1 /* 2 * Copyright 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 "TSPacketizer" 19 #include <utils/Log.h> 20 21 #include "TSPacketizer.h" 22 #include "include/avc_utils.h" 23 24 #include <media/stagefright/foundation/ABuffer.h> 25 #include <media/stagefright/foundation/ADebug.h> 26 #include <media/stagefright/foundation/AMessage.h> 27 #include <media/stagefright/foundation/hexdump.h> 28 #include <media/stagefright/MediaDefs.h> 29 #include <media/stagefright/MediaErrors.h> 30 31 #include <arpa/inet.h> 32 33 namespace android { 34 35 struct TSPacketizer::Track : public RefBase { 36 Track(const sp<AMessage> &format, 37 unsigned PID, unsigned streamType, unsigned streamID); 38 39 unsigned PID() const; 40 unsigned streamType() const; 41 unsigned streamID() const; 42 43 // Returns the previous value. 44 unsigned incrementContinuityCounter(); 45 46 bool isAudio() const; 47 bool isVideo() const; 48 49 bool isH264() const; 50 bool isAAC() const; 51 bool lacksADTSHeader() const; 52 bool isPCMAudio() const; 53 54 sp<ABuffer> prependCSD(const sp<ABuffer> &accessUnit) const; 55 sp<ABuffer> prependADTSHeader(const sp<ABuffer> &accessUnit) const; 56 57 size_t countDescriptors() const; 58 sp<ABuffer> descriptorAt(size_t index) const; 59 60 void finalize(); 61 void extractCSDIfNecessary(); 62 63 protected: 64 virtual ~Track(); 65 66 private: 67 sp<AMessage> mFormat; 68 69 unsigned mPID; 70 unsigned mStreamType; 71 unsigned mStreamID; 72 unsigned mContinuityCounter; 73 74 AString mMIME; 75 Vector<sp<ABuffer> > mCSD; 76 77 Vector<sp<ABuffer> > mDescriptors; 78 79 bool mAudioLacksATDSHeaders; 80 bool mFinalized; 81 bool mExtractedCSD; 82 83 DISALLOW_EVIL_CONSTRUCTORS(Track); 84 }; 85 86 TSPacketizer::Track::Track( 87 const sp<AMessage> &format, 88 unsigned PID, unsigned streamType, unsigned streamID) 89 : mFormat(format), 90 mPID(PID), 91 mStreamType(streamType), 92 mStreamID(streamID), 93 mContinuityCounter(0), 94 mAudioLacksATDSHeaders(false), 95 mFinalized(false), 96 mExtractedCSD(false) { 97 CHECK(format->findString("mime", &mMIME)); 98 } 99 100 void TSPacketizer::Track::extractCSDIfNecessary() { 101 if (mExtractedCSD) { 102 return; 103 } 104 105 if (!strcasecmp(mMIME.c_str(), MEDIA_MIMETYPE_VIDEO_AVC) 106 || !strcasecmp(mMIME.c_str(), MEDIA_MIMETYPE_AUDIO_AAC)) { 107 for (size_t i = 0;; ++i) { 108 sp<ABuffer> csd; 109 if (!mFormat->findBuffer(StringPrintf("csd-%d", i).c_str(), &csd)) { 110 break; 111 } 112 113 mCSD.push(csd); 114 } 115 116 if (!strcasecmp(mMIME.c_str(), MEDIA_MIMETYPE_AUDIO_AAC)) { 117 int32_t isADTS; 118 if (!mFormat->findInt32("is-adts", &isADTS) || isADTS == 0) { 119 mAudioLacksATDSHeaders = true; 120 } 121 } 122 } 123 124 mExtractedCSD = true; 125 } 126 127 TSPacketizer::Track::~Track() { 128 } 129 130 unsigned TSPacketizer::Track::PID() const { 131 return mPID; 132 } 133 134 unsigned TSPacketizer::Track::streamType() const { 135 return mStreamType; 136 } 137 138 unsigned TSPacketizer::Track::streamID() const { 139 return mStreamID; 140 } 141 142 unsigned TSPacketizer::Track::incrementContinuityCounter() { 143 unsigned prevCounter = mContinuityCounter; 144 145 if (++mContinuityCounter == 16) { 146 mContinuityCounter = 0; 147 } 148 149 return prevCounter; 150 } 151 152 bool TSPacketizer::Track::isAudio() const { 153 return !strncasecmp("audio/", mMIME.c_str(), 6); 154 } 155 156 bool TSPacketizer::Track::isVideo() const { 157 return !strncasecmp("video/", mMIME.c_str(), 6); 158 } 159 160 bool TSPacketizer::Track::isH264() const { 161 return !strcasecmp(mMIME.c_str(), MEDIA_MIMETYPE_VIDEO_AVC); 162 } 163 164 bool TSPacketizer::Track::isAAC() const { 165 return !strcasecmp(mMIME.c_str(), MEDIA_MIMETYPE_AUDIO_AAC); 166 } 167 168 bool TSPacketizer::Track::isPCMAudio() const { 169 return !strcasecmp(mMIME.c_str(), MEDIA_MIMETYPE_AUDIO_RAW); 170 } 171 172 bool TSPacketizer::Track::lacksADTSHeader() const { 173 return mAudioLacksATDSHeaders; 174 } 175 176 sp<ABuffer> TSPacketizer::Track::prependCSD( 177 const sp<ABuffer> &accessUnit) const { 178 size_t size = 0; 179 for (size_t i = 0; i < mCSD.size(); ++i) { 180 size += mCSD.itemAt(i)->size(); 181 } 182 183 sp<ABuffer> dup = new ABuffer(accessUnit->size() + size); 184 size_t offset = 0; 185 for (size_t i = 0; i < mCSD.size(); ++i) { 186 const sp<ABuffer> &csd = mCSD.itemAt(i); 187 188 memcpy(dup->data() + offset, csd->data(), csd->size()); 189 offset += csd->size(); 190 } 191 192 memcpy(dup->data() + offset, accessUnit->data(), accessUnit->size()); 193 194 return dup; 195 } 196 197 sp<ABuffer> TSPacketizer::Track::prependADTSHeader( 198 const sp<ABuffer> &accessUnit) const { 199 CHECK_EQ(mCSD.size(), 1u); 200 201 const uint8_t *codec_specific_data = mCSD.itemAt(0)->data(); 202 203 const uint32_t aac_frame_length = accessUnit->size() + 7; 204 205 sp<ABuffer> dup = new ABuffer(aac_frame_length); 206 207 unsigned profile = (codec_specific_data[0] >> 3) - 1; 208 209 unsigned sampling_freq_index = 210 ((codec_specific_data[0] & 7) << 1) 211 | (codec_specific_data[1] >> 7); 212 213 unsigned channel_configuration = 214 (codec_specific_data[1] >> 3) & 0x0f; 215 216 uint8_t *ptr = dup->data(); 217 218 *ptr++ = 0xff; 219 *ptr++ = 0xf1; // b11110001, ID=0, layer=0, protection_absent=1 220 221 *ptr++ = 222 profile << 6 223 | sampling_freq_index << 2 224 | ((channel_configuration >> 2) & 1); // private_bit=0 225 226 // original_copy=0, home=0, copyright_id_bit=0, copyright_id_start=0 227 *ptr++ = 228 (channel_configuration & 3) << 6 229 | aac_frame_length >> 11; 230 *ptr++ = (aac_frame_length >> 3) & 0xff; 231 *ptr++ = (aac_frame_length & 7) << 5; 232 233 // adts_buffer_fullness=0, number_of_raw_data_blocks_in_frame=0 234 *ptr++ = 0; 235 236 memcpy(ptr, accessUnit->data(), accessUnit->size()); 237 238 return dup; 239 } 240 241 size_t TSPacketizer::Track::countDescriptors() const { 242 return mDescriptors.size(); 243 } 244 245 sp<ABuffer> TSPacketizer::Track::descriptorAt(size_t index) const { 246 CHECK_LT(index, mDescriptors.size()); 247 return mDescriptors.itemAt(index); 248 } 249 250 void TSPacketizer::Track::finalize() { 251 if (mFinalized) { 252 return; 253 } 254 255 if (isH264()) { 256 { 257 // AVC video descriptor (40) 258 259 sp<ABuffer> descriptor = new ABuffer(6); 260 uint8_t *data = descriptor->data(); 261 data[0] = 40; // descriptor_tag 262 data[1] = 4; // descriptor_length 263 264 if (mCSD.size() > 0) { 265 CHECK_GE(mCSD.size(), 1u); 266 const sp<ABuffer> &sps = mCSD.itemAt(0); 267 CHECK(!memcmp("\x00\x00\x00\x01", sps->data(), 4)); 268 CHECK_GE(sps->size(), 7u); 269 // profile_idc, constraint_set*, level_idc 270 memcpy(&data[2], sps->data() + 4, 3); 271 } else { 272 int32_t profileIdc, levelIdc, constraintSet; 273 CHECK(mFormat->findInt32("profile-idc", &profileIdc)); 274 CHECK(mFormat->findInt32("level-idc", &levelIdc)); 275 CHECK(mFormat->findInt32("constraint-set", &constraintSet)); 276 CHECK_GE(profileIdc, 0u); 277 CHECK_GE(levelIdc, 0u); 278 data[2] = profileIdc; // profile_idc 279 data[3] = constraintSet; // constraint_set* 280 data[4] = levelIdc; // level_idc 281 } 282 283 // AVC_still_present=0, AVC_24_hour_picture_flag=0, reserved 284 data[5] = 0x3f; 285 286 mDescriptors.push_back(descriptor); 287 } 288 289 { 290 // AVC timing and HRD descriptor (42) 291 292 sp<ABuffer> descriptor = new ABuffer(4); 293 uint8_t *data = descriptor->data(); 294 data[0] = 42; // descriptor_tag 295 data[1] = 2; // descriptor_length 296 297 // hrd_management_valid_flag = 0 298 // reserved = 111111b 299 // picture_and_timing_info_present = 0 300 301 data[2] = 0x7e; 302 303 // fixed_frame_rate_flag = 0 304 // temporal_poc_flag = 0 305 // picture_to_display_conversion_flag = 0 306 // reserved = 11111b 307 data[3] = 0x1f; 308 309 mDescriptors.push_back(descriptor); 310 } 311 } else if (isPCMAudio()) { 312 // LPCM audio stream descriptor (0x83) 313 314 int32_t channelCount; 315 CHECK(mFormat->findInt32("channel-count", &channelCount)); 316 CHECK_EQ(channelCount, 2); 317 318 int32_t sampleRate; 319 CHECK(mFormat->findInt32("sample-rate", &sampleRate)); 320 CHECK(sampleRate == 44100 || sampleRate == 48000); 321 322 sp<ABuffer> descriptor = new ABuffer(4); 323 uint8_t *data = descriptor->data(); 324 data[0] = 0x83; // descriptor_tag 325 data[1] = 2; // descriptor_length 326 327 unsigned sampling_frequency = (sampleRate == 44100) ? 1 : 2; 328 329 data[2] = (sampling_frequency << 5) 330 | (3 /* reserved */ << 1) 331 | 0 /* emphasis_flag */; 332 333 data[3] = 334 (1 /* number_of_channels = stereo */ << 5) 335 | 0xf /* reserved */; 336 337 mDescriptors.push_back(descriptor); 338 } 339 340 mFinalized = true; 341 } 342 343 //////////////////////////////////////////////////////////////////////////////// 344 345 TSPacketizer::TSPacketizer(uint32_t flags) 346 : mFlags(flags), 347 mPATContinuityCounter(0), 348 mPMTContinuityCounter(0) { 349 initCrcTable(); 350 351 if (flags & (EMIT_HDCP20_DESCRIPTOR | EMIT_HDCP21_DESCRIPTOR)) { 352 int32_t hdcpVersion; 353 if (flags & EMIT_HDCP20_DESCRIPTOR) { 354 CHECK(!(flags & EMIT_HDCP21_DESCRIPTOR)); 355 hdcpVersion = 0x20; 356 } else { 357 CHECK(!(flags & EMIT_HDCP20_DESCRIPTOR)); 358 359 // HDCP2.0 _and_ HDCP 2.1 specs say to set the version 360 // inside the HDCP descriptor to 0x20!!! 361 hdcpVersion = 0x20; 362 } 363 364 // HDCP descriptor 365 sp<ABuffer> descriptor = new ABuffer(7); 366 uint8_t *data = descriptor->data(); 367 data[0] = 0x05; // descriptor_tag 368 data[1] = 5; // descriptor_length 369 data[2] = 'H'; 370 data[3] = 'D'; 371 data[4] = 'C'; 372 data[5] = 'P'; 373 data[6] = hdcpVersion; 374 375 mProgramInfoDescriptors.push_back(descriptor); 376 } 377 } 378 379 TSPacketizer::~TSPacketizer() { 380 } 381 382 ssize_t TSPacketizer::addTrack(const sp<AMessage> &format) { 383 AString mime; 384 CHECK(format->findString("mime", &mime)); 385 386 unsigned PIDStart; 387 bool isVideo = !strncasecmp("video/", mime.c_str(), 6); 388 bool isAudio = !strncasecmp("audio/", mime.c_str(), 6); 389 390 if (isVideo) { 391 PIDStart = 0x1011; 392 } else if (isAudio) { 393 PIDStart = 0x1100; 394 } else { 395 return ERROR_UNSUPPORTED; 396 } 397 398 unsigned streamType; 399 unsigned streamIDStart; 400 unsigned streamIDStop; 401 402 if (!strcasecmp(mime.c_str(), MEDIA_MIMETYPE_VIDEO_AVC)) { 403 streamType = 0x1b; 404 streamIDStart = 0xe0; 405 streamIDStop = 0xef; 406 } else if (!strcasecmp(mime.c_str(), MEDIA_MIMETYPE_AUDIO_AAC)) { 407 streamType = 0x0f; 408 streamIDStart = 0xc0; 409 streamIDStop = 0xdf; 410 } else if (!strcasecmp(mime.c_str(), MEDIA_MIMETYPE_AUDIO_RAW)) { 411 streamType = 0x83; 412 streamIDStart = 0xbd; 413 streamIDStop = 0xbd; 414 } else { 415 return ERROR_UNSUPPORTED; 416 } 417 418 size_t numTracksOfThisType = 0; 419 unsigned PID = PIDStart; 420 421 for (size_t i = 0; i < mTracks.size(); ++i) { 422 const sp<Track> &track = mTracks.itemAt(i); 423 424 if (track->streamType() == streamType) { 425 ++numTracksOfThisType; 426 } 427 428 