media/mp4/mp4_stream_parser.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/mp4_stream_parser.h"
   6
   7 #include "base/callback.h"
   8 #include "base/callback_helpers.h"
   9 #include "base/logging.h"
  10 #include "base/time.h"
  11 #include "media/base/audio_decoder_config.h"
  12 #include "media/base/stream_parser_buffer.h"
  13 #include "media/base/video_decoder_config.h"
  14 #include "media/base/video_util.h"
  15 #include "media/mp4/box_definitions.h"
  16 #include "media/mp4/box_reader.h"
  17 #include "media/mp4/es_descriptor.h"
  18 #include "media/mp4/rcheck.h"
  19
  20 namespace media {
  21 namespace mp4 {
  22
  23 // TODO(xhwang): Figure out the init data type appropriately once it's spec'ed.
  24 static const char kMp4InitDataType[] = "video/mp4";
  25
  26 MP4StreamParser::MP4StreamParser(const std::set<int>& audio_object_types,
  27                                  bool has_sbr)
  28     : state_(kWaitingForInit),
  29       moof_head_(0),
  30       mdat_tail_(0),
  31       has_audio_(false),
  32       has_video_(false),
  33       audio_track_id_(0),
  34       video_track_id_(0),
  35       audio_object_types_(audio_object_types),
  36       has_sbr_(has_sbr),
  37       is_audio_track_encrypted_(false),
  38       is_video_track_encrypted_(false) {
  39 }
  40
  41 MP4StreamParser::~MP4StreamParser() {}
  42
  43 void MP4StreamParser::Init(const InitCB& init_cb,
  44                            const NewConfigCB& config_cb,
  45                            const NewBuffersCB& audio_cb,
  46                            const NewBuffersCB& video_cb,
  47                            const NeedKeyCB& need_key_cb,
  48                            const NewMediaSegmentCB& new_segment_cb,
  49                            const base::Closure& end_of_segment_cb,
  50                            const LogCB& log_cb) {
  51   DCHECK_EQ(state_, kWaitingForInit);
  52   DCHECK(init_cb_.is_null());
  53   DCHECK(!init_cb.is_null());
  54   DCHECK(!config_cb.is_null());
  55   DCHECK(!audio_cb.is_null() || !video_cb.is_null());
  56   DCHECK(!need_key_cb.is_null());
  57   DCHECK(!end_of_segment_cb.is_null());
  58
  59   ChangeState(kParsingBoxes);
  60   init_cb_ = init_cb;
  61   config_cb_ = config_cb;
  62   audio_cb_ = audio_cb;
  63   video_cb_ = video_cb;
  64   need_key_cb_ = need_key_cb;
  65   new_segment_cb_ = new_segment_cb;
  66   end_of_segment_cb_ = end_of_segment_cb;
  67   log_cb_ = log_cb;
  68 }
  69
  70 void MP4StreamParser::Reset() {
  71   queue_.Reset();
  72   moov_.reset();
  73   runs_.reset();
  74   moof_head_ = 0;
  75   mdat_tail_ = 0;
  76 }
  77
  78 void MP4StreamParser::Flush() {
  79   DCHECK_NE(state_, kWaitingForInit);
  80   Reset();
  81   ChangeState(kParsingBoxes);
  82 }
  83
  84 bool MP4StreamParser::Parse(const uint8* buf, int size) {
  85   DCHECK_NE(state_, kWaitingForInit);
  86
  87   if (state_ == kError)
  88     return false;
  89
  90   queue_.Push(buf, size);
  91
  92   BufferQueue audio_buffers;
  93   BufferQueue video_buffers;
  94
  95   bool result, err = false;
  96
  97   do {
  98     if (state_ == kParsingBoxes) {
  99       result = ParseBox(&err);
 100     } else {
 101       DCHECK_EQ(kEmittingSamples, state_);
 102       result = EnqueueSample(&audio_buffers, &video_buffers, &err);
 103       if (result) {
 104         int64 max_clear = runs_->GetMaxClearOffset() + moof_head_;
 105         err = !ReadAndDiscardMDATsUntil(max_clear);
 106       }
 107     }
 108   } while (result && !err);
 109
 110   if (!err)
 111     err = !SendAndFlushSamples(&audio_buffers, &video_buffers);
 112
 113   if (err) {
 114     DLOG(ERROR) << "Error while parsing MP4";
 115     Reset();
 116     ChangeState(kError);
 117     return false;
 118   }
 119
 120   return true;
 121 }
 122
 123 bool MP4StreamParser::ParseBox(bool* err) {
 124   const uint8* buf;
 125   int size;
 126   queue_.Peek(&buf, &size);
 127   if (!size) return false;
 128
 129   scoped_ptr<BoxReader> reader(
 130       BoxReader::ReadTopLevelBox(buf, size, log_cb_, err));
 131   if (reader.get() == NULL) return false;
 132
 133   if (reader->type() == FOURCC_MOOV) {
 134     *err = !ParseMoov(reader.get());
 135   } else if (reader->type() == FOURCC_MOOF) {
 136     moof_head_ = queue_.head();
 137     *err = !ParseMoof(reader.get());
 138
 139     // Set up first mdat offset for ReadMDATsUntil().
