media/webm/webm_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/webm/webm_stream_parser.h"
   6
   7 #include <string>
   8
   9 #include "base/callback.h"
  10 #include "base/logging.h"
  11 #include "base/stl_util.h"
  12 #include "media/webm/webm_cluster_parser.h"
  13 #include "media/webm/webm_constants.h"
  14 #include "media/webm/webm_content_encodings.h"
  15 #include "media/webm/webm_crypto_helpers.h"
  16 #include "media/webm/webm_info_parser.h"
  17 #include "media/webm/webm_tracks_parser.h"
  18
  19 namespace media {
  20
  21 WebMStreamParser::WebMStreamParser()
  22     : state_(kWaitingForInit),
  23       waiting_for_buffers_(false) {
  24 }
  25
  26 WebMStreamParser::~WebMStreamParser() {
  27   STLDeleteValues(&text_track_map_);
  28 }
  29
  30 void WebMStreamParser::Init(const InitCB& init_cb,
  31                             const NewConfigCB& config_cb,
  32                             const NewBuffersCB& new_buffers_cb,
  33                             const NewTextBuffersCB& text_cb,
  34                             const NeedKeyCB& need_key_cb,
  35                             const AddTextTrackCB& add_text_track_cb,
  36                             const NewMediaSegmentCB& new_segment_cb,
  37                             const base::Closure& end_of_segment_cb,
  38                             const LogCB& log_cb) {
  39   DCHECK_EQ(state_, kWaitingForInit);
  40   DCHECK(init_cb_.is_null());
  41   DCHECK(!init_cb.is_null());
  42   DCHECK(!config_cb.is_null());
  43   DCHECK(!new_buffers_cb.is_null());
  44   DCHECK(!text_cb.is_null());
  45   DCHECK(!need_key_cb.is_null());
  46   DCHECK(!new_segment_cb.is_null());
  47   DCHECK(!end_of_segment_cb.is_null());
  48
  49   ChangeState(kParsingHeaders);
  50   init_cb_ = init_cb;
  51   config_cb_ = config_cb;
  52   new_buffers_cb_ = new_buffers_cb;
  53   text_cb_ = text_cb;
  54   need_key_cb_ = need_key_cb;
  55   add_text_track_cb_ = add_text_track_cb;
  56   new_segment_cb_ = new_segment_cb;
  57   end_of_segment_cb_ = end_of_segment_cb;
  58   log_cb_ = log_cb;
  59 }
  60
  61 void WebMStreamParser::Flush() {
  62   DCHECK_NE(state_, kWaitingForInit);
  63
  64   byte_queue_.Reset();
  65
  66   if (state_ != kParsingClusters)
  67     return;
  68
  69   cluster_parser_->Reset();
  70 }
  71
  72 bool WebMStreamParser::Parse(const uint8* buf, int size) {
  73   DCHECK_NE(state_, kWaitingForInit);
  74
  75   if (state_ == kError)
  76     return false;
  77
  78   byte_queue_.Push(buf, size);
  79
  80   int result = 0;
  81   int bytes_parsed = 0;
  82   const uint8* cur = NULL;
  83   int cur_size = 0;
  84
  85   byte_queue_.Peek(&cur, &cur_size);
  86   while (cur_size > 0) {
  87     State oldState = state_;
  88     switch (state_) {
  89       case kParsingHeaders:
  90         result = ParseInfoAndTracks(cur, cur_size);
  91         break;
  92
  93       case kParsingClusters:
  94         result = ParseCluster(cur, cur_size);
  95         break;
  96
  97       case kWaitingForInit:
  98       case kError:
  99         return false;
 100     }
 101
 102     if (result < 0) {
 103       ChangeState(kError);
 104       return false;
 105     }
 106
 107     if (state_ == oldState && result == 0)
 108       break;
 109
 110     DCHECK_GE(result, 0);
 111     cur += result;
 112     cur_size -= result;
 113     bytes_parsed += result;
 114   }
 115
 116   byte_queue_.Pop(bytes_parsed);
 117   return true;
 118 }
 119
 120 void WebMStreamParser::ChangeState(State new_state) {
