media/mp4/box_definitions.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "media/mp4/box_definitions.h"
   6
   7 #include "base/logging.h"
   8 #include "media/mp4/es_descriptor.h"
   9 #include "media/mp4/rcheck.h"
  10
  11 namespace media {
  12 namespace mp4 {
  13
  14 FileType::FileType() {}
  15 FileType::~FileType() {}
  16 FourCC FileType::BoxType() const { return FOURCC_FTYP; }
  17
  18 bool FileType::Parse(BoxReader* reader) {
  19   RCHECK(reader->ReadFourCC(&major_brand) && reader->Read4(&minor_version));
  20   size_t num_brands = (reader->size() - reader->pos()) / sizeof(FourCC);
  21   return reader->SkipBytes(sizeof(FourCC) * num_brands);  // compatible_brands
  22 }
  23
  24 ProtectionSystemSpecificHeader::ProtectionSystemSpecificHeader() {}
  25 ProtectionSystemSpecificHeader::~ProtectionSystemSpecificHeader() {}
  26 FourCC ProtectionSystemSpecificHeader::BoxType() const { return FOURCC_PSSH; }
  27
  28 bool ProtectionSystemSpecificHeader::Parse(BoxReader* reader) {
  29   // Validate the box's contents and hang on to the system ID.
  30   uint32 size;
  31   RCHECK(reader->ReadFullBoxHeader() &&
  32          reader->ReadVec(&system_id, 16) &&
  33          reader->Read4(&size) &&
  34          reader->HasBytes(size));
  35
  36   // Copy the entire box, including the header, for passing to EME as initData.
  37   DCHECK(raw_box.empty());
  38   raw_box.assign(reader->data(), reader->data() + reader->size());
  39   return true;
  40 }
  41
  42 SampleAuxiliaryInformationOffset::SampleAuxiliaryInformationOffset() {}
  43 SampleAuxiliaryInformationOffset::~SampleAuxiliaryInformationOffset() {}
  44 FourCC SampleAuxiliaryInformationOffset::BoxType() const { return FOURCC_SAIO; }
  45
  46 bool SampleAuxiliaryInformationOffset::Parse(BoxReader* reader) {
  47   RCHECK(reader->ReadFullBoxHeader());
  48   if (reader->flags() & 1)
  49     RCHECK(reader->SkipBytes(8));
  50
  51   uint32 count;
  52   RCHECK(reader->Read4(&count) &&
  53          reader->HasBytes(count * (reader->version() == 1 ? 8 : 4)));
  54   offsets.resize(count);
  55
  56   for (uint32 i = 0; i < count; i++) {
  57     if (reader->version() == 1) {
  58       RCHECK(reader->Read8(&offsets[i]));
  59     } else {
  60       RCHECK(reader->Read4Into8(&offsets[i]));
  61     }
  62   }
  63   return true;
  64 }
  65
  66 SampleAuxiliaryInformationSize::SampleAuxiliaryInformationSize()
  67   : default_sample_info_size(0), sample_count(0) {
  68 }
  69 SampleAuxiliaryInformationSize::~SampleAuxiliaryInformationSize() {}
  70 FourCC SampleAuxiliaryInformationSize::BoxType() const { return FOURCC_SAIZ; }
  71
  72 bool SampleAuxiliaryInformationSize::Parse(BoxReader* reader) {
  73   RCHECK(reader->ReadFullBoxHeader());
  74   if (reader->flags() & 1)
  75     RCHECK(reader->SkipBytes(8));
  76
  77   RCHECK(reader->Read1(&default_sample_info_size) &&
  78          reader->Read4(&sample_count));
  79   if (default_sample_info_size == 0)
  80     return reader->ReadVec(&sample_info_sizes, sample_count);
  81   return true;
  82 }
  83
  84 OriginalFormat::OriginalFormat() : format(FOURCC_NULL) {}
  85 OriginalFormat::~OriginalFormat() {}
  86 FourCC OriginalFormat::BoxType() const { return FOURCC_FRMA; }
  87
  88 bool OriginalFormat::Parse(BoxReader* reader) {
  89   return reader->ReadFourCC(&format);
  90 }
  91
  92 SchemeType::SchemeType() : type(FOURCC_NULL), version(0) {}
  93 SchemeType::~SchemeType() {}
  94 FourCC SchemeType::BoxType() const { return FOURCC_SCHM; }