 140     mdat_tail_ = queue_.head() + reader->size();
 141
 142     // Return early to avoid evicting 'moof' data from queue. Auxiliary info may
 143     // be located anywhere in the file, including inside the 'moof' itself.
 144     // (Since 'default-base-is-moof' is mandated, no data references can come
 145     // before the head of the 'moof', so keeping this box around is sufficient.)
 146     return !(*err);
 147   } else {
 148     MEDIA_LOG(log_cb_) << "Skipping unrecognized top-level box: "
 149                        << FourCCToString(reader->type());
 150   }
 151
 152   queue_.Pop(reader->size());
 153   return !(*err);
 154 }
 155
 156
 157 bool MP4StreamParser::ParseMoov(BoxReader* reader) {
 158   moov_.reset(new Movie);
 159   RCHECK(moov_->Parse(reader));
 160   runs_.reset(new TrackRunIterator(moov_.get(), log_cb_));
 161
 162   has_audio_ = false;
 163   has_video_ = false;
 164
 165   AudioDecoderConfig audio_config;
 166   VideoDecoderConfig video_config;
 167
 168   for (std::vector<Track>::const_iterator track = moov_->tracks.begin();
 169        track != moov_->tracks.end(); ++track) {
 170     // TODO(strobe): Only the first audio and video track present in a file are
 171     // used. (Track selection is better accomplished via Source IDs, though, so
 172     // adding support for track selection within a stream is low-priority.)
 173     const SampleDescription& samp_descr =
 174         track->media.information.sample_table.description;
 175
 176     // TODO(strobe): When codec reconfigurations are supported, detect and send
 177     // a codec reconfiguration for fragments using a sample description index
 178     // different from the previous one
 179     size_t desc_idx = 0;
 180     for (size_t t = 0; t < moov_->extends.tracks.size(); t++) {
 181       const TrackExtends& trex = moov_->extends.tracks[t];
 182       if (trex.track_id == track->header.track_id) {
 183         desc_idx = trex.default_sample_description_index;
 184         break;
 185       }
 186     }
 187     RCHECK(desc_idx > 0);
 188     desc_idx -= 1;  // BMFF descriptor index is one-based
 189
 190     if (track->media.handler.type == kAudio && !audio_config.IsValidConfig()) {
 191       RCHECK(!samp_descr.audio_entries.empty());
 192
 193       // It is not uncommon to find otherwise-valid files with incorrect sample
 194       // description indices, so we fail gracefully in that case.
