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 35namespace android { 36 37struct MPEG2TSWriter::SourceInfo : public AHandler { 38 SourceInfo(const sp<IMediaSource> &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 61protected: 62 virtual void onMessageReceived(const sp<AMessage> &msg); 63 64 virtual ~SourceInfo(); 65 66private: 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> 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 96MPEG2TSWriter::SourceInfo::SourceInfo(const sp<IMediaSource> &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 117MPEG2TSWriter::SourceInfo::~SourceInfo() { 118} 119 120unsigned MPEG2TSWriter::SourceInfo::streamType() const { 121 return mStreamType; 122} 123 124unsigned MPEG2TSWriter::SourceInfo::incrementContinuityCounter() { 125 if (++mContinuityCounter == 16) { 126 mContinuityCounter = 0; 127 } 128 129 return mContinuityCounter; 130} 131 132void MPEG2TSWriter::SourceInfo::start(const sp<AMessage> ¬ify) { 133 mLooper->registerHandler(this); 134 mLooper->start(); 135 136 mNotify = notify; 137 138 (new AMessage(kWhatStart, this))->post(); 139} 140 141void MPEG2TSWriter::SourceInfo::stop() { 142 mLooper->unregisterHandler(id()); 143 mLooper->stop(); 144 145 mSource->stop(); 146} 147 148void 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 253void 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 278bool 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 348bool 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 363void MPEG2TSWriter::SourceInfo::readMore() { 364 (new AMessage(kWhatRead, this))->post(); 365} 366 367void 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 439sp<ABuffer> MPEG2TSWriter::SourceInfo::lastAccessUnit() { 440 return mLastAccessUnit; 441} 442 443void MPEG2TSWriter::SourceInfo::setLastAccessUnit( 444 const sp<ABuffer> &accessUnit) { 445 mLastAccessUnit = accessUnit; 446} 447 448int64_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 459void MPEG2TSWriter::SourceInfo::setEOSReceived() { 460 CHECK(!mEOSReceived); 461 mEOSReceived = true; 462} 463 464bool MPEG2TSWriter::SourceInfo::eosReceived() const { 465 return mEOSReceived; 466} 467 468//////////////////////////////////////////////////////////////////////////////// 469 470MPEG2TSWriter::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 483MPEG2TSWriter::MPEG2TSWriter( 484 void *cookie, 485 ssize_t (*write)(void *cookie, const void *data, size_t size)) 486 : mFile(NULL), 487 mWriteCookie(cookie), 488 mWriteFunc(write), 489 mStarted(false), 490 mNumSourcesDone(0), 491 mNumTSPacketsWritten(0), 492 mNumTSPacketsBeforeMeta(0), 493 mPATContinuityCounter(0), 494 mPMTContinuityCounter(0) { 495 init(); 496} 497 498void MPEG2TSWriter::init() { 499 CHECK(mFile != NULL || mWriteFunc != NULL); 500 501 initCrcTable(); 502 503 mLooper = new ALooper; 504 mLooper->setName("MPEG2TSWriter"); 505 506 mReflector = new AHandlerReflector<MPEG2TSWriter>(this); 507 508 mLooper->registerHandler(mReflector); 509 mLooper->start(); 510} 511 512MPEG2TSWriter::~MPEG2TSWriter() { 513 if (mStarted) { 514 reset(); 515 } 516 517 mLooper->unregisterHandler(mReflector->id()); 518 mLooper->stop(); 519 520 if (mFile != NULL) { 521 fclose(mFile); 522 mFile = NULL; 523 } 524} 525 526status_t MPEG2TSWriter::addSource(const sp<IMediaSource> &source) { 527 CHECK(!mStarted); 528 529 sp<MetaData> meta = source->getFormat(); 530 const char *mime; 531 CHECK(meta->findCString(kKeyMIMEType, &mime)); 532 533 if (strcasecmp(mime, MEDIA_MIMETYPE_VIDEO_AVC) 534 && strcasecmp(mime, MEDIA_MIMETYPE_AUDIO_AAC)) { 