media/formats/webm/webm_stream_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_stream_parser.h"
   6
   7 #include <string>
   8
   9 #include "base/callback.h"
  10 #include "base/callback_helpers.h"
  11 #include "base/logging.h"
  12 #include "media/formats/webm/webm_cluster_parser.h"
  13 #include "media/formats/webm/webm_constants.h"
  14 #include "media/formats/webm/webm_content_encodings.h"
  15 #include "media/formats/webm/webm_info_parser.h"
  16 #include "media/formats/webm/webm_tracks_parser.h"
  17
  18 namespace media {
  19
  20 WebMStreamParser::WebMStreamParser()
  21     : state_(kWaitingForInit),
  22       unknown_segment_size_(false) {
  23 }
  24
  25 WebMStreamParser::~WebMStreamParser() {
  26 }
  27
  28 void WebMStreamParser::Init(
  29     const InitCB& init_cb,
  30     const NewConfigCB& config_cb,
  31     const NewBuffersCB& new_buffers_cb,
  32     bool ignore_text_tracks,
  33     const EncryptedMediaInitDataCB& encrypted_media_init_data_cb,
  34     const NewMediaSegmentCB& new_segment_cb,
  35     const base::Closure& end_of_segment_cb,
  36     const LogCB& log_cb) {
  37   DCHECK_EQ(state_, kWaitingForInit);
  38   DCHECK(init_cb_.is_null());
  39   DCHECK(!init_cb.is_null());
  40   DCHECK(!config_cb.is_null());
  41   DCHECK(!new_buffers_cb.is_null());
  42   DCHECK(!encrypted_media_init_data_cb.is_null());
  43   DCHECK(!new_segment_cb.is_null());
  44   DCHECK(!end_of_segment_cb.is_null());
  45
  46   ChangeState(kParsingHeaders);
  47   init_cb_ = init_cb;
  48   config_cb_ = config_cb;
  49   new_buffers_cb_ = new_buffers_cb;
  50   ignore_text_tracks_ = ignore_text_tracks;
  51   encrypted_media_init_data_cb_ = encrypted_media_init_data_cb;
  52   new_segment_cb_ = new_segment_cb;
  53   end_of_segment_cb_ = end_of_segment_cb;
  54   log_cb_ = log_cb;
  55 }
  56
  57 void WebMStreamParser::Flush() {
  58   DCHECK_NE(state_, kWaitingForInit);
  59
  60   byte_queue_.Reset();
  61   if (cluster_parser_)
  62     cluster_parser_->Reset();
  63   if (state_ == kParsingClusters) {
  64     ChangeState(kParsingHeaders);
  65     end_of_segment_cb_.Run();
  66   }
  67 }
  68
  69 bool WebMStreamParser::Parse(const uint8* buf, int size) {
  70   DCHECK_NE(state_, kWaitingForInit);
  71
  72   if (state_ == kError)
  73     return false;
  74
  75   byte_queue_.Push(buf, size);
  76
  77   int result = 0;
  78   int bytes_parsed = 0;
  79   const uint8* cur = NULL;
  80   int cur_size = 0;
  81
  82   byte_queue_.Peek(&cur, &cur_size);
  83   while (cur_size > 0) {
  84     State oldState = state_;
  85     switch (state_) {
  86       case kParsingHeaders:
  87         result = ParseInfoAndTracks(cur, cur_size);
  88         break;
  89
  90       case kParsingClusters:
  91         result = ParseCluster(cur, cur_size);
  92         break;
  93
  94       case kWaitingForInit:
  95       case kError:
  96         return false;
  97     }
  98
  99     if (result < 0) {
 100       ChangeState(kError);
 101       return false;
 102     }
 103
 104     if (state_ == oldState && result == 0)
 105       break;
 106
 107     DCHECK_GE(result, 0);
 108     cur += result;
 109     cur_size -= result;
 110     bytes_parsed += result;
 111   }
 112
 113   byte_queue_.Pop(bytes_parsed);
 114   return true;
 115 }
 116
 117 void WebMStreamParser::ChangeState(State new_state) {
 118   DVLOG(1) << "ChangeState() : " << state_ << " -> " << new_state;
 119   state_ = new_state;
 120 }
 121
 122 int WebMStreamParser::ParseInfoAndTracks(const uint8* data, int size) {
 123   DVLOG(2) << "ParseInfoAndTracks()";
 124   DCHECK(data);
 125   DCHECK_GT(size, 0);
 126
 127   const uint8* cur = data;
 128   int cur_size = size;
 129   int bytes_parsed = 0;
 130
 131   int id;
 132   int64 element_size;
 133   int result = WebMParseElementHeader(cur, cur_size, &id, &element_size);
 134
 135   if (result <= 0)
 136     return result;
 137
 138   switch (id) {
 139     case kWebMIdEBMLHeader:
 140     case kWebMIdSeekHead:
 141     case kWebMIdVoid:
 142     case kWebMIdCRC32:
 143     case kWebMIdCues:
 144     case kWebMIdChapters:
 145     case kWebMIdTags:
 146     case kWebMIdAttachments:
 147       // TODO(matthewjheaney): Implement support for chapters.
 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 kWebMIdCluster:
 156       if (!cluster_parser_) {
 157         MEDIA_LOG(ERROR, log_cb_) << "Found Cluster element before Info.";
 158         return -1;
 159       }
 160       ChangeState(kParsingClusters);
 161       new_segment_cb_.Run();
 162       return 0;
 163       break;
 164     case kWebMIdSegment:
 165       // Segment of unknown size indicates live stream.
 166       if (element_size == kWebMUnknownSize)
 167         unknown_segment_size_ = true;
 168       // Just consume the segment header.
 169       return