 195       if (desc_idx >= samp_descr.audio_entries.size())
 196         desc_idx = 0;
 197       const AudioSampleEntry& entry = samp_descr.audio_entries[desc_idx];
 198       const AAC& aac = entry.esds.aac;
 199
 200       if (!(entry.format == FOURCC_MP4A ||
 201             (entry.format == FOURCC_ENCA &&
 202              entry.sinf.format.format == FOURCC_MP4A))) {
 203         MEDIA_LOG(log_cb_) << "Unsupported audio format 0x"
 204                            << std::hex << entry.format << " in stsd box.";
 205         return false;
 206       }
 207
 208       int audio_type = entry.esds.object_type;
 209       DVLOG(1) << "audio_type " << std::hex << audio_type;
 210       if (audio_object_types_.find(audio_type) == audio_object_types_.end()) {
 211         MEDIA_LOG(log_cb_) << "audio object type 0x" << std::hex << audio_type
 212                            << " does not match what is specified in the"
 213                            << " mimetype.";
 214         return false;
 215       }
 216
 217       // Check if it is MPEG4 AAC defined in ISO 14496 Part 3 or
 218       // supported MPEG2 AAC varients.
 219       if (audio_type != kISO_14496_3 && audio_type != kISO_13818_7_AAC_LC) {
 220         MEDIA_LOG(log_cb_) << "Unsupported audio object type 0x" << std::hex
 221                            << audio_type << " in esds.";
 222         return false;
 223       }
 224
 225       SampleFormat sample_format;
 226       if (entry.samplesize == 8) {
 227         sample_format = kSampleFormatU8;
 228       } else if (entry.samplesize == 16) {
 229         sample_format = kSampleFormatS16;
 230       } else if (entry.samplesize == 32) {
 231         sample_format = kSampleFormatS32;
 232       } else {
 233         LOG(ERROR) << "Unsupported sample size.";
 234         return false;
 235       }
 236
 237       is_audio_track_encrypted_ = entry.sinf.info.track_encryption.is_encrypted;
 238       DVLOG(1) << "is_audio_track_encrypted_: " << is_audio_track_encrypted_;
 239       audio_config.Initialize(kCodecAAC, sample_format,
 240                               aac.GetChannelLayout(has_sbr_),
 241                               aac.GetOutputSamplesPerSecond(has_sbr_),
 242                               NULL, 0, is_audio_track_encrypted_, false);
 243       has_audio_ = true;
 244       audio_track_id_ = track->header.track_id;
 245     }
 246     if (track->media.handler.type == kVideo && !video_config.IsValidConfig()) {
 247       RCHECK(!samp_descr.video_entries.empty());
 248       if (desc_idx >= samp_descr.video_entries.size())
 249         desc_idx = 0;
 250       const VideoSampleEntry& entry = samp_descr.video_entries[desc_idx];
 251
 252       if (!(entry.format == FOURCC_AVC1 ||
 253             (entry.format == FOURCC_ENCV &&
 254              entry.sinf.format.format == FOURCC_AVC1))) {
 255         MEDIA_LOG(log_cb_) << "Unsupported video format 0x"
 256                            << std::hex << entry.format << " in stsd box.";
 257         return false;
 258       }
 259
 260       // TODO(strobe): Recover correct crop box
 261       gfx::Size coded_size(entry.width, entry.height);
 262       gfx::Rect visible_rect(coded_size);
 263       gfx::Size natural_size = GetNaturalSize(visible_rect.size(),
 264                                               entry.pixel_aspect.h_spacing,
 265                                               entry.pixel_aspect.v_spacing);
 266       is_video_track_encrypted_ = entry.sinf.info.track_encryption.is_encrypted;
 267       DVLOG(1) << "is_video_track_encrypted_: " << is_video_track_encrypted_;
 268       video_config.Initialize(kCodecH264, H264PROFILE_MAIN,  VideoFrame::YV12,
 269                               coded_size, visible_rect, natural_size,
 270                               // No decoder-specific buffer needed for AVC;
 271                               // SPS/PPS are embedded in the video stream
 272                               NULL, 0, is_video_track_encrypted_, true);
 273       has_video_ = true;