535 return ERROR_UNSUPPORTED; 536 } 537 538 sp<SourceInfo> info = new SourceInfo(source); 539 540 mSources.push(info); 541 542 return OK; 543} 544 545status_t MPEG2TSWriter::start(MetaData * /* param */) { 546 CHECK(!mStarted); 547 548 mStarted = true; 549 mNumSourcesDone = 0; 550 mNumTSPacketsWritten = 0; 551 mNumTSPacketsBeforeMeta = 0; 552 553 for (size_t i = 0; i < mSources.size(); ++i) { 554 sp<AMessage> notify = 555 new AMessage(kWhatSourceNotify, mReflector); 556 557 notify->setInt32("source-index", i); 558 559 mSources.editItemAt(i)->start(notify); 560 } 561 562 return OK; 563} 564 565status_t MPEG2TSWriter::reset() { 566 CHECK(mStarted); 567 568 for (size_t i = 0; i < mSources.size(); ++i) { 569 mSources.editItemAt(i)->stop(); 570 } 571 mStarted = false; 572 573 return OK; 574} 575 576status_t MPEG2TSWriter::pause() { 577 CHECK(mStarted); 578 579 return OK; 580} 581 582bool MPEG2TSWriter::reachedEOS() { 583 return !mStarted || (mNumSourcesDone == mSources.size() ? true : false); 584} 585 586status_t MPEG2TSWriter::dump( 587 int /* fd */, const Vector<String16> & /* args */) { 588 return OK; 589} 590 591void MPEG2TSWriter::onMessageReceived(const sp<AMessage> &msg) { 592 switch (msg->what()) { 593 case kWhatSourceNotify: 594 { 595 int32_t sourceIndex; 596 CHECK(msg->findInt32("source-index", &sourceIndex)); 597 598 int32_t what; 599 CHECK(msg->findInt32("what", &what)); 600 601 if (what == SourceInfo::kNotifyReachedEOS 602 || what == SourceInfo::kNotifyStartFailed) { 603 sp<SourceInfo> source = mSources.editItemAt(sourceIndex); 604 source->setEOSReceived(); 605 606 sp<ABuffer> buffer = source->lastAccessUnit(); 607 source->setLastAccessUnit(NULL); 608 609 if (buffer != NULL) { 610 writeTS(); 611 writeAccessUnit(sourceIndex, buffer); 612 } 613 614 ++mNumSourcesDone; 615 } else if (what == SourceInfo::kNotifyBuffer) { 616 sp<ABuffer> buffer; 617 CHECK(msg->findBuffer("buffer", &buffer)); 618 619 int32_t oob; 620 if (msg->findInt32("oob", &oob) && oob) { 621 // This is codec specific data delivered out of band. 622 // It can be written out immediately. 623 writeTS(); 624 writeAccessUnit(sourceIndex, buffer); 625 break; 626 } 627 628 // We don't just write out data as we receive it from 629 // the various sources. That would essentially write them 630 // out in random order (as the thread scheduler determines 631 // how the messages are dispatched). 632 // Instead we gather an access unit for all tracks and 633 // write out the one with the smallest timestamp, then 634 // request more data for the written out track. 635 // Rinse, repeat. 636 // If we don't have data on any track we don't write 637 // anything just yet. 638 639 sp<SourceInfo> source = mSources.editItemAt(sourceIndex); 640 641 CHECK(source->lastAccessUnit() == NULL); 642 source->setLastAccessUnit(buffer); 643 644 ALOGV("lastAccessUnitTimeUs[%d] = %.2f secs", 645 sourceIndex, source->lastAccessUnitTimeUs() / 1E6); 646 647 int64_t minTimeUs = -1; 648 size_t minIndex = 0; 649 650 for (size_t i = 0; i < mSources.size(); ++i) { 651 const sp<SourceInfo> &source = mSources.editItemAt(i); 652 653 if (source->eosReceived()) { 654 continue; 655 } 656 657 int64_t timeUs = source->lastAccessUnitTimeUs(); 658 if (timeUs < 0) { 659 minTimeUs = -1; 660 break; 661 } else if (minTimeUs < 0 || timeUs < minTimeUs) { 662 minTimeUs = timeUs; 663 minIndex = i; 664 } 665 } 666 667 if (minTimeUs < 0) { 668 ALOGV("not a all tracks have valid data."); 669 break; 670 } 671 672 ALOGV("writing access unit at time %.2f