media/formats/webm/webm_tracks_parser.cc

   1 // Copyright 2014 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/formats/webm/webm_tracks_parser.h"
   6
   7 #include "base/logging.h"
   8 #include "base/strings/string_number_conversions.h"
   9 #include "base/strings/string_util.h"
  10 #include "media/base/timestamp_constants.h"
  11 #include "media/formats/webm/webm_constants.h"
  12 #include "media/formats/webm/webm_content_encodings.h"
  13
  14 namespace media {
  15
  16 static TextKind CodecIdToTextKind(const std::string& codec_id) {
  17   if (codec_id == kWebMCodecSubtitles)
  18     return kTextSubtitles;
  19
  20   if (codec_id == kWebMCodecCaptions)
  21     return kTextCaptions;
  22
  23   if (codec_id == kWebMCodecDescriptions)
  24     return kTextDescriptions;
  25
  26   if (codec_id == kWebMCodecMetadata)
  27     return kTextMetadata;
  28
  29   return kTextNone;
  30 }
  31
  32 static base::TimeDelta PrecisionCappedDefaultDuration(
  33     const double timecode_scale_in_us, const int64 duration_in_ns) {
  34   if (duration_in_ns <= 0)
  35     return kNoTimestamp();
  36
  37   int64 mult = duration_in_ns / 1000;
  38   mult /= timecode_scale_in_us;
  39   if (mult == 0)
  40     return kNoTimestamp();
  41
  42   mult = static_cast<double>(mult) * timecode_scale_in_us;
  43   return base::TimeDelta::FromMicroseconds(mult);
  44 }
  45
  46 WebMTracksParser::WebMTracksParser(const scoped_refptr<MediaLog>& media_log,
  47                                    bool ignore_text_tracks)
  48     : track_type_(-1),
  49       track_num_(-1),
  50       seek_preroll_(-1),
  51       codec_delay_(-1),
  52       default_duration_(-1),
  53       audio_track_num_(-1),
  54       audio_default_duration_(-1),
  55       video_track_num_(-1),
  56       video_default_duration_(-1),
  57       ignore_text_tracks_(ignore_text_tracks),
  58       media_log_(media_log),
  59       audio_client_(media_log),
  60       video_client_(media_log) {
  61 }
  62
  63 WebMTracksParser::~WebMTracksParser() {}
  64
  65 int WebMTracksParser::Parse(const uint8* buf, int size) {
  66   track_type_ =-1;
  67   track_num_ = -1;
  68   default_duration_ = -1;
  69   track_name_.clear();
  70   track_language_.clear();
  71   audio_track_num_ = -1;
  72   audio_default_duration_ = -1;
  73   audio_decoder_config_ = AudioDecoderConfig();
  74   video_track_num_ = -1;
  75   video_default_duration_ = -1;
  76   video_decoder_config_ = VideoDecoderConfig();
  77   text_tracks_.clear();
  78   ignored_tracks_.clear();
  79
  80   WebMListParser parser(kWebMIdTracks, this);
  81   int result = parser.Parse(buf, size);
  82
  83   if (result <= 0)
  84     return result;
  85
  86   // For now we do all or nothing parsing.