 274       video_track_id_ = track->header.track_id;
 275     }
 276   }
 277
 278   RCHECK(config_cb_.Run(audio_config, video_config));
 279
 280   base::TimeDelta duration;
 281   if (moov_->extends.header.fragment_duration > 0) {
 282     duration = TimeDeltaFromRational(moov_->extends.header.fragment_duration,
 283                                      moov_->header.timescale);
 284   } else if (moov_->header.duration > 0 &&
 285              moov_->header.duration != kuint64max) {
 286     duration = TimeDeltaFromRational(moov_->header.duration,
 287                                      moov_->header.timescale);
 288   } else {
 289     duration = kInfiniteDuration();
 290   }
 291
 292   if (!init_cb_.is_null())
 293     base::ResetAndReturn(&init_cb_).Run(true, duration);
 294
 295   RCHECK(EmitNeedKeyIfNecessary(moov_->pssh));
 296   return true;
 297 }
 298
 299 bool MP4StreamParser::ParseMoof(BoxReader* reader) {
 300   RCHECK(moov_.get());  // Must already have initialization segment
 301   MovieFragment moof;
 302   RCHECK(moof.Parse(reader));
 303   RCHECK(runs_->Init(moof));
 304   RCHECK(EmitNeedKeyIfNecessary(moof.pssh));
 305   new_segment_cb_.Run(runs_->GetMinDecodeTimestamp());
 306   ChangeState(kEmittingSamples);
 307   return true;
 308 }
 309
 310 bool MP4StreamParser::EmitNeedKeyIfNecessary(
 311     const std::vector<ProtectionSystemSpecificHeader>& headers) {
 312   // TODO(strobe): ensure that the value of init_data (all PSSH headers
 313   // concatenated in arbitrary order) matches the EME spec.
 314   // See https://www.w3.org/Bugs/Public/show_bug.cgi?id=17673.
 315   if (headers.empty())
 316     return true;
 317
 318   size_t total_size = 0;
 319   for (size_t i = 0; i < headers.size(); i++)
 320     total_size += headers[i].raw_box.size();
 321
 322   scoped_ptr<uint8[]> init_data(new uint8[total_size]);
 323   size_t pos = 0;
 324   for (size_t i = 0; i < headers.size(); i++) {
 325     memcpy(&init_data.get()[pos], &headers[i].raw_box[0],
 326            headers[i].raw_box.size());
 327     pos += headers[i].raw_box.size();
 328   }
 329   return need_key_cb_.Run(kMp4InitDataType, init_data.Pass(), total_size);
 330 }
 331
 332 bool MP4StreamParser::PrepareAVCBuffer(
 333     const AVCDecoderConfigurationRecord& avc_config,
 334     std::vector<uint8>* frame_buf,
 335     std::vector<SubsampleEntry>* subsamples) const {
 336   // Convert the AVC NALU length fields to Annex B headers, as expected by
 337   // decoding libraries. Since this may enlarge the size of the buffer, we also
 338   // update the clear byte count for each subsample if encryption is used to
 339   // account for the difference in size between the length prefix and Annex B
 340   // start code.
 341   RCHECK(AVC::ConvertFrameToAnnexB(avc_config.length_size, frame_buf));
 342   if (!subsamples->empty()) {
 343     const int nalu_size_diff = 4 - avc_config.length_size;
 344     size_t expected_size = runs_->sample_size() +
 345         subsamples->size() * nalu_size_diff;
 346     RCHECK(frame_buf->size() == expected_size);
 347     for (size_t i = 0; i < subsamples->size(); i++)
 348       (*subsamples)[i].clear_bytes += nalu_size_diff;
 349   }
 350
 351   if (runs_->is_keyframe()) {
 352     // If this is a keyframe, we (re-)inject SPS and PPS headers at the start of
 353     // a frame. If subsample info is present, we also update the clear byte
 354     // count for that first subsample.
 355     std::vector<uint8> param_sets;
 356     RCHECK(AVC::ConvertConfigToAnnexB(avc_config, &param_sets));
 357     frame_buf->insert(frame_buf->begin(),
 358                       param_sets.begin(), param_sets.end());
 359     if (!subsamples->empty())
 360       (*subsamples)[0].clear_bytes += param_sets.size();
 361   }
 362   return true;
 363 }
 364
 365 bool MP4StreamParser::PrepareAACBuffer(
 366     const AAC& aac_config, std::vector<uint8>* frame_buf,
 367     std::vector<SubsampleEntry>* subsamples) const {
 368   // Append an ADTS header to every audio sample.