 121   DVLOG(1) << "ChangeState() : " << state_ << " -> " << new_state;
 122   state_ = new_state;
 123 }
 124
 125 int WebMStreamParser::ParseInfoAndTracks(const uint8* data, int size) {
 126   DVLOG(2) << "ParseInfoAndTracks()";
 127   DCHECK(data);
 128   DCHECK_GT(size, 0);
 129
 130   const uint8* cur = data;
 131   int cur_size = size;
 132   int bytes_parsed = 0;
 133
 134   int id;
 135   int64 element_size;
 136   int result = WebMParseElementHeader(cur, cur_size, &id, &element_size);
 137
 138   if (result <= 0)
 139     return result;
 140
 141   switch (id) {
 142     case kWebMIdEBMLHeader:
 143     case kWebMIdSeekHead:
 144     case kWebMIdVoid:
 145     case kWebMIdCRC32:
 146     case kWebMIdCues:
 147     case kWebMIdChapters:
 148       if (cur_size < (result + element_size)) {
 149         // We don't have the whole element yet. Signal we need more data.
 150         return 0;
 151       }
 152       // Skip the element.
 153       return result + element_size;
 154       break;
 155     case kWebMIdSegment:
 156       // Just consume the segment header.
 157       return result;
 158       break;
 159     case kWebMIdInfo:
 160       // We've found the element we are looking for.
 161       break;
 162     default: {
 163       MEDIA_LOG(log_cb_) << "Unexpected element ID 0x" << std::hex << id;
 164       return -1;
 165     }
 166   }
 167
 168   WebMInfoParser info_parser;
 169   result = info_parser.Parse(cur, cur_size);
 170
 171   if (result <= 0)
 172     return result;
 173
 174   cur += result;
 175   cur_size -= result;
 176   bytes_parsed += result;
 177
 178   WebMTracksParser tracks_parser(log_cb_, add_text_track_cb_.is_null());
 179   result = tracks_parser.Parse(cur, cur_size);
 180
 181   if (result <= 0)
 182     return result;
 183
 184   bytes_parsed += result;
 185
 186   base::TimeDelta duration = kInfiniteDuration();
 187
 188   if (info_parser.duration() > 0) {
 189     double mult = info_parser.timecode_scale() / 1000.0;
 190     int64 duration_in_us = info_parser.duration() * mult;
 191     duration = base::TimeDelta::FromMicroseconds(duration_in_us);
 192   }
 193
 194   const AudioDecoderConfig& audio_config = tracks_parser.audio_decoder_config();
 195   if (audio_config.is_encrypted())
 196     FireNeedKey(tracks_parser.audio_encryption_key_id());
 197
 198   const VideoDecoderConfig& video_config = tracks_parser.video_decoder_config();
 199   if (video_config.is_encrypted())
 200     FireNeedKey(tracks_parser.video_encryption_key_id());
 201
 202   if (!config_cb_.Run(audio_config, video_config)) {
 203     DVLOG(1) << "New config data isn't allowed.";
 204     return -1;
 205   }
 206
 207   typedef WebMTracksParser::TextTracks TextTracks;
 208   const TextTracks& text_tracks = tracks_parser.text_tracks();
 209
 210   for (TextTracks::const_iterator itr = text_tracks.begin();
 211        itr != text_tracks.end(); ++itr) {
 212     const WebMTracksParser::TextTrackInfo& text_track_info = itr->second;
 213
 214     // TODO(matthewjheaney): verify that WebVTT uses ISO 639-2 for lang
 215     scoped_ptr<TextTrack> text_track =
 216         add_text_track_cb_.Run(text_track_info.kind,
 217                                text_track_info.name,
 218                                text_track_info.language);
 219
 220     // Assume ownership of pointer, and cache the text track object, for use
 221     // later when we have text track buffers. (The text track objects are
 222     // deallocated in the dtor for this class.)