secs (index %zu)", 673 minTimeUs / 1E6, minIndex); 674 675 source = mSources.editItemAt(minIndex); 676 677 buffer = source->lastAccessUnit(); 678 source->setLastAccessUnit(NULL); 679 680 writeTS(); 681 writeAccessUnit(minIndex, buffer); 682 683 source->readMore(); 684 } 685 break; 686 } 687 688 default: 689 TRESPASS(); 690 } 691} 692 693void MPEG2TSWriter::writeProgramAssociationTable() { 694 // 0x47 695 // transport_error_indicator = b0 696 // payload_unit_start_indicator = b1 697 // transport_priority = b0 698 // PID = b0000000000000 (13 bits) 699 // transport_scrambling_control = b00 700 // adaptation_field_control = b01 (no adaptation field, payload only) 701 // continuity_counter = b???? 702 // skip = 0x00 703 // --- payload follows 704 // table_id = 0x00 705 // section_syntax_indicator = b1 706 // must_be_zero = b0 707 // reserved = b11 708 // section_length = 0x00d 709 // transport_stream_id = 0x0000 710 // reserved = b11 711 // version_number = b00001 712 // current_next_indicator = b1 713 // section_number = 0x00 714 // last_section_number = 0x00 715 // one program follows: 716 // program_number = 0x0001 717 // reserved = b111 718 // program_map_PID = 0x01e0 (13 bits!) 719 // CRC = 0x???????? 720 721 static const uint8_t kData[] = { 722 0x47, 723 0x40, 0x00, 0x10, 0x00, // b0100 0000 0000 0000 0001 ???? 0000 0000 724 0x00, 0xb0, 0x0d, 0x00, // b0000 0000 1011 0000 0000 1101 0000 0000 725 0x00, 0xc3, 0x00, 0x00, // b0000 0000 1100 0011 0000 0000 0000 0000 726 0x00, 0x01, 0xe1, 0xe0, // b0000 0000 0000 0001 1110 0001 1110 0000 727 0x00, 0x00, 0x00, 0x00 // b???? ???? ???? ???? ???? ???? ???? ???? 728 }; 729 730 sp<ABuffer> buffer = new ABuffer(188); 731 memset(buffer->data(), 0xff, buffer->size()); 732 memcpy(buffer->data(), kData, sizeof(kData)); 733 734 if (++mPATContinuityCounter == 16) { 735 mPATContinuityCounter = 0; 736 } 737 buffer->data()[3] |= mPATContinuityCounter; 738 739 uint32_t crc = htonl(crc32(&buffer->data()[5], 12)); 740 memcpy(&buffer->data()[17], &crc, sizeof(crc)); 741 742 CHECK_EQ(internalWrite(buffer->data(), buffer->size()), buffer->size()); 743} 744 745void MPEG2TSWriter::writeProgramMap() { 746 // 0x47 747 // transport_error_indicator = b0 748 // payload_unit_start_indicator = b1 749 // transport_priority = b0 750 // PID = b0 0001 1110 0000 (13 bits) [0x1e0] 751 // transport_scrambling_control = b00 752 // adaptation_field_control = b01 (no adaptation field, payload only) 753 // continuity_counter = b???? 754 // skip = 0x00 755 // -- payload follows 756 // table_id = 0x02 757 // section_syntax_indicator = b1 758 // must_be_zero = b0 759 // reserved = b11 760 // section_length = 0x??? 761 // program_number = 0x0001 762 // reserved = b11 763 // version_number = b00001 764 // current_next_indicator = b1 765 // section_number = 0x00 766 // last_section_number = 0x00 767 // reserved = b111 768 // PCR_PID = b? ???? ???? ???? (13 bits) 769 // reserved = b1111 770 // program_info_length = 0x000 771 // one or more elementary stream descriptions follow: 772 // stream_type = 0x?? 773 // reserved = b111 774 // elementary_PID = b? ???? ???? ???? (13 bits) 775 // reserved = b1111 776 // ES_info_length = 0x000 777 // CRC = 0x???????? 778 779 static const uint8_t kData[] = { 780 0x47, 781 0x41, 0xe0, 0x10, 0x00, // b0100 0001 1110 0000 0001 ???? 0000 0000 782 0x02, 0xb0, 0x00, 0x00, // b0000 0010 1011 ???? ???? ???? 0000 0000 783 0x01, 0xc3, 0x00, 0x00, // b0000 0001 1100 0011 0000 0000 0000 0000 784 0xe0, 0x00, 0xf0, 0x00 // b111? ???? ???? ???? 