 369   RCHECK(aac_config.ConvertEsdsToADTS(frame_buf));
 370
 371   // As above, adjust subsample information to account for the headers. AAC is
 372   // not required to use subsample encryption, so we may need to add an entry.
 373   if (subsamples->empty()) {
 374     SubsampleEntry entry;
 375     entry.clear_bytes = AAC::kADTSHeaderSize;
 376     entry.cypher_bytes = frame_buf->size() - AAC::kADTSHeaderSize;
 377     subsamples->push_back(entry);
 378   } else {
 379     (*subsamples)[0].clear_bytes += AAC::kADTSHeaderSize;
 380   }
 381   return true;
 382 }
 383
 384 bool MP4StreamParser::EnqueueSample(BufferQueue* audio_buffers,
 385                                     BufferQueue* video_buffers,
 386                                     bool* err) {
 387   if (!runs_->IsRunValid()) {
 388     // Flush any buffers we've gotten in this chunk so that buffers don't
 389     // cross NewSegment() calls
 390     *err = !SendAndFlushSamples(audio_buffers, video_buffers);
 391     if (*err)
 392       return false;
 393
 394     // Remain in kEnqueueingSamples state, discarding data, until the end of
 395     // the current 'mdat' box has been appended to the queue.
 396     if (!queue_.Trim(mdat_tail_))
 397       return false;
 398
 399     ChangeState(kParsingBoxes);
 400     end_of_segment_cb_.Run();
 401     return true;
 402   }
 403
 404   if (!runs_->IsSampleValid()) {
 405     runs_->AdvanceRun();
 406     return true;
 407   }
 408
 409   DCHECK(!(*err));
 410
 411   const uint8* buf;
 412   int buf_size;
 413   queue_.Peek(&buf, &buf_size);
 414   if (!buf_size) return false;
 415
 416   bool audio = has_audio_ && audio_track_id_ == runs_->track_id();
 417   bool video = has_video_ && video_track_id_ == runs_->track_id();
 418
 419   // Skip this entire track if it's not one we're interested in
 420   if (!audio && !video)
 421     runs_->AdvanceRun();
 422
 423   // Attempt to cache the auxiliary information first. Aux info is usually
 424   // placed in a contiguous block before the sample data, rather than being
 425   // interleaved. If we didn't cache it, this would require that we retain the
 426   // start of the segment buffer while reading samples. Aux info is typically
 427   // quite small compared to sample data, so this pattern is useful on
 428   // memory-constrained devices where the source buffer consumes a substantial
 429   // portion of the total system memory.
 430   if (runs_->AuxInfoNeedsToBeCached()) {
 431     queue_.PeekAt(runs_->aux_info_offset() + moof_head_, &buf, &buf_size);
 432     if (buf_size < runs_->aux_info_size()) return false;
 433     *err = !runs_->CacheAuxInfo(buf, buf_size);
 434     return !*err;
 435   }
 436
 437   queue_.PeekAt(runs_->sample_offset() + moof_head_, &buf, &buf_size);
 438   if (buf_size < runs_->sample_size()) return false;
 439
 440   scoped_ptr<DecryptConfig> decrypt_config;
 441   std::vector<SubsampleEntry> subsamples;
 442   if (runs_->is_encrypted()) {
 443     decrypt_config = runs_->GetDecryptConfig();
 444     subsamples = decrypt_config->subsamples();
 445   }
 446
 447   std::vector<uint8> frame_buf(buf, buf + runs_->sample_size());
 448   if (video) {
 449     if (!PrepareAVCBuffer(runs_->video_description().avcc,
 450                           &frame_buf, &subsamples)) {
 451       MEDIA_LOG(log_cb_) << "Failed to prepare AVC sample for decode";
 452       *err = true;
 453       return false;
 454     }
 455   }
 456
 457   if (audio) {
 458     if (!PrepareAACBuffer(runs_->audio_description().esds.aac,
 459                           &frame_buf, &subsamples)) {
 460       MEDIA_LOG(log_cb_) << "Failed to prepare AAC sample for decode";
 461       *err = true;
 462       return false;
 463     }
 464   }
 465
 466   if (decrypt_config) {
 467     if (!subsamples.empty()) {
 468     // Create a new config with the updated subsamples.