 223
 224     if (text_track)
 225       text_track_map_.insert(std::make_pair(itr->first, text_track.release()));
 226   }
 227
 228   cluster_parser_.reset(new WebMClusterParser(
 229       info_parser.timecode_scale(),
 230       tracks_parser.audio_track_num(),
 231       tracks_parser.video_track_num(),
 232       text_tracks,
 233       tracks_parser.ignored_tracks(),
 234       tracks_parser.audio_encryption_key_id(),
 235       tracks_parser.video_encryption_key_id(),
 236       log_cb_));
 237
 238   ChangeState(kParsingClusters);
 239
 240   if (!init_cb_.is_null()) {
 241     init_cb_.Run(true, duration);
 242     init_cb_.Reset();
 243   }
 244
 245   return bytes_parsed;
 246 }
 247
 248 int WebMStreamParser::ParseCluster(const uint8* data, int size) {
 249   if (!cluster_parser_)
 250     return -1;
 251
 252   int id;
 253   int64 element_size;
 254   int result = WebMParseElementHeader(data, size, &id, &element_size);
 255
 256   if (result <= 0)
 257     return result;
 258
 259   if (id == kWebMIdCluster)
 260     waiting_for_buffers_ = true;
 261
 262   // TODO(matthewjheaney): implement support for chapters
 263   if (id == kWebMIdCues || id == kWebMIdChapters) {
 264     if (size < (result + element_size)) {
 265       // We don't have the whole element yet. Signal we need more data.
 266       return 0;
 267     }
 268     // Skip the element.
 269     return result + element_size;
 270   }
 271
 272   if (id == kWebMIdEBMLHeader) {
 273     ChangeState(kParsingHeaders);
 274     return 0;
 275   }
 276
 277   int bytes_parsed = cluster_parser_->Parse(data, size);
 278
 279   if (bytes_parsed <= 0)
 280     return bytes_parsed;
 281
 282   const BufferQueue& audio_buffers = cluster_parser_->audio_buffers();
 283   const BufferQueue& video_buffers = cluster_parser_->video_buffers();
 284   bool cluster_ended = cluster_parser_->cluster_ended();
 285
 286   if (waiting_for_buffers_ &&
 287       cluster_parser_->cluster_start_time() != kNoTimestamp()) {
 288     new_segment_cb_.Run();
 289     waiting_for_buffers_ = false;
 290   }
 291
 292   if ((!audio_buffers.empty() || !video_buffers.empty()) &&
 293       !new_buffers_cb_.Run(audio_buffers, video_buffers)) {
 294     return -1;
 295   }
 296
 297   WebMClusterParser::TextTrackIterator text_track_iter =
 298     cluster_parser_->CreateTextTrackIterator();
 299
 300   int text_track_num;
 301   const BufferQueue* text_buffers;
 302
 303   while (text_track_iter(&text_track_num, &text_buffers)) {
 304     TextTrackMap::iterator find_result = text_track_map_.find(text_track_num);
 305
 306     if (find_result == text_track_map_.end())
 307       continue;
 308
 309     TextTrack* const text_track = find_result->second;
 310
 311     if (!text_buffers->empty() && !text_cb_.Run(text_track, *text_buffers))
 312       return -1;
 313   }
 314
 315   if (cluster_ended)
 316     end_of_segment_cb_.Run();
 317
 318   return bytes_parsed;
 319 }
 320
 321 void WebMStreamParser::FireNeedKey(const std::string& key_id) {
 322   std::vector<uint8> key_id_vector(key_id.begin(), key_id.end());
 323   need_key_cb_.Run(kWebMEncryptInitDataType, key_id_vector);
 324 }
 325
 326 }  // namespace media