1111 0000 0000 0000 785 }; 786 787 sp<ABuffer> buffer = new ABuffer(188); 788 memset(buffer->data(), 0xff, buffer->size()); 789 memcpy(buffer->data(), kData, sizeof(kData)); 790 791 if (++mPMTContinuityCounter == 16) { 792 mPMTContinuityCounter = 0; 793 } 794 buffer->data()[3] |= mPMTContinuityCounter; 795 796 size_t section_length = 5 * mSources.size() + 4 + 9; 797 buffer->data()[6] |= section_length >> 8; 798 buffer->data()[7] = section_length & 0xff; 799 800 static const unsigned kPCR_PID = 0x1e1; 801 buffer->data()[13] |= (kPCR_PID >> 8) & 0x1f; 802 buffer->data()[14] = kPCR_PID & 0xff; 803 804 uint8_t *ptr = &buffer->data()[sizeof(kData)]; 805 for (size_t i = 0; i < mSources.size(); ++i) { 806 *ptr++ = mSources.editItemAt(i)->streamType(); 807 808 const unsigned ES_PID = 0x1e0 + i + 1; 809 *ptr++ = 0xe0 | (ES_PID >> 8); 810 *ptr++ = ES_PID & 0xff; 811 *ptr++ = 0xf0; 812 *ptr++ = 0x00; 813 } 814 815 uint32_t crc = htonl(crc32(&buffer->data()[5], 12+mSources.size()*5)); 816 memcpy(&buffer->data()[17+mSources.size()*5], &crc, sizeof(crc)); 817 818 CHECK_EQ(internalWrite(buffer->data(), buffer->size()), buffer->size()); 819} 820 821void MPEG2TSWriter::writeAccessUnit( 822 int32_t sourceIndex, const sp<ABuffer> &accessUnit) { 823 // 0x47 824 // transport_error_indicator = b0 825 // payload_unit_start_indicator = b1 826 // transport_priority = b0 827 // PID = b0 0001 1110 ???? (13 bits) [0x1e0 + 1 + sourceIndex] 828 // transport_scrambling_control = b00 829 // adaptation_field_control = b?? 830 // continuity_counter = b???? 831 // -- payload follows 832 // packet_startcode_prefix = 0x000001 833 // stream_id = 0x?? (0xe0 for avc video, 0xc0 for aac audio) 834 // PES_packet_length = 0x???? 835 // reserved = b10 836 // PES_scrambling_control = b00 837 // PES_priority = b0 838 // data_alignment_indicator = b1 839 // copyright = b0 840 // original_or_copy = b0 841 // PTS_DTS_flags = b10 (PTS only) 842 // ESCR_flag = b0 843 // ES_rate_flag = b0 844 // DSM_trick_mode_flag = b0 845 // additional_copy_info_flag = b0 846 // PES_CRC_flag = b0 847 // PES_extension_flag = b0 848 // PES_header_data_length = 0x05 849 // reserved = b0010 (PTS) 850 // PTS[32..30] = b??? 851 // reserved = b1 852 // PTS[29..15] = b??? ???? ???? ???? (15 bits) 853 // reserved = b1 854 // PTS[14..0] = b??? ???? ???? ???? (15 bits) 855 // reserved = b1 856 // the first fragment of "buffer" follows 857 858 sp<ABuffer> buffer = new ABuffer(188); 859 memset(buffer->data(), 0xff, buffer->size()); 860 861 const unsigned PID = 0x1e0 + sourceIndex + 1; 862 863 const unsigned continuity_counter = 864 mSources.editItemAt(sourceIndex)->incrementContinuityCounter(); 865 866 // XXX if there are multiple streams of a kind (more than 1 audio or 867 // more than 1 video) they need distinct stream_ids. 868 const unsigned stream_id = 869 mSources.editItemAt(sourceIndex)->streamType() == 0x0f ? 0xc0 : 0xe0; 870 871 int64_t timeUs; 872 CHECK(accessUnit->meta()->findInt64("timeUs", &timeUs)); 873 874 uint32_t PTS = (timeUs * 9ll) / 100ll; 875 876 size_t PES_packet_length = accessUnit->size() + 8; 877 bool padding = (accessUnit->size() < (188 - 18)); 878 879 if (PES_packet_length >= 65536) { 880 // This really should only happen for video. 881 CHECK_EQ(stream_id, 0xe0u); 882 883 // It's valid to set this to 0 for video according to the specs. 884 PES_packet_length = 0; 885 } 886 887 uint8_t *ptr = buffer->data(); 888 *ptr++ = 0x47; 889 *ptr++ = 0x40 | (PID >> 8); 890 *ptr++ = PID & 0xff; 891 *ptr++ = (padding ? 