  95
  96 bool SchemeType::Parse(BoxReader* reader) {
  97   RCHECK(reader->ReadFullBoxHeader() &&
  98          reader->ReadFourCC(&type) &&
  99          reader->Read4(&version));
 100   return true;
 101 }
 102
 103 TrackEncryption::TrackEncryption()
 104   : is_encrypted(false), default_iv_size(0) {
 105 }
 106 TrackEncryption::~TrackEncryption() {}
 107 FourCC TrackEncryption::BoxType() const { return FOURCC_TENC; }
 108
 109 bool TrackEncryption::Parse(BoxReader* reader) {
 110   uint8 flag;
 111   RCHECK(reader->ReadFullBoxHeader() &&
 112          reader->SkipBytes(2) &&
 113          reader->Read1(&flag) &&
 114          reader->Read1(&default_iv_size) &&
 115          reader->ReadVec(&default_kid, 16));
 116   is_encrypted = (flag != 0);
 117   if (is_encrypted) {
 118     RCHECK(default_iv_size == 8 || default_iv_size == 16);
 119   } else {
 120     RCHECK(default_iv_size == 0);
 121   }
 122   return true;
 123 }
 124
 125 SchemeInfo::SchemeInfo() {}
 126 SchemeInfo::~SchemeInfo() {}
 127 FourCC SchemeInfo::BoxType() const { return FOURCC_SCHI; }
 128
 129 bool SchemeInfo::Parse(BoxReader* reader) {
 130   return reader->ScanChildren() && reader->ReadChild(&track_encryption);
 131 }
 132
 133 ProtectionSchemeInfo::ProtectionSchemeInfo() {}
 134 ProtectionSchemeInfo::~ProtectionSchemeInfo() {}
 135 FourCC ProtectionSchemeInfo::BoxType() const { return FOURCC_SINF; }
 136
 137 bool ProtectionSchemeInfo::Parse(BoxReader* reader) {
 138   RCHECK(reader->ScanChildren() &&
 139          reader->ReadChild(&format) &&
 140          reader->ReadChild(&type));
 141   if (type.type == FOURCC_CENC)
 142     RCHECK(reader->ReadChild(&info));
 143   // Other protection schemes are silently ignored. Since the protection scheme
 144   // type can't be determined until this box is opened, we return 'true' for
 145   // non-CENC protection scheme types. It is the parent box's responsibility to
 146   // ensure that this scheme type is a supported one.
 147   return true;
 148 }
 149
 150 MovieHeader::MovieHeader()
 151     : creation_time(0),
 152       modification_time(0),
 153       timescale(0),
 154       duration(0),
 155       rate(-1),
 156       volume(-1),
 157       next_track_id(0) {}
 158 MovieHeader::~MovieHeader() {}
 159 FourCC MovieHeader::BoxType() const { return FOURCC_MVHD; }
 160
 161 bool MovieHeader::Parse(BoxReader* reader) {
 162   RCHECK(reader->ReadFullBoxHeader());
 163
 164   if (reader->version() == 1) {
 165     RCHECK(reader->Read8(&creation_time) &&
 166            reader->Read8(&modification_time) &&
 167            reader->Read4(&timescale) &&
 168            reader->Read8(&duration));
 169   } else {
 170     RCHECK(reader->Read4Into8(&creation_time) &&
 171            reader->Read4Into8(&modification_time) &&
 172            reader->Read4(&timescale) &&
 173            reader->Read4Into8(&duration));
 174   }
 175
 176   RCHECK(reader->Read4s(&rate) &&
 177          reader->Read2s(&volume) &&
 178          reader->SkipBytes(10) &&  // reserved
 179          reader->SkipBytes(36) &&  // matrix
 180          reader->SkipBytes(24) &&  // predefined zero
 181          reader->Read4(&next_track_id));
 182   return true;
 183 }
 184
 185 TrackHeader::TrackHeader()
 186     : creation_time(0),
 187       modification_time(0),
 188       track_id(0),
 189       duration(0),
 190       layer(-1),
 191       alternate_group(-1),
 192       volume(-1),
 193       width(0),
 194       height(0) {}
 195 TrackHeader::~TrackHeader() {}