 469     decrypt_config.reset(new DecryptConfig(
 470         decrypt_config->key_id(),
 471         decrypt_config->iv(),
 472         decrypt_config->data_offset(),
 473         subsamples));
 474     }
 475     // else, use the existing config.
 476   } else if ((audio && is_audio_track_encrypted_) ||
 477              (video && is_video_track_encrypted_)) {
 478     // The media pipeline requires a DecryptConfig with an empty |iv|.
 479     // TODO(ddorwin): Refactor so we do not need a fake key ID ("1");
 480     decrypt_config.reset(
 481         new DecryptConfig("1", "", 0, std::vector<SubsampleEntry>()));
 482   }
 483
 484   scoped_refptr<StreamParserBuffer> stream_buf =
 485     StreamParserBuffer::CopyFrom(&frame_buf[0], frame_buf.size(),
 486                                  runs_->is_keyframe());
 487
 488   if (decrypt_config)
 489     stream_buf->SetDecryptConfig(decrypt_config.Pass());
 490
 491   stream_buf->SetDuration(runs_->duration());
 492   stream_buf->SetTimestamp(runs_->cts());
 493   stream_buf->SetDecodeTimestamp(runs_->dts());
 494
 495   DVLOG(3) << "Pushing frame: aud=" << audio
 496            << ", key=" << runs_->is_keyframe()
 497            << ", dur=" << runs_->duration().InMilliseconds()
 498            << ", dts=" << runs_->dts().InMilliseconds()
 499            << ", cts=" << runs_->cts().InMilliseconds()
 500            << ", size=" << runs_->sample_size();
 501
 502   if (audio) {
 503     audio_buffers->push_back(stream_buf);
 504   } else {
 505     video_buffers->push_back(stream_buf);
 506   }
 507
 508   runs_->AdvanceSample();
 509   return true;
 510 }
 511
 512 bool MP4StreamParser::SendAndFlushSamples(BufferQueue* audio_buffers,
 513                                           BufferQueue* video_buffers) {
 514   bool err = false;
 515   if (!audio_buffers->empty()) {
 516     err |= (audio_cb_.is_null() || !audio_cb_.Run(*audio_buffers));
 517     audio_buffers->clear();
 518   }
 519   if (!video_buffers->empty()) {
 520     err |= (video_cb_.is_null() || !video_cb_.Run(*video_buffers));
 521     video_buffers->clear();
 522   }
 523   return !err;
 524 }
 525
 526 bool MP4StreamParser::ReadAndDiscardMDATsUntil(const int64 offset) {
 527   bool err = false;
 528   while (mdat_tail_ < offset) {
 529     const uint8* buf;
 530     int size;
 531     queue_.PeekAt(mdat_tail_, &buf, &size);
 532
 533     FourCC type;
 534     int box_sz;
 535     if (!BoxReader::StartTopLevelBox(buf, size, log_cb_,
 536                                      &type, &box_sz, &err))
 537       break;
 538
 539     if (type != FOURCC_MDAT) {
 540       MEDIA_LOG(log_cb_) << "Unexpected box type while parsing MDATs: "
 541                          << FourCCToString(type);
 542     }
 543     mdat_tail_ += box_sz;
 544   }
 545   queue_.Trim(std::min(mdat_tail_, offset));
 546   return !err;
 547 }
 548
 549 void MP4StreamParser::ChangeState(State new_state) {
 550   DVLOG(2) << "Changing state: " << new_state;
 551   state_ = new_state;
 552 }
 553
 554 }  // namespace mp4
 555 }  // namespace media