if ((isAudio && track->isAudio()) || (isVideo && track->isVideo())) { 429 ++PID; 430 } 431 } 432 433 unsigned streamID = streamIDStart + numTracksOfThisType; 434 if (streamID > streamIDStop) { 435 return -ERANGE; 436 } 437 438 sp<Track> track = new Track(format, PID, streamType, streamID); 439 return mTracks.add(track); 440 } 441 442 status_t TSPacketizer::extractCSDIfNecessary(size_t trackIndex) { 443 if (trackIndex >= mTracks.size()) { 444 return -ERANGE; 445 } 446 447 const sp<Track> &track = mTracks.itemAt(trackIndex); 448 track->extractCSDIfNecessary(); 449 450 return OK; 451 } 452 453 status_t TSPacketizer::packetize( 454 size_t trackIndex, 455 const sp<ABuffer> &_accessUnit, 456 sp<ABuffer> *packets, 457 uint32_t flags, 458 const uint8_t *PES_private_data, size_t PES_private_data_len, 459 size_t numStuffingBytes) { 460 sp<ABuffer> accessUnit = _accessUnit; 461 462 int64_t timeUs; 463 CHECK(accessUnit->meta()->findInt64("timeUs", &timeUs)); 464 465 packets->clear(); 466 467 if (trackIndex >= mTracks.size()) { 468 return -ERANGE; 469 } 470 471 const sp<Track> &track = mTracks.itemAt(trackIndex); 472 473 if (track->isH264() && (flags & PREPEND_SPS_PPS_TO_IDR_FRAMES) 474 && IsIDR(accessUnit)) { 475 // prepend codec specific data, i.e. SPS and PPS. 476 accessUnit = track->prependCSD(accessUnit); 477 } else if (track->isAAC() && track->lacksADTSHeader()) { 478 CHECK(!(flags & IS_ENCRYPTED)); 479 accessUnit = track->prependADTSHeader(accessUnit); 480 } 481 482 // 0x47 483 // transport_error_indicator = b0 484 // payload_unit_start_indicator = b1 485 // transport_priority = b0 486 // PID 487 // transport_scrambling_control = b00 488 // adaptation_field_control = b?? 489 // continuity_counter = b???? 490 // -- payload follows 491 // packet_startcode_prefix = 0x000001 492 // stream_id 493 // PES_packet_length = 0x???? 494 // reserved = b10 495 // PES_scrambling_control = b00 496 // PES_priority = b0 497 // data_alignment_indicator = b1 498 // copyright = b0 499 // original_or_copy = b0 500 // PTS_DTS_flags = b10 (PTS only) 501 // ESCR_flag = b0 502 // ES_rate_flag = b0 503 // DSM_trick_mode_flag = b0 504 // additional_copy_info_flag = b0 505 // PES_CRC_flag = b0 506 // PES_extension_flag = b0 507 // PES_header_data_length = 0x05 508 // reserved = b0010 (PTS) 509 // PTS[32..30] = b??? 510 // reserved = b1 511 // PTS[29..15] = b??? ???? ???? ???? (15 bits) 512 // reserved = b1 513 // PTS[14..0] = b??? ???? ???? ???? (15 bits) 514 // reserved = b1 515 // the first fragment of "buffer" follows 516 517 // Each transport packet (except for the last one contributing to the PES 518 // payload) must contain a multiple of 16 bytes of payload per HDCP spec. 519 bool alignPayload = 520 (mFlags & (EMIT_HDCP20_DESCRIPTOR | EMIT_HDCP21_DESCRIPTOR)); 521 522 /* 523 a) The very first PES transport stream packet contains 524 525 4 bytes of TS header 526 ... padding 527 14 bytes of static PES header 528 PES_private_data_len + 1 bytes (only if PES_private_data_len > 0) 529 numStuffingBytes bytes 530 531 followed by the payload 532 533 b) Subsequent PES transport stream packets contain 534 535 4 bytes of TS header 536 ... padding 537 538 followed by the payload 539 */ 540 541 size_t PES_packet_length = accessUnit->size() + 8 + numStuffingBytes; 542 if (PES_private_data_len > 0) { 543 PES_packet_length += PES_private_data_len + 1; 544 } 545 546 size_t numTSPackets = 1; 547 548 { 549 // Make sure the PES header fits into a single TS packet: 550 size_t PES_header_size = 14 + numStuffingBytes; 551 if (PES_private_data_len > 0) { 552 PES_header_size += PES_private_data_len + 1; 553 } 554 555 