 196 FourCC TrackHeader::BoxType() const { return FOURCC_TKHD; }
 197
 198 bool TrackHeader::Parse(BoxReader* reader) {
 199   RCHECK(reader->ReadFullBoxHeader());
 200   if (reader->version() == 1) {
 201     RCHECK(reader->Read8(&creation_time) &&
 202            reader->Read8(&modification_time) &&
 203            reader->Read4(&track_id) &&
 204            reader->SkipBytes(4) &&    // reserved
 205            reader->Read8(&duration));
 206   } else {
 207     RCHECK(reader->Read4Into8(&creation_time) &&
 208            reader->Read4Into8(&modification_time) &&
 209            reader->Read4(&track_id) &&
 210            reader->SkipBytes(4) &&   // reserved
 211            reader->Read4Into8(&duration));
 212   }
 213
 214   RCHECK(reader->SkipBytes(8) &&  // reserved
 215          reader->Read2s(&layer) &&
 216          reader->Read2s(&alternate_group) &&
 217          reader->Read2s(&volume) &&
 218          reader->SkipBytes(2) &&  // reserved
 219          reader->SkipBytes(36) &&  // matrix
 220          reader->Read4(&width) &&
 221          reader->Read4(&height));
 222   width >>= 16;
 223   height >>= 16;
 224   return true;
 225 }
 226
 227 SampleDescription::SampleDescription() : type(kInvalid) {}
 228 SampleDescription::~SampleDescription() {}
 229 FourCC SampleDescription::BoxType() const { return FOURCC_STSD; }
 230
 231 bool SampleDescription::Parse(BoxReader* reader) {
 232   uint32 count;
 233   RCHECK(reader->SkipBytes(4) &&
 234          reader->Read4(&count));
 235   video_entries.clear();
 236   audio_entries.clear();
 237
 238   // Note: this value is preset before scanning begins. See comments in the
 239   // Parse(Media*) function.
 240   if (type == kVideo) {
 241     RCHECK(reader->ReadAllChildren(&video_entries));
 242   } else if (type == kAudio) {
 243     RCHECK(reader->ReadAllChildren(&audio_entries));
 244   }
 245   return true;
 246 }
 247
 248 SampleTable::SampleTable() {}
 249 SampleTable::~SampleTable() {}
 250 FourCC SampleTable::BoxType() const { return FOURCC_STBL; }
 251
 252 bool SampleTable::Parse(BoxReader* reader) {
 253   return reader->ScanChildren() &&
 254          reader->ReadChild(&description);
 255 }
 256
 257 EditList::EditList() {}
 258 EditList::~EditList() {}
 259 FourCC EditList::BoxType() const { return FOURCC_ELST; }
 260
 261 bool EditList::Parse(BoxReader* reader) {
 262   uint32 count;
 263   RCHECK(reader->ReadFullBoxHeader() && reader->Read4(&count));
 264
 265   if (reader->version() == 1) {
 266     RCHECK(reader->HasBytes(count * 20));
 267   } else {
 268     RCHECK(reader->HasBytes(count * 12));
 269   }
 270   edits.resize(count);
 271
 272   for (std::vector<EditListEntry>::iterator edit = edits.begin();
 273        edit != edits.end(); ++edit) {
 274     if (reader->version() == 1) {
 275       RCHECK(reader->Read8(&edit->segment_duration) &&
 276              reader->Read8s(&edit->media_time));
 277     } else {
 278       RCHECK(reader->Read4Into8(&edit->segment_duration) &&
 279              reader->Read4sInto8s(&edit->media_time));
 280     }
 281     RCHECK(reader->Read2s(&edit->media_rate_integer) &&
 282            reader->Read2s(&edit->media_rate_fraction));
 283   }
 284   return true;
 285 }
 286
 287 Edit::Edit() {}
 288 Edit::~Edit() {}
 289 FourCC Edit::BoxType() const { return FOURCC_EDTS; }
 290
 291 bool Edit::Parse(BoxReader* reader) {
 292   return reader->ScanChildren() && reader->ReadChild(&list);
 293 }
 294
 295 HandlerReference::HandlerReference() : type(kInvalid) {}