0x30 : 0x10) | continuity_counter; 892 if (padding) { 893 int paddingSize = 188 - accessUnit->size() - 18; 894 *ptr++ = paddingSize - 1; 895 if (paddingSize >= 2) { 896 *ptr++ = 0x00; 897 ptr += paddingSize - 2; 898 } 899 } 900 *ptr++ = 0x00; 901 *ptr++ = 0x00; 902 *ptr++ = 0x01; 903 *ptr++ = stream_id; 904 *ptr++ = PES_packet_length >> 8; 905 *ptr++ = PES_packet_length & 0xff; 906 *ptr++ = 0x84; 907 *ptr++ = 0x80; 908 *ptr++ = 0x05; 909 *ptr++ = 0x20 | (((PTS >> 30) & 7) << 1) | 1; 910 *ptr++ = (PTS >> 22) & 0xff; 911 *ptr++ = (((PTS >> 15) & 0x7f) << 1) | 1; 912 *ptr++ = (PTS >> 7) & 0xff; 913 *ptr++ = ((PTS & 0x7f) << 1) | 1; 914 915 size_t sizeLeft = buffer->data() + buffer->size() - ptr; 916 size_t copy = accessUnit->size(); 917 if (copy > sizeLeft) { 918 copy = sizeLeft; 919 } 920 921 memcpy(ptr, accessUnit->data(), copy); 922 923 CHECK_EQ(internalWrite(buffer->data(), buffer->size()), buffer->size()); 924 925 size_t offset = copy; 926 while (offset < accessUnit->size()) { 927 bool lastAccessUnit = ((accessUnit->size() - offset) < 184); 928 // for subsequent fragments of "buffer": 929 // 0x47 930 // transport_error_indicator = b0 931 // payload_unit_start_indicator = b0 932 // transport_priority = b0 933 // PID = b0 0001 1110 ???? (13 bits) [0x1e0 + 1 + sourceIndex] 934 // transport_scrambling_control = b00 935 // adaptation_field_control = b?? 936 // continuity_counter = b???? 937 // the fragment of "buffer" follows. 938 939 memset(buffer->data(), 0xff, buffer->size()); 940 941 const unsigned continuity_counter = 942 mSources.editItemAt(sourceIndex)->incrementContinuityCounter(); 943 944 ptr = buffer->data(); 945 *ptr++ = 0x47; 946 *ptr++ = 0x00 | (PID >> 8); 947 *ptr++ = PID & 0xff; 948 *ptr++ = (lastAccessUnit ? 0x30 : 0x10) | continuity_counter; 949 950 if (lastAccessUnit) { 951 // Pad packet using an adaptation field 952 // Adaptation header all to 0 execpt size 953 uint8_t paddingSize = (uint8_t)184 - (accessUnit->size() - offset); 954 *ptr++ = paddingSize - 1; 955 if (paddingSize >= 2) { 956 *ptr++ = 0x00; 957 ptr += paddingSize - 2; 958 } 959 } 960 961 size_t sizeLeft = buffer->data() + buffer->size() - ptr; 962 size_t copy = accessUnit->size() - offset; 963 if (copy > sizeLeft) { 964 copy = sizeLeft; 965 } 966 967 memcpy(ptr, accessUnit->data() + offset, copy); 968 CHECK_EQ(internalWrite(buffer->data(), buffer->size()), 969 buffer->size()); 970 971 offset += copy; 972 } 973} 974 975void MPEG2TSWriter::writeTS() { 976 if (mNumTSPacketsWritten >= mNumTSPacketsBeforeMeta) { 977 writeProgramAssociationTable(); 978 writeProgramMap(); 979 980 mNumTSPacketsBeforeMeta = mNumTSPacketsWritten + 2500; 981 } 982} 983 984void MPEG2TSWriter::initCrcTable() { 985 uint32_t poly = 0x04C11DB7; 986 987 for (int i = 0; i < 256; i++) { 988 uint32_t crc = i << 24; 989 for (int j = 0; j < 8; j++) { 990 crc = (crc << 1) ^ ((crc & 0x80000000) ? (poly) : 0); 991 } 992 mCrcTable[i] = crc; 993 } 994} 995 996/** 997 * Compute CRC32 checksum for buffer starting at offset start and for length 998 * bytes. 999 */ 1000uint32_t MPEG2TSWriter::crc32(const uint8_t *p_start, size_t length) { 1001 uint32_t crc = 0xFFFFFFFF; 1002 const uint8_t *p; 1003 1004 for (p = p_start; p < p_start + length; p++) { 1005 crc = (crc << 8) ^ mCrcTable[((crc >> 24) ^ *p) & 0xFF]; 1006 } 1007 1008 return crc; 1009} 1010 1011ssize_t MPEG2TSWriter::internalWrite(const void *data, size_t size) { 1012 if (mFile != NULL) { 1013 return fwrite(data, 1, size, mFile); 1014 } 1015 1016 return (*mWriteFunc)(mWriteCookie, data, size); 1017} 1018 1019} // namespace android 1020 1021