setEOSReceived(); 617 618 sp<ABuffer> buffer = source->lastAccessUnit(); 619 source->setLastAccessUnit(NULL); 620 621 if (buffer != NULL) { 622 writeTS(); 623 writeAccessUnit(sourceIndex, buffer); 624 } 625 626 ++mNumSourcesDone; 627 } else if (what == SourceInfo::kNotifyBuffer) { 628 sp<ABuffer> buffer; 629 CHECK(msg->findBuffer("buffer", &buffer)); 630 631 int32_t oob; 632 if (msg->findInt32("oob", &oob) && oob) { 633 // This is codec specific data delivered out of band. 634 // It can be written out immediately. 635 writeTS(); 636 writeAccessUnit(sourceIndex, buffer); 637 break; 638 } 639 640 // We don't just write out data as we receive it from 641 // the various sources. That would essentially write them 642 // out in random order (as the thread scheduler determines 643 // how the messages are dispatched). 644 // Instead we gather an access unit for all tracks and 645 // write out the one with the smallest timestamp, then 646 // request more data for the written out track. 647 // Rinse, repeat. 648 // If we don't have data on any track we don't write 649 // anything just yet. 650 651 sp<SourceInfo> source = mSources.editItemAt(sourceIndex); 652 653 CHECK(source->lastAccessUnit() == NULL); 654 source->setLastAccessUnit(buffer); 655 656 ALOGV("lastAccessUnitTimeUs[%d] = %.2f secs", 657 sourceIndex, source->lastAccessUnitTimeUs() / 1E6); 658 659 int64_t minTimeUs = -1; 660 size_t minIndex = 0; 661 662 for (size_t i = 0; i < mSources.size(); ++i) { 663 const sp<SourceInfo> &source = mSources.editItemAt(i); 664 665 if (source->eosReceived()) { 666 continue; 667 } 668 669 int64_t timeUs = source->lastAccessUnitTimeUs(); 670 if (timeUs < 0) { 671 minTimeUs = -1; 672 break; 673 } else if (minTimeUs < 0 || timeUs < minTimeUs) { 674 minTimeUs = timeUs; 675 minIndex = i; 676 } 677 } 678 679 if (minTimeUs < 0) { 680 ALOGV("not a all tracks have valid data."); 681 break; 682 } 683 684 ALOGV("writing access unit at time %.2f secs (index %d)", 685 minTimeUs / 1E6, minIndex); 686 687 source = mSources.editItemAt(minIndex); 688 689 buffer = source->lastAccessUnit(); 690 source->setLastAccessUnit(NULL); 691 692 writeTS(); 693 writeAccessUnit(minIndex, buffer); 694 695 source->readMore(); 696 } 697 break; 698 } 699 700 default: 701 TRESPASS(); 702 } 703 } 704 705 void MPEG2TSWriter::writeProgramAssociationTable() { 706 // 0x47 707 // transport_error_indicator = b0 708 // payload_unit_start_indicator = b1 709 // transport_priority = b0 710 // PID = b0000000000000 (13 bits) 711 // transport_scrambling_control = b00 712 // adaptation_field_control = b01 (no adaptation field, payload only) 713 // continuity_counter = b???? 714 // skip = 0x00 715 // --- payload follows 716 // table_id = 0x00 717 // section_syntax_indicator = b1 718 // must_be_zero = b0 719 // reserved = b11 720 // section_length = 0x00d 721 // transport_stream_id = 0x0000 722 // reserved = b11 723 // version_number = b00001 724 // current_next_indicator = b1 725 // section_number = 0x00 726 // last_section_number = 0x00 727 // one program follows: 728 // program_number = 0x0001 729 // reserved = b111 730 // program_map_PID = 0x01e0 (13 bits!) 731 // CRC = 0x???????? 732 733 static const uint8_t kData[] = { 734 0x47, 735 0x40, 0x00, 0x10, 0x00, // b0100 0000 0000 0000 0001 ???? 