 296 HandlerReference::~HandlerReference() {}
 297 FourCC HandlerReference::BoxType() const { return FOURCC_HDLR; }
 298
 299 bool HandlerReference::Parse(BoxReader* reader) {
 300   FourCC hdlr_type;
 301   RCHECK(reader->SkipBytes(8) && reader->ReadFourCC(&hdlr_type));
 302   // Note: remaining fields in box ignored
 303   if (hdlr_type == FOURCC_VIDE) {
 304     type = kVideo;
 305   } else if (hdlr_type == FOURCC_SOUN) {
 306     type = kAudio;
 307   } else {
 308     type = kInvalid;
 309   }
 310   return true;
 311 }
 312
 313 AVCDecoderConfigurationRecord::AVCDecoderConfigurationRecord()
 314     : version(0),
 315       profile_indication(0),
 316       profile_compatibility(0),
 317       avc_level(0),
 318       length_size(0) {}
 319
 320 AVCDecoderConfigurationRecord::~AVCDecoderConfigurationRecord() {}
 321 FourCC AVCDecoderConfigurationRecord::BoxType() const { return FOURCC_AVCC; }
 322
 323 bool AVCDecoderConfigurationRecord::Parse(BoxReader* reader) {
 324   RCHECK(reader->Read1(&version) && version == 1 &&
 325          reader->Read1(&profile_indication) &&
 326          reader->Read1(&profile_compatibility) &&
 327          reader->Read1(&avc_level));
 328
 329   uint8 length_size_minus_one;
 330   RCHECK(reader->Read1(&length_size_minus_one) &&
 331          (length_size_minus_one & 0xfc) == 0xfc);
 332   length_size = (length_size_minus_one & 0x3) + 1;
 333
 334   uint8 num_sps;
 335   RCHECK(reader->Read1(&num_sps) && (num_sps & 0xe0) == 0xe0);
 336   num_sps &= 0x1f;
 337
 338   sps_list.resize(num_sps);
 339   for (int i = 0; i < num_sps; i++) {
 340     uint16 sps_length;
 341     RCHECK(reader->Read2(&sps_length) &&
 342            reader->ReadVec(&sps_list[i], sps_length));
 343   }
 344
 345   uint8 num_pps;
 346   RCHECK(reader->Read1(&num_pps));
 347
 348   pps_list.resize(num_pps);
 349   for (int i = 0; i < num_pps; i++) {
 350     uint16 pps_length;
 351     RCHECK(reader->Read2(&pps_length) &&
 352            reader->ReadVec(&pps_list[i], pps_length));
 353   }
 354
 355   return true;
 356 }
 357
 358 PixelAspectRatioBox::PixelAspectRatioBox() : h_spacing(1), v_spacing(1) {}
 359 PixelAspectRatioBox::~PixelAspectRatioBox() {}
 360 FourCC PixelAspectRatioBox::BoxType() const { return FOURCC_PASP; }
 361
 362 bool PixelAspectRatioBox::Parse(BoxReader* reader) {
 363   RCHECK(reader->Read4(&h_spacing) &&
 364          reader->Read4(&v_spacing));
 365   return true;
 366 }
 367
 368 VideoSampleEntry::VideoSampleEntry()
 369     : format(FOURCC_NULL),
 370       data_reference_index(0),
 371       width(0),
 372       height(0) {}
 373
 374 VideoSampleEntry::~VideoSampleEntry() {}
 375 FourCC VideoSampleEntry::BoxType() const {
 376   DCHECK(false) << "VideoSampleEntry should be parsed according to the "
 377                 << "handler type recovered in its Media ancestor.";
 378   return FOURCC_NULL;
 379 }
 380
 381 bool VideoSampleEntry::Parse(BoxReader* reader) {
 382   format = reader->type();
 383   RCHECK(reader->SkipBytes(6) &&
 384          reader->Read2(&data_reference_index) &&
 385          reader->SkipBytes(16) &&
 386          reader->Read2(&width) &&
 387          reader->Read2(&height) &&
 388          reader->SkipBytes(50));
 389
 390   RCHECK(reader->ScanChildren() &&
 391          reader->MaybeReadChild(&pixel_aspect));
 392
 393   if (format == FOURCC_ENCV) {
 394     // Continue scanning until a recognized protection scheme is found, or until
 395     // we run out of protection schemes.