  87   return parser.IsParsingComplete() ? result : 0;
  88 }
  89
  90 base::TimeDelta WebMTracksParser::GetAudioDefaultDuration(
  91     const double timecode_scale_in_us) const {
  92   return PrecisionCappedDefaultDuration(timecode_scale_in_us,
  93                                         audio_default_duration_);
  94 }
  95
  96 base::TimeDelta WebMTracksParser::GetVideoDefaultDuration(
  97     const double timecode_scale_in_us) const {
  98   return PrecisionCappedDefaultDuration(timecode_scale_in_us,
  99                                         video_default_duration_);
 100 }
 101
 102 WebMParserClient* WebMTracksParser::OnListStart(int id) {
 103   if (id == kWebMIdContentEncodings) {
 104     DCHECK(!track_content_encodings_client_.get());
 105     track_content_encodings_client_.reset(
 106         new WebMContentEncodingsClient(media_log_));
 107     return track_content_encodings_client_->OnListStart(id);
 108   }
 109
 110   if (id == kWebMIdTrackEntry) {
 111     track_type_ = -1;
 112     track_num_ = -1;
 113     default_duration_ = -1;
 114     track_name_.clear();
 115     track_language_.clear();
 116     codec_id_ = "";
 117     codec_private_.clear();
 118     audio_client_.Reset();
 119     video_client_.Reset();
 120     return this;
 121   }
 122
 123   if (id == kWebMIdAudio)
 124     return &audio_client_;
 125
 126   if (id == kWebMIdVideo)
 127     return &video_client_;
 128
 129   return this;
 130 }
 131
 132 bool WebMTracksParser::OnListEnd(int id) {
 133   if (id == kWebMIdContentEncodings) {
 134     DCHECK(track_content_encodings_client_.get());
 135     return track_content_encodings_client_->OnListEnd(id);
 136   }
 137
 138   if (id == kWebMIdTrackEntry) {
 139     if (track_type_ == -1 || track_num_ == -1) {
 140       MEDIA_LOG(ERROR, media_log_) << "Missing TrackEntry data for "
 141                                    << " TrackType " << track_type_
 142                                    << " TrackNum " << track_num_;
 143       return false;
 144     }
 145
 146     if (track_type_ != kWebMTrackTypeAudio &&
 147         track_type_ != kWebMTrackTypeVideo &&
 148         track_type_ != kWebMTrackTypeSubtitlesOrCaptions &&
 149         track_type_ != kWebMTrackTypeDescriptionsOrMetadata) {
 150       MEDIA_LOG(ERROR, media_log_) << "Unexpected TrackType " << track_type_;
 151       return false;
 152     }
 153
 154     TextKind text_track_kind = kTextNone;
 155     if (track_type_ == kWebMTrackTypeSubtitlesOrCaptions) {
 156       text_track_kind = CodecIdToTextKind(codec_id_);
 157       if (text_track_kind == kTextNone) {
 158         MEDIA_LOG(ERROR, media_log_) << "Missing TrackEntry CodecID"
 159                                      << " TrackNum " << track_num_;
 160         return false;
 161       }
 162
 163       if (text_track_kind != kTextSubtitles &&
 164           text_track_kind != kTextCaptions) {
 165         MEDIA_LOG(ERROR, media_log_) << "Wrong TrackEntry CodecID"
 166                                      << " TrackNum " << track_num_;
 167         return false;
 168       }
 169     } else if (track_type_ == kWebMTrackTypeDescriptionsOrMetadata) {
 170       text_track_kind = CodecIdToTextKind(codec_id_);
 171       if (text_track_kind == kTextNone) {
 172         MEDIA_LOG(ERROR, media_log_) << "Missing TrackEntry CodecID"
 173                                      << " TrackNum " << track_num_;
 174         return false;
 175       }
 176
 177       if (text_track_kind != kTextDescriptions &&
 178           text_track_kind != kTextMetadata) {
 179         MEDIA_LOG(ERROR, media_log_) << "Wrong TrackEntry CodecID"
 180                                      << " TrackNum " << track_num_;
 181         return false;
 182       }
 183     }
 184
 185     std::string encryption_key_id;
 186     if (track_content_encodings_client_) {
 187       DCHECK(!track_content_encodings_client_->content_encodings().empty());
 188       // If we have multiple ContentEncoding in one track. Always choose the
 189       // key id in the first ContentEncoding as the key id of the track.