CHECK_LE(PES_header_size, 188u - 4u); 556 557 size_t sizeAvailableForPayload = 188 - 4 - PES_header_size; 558 size_t numBytesOfPayload = accessUnit->size(); 559 560 if (numBytesOfPayload > sizeAvailableForPayload) { 561 numBytesOfPayload = sizeAvailableForPayload; 562 563 if (alignPayload && numBytesOfPayload > 16) { 564 numBytesOfPayload -= (numBytesOfPayload % 16); 565 } 566 } 567 568 // size_t numPaddingBytes = sizeAvailableForPayload - numBytesOfPayload; 569 ALOGV("packet 1 contains %zd padding bytes and %zd bytes of payload", 570 numPaddingBytes, numBytesOfPayload); 571 572 size_t numBytesOfPayloadRemaining = accessUnit->size() - numBytesOfPayload; 573 574 #if 0 575 // The following hopefully illustrates the logic that led to the 576 // more efficient computation in the #else block... 577 578 while (numBytesOfPayloadRemaining > 0) { 579 size_t sizeAvailableForPayload = 188 - 4; 580 581 size_t numBytesOfPayload = numBytesOfPayloadRemaining; 582 583 if (numBytesOfPayload > sizeAvailableForPayload) { 584 numBytesOfPayload = sizeAvailableForPayload; 585 586 if (alignPayload && numBytesOfPayload > 16) { 587 numBytesOfPayload -= (numBytesOfPayload % 16); 588 } 589 } 590 591 size_t numPaddingBytes = sizeAvailableForPayload - numBytesOfPayload; 592 ALOGI("packet %zd contains %zd padding bytes and %zd bytes of payload", 593 numTSPackets + 1, numPaddingBytes, numBytesOfPayload); 594 595 numBytesOfPayloadRemaining -= numBytesOfPayload; 596 ++numTSPackets; 597 } 598 #else 599 // This is how many bytes of payload each subsequent TS packet 600 // can contain at most. 601 sizeAvailableForPayload = 188 - 4; 602 size_t sizeAvailableForAlignedPayload = sizeAvailableForPayload; 603 if (alignPayload) { 604 // We're only going to use a subset of the available space 605 // since we need to make each fragment a multiple of 16 in size. 606 sizeAvailableForAlignedPayload -= 607 (sizeAvailableForAlignedPayload % 16); 608 } 609 610 size_t numFullTSPackets = 611 numBytesOfPayloadRemaining / sizeAvailableForAlignedPayload; 612 613 numTSPackets += numFullTSPackets; 614 615 numBytesOfPayloadRemaining -= 616 numFullTSPackets * sizeAvailableForAlignedPayload; 617 618 // numBytesOfPayloadRemaining < sizeAvailableForAlignedPayload 619 if (numFullTSPackets == 0 && numBytesOfPayloadRemaining > 0) { 620 // There wasn't enough payload left to form a full aligned payload, 621 // the last packet doesn't have to be aligned. 622 ++numTSPackets; 623 } else if (numFullTSPackets > 0 624 && numBytesOfPayloadRemaining 625 + sizeAvailableForAlignedPayload > sizeAvailableForPayload) { 626 // The last packet emitted had a full aligned payload and together 627 // with the bytes remaining does exceed the unaligned payload 628 // size, so we need another packet. 629 ++numTSPackets; 630 } 631 #endif 632 } 633 634 if (flags & EMIT_PAT_AND_PMT) { 635 numTSPackets += 2; 636 } 637 638 if (flags & EMIT_PCR) { 639 ++numTSPackets; 640 } 641 642 sp<ABuffer> buffer = new ABuffer(numTSPackets * 188); 643 uint8_t *packetDataStart = buffer->data(); 644 645 if (flags & EMIT_PAT_AND_PMT) { 646 // Program Association Table (PAT): 647 // 0x47 648 // transport_error_indicator = b0 649 // payload_unit_start_indicator = b1 650 // transport_priority = b0 651 // PID = b0000000000000 (13 bits) 652 // transport_scrambling_control = b00 653 // adaptation_field_control = b01 (no adaptation field, payload only) 654 // continuity_counter = b???? 655 // skip = 0x00 656 // --- payload follows 657 // table_id = 0x00 658 // section_syntax_indicator = b1 659 // must_be_zero = b0 660 // reserved = b11 661 // section_length = 0x00d 662 // transport_stream_id = 0x0000 663 // reserved = b11 664 // version_number = b00001 665 // current_next_indicator = b1 666 // section_number = 0x00 667 // last_section_number = 0x00 668 // one program follows: 669 // program_number = 0x0001 670 // reserved = b111 671 // program_map_PID = kPID_PMT (13 bits!) 672 // CRC = 0x???????? 673 674 if (++mPATContinuityCounter == 16) { 675 mPATContinuityCounter = 0; 676 } 677 678 uint8_t *ptr = packetDataStart; 679 *ptr++ = 0x47; 680 *ptr++ = 0x40; 681 *ptr++ = 0x00; 682 *ptr++ = 0x10 | mPATContinuityCounter; 683 *ptr++ = 0x00; 684 685 uint8_t *crcDataStart = ptr; 686 *ptr++ = 0x00; 687 *ptr++ = 0xb0; 688 *ptr++ = 0x0d; 689 *ptr++ = 0x00; 690 *ptr++ = 0x00; 691 *ptr++ = 0xc3; 692 *ptr++ = 0x00; 693 *ptr++ = 0x00; 694 *ptr++ = 0x00; 695 *ptr++ = 0x01; 696 *ptr++ = 0xe0 | (kPID_PMT >> 8); 697 *ptr++ = kPID_PMT & 0xff; 698 699 CHECK_EQ(ptr - crcDataStart, 12); 700 uint32_t crc = htonl(crc32(crcDataStart, ptr - crcDataStart)); 701 memcpy(ptr, &crc, 4); 702 ptr += 4; 703 704 size_t sizeLeft = packetDataStart + 188 - ptr; 705 memset(ptr, 0xff, sizeLeft); 706 707 packetDataStart += 188; 708 709 // Program Map (PMT): 710 // 0x47 711 // transport_error_indicator = b0 712 // payload_unit_start_indicator = b1 713 // transport_priority = b0 714 // PID = kPID_PMT (13 bits) 715 // transport_scrambling_control = b00 716 // adaptation_field_control = b01 (no adaptation field, payload only) 717 // continuity_counter = b???? 718 // skip = 0x00 719 // -- payload follows 720 // table_id = 0x02 721 // section_syntax_indicator = b1 722 // must_be_zero = b0 723 // reserved = b11 724 // section_length = 0x??? 725 // program_number = 0x0001 726 // reserved = b11 727 // version_number = b00001 728 // current_next_indicator = b1 729 // section_number = 0x00 730 // last_section_number = 0x00 731 // reserved = b111 732 // PCR_PID = kPCR_PID (13 bits) 733 // reserved = b1111 734 // program_info_length = 0x??? 735 // program_info_descriptors follow 736 // one or more elementary stream descriptions follow: 737 // stream_type = 0x?? 738 // reserved = b111 739 // elementary_PID = b? ???? ???? ???? (13 bits) 740 // reserved = b1111 741 // ES_info_length = 0x000 742 // CRC = 0x???????? 743 744 if (++mPMTContinuityCounter == 16) { 745 mPMTContinuityCounter = 0; 746 } 747 748 ptr = packetDataStart; 749 *ptr++ = 0x47; 750 *ptr++ = 0x40 | (kPID_PMT >> 8); 751 *ptr++ = kPID_PMT & 0xff; 752 *ptr++ = 0x10 | mPMTContinuityCounter; 753 *ptr++ = 0x00; 754 755 crcDataStart = ptr; 756 *ptr++ = 0x02; 757 758 *ptr++ = 0x00; // section_length to be filled in below. 759 *ptr++ = 0x00; 760 761 *ptr++ = 0x00; 762 *ptr++ = 0x01; 763 *ptr++ = 0xc3; 764 *ptr++ = 0x00; 765 *ptr++ = 0x00; 766 *ptr++ = 0xe0 | (kPID_PCR >> 8); 767 *ptr++ = kPID_PCR & 0xff; 768 769 size_t program_info_length = 0; 770 for (size_t i = 0; i < mProgramInfoDescriptors.size(); ++i) { 771 program_info_length += mProgramInfoDescriptors.itemAt(i)->size(); 772 } 773 774 CHECK_LT(program_info_length, 0x400); 775 *ptr++ = 0xf0 | (program_info_length >> 8); 776 *ptr++ = (program_info_length & 0xff); 777 778 for (size_t i = 0; i < mProgramInfoDescriptors.size(); ++i) { 779 const sp<ABuffer> &desc = mProgramInfoDescriptors.itemAt(i); 780 memcpy(ptr, desc->data(), desc->size()); 781 ptr += desc->size(); 782 } 783 784 for (size_t i = 0; i < mTracks.size(); ++i) { 785 const sp<Track> &track = mTracks.itemAt(i); 786 787 // Make sure all the decriptors have been added. 