 396     while (sinf.type.type != FOURCC_CENC) {
 397       if (!reader->ReadChild(&sinf))
 398         return false;
 399     }
 400   }
 401
 402   if (format == FOURCC_AVC1 ||
 403       (format == FOURCC_ENCV && sinf.format.format == FOURCC_AVC1)) {
 404     RCHECK(reader->ReadChild(&avcc));
 405   }
 406   return true;
 407 }
 408
 409 ElementaryStreamDescriptor::ElementaryStreamDescriptor()
 410     : object_type(kForbidden) {}
 411
 412 ElementaryStreamDescriptor::~ElementaryStreamDescriptor() {}
 413
 414 FourCC ElementaryStreamDescriptor::BoxType() const {
 415   return FOURCC_ESDS;
 416 }
 417
 418 bool ElementaryStreamDescriptor::Parse(BoxReader* reader) {
 419   std::vector<uint8> data;
 420   ESDescriptor es_desc;
 421
 422   RCHECK(reader->ReadFullBoxHeader());
 423   RCHECK(reader->ReadVec(&data, reader->size() - reader->pos()));
 424   RCHECK(es_desc.Parse(data));
 425
 426   object_type = es_desc.object_type();
 427
 428   RCHECK(aac.Parse(es_desc.decoder_specific_info()));
 429
 430   return true;
 431 }
 432
 433 AudioSampleEntry::AudioSampleEntry()
 434     : format(FOURCC_NULL),
 435       data_reference_index(0),
 436       channelcount(0),
 437       samplesize(0),
 438       samplerate(0) {}
 439
 440 AudioSampleEntry::~AudioSampleEntry() {}
 441
 442 FourCC AudioSampleEntry::BoxType() const {
 443   DCHECK(false) << "AudioSampleEntry should be parsed according to the "
 444                 << "handler type recovered in its Media ancestor.";
 445   return FOURCC_NULL;
 446 }
 447
 448 bool AudioSampleEntry::Parse(BoxReader* reader) {
 449   format = reader->type();
 450   RCHECK(reader->SkipBytes(6) &&
 451          reader->Read2(&data_reference_index) &&
 452          reader->SkipBytes(8) &&
 453          reader->Read2(&channelcount) &&
 454          reader->Read2(&samplesize) &&
 455          reader->SkipBytes(4) &&
 456          reader->Read4(&samplerate));
 457   // Convert from 16.16 fixed point to integer
 458   samplerate >>= 16;
 459
 460   RCHECK(reader->ScanChildren());
 461   if (format == FOURCC_ENCA) {
 462     // Continue scanning until a recognized protection scheme is found, or until
 463     // we run out of protection schemes.