 190       encryption_key_id = track_content_encodings_client_->
 191           content_encodings()[0]->encryption_key_id();
 192     }
 193
 194     if (track_type_ == kWebMTrackTypeAudio) {
 195       if (audio_track_num_ == -1) {
 196         audio_track_num_ = track_num_;
 197         audio_encryption_key_id_ = encryption_key_id;
 198
 199         if (default_duration_ == 0) {
 200           MEDIA_LOG(ERROR, media_log_) << "Illegal 0ns audio TrackEntry "
 201                                           "DefaultDuration";
 202           return false;
 203         }
 204         audio_default_duration_ = default_duration_;
 205
 206         DCHECK(!audio_decoder_config_.IsValidConfig());
 207         if (!audio_client_.InitializeConfig(
 208                 codec_id_, codec_private_, seek_preroll_, codec_delay_,
 209                 !audio_encryption_key_id_.empty(), &audio_decoder_config_)) {
 210           return false;
 211         }
 212       } else {
 213         MEDIA_LOG(DEBUG, media_log_) << "Ignoring audio track " << track_num_;
 214         ignored_tracks_.insert(track_num_);
 215       }
 216     } else if (track_type_ == kWebMTrackTypeVideo) {
 217       if (video_track_num_ == -1) {
 218         video_track_num_ = track_num_;
 219         video_encryption_key_id_ = encryption_key_id;
 220
 221         if (default_duration_ == 0) {
 222           MEDIA_LOG(ERROR, media_log_) << "Illegal 0ns video TrackEntry "
 223                                           "DefaultDuration";
 224           return false;
 225         }
 226         video_default_duration_ = default_duration_;
 227
 228         DCHECK(!video_decoder_config_.IsValidConfig());
 229         if (!video_client_.InitializeConfig(
 230                 codec_id_, codec_private_, !video_encryption_key_id_.empty(),
 231                 &video_decoder_config_)) {
 232           return false;
 233         }
 234       } else {
 235         MEDIA_LOG(DEBUG, media_log_) << "Ignoring video track " << track_num_;
 236         ignored_tracks_.insert(track_num_);
 237       }
 238     } else if (track_type_ == kWebMTrackTypeSubtitlesOrCaptions ||
 239                track_type_ == kWebMTrackTypeDescriptionsOrMetadata) {
 240       if (ignore_text_tracks_) {
 241         MEDIA_LOG(DEBUG, media_log_) << "Ignoring text track " << track_num_;
 242         ignored_tracks_.insert(track_num_);
 243       } else {
 244         std::string track_num = base::Int64ToString(track_num_);
 245         text_tracks_[track_num_] = TextTrackConfig(
 246             text_track_kind, track_name_, track_language_, track_num);
 247       }
 248     } else {
 249       MEDIA_LOG(ERROR, media_log_) << "Unexpected TrackType " << track_type_;
 250       return false;
 251     }
 252
 253     track_type_ = -1;
 254     track_num_ = -1;
 255     default_duration_ = -1;
 256     track_name_.clear();
 257     track_language_.clear();
 258     codec_id_ = "";
 259     codec_private_.clear();
 260     track_content_encodings_client_.reset();
 261
 262     audio_client_.Reset();
 263     video_client_.Reset();
 264     return true;
 265   }
 266
 267   return true;
 268 }
 269
 270 bool WebMTracksParser::OnUInt(int id, int64 val) {
 271   int64* dst = NULL;
 272
 273   switch (id) {
 274     case kWebMIdTrackNumber:
 275       dst = &track_num_;
 276       break;
 277     case kWebMIdTrackType:
 278       dst = &track_type_;
 279       break;
 280     case kWebMIdSeekPreRoll:
 281       dst = &seek_preroll_;
 282       break;
 283     case kWebMIdCodecDelay:
 284       dst = &codec_delay_;
 285       break;
 286     case kWebMIdDefaultDuration:
 287       dst = &default_duration_;
 288       break;
 289     default:
 290       return true;
 291   }
 292
 293   if (*dst != -1) {
 294     MEDIA_LOG(ERROR, media_log_) << "Multiple values for id " << std::hex << id
 295                                  << " specified";
 296     return false;
 297   }
 298
 299   *dst = val;
 300   return true;
 301 }
 302
 303 bool WebMTracksParser::OnFloat(int id, double val) {
 304   return true;
 305 }
 306
 307 bool WebMTracksParser::OnBinary(int id, const uint8* data, int size) {
 308   if (id == kWebMIdCodecPrivate) {
 309     if (!codec_private_.empty()) {
 310       MEDIA_LOG(ERROR, media_log_)
 311           << "Multiple CodecPrivate fields in a track.";
 312       return false;
 313     }
 314     codec_private_.assign(data, data + size);
 315     return true;
 316   }
 317   return true;
 318 }
 319
 320 bool WebMTracksParser::OnString(int id, const std::string& str) {
 321   if (id == kWebMIdCodecID) {
 322     if (!codec_id_.empty()) {
 323       MEDIA_LOG(ERROR, media_log_) << "Multiple CodecID fields in a track";
 324       return false;
 325     }
 326
 327     codec_id_ = str;
 328     return true;
 329   }
 330
 331   if (id == kWebMIdName) {
 332     track_name_ = str;
 333     return true;
 334   }
 335
 336   if (id == kWebMIdLanguage) {
 337     track_language_ = str;
 338     return true;
 339   }
 340
 341   return true;
 342 }
 343
 344 }  // namespace media