0000 0000 736 0x00, 0xb0, 0x0d, 0x00, // b0000 0000 1011 0000 0000 1101 0000 0000 737 0x00, 0xc3, 0x00, 0x00, // b0000 0000 1100 0011 0000 0000 0000 0000 738 0x00, 0x01, 0xe1, 0xe0, // b0000 0000 0000 0001 1110 0001 1110 0000 739 0x00, 0x00, 0x00, 0x00 // b???? ???? ???? ???? ???? ???? ???? ???? 740 }; 741 742 sp<ABuffer> buffer = new ABuffer(188); 743 memset(buffer->data(), 0xff, buffer->size()); 744 memcpy(buffer->data(), kData, sizeof(kData)); 745 746 if (++mPATContinuityCounter == 16) { 747 mPATContinuityCounter = 0; 748 } 749 buffer->data()[3] |= mPATContinuityCounter; 750 751 uint32_t crc = htonl(crc32(&buffer->data()[5], 12)); 752 memcpy(&buffer->data()[17], &crc, sizeof(crc)); 753 754 CHECK_EQ(internalWrite(buffer->data(), buffer->size()), buffer->size()); 755 } 756 757 void MPEG2TSWriter::writeProgramMap() { 758 // 0x47 759 // transport_error_indicator = b0 760 // payload_unit_start_indicator = b1 761 // transport_priority = b0 762 // PID = b0 0001 1110 0000 (13 bits) [0x1e0] 763 // transport_scrambling_control = b00 764 // adaptation_field_control = b01 (no adaptation field, payload only) 765 // continuity_counter = b???? 766 // skip = 0x00 767 // -- payload follows 768 // table_id = 0x02 769 // section_syntax_indicator = b1 770 // must_be_zero = b0 771 // reserved = b11 772 // section_length = 0x??? 773 // program_number = 0x0001 774 // reserved = b11 775 // version_number = b00001 776 // current_next_indicator = b1 777 // section_number = 0x00 778 // last_section_number = 0x00 779 // reserved = b111 780 // PCR_PID = b? ???? ???? ???? (13 bits) 781 // reserved = b1111 782 // program_info_length = 0x000 783 // one or more elementary stream descriptions follow: 784 // stream_type = 0x?? 785 // reserved = b111 786 // elementary_PID = b? ???? ???? ???? (13 bits) 787 // reserved = b1111 788 // ES_info_length = 0x000 789 // CRC = 0x???????? 790 791 static const uint8_t kData[] = { 792 0x47, 793 0x41, 0xe0, 0x10, 0x00, // b0100 0001 1110 0000 0001 ???? 0000 0000 794 0x02, 0xb0, 0x00, 0x00, // b0000 0010 1011 ???? ???? ???? 0000 0000 795 0x01, 0xc3, 0x00, 0x00, // b0000 0001 1100 0011 0000 0000 0000 0000 796 0xe0, 0x00, 0xf0, 0x00 // b111? ???? ???? ???? 1111 0000 0000 0000 797 }; 798 799 sp<ABuffer> buffer = new ABuffer(188); 800 memset(buffer->data(), 0xff, buffer->size()); 801 memcpy(buffer->data(), kData, sizeof(kData)); 802 803 if (++mPMTContinuityCounter == 16) { 804 mPMTContinuityCounter = 0; 805 } 806 buffer->data()[3] |= mPMTContinuityCounter; 807 808 size_t section_length = 5 * mSources.size() + 4 + 9; 809 buffer->data()[6] |= section_length >> 8; 810 buffer->data()[7] = section_length & 0xff; 811 812 static const unsigned kPCR_PID = 0x1e1; 813 buffer->data()[13] |= (kPCR_PID >> 8) & 0x1f; 814 buffer->data()[14] = kPCR_PID & 0xff; 815 816 uint8_t *ptr = &buffer->data()[sizeof(kData)]; 817 for (size_t i = 0; i < mSources.size(); ++i) { 818 *ptr++ = mSources.editItemAt(i)->streamType(); 819 820 const unsigned ES_PID = 0x1e0 + i + 1; 821 *ptr++ = 0xe0 | (ES_PID >> 8); 822 *ptr++ = ES_PID & 0xff; 823 *ptr++ = 0xf0; 824 *ptr++ = 0x00; 825 } 826 827 uint32_t crc = htonl(crc32(&buffer->data()[5], 12+mSources.size()*5)); 828 memcpy(&buffer->data()[17+mSources.size()*5], &crc, sizeof(crc)); 829 830 CHECK_EQ(internalWrite(buffer->data(), buffer->size()), buffer->size()); 831 } 832 833 void MPEG2TSWriter::writeAccessUnit( 834 int32_t sourceIndex, const sp<ABuffer> &accessUnit) { 835 // 0x47 836 // transport_error_indicator = b0 837 // payload_unit_start_indicator = b1 838 // transport_priority = b0 839 // PID = b0 0001 1110 ???? (13 bits) [0x1e0 + 1 + sourceIndex] 840 // transport_scrambling_control = b00 841 // adaptation_field_control = b?? 842 // continuity_counter = b???? 843 // -- payload follows 844 // packet_startcode_prefix = 0x000001 845 // stream_id = 0x?? (0xe0 for avc video, 0xc0 for aac audio) 846 // PES_packet_length = 0x???? 847 // reserved = b10 848 // PES_scrambling_control = b00 849 // PES_priority = b0 850 // data_alignment_indicator = b1 851 // copyright = b0 852 // original_or_copy = b0 853 // PTS_DTS_flags = b10 (PTS only) 854 // ESCR_flag = b0 855 // ES_rate_flag = b0 856 // DSM_trick_mode_flag = b0 857 // additional_copy_info_flag = b0 858 // PES_CRC_flag = b0 859 // PES_extension_flag = b0 860 // PES_header_data_length = 0x05 861 // reserved = b0010 (PTS) 862 // PTS[32..30] = b??? 863 // reserved = b1 864 // PTS[29..15] = b??? ???? ???? ???? (15 bits) 865 // reserved = b1 866 // PTS[14..0] = b??? ???? ???? ???? (15 bits) 867 // reserved = b1 868 // the first fragment of "buffer" follows 869 870 sp<ABuffer> buffer = new ABuffer(188); 871 memset(buffer->data(), 0xff, buffer->size()); 872 873 const unsigned PID = 0x1e0 + sourceIndex + 1; 874 875 const unsigned continuity_counter = 876 mSources.editItemAt(sourceIndex)->incrementContinuityCounter(); 877 878 // XXX if there are multiple streams of a kind (more than 1 audio or 879 // more than 1 video) they need distinct stream_ids. 880 const unsigned stream_id = 881 mSources.editItemAt(sourceIndex)->streamType() == 0x0f ? 0xc0 : 0xe0; 882 883 int64_t timeUs; 884 CHECK(accessUnit->meta()->findInt64("timeUs", &timeUs)); 885 886 uint32_t PTS = (timeUs * 9ll) / 100ll; 887 888 size_t PES_packet_length = accessUnit->size() + 8; 889 bool padding = (accessUnit->size() < (188 - 18)); 890 891 if (PES_packet_length >= 65536) { 892 // This really should only happen for video. 893 CHECK_EQ(stream_id, 0xe0u); 894 895 // It's valid to set this to 0 for video according to the specs. 896 PES_packet_length = 0; 897 } 898 899 uint8_t *ptr = buffer->data(); 900 *ptr++ = 0x47; 901 *ptr++ = 0x40 | (PID >> 8); 902 *ptr++ = PID & 0xff; 903 *ptr++ = (padding ? 