 464     while (sinf.type.type != FOURCC_CENC) {
 465       if (!reader->ReadChild(&sinf))
 466         return false;
 467     }
 468   }
 469
 470   RCHECK(reader->ReadChild(&esds));
 471   return true;
 472 }
 473
 474 MediaHeader::MediaHeader()
 475     : creation_time(0),
 476       modification_time(0),
 477       timescale(0),
 478       duration(0) {}
 479 MediaHeader::~MediaHeader() {}
 480 FourCC MediaHeader::BoxType() const { return FOURCC_MDHD; }
 481
 482 bool MediaHeader::Parse(BoxReader* reader) {
 483   RCHECK(reader->ReadFullBoxHeader());
 484
 485   if (reader->version() == 1) {
 486     RCHECK(reader->Read8(&creation_time) &&
 487            reader->Read8(&modification_time) &&
 488            reader->Read4(&timescale) &&
 489            reader->Read8(&duration));
 490   } else {
 491     RCHECK(reader->Read4Into8(&creation_time) &&
 492            reader->Read4Into8(&modification_time) &&
 493            reader->Read4(&timescale) &&
 494            reader->Read4Into8(&duration));
 495   }
 496   // Skip language information
 497   return reader->SkipBytes(4);
 498 }
 499
 500 MediaInformation::MediaInformation() {}
 501 MediaInformation::~MediaInformation() {}
 502 FourCC MediaInformation::BoxType() const { return FOURCC_MINF; }
 503
 504 bool MediaInformation::Parse(BoxReader* reader) {
 505   return reader->ScanChildren() &&
 506          reader->ReadChild(&sample_table);
 507 }
 508
 509 Media::Media() {}
 510 Media::~Media() {}
 511 FourCC Media::BoxType() const { return FOURCC_MDIA; }
 512
 513 bool Media::Parse(BoxReader* reader) {
 514   RCHECK(reader->ScanChildren() &&
 515          reader->ReadChild(&header) &&
 516          reader->ReadChild(&handler));
 517
 518   // Maddeningly, the HandlerReference box specifies how to parse the
 519   // SampleDescription box, making the latter the only box (of those that we
 520   // support) which cannot be parsed correctly on its own (or even with
 521   // information from its strict ancestor tree). We thus copy the handler type
 522   // to the sample description box *before* parsing it to provide this
 523   // information while parsing.
 524   information.sample_table.description.type = handler.type;
 525   RCHECK(reader->ReadChild(&information));
 526   return true;
 527 }
 528
 529 Track::Track() {}
 530 Track::~Track() {}
 531 FourCC Track::BoxType() const { return FOURCC_TRAK; }
 532
 533 bool Track::Parse(BoxReader* reader) {
 534   RCHECK(reader->ScanChildren() &&
 535          reader->ReadChild(&header) &&
 536          reader->ReadChild(&media) &&
 537          reader->MaybeReadChild(&edit));
 538   return true;
 539 }
 540
 541 MovieExtendsHeader::MovieExtendsHeader() : fragment_duration(0) {}
 542 MovieExtendsHeader::~MovieExtendsHeader() {}
 543 FourCC MovieExtendsHeader::BoxType() const { return FOURCC_MEHD; }
 544
 545 bool MovieExtendsHeader::Parse(BoxReader* reader) {
 546   RCHECK(reader->ReadFullBoxHeader());
 547   if (reader->version() == 1) {
 548     RCHECK(reader->Read8(&fragment_duration));
 549   } else {
 550     RCHECK(reader->Read4Into8(&fragment_duration));
 551   }
 552   return true;
 553 }
 554
 555 TrackExtends::TrackExtends()