788 track->finalize(); 789 790 *ptr++ = track->streamType(); 791 *ptr++ = 0xe0 | (track->PID() >> 8); 792 *ptr++ = track->PID() & 0xff; 793 794 size_t ES_info_length = 0; 795 for (size_t i = 0; i < track->countDescriptors(); ++i) { 796 ES_info_length += track->descriptorAt(i)->size(); 797 } 798 CHECK_LE(ES_info_length, 0xfff); 799 800 *ptr++ = 0xf0 | (ES_info_length >> 8); 801 *ptr++ = (ES_info_length & 0xff); 802 803 for (size_t i = 0; i < track->countDescriptors(); ++i) { 804 const sp<ABuffer> &descriptor = track->descriptorAt(i); 805 memcpy(ptr, descriptor->data(), descriptor->size()); 806 ptr += descriptor->size(); 807 } 808 } 809 810 size_t section_length = ptr - (crcDataStart + 3) + 4 /* CRC */; 811 812 crcDataStart[1] = 0xb0 | (section_length >> 8); 813 crcDataStart[2] = section_length & 0xff; 814 815 crc = htonl(crc32(crcDataStart, ptr - crcDataStart)); 816 memcpy(ptr, &crc, 4); 817 ptr += 4; 818 819 sizeLeft = packetDataStart + 188 - ptr; 820 memset(ptr, 0xff, sizeLeft); 821 822 packetDataStart += 188; 823 } 824 825 if (flags & EMIT_PCR) { 826 // PCR stream 827 // 0x47 828 // transport_error_indicator = b0 829 // payload_unit_start_indicator = b1 830 // transport_priority = b0 831 // PID = kPCR_PID (13 bits) 832 // transport_scrambling_control = b00 833 // adaptation_field_control = b10 (adaptation field only, no payload) 834 // continuity_counter = b0000 (does not increment) 835 // adaptation_field_length = 183 836 // discontinuity_indicator = b0 837 // random_access_indicator = b0 838 // elementary_stream_priority_indicator = b0 839 // PCR_flag = b1 840 // OPCR_flag = b0 841 // splicing_point_flag = b0 842 // transport_private_data_flag = b0 843 // adaptation_field_extension_flag = b0 844 // program_clock_reference_base = b????????????????????????????????? 845 // reserved = b111111 846 // program_clock_reference_extension = b????????? 847 848 int64_t nowUs = ALooper::GetNowUs(); 849 850 uint64_t PCR = nowUs * 27; // PCR based on a 27MHz clock 851 uint64_t PCR_base = PCR / 300; 852 uint32_t PCR_ext = PCR % 300; 853 854 uint8_t *ptr = packetDataStart; 855 *ptr++ = 0x47; 856 *ptr++ = 0x40 | (kPID_PCR >> 8); 857 *ptr++ = kPID_PCR & 0xff; 858 *ptr++ = 0x20; 859 *ptr++ = 0xb7; // adaptation_field_length 860 *ptr++ = 0x10; 861 *ptr++ = (PCR_base >> 25) & 0xff; 862 *ptr++ = (PCR_base >> 17) & 0xff; 863 *ptr++ = (PCR_base >> 9) & 0xff; 864 *ptr++ = ((PCR_base & 1) << 7) | 0x7e | ((PCR_ext >> 8) & 1); 865 *ptr++ = (PCR_ext & 0xff); 866 867 size_t sizeLeft = packetDataStart + 188 - ptr; 868 memset(ptr, 0xff, sizeLeft); 869 870 packetDataStart += 188; 871 } 872 873 uint64_t PTS = (timeUs * 9ll) / 100ll; 874 875 if (PES_packet_length >= 65536) { 876 // This really should only happen for video. 877 CHECK(track->isVideo()); 878 879 // It's valid to set this to 0 for video according to the specs. 880 PES_packet_length = 0; 881 } 882 883 size_t sizeAvailableForPayload = 188 - 4 - 14 - numStuffingBytes; 884 if (PES_private_data_len > 0) { 885 sizeAvailableForPayload -= PES_private_data_len + 1; 886 } 887 888 size_t copy = accessUnit->size(); 889 890 if (copy > sizeAvailableForPayload) { 891 copy = sizeAvailableForPayload; 892 893 if (alignPayload && copy > 16) { 894 copy -= (copy % 16); 895 } 896 } 897 898 size_t numPaddingBytes = sizeAvailableForPayload - copy; 899 900 uint8_t *ptr = packetDataStart; 901 *ptr++ = 0x47; 902 *ptr++ = 0x40 | (track->PID() >> 8); 903 *ptr++ = track->PID() & 0xff; 904 905 *ptr++ = (numPaddingBytes > 0 ? 0x30 : 0x10) 906 | track->incrementContinuityCounter(); 907 908 if (numPaddingBytes > 0) { 909 *ptr++ = numPaddingBytes - 1; 910 if (numPaddingBytes >= 2) { 911 *ptr++ = 0x00; 912 memset(ptr, 0xff, numPaddingBytes - 2); 913 ptr += numPaddingBytes - 2; 914 } 915 } 916 917 *ptr++ = 0x00; 918 *ptr++ = 0x00; 919 *ptr++ = 0x01; 920 *ptr++ = track->streamID(); 921 *ptr++ = PES_packet_length >> 8; 922 *ptr++ = PES_packet_length & 0xff; 923 *ptr++ = 0x84; 924 *ptr++ = (PES_private_data_len > 0) ? 