0x30 : 0x10) | continuity_counter; 904 if (padding) { 905 int paddingSize = 188 - accessUnit->size() - 18; 906 *ptr++ = paddingSize - 1; 907 if (paddingSize >= 2) { 908 *ptr++ = 0x00; 909 ptr += paddingSize - 2; 910 } 911 } 912 *ptr++ = 0x00; 913 *ptr++ = 0x00; 914 *ptr++ = 0x01; 915 *ptr++ = stream_id; 916 *ptr++ = PES_packet_length >> 8; 917 *ptr++ = PES_packet_length & 0xff; 918 *ptr++ = 0x84; 919 *ptr++ = 0x80; 920 *ptr++ = 0x05; 921 *ptr++ = 0x20 | (((PTS >> 30) & 7) << 1) | 1; 922 *ptr++ = (PTS >> 22) & 0xff; 923 *ptr++ = (((PTS >> 15) & 0x7f) << 1) | 1; 924 *ptr++ = (PTS >> 7) & 0xff; 925 *ptr++ = ((PTS & 0x7f) << 1) | 1; 926 927 size_t sizeLeft = buffer->data() + buffer->size() - ptr; 928 size_t copy = accessUnit->size(); 929 if (copy > sizeLeft) { 930 copy = sizeLeft; 931 } 932 933 memcpy(ptr, accessUnit->data(), copy); 934 935 CHECK_EQ(internalWrite(buffer->data(), buffer->size()), buffer->size()); 936 937 size_t offset = copy; 938 while (offset < accessUnit->size()) { 939 bool lastAccessUnit = ((accessUnit->size() - offset) < 184); 940 // for subsequent fragments of "buffer": 941 // 0x47 942 // transport_error_indicator = b0 943 // payload_unit_start_indicator = b0 944 // transport_priority = b0 945 // PID = b0 0001 1110 ???? (13 bits) [0x1e0 + 1 + sourceIndex] 946 // transport_scrambling_control = b00 947 // adaptation_field_control = b?? 948 // continuity_counter = b???? 949 // the fragment of "buffer" follows. 950 951 memset(buffer->data(), 0xff, buffer->size()); 952 953 const unsigned continuity_counter = 954 mSources.editItemAt(sourceIndex)->incrementContinuityCounter(); 955 956 ptr = buffer->data(); 957 *ptr++ = 0x47; 958 *ptr++ = 0x00 | (PID >> 8); 959 *ptr++ = PID & 0xff; 960 *ptr++ = (lastAccessUnit ? 0x30 : 0x10) | continuity_counter; 961 962 if (lastAccessUnit) { 963 // Pad packet using an adaptation field 964 // Adaptation header all to 0 execpt size 965 uint8_t paddingSize = (uint8_t)184 - (accessUnit->size() - offset); 966 *ptr++ = paddingSize - 1; 967 if (paddingSize >= 2) { 968 *ptr++ = 0x00; 969 ptr += paddingSize - 2; 970 } 971 } 972 973 size_t sizeLeft = buffer->data() + buffer->size() - ptr; 974 size_t copy = accessUnit->size() - offset; 975 if (copy > sizeLeft) { 976 copy = sizeLeft; 977 } 978 979 memcpy(ptr, accessUnit->data() + offset, copy); 980 CHECK_EQ(internalWrite(buffer->data(), buffer->size()), 981 buffer->size()); 982 983 offset += copy; 984 } 985 } 986 987 void MPEG2TSWriter::writeTS() { 988 if (mNumTSPacketsWritten >= mNumTSPacketsBeforeMeta) { 989 writeProgramAssociationTable(); 990 writeProgramMap(); 991 992 mNumTSPacketsBeforeMeta = mNumTSPacketsWritten + 2500; 993 } 994 } 995 996 void MPEG2TSWriter::initCrcTable() { 997 uint32_t poly = 0x04C11DB7; 998 999 for (int i = 0; i < 256; i++) { 1000 uint32_t crc = i << 24; 1001 for (int j = 0; j < 8; j++) { 1002 crc = (crc << 1) ^ ((crc & 0x80000000) ? (poly) : 0); 1003 } 1004 mCrcTable[i] = crc; 1005 } 1006 } 1007 1008 /** 1009 * Compute CRC32 checksum for buffer starting at offset start and for length 1010 * bytes. 1011 */ 1012 uint32_t MPEG2TSWriter::crc32(const uint8_t *p_start, size_t length) { 1013 uint32_t crc = 0xFFFFFFFF; 1014 const uint8_t *p; 1015 1016 for (p = p_start; p < p_start + length; p++) { 1017 crc = (crc << 8) ^ mCrcTable[((crc >> 24) ^ *p) & 0xFF]; 1018 } 1019 1020 return crc; 1021 } 1022 1023 ssize_t MPEG2TSWriter::internalWrite(const void *data, size_t size) { 1024 if (mFile != NULL) { 1025 return fwrite(data, 1, size, mFile); 1026 } 1027 1028 return (*mWriteFunc)(mWriteCookie, data, size); 1029 } 1030 1031 } // namespace android 1032 1033