 556     : track_id(0),
 557       default_sample_description_index(0),
 558       default_sample_duration(0),
 559       default_sample_size(0),
 560       default_sample_flags(0) {}
 561 TrackExtends::~TrackExtends() {}
 562 FourCC TrackExtends::BoxType() const { return FOURCC_TREX; }
 563
 564 bool TrackExtends::Parse(BoxReader* reader) {
 565   RCHECK(reader->ReadFullBoxHeader() &&
 566          reader->Read4(&track_id) &&
 567          reader->Read4(&default_sample_description_index) &&
 568          reader->Read4(&default_sample_duration) &&
 569          reader->Read4(&default_sample_size) &&
 570          reader->Read4(&default_sample_flags));
 571   return true;
 572 }
 573
 574 MovieExtends::MovieExtends() {}
 575 MovieExtends::~MovieExtends() {}
 576 FourCC MovieExtends::BoxType() const { return FOURCC_MVEX; }
 577
 578 bool MovieExtends::Parse(BoxReader* reader) {
 579   header.fragment_duration = 0;
 580   return reader->ScanChildren() &&
 581          reader->MaybeReadChild(&header) &&
 582          reader->ReadChildren(&tracks);
 583 }
 584
 585 Movie::Movie() : fragmented(false) {}
 586 Movie::~Movie() {}
 587 FourCC Movie::BoxType() const { return FOURCC_MOOV; }
 588
 589 bool Movie::Parse(BoxReader* reader) {
 590   return reader->ScanChildren() &&
 591          reader->ReadChild(&header) &&
 592          reader->ReadChildren(&tracks) &&
 593          // Media Source specific: 'mvex' required
 594          reader->ReadChild(&extends) &&
 595          reader->MaybeReadChildren(&pssh);
 596 }
 597
 598 TrackFragmentDecodeTime::TrackFragmentDecodeTime() : decode_time(0) {}
 599 TrackFragmentDecodeTime::~TrackFragmentDecodeTime() {}
 600 FourCC TrackFragmentDecodeTime::BoxType() const { return FOURCC_TFDT; }
 601
 602 bool TrackFragmentDecodeTime::Parse(BoxReader* reader) {
 603   RCHECK(reader->ReadFullBoxHeader());
 604   if (reader->version() == 1)
 605     return reader->Read8(&decode_time);
 606   else
 607     return reader->Read4Into8(&decode_time);
 608 }
 609
 610 MovieFragmentHeader::MovieFragmentHeader() : sequence_number(0) {}
 611 MovieFragmentHeader::~MovieFragmentHeader() {}
 612 FourCC MovieFragmentHeader::BoxType() const { return FOURCC_MFHD; }
 613
 614 bool MovieFragmentHeader::Parse(BoxReader* reader) {
 615   return reader->SkipBytes(4) && reader->Read4(&sequence_number);
 616 }
 617
 618 TrackFragmentHeader::TrackFragmentHeader()
 619     : track_id(0),
 620       sample_description_index(0),
 621       default_sample_duration(0),
 622       default_sample_size(0),
 623       default_sample_flags(0),
 624       has_default_sample_flags(false) {}
 625
 626 TrackFragmentHeader::~TrackFragmentHeader() {}
 627 FourCC TrackFragmentHeader::BoxType() const { return FOURCC_TFHD; }
 628
 629 bool TrackFragmentHeader::Parse(BoxReader* reader) {
 630   RCHECK(reader->ReadFullBoxHeader() && reader->Read4(&track_id));
 631
 632   // Media Source specific: reject tracks that set 'base-data-offset-present'.
 633   // Although the Media Source requires that 'default-base-is-moof' (14496-12
 634   // Amendment 2) be set, we omit this check as many otherwise-valid files in
 635   // the wild don't set it.