0x81 : 0x80; 925 926 size_t headerLength = 0x05 + numStuffingBytes; 927 if (PES_private_data_len > 0) { 928 headerLength += 1 + PES_private_data_len; 929 } 930 931 *ptr++ = headerLength; 932 933 *ptr++ = 0x20 | (((PTS >> 30) & 7) << 1) | 1; 934 *ptr++ = (PTS >> 22) & 0xff; 935 *ptr++ = (((PTS >> 15) & 0x7f) << 1) | 1; 936 *ptr++ = (PTS >> 7) & 0xff; 937 *ptr++ = ((PTS & 0x7f) << 1) | 1; 938 939 if (PES_private_data_len > 0) { 940 *ptr++ = 0x8e; // PES_private_data_flag, reserved. 941 memcpy(ptr, PES_private_data, PES_private_data_len); 942 ptr += PES_private_data_len; 943 } 944 945 for (size_t i = 0; i < numStuffingBytes; ++i) { 946 *ptr++ = 0xff; 947 } 948 949 memcpy(ptr, accessUnit->data(), copy); 950 ptr += copy; 951 952 CHECK_EQ(ptr, packetDataStart + 188); 953 packetDataStart += 188; 954 955 size_t offset = copy; 956 while (offset < accessUnit->size()) { 957 // for subsequent fragments of "buffer": 958 // 0x47 959 // transport_error_indicator = b0 960 // payload_unit_start_indicator = b0 961 // transport_priority = b0 962 // PID = b0 0001 1110 ???? (13 bits) [0x1e0 + 1 + sourceIndex] 963 // transport_scrambling_control = b00 964 // adaptation_field_control = b?? 965 // continuity_counter = b???? 966 // the fragment of "buffer" follows. 967 968 size_t sizeAvailableForPayload = 188 - 4; 969 970 size_t copy = accessUnit->size() - offset; 971 972 if (copy > sizeAvailableForPayload) { 973 copy = sizeAvailableForPayload; 974 975 if (alignPayload && copy > 16) { 976 copy -= (copy % 16); 977 } 978 } 979 980 size_t numPaddingBytes = sizeAvailableForPayload - copy; 981 982 uint8_t *ptr = packetDataStart; 983 *ptr++ = 0x47; 984 *ptr++ = 0x00 | (track->PID() >> 8); 985 *ptr++ = track->PID() & 0xff; 986 987 *ptr++ = (numPaddingBytes > 0 ? 0x30 : 0x10) 988 | track->incrementContinuityCounter(); 989 990 if (numPaddingBytes > 0) { 991 *ptr++ = numPaddingBytes - 1; 992 if (numPaddingBytes >= 2) { 993 *ptr++ = 0x00; 994 memset(ptr, 0xff, numPaddingBytes - 2); 995 ptr += numPaddingBytes - 2; 996 } 997 } 998 999 memcpy(ptr, accessUnit->data() + offset, copy); 1000 ptr += copy; 1001 CHECK_EQ(ptr, packetDataStart + 188); 1002 1003 offset += copy; 1004 packetDataStart += 188; 1005 } 1006 1007 CHECK(packetDataStart == buffer->data() + buffer->capacity()); 1008 1009 *packets = buffer; 1010 1011 return OK; 1012 } 1013 1014 void TSPacketizer::initCrcTable() { 1015 uint32_t poly = 0x04C11DB7; 1016 1017 for (int i = 0; i < 256; i++) { 1018 uint32_t crc = i << 24; 1019 for (int j = 0; j < 8; j++) { 1020 crc = (crc << 1) ^ ((crc & 0x80000000) ? (poly) : 0); 1021 } 1022 mCrcTable[i] = crc; 1023 } 1024 } 1025 1026 uint32_t TSPacketizer::crc32(const uint8_t *start, size_t size) const { 1027 uint32_t crc = 0xFFFFFFFF; 1028 const uint8_t *p; 1029 1030 for (p = start; p < start + size; ++p) { 1031 crc = (crc << 8) ^ mCrcTable[((crc >> 24) ^ *p) & 0xFF]; 1032 } 1033 1034 return crc; 1035 } 1036 1037 sp<ABuffer> TSPacketizer::prependCSD( 1038 size_t trackIndex, const sp<ABuffer> &accessUnit) const { 1039 CHECK_LT(trackIndex, mTracks.size()); 1040 1041 const sp<Track> &track = mTracks.itemAt(trackIndex); 1042 CHECK(track->isH264() && IsIDR(accessUnit)); 1043 1044 int64_t timeUs; 1045 CHECK(accessUnit->meta()->findInt64("timeUs", &timeUs)); 1046 1047 sp<ABuffer> accessUnit2 = track->prependCSD(accessUnit); 1048 1049 accessUnit2->meta()->setInt64("timeUs", timeUs); 1050 1051 return accessUnit2; 1052 } 1053 1054 } // namespace android 1055 1056