 636   //
 637   //  RCHECK((flags & 0x020000) && !(flags & 0x1));
 638   RCHECK(!(reader->flags() & 0x1));
 639
 640   if (reader->flags() & 0x2) {
 641     RCHECK(reader->Read4(&sample_description_index));
 642   } else {
 643     sample_description_index = 0;
 644   }
 645
 646   if (reader->flags() & 0x8) {
 647     RCHECK(reader->Read4(&default_sample_duration));
 648   } else {
 649     default_sample_duration = 0;
 650   }
 651
 652   if (reader->flags() & 0x10) {
 653     RCHECK(reader->Read4(&default_sample_size));
 654   } else {
 655     default_sample_size = 0;
 656   }
 657
 658   if (reader->flags() & 0x20) {
 659     RCHECK(reader->Read4(&default_sample_flags));
 660     has_default_sample_flags = true;
 661   } else {
 662     has_default_sample_flags = false;
 663   }
 664
 665   return true;
 666 }
 667
 668 TrackFragmentRun::TrackFragmentRun()
 669     : sample_count(0), data_offset(0) {}
 670 TrackFragmentRun::~TrackFragmentRun() {}
 671 FourCC TrackFragmentRun::BoxType() const { return FOURCC_TRUN; }
 672
 673 bool TrackFragmentRun::Parse(BoxReader* reader) {
 674   RCHECK(reader->ReadFullBoxHeader() &&
 675          reader->Read4(&sample_count));
 676   const uint32 flags = reader->flags();
 677
 678   bool data_offset_present = (flags & 0x1) != 0;
 679   bool first_sample_flags_present = (flags & 0x4) != 0;
 680   bool sample_duration_present = (flags & 0x100) != 0;
 681   bool sample_size_present = (flags & 0x200) != 0;
 682   bool sample_flags_present = (flags & 0x400) != 0;
 683   bool sample_composition_time_offsets_present = (flags & 0x800) != 0;
 684
 685   if (data_offset_present) {
 686     RCHECK(reader->Read4(&data_offset));
 687   } else {
 688     data_offset = 0;
 689   }
 690
 691   uint32 first_sample_flags;
 692   if (first_sample_flags_present)
 693     RCHECK(reader->Read4(&first_sample_flags));
 694
 695   int fields = sample_duration_present + sample_size_present +
 696       sample_flags_present + sample_composition_time_offsets_present;
 697   RCHECK(reader->HasBytes(fields * sample_count));
 698
 699   if (sample_duration_present)
 700     sample_durations.resize(sample_count);
 701   if (sample_size_present)
 702     sample_sizes.resize(sample_count);
 703   if (sample_flags_present)
 704     sample_flags.resize(sample_count);
 705   if (sample_composition_time_offsets_present)
 706     sample_composition_time_offsets.resize(sample_count);
 707
 708   for (uint32 i = 0; i < sample_count; ++i) {
 709     if (sample_duration_present)
 710       RCHECK(reader->Read4(&sample_durations[i]));
 711     if (sample_size_present)
 712       RCHECK(reader->Read4(&sample_sizes[i]));
 713     if (sample_flags_present)
 714       RCHECK(reader->Read4(&sample_flags[i]));
 715     if (sample_composition_time_offsets_present)
 716       RCHECK(reader->Read4s(&sample_composition_time_offsets[i]));
 717   }
 718
 719   if (first_sample_flags_present) {
 720     if (sample_flags.size() == 0) {
 721       sample_flags.push_back(first_sample_flags);
 722     } else {
 723       sample_flags[0] = first_sample_flags;
 724     }
 725   }
 726   return true;
 727 }
 728
 729 TrackFragment::TrackFragment() {}
 730 TrackFragment::~TrackFragment() {}
 731 FourCC TrackFragment::BoxType() const { return FOURCC_TRAF; }
 732
 733 bool TrackFragment::Parse(BoxReader* reader) {
 734   return reader->ScanChildren() &&
 735          reader->ReadChild(&header) &&
 736          // Media Source specific: 'tfdt' required
 737          reader->ReadChild(&decode_time) &&
 738          reader->MaybeReadChildren(&runs) &&
 739          reader->MaybeReadChild(&auxiliary_offset) &&
 740          reader->MaybeReadChild(&auxiliary_size);
 741 }
 742
 743 MovieFragment::MovieFragment() {}
 744 MovieFragment::~MovieFragment() {}
 745 FourCC MovieFragment::BoxType() const { return FOURCC_MOOF; }
 746
 747 bool MovieFragment::Parse(BoxReader* reader) {
 748   RCHECK(reader->ScanChildren() &&
 749          reader->ReadChild(&header) &&
 750          reader->ReadChildren(&tracks) &&
 751          reader->MaybeReadChildren(&pssh));
 752   return true;
 753 }
 754
 755 }  // namespace mp4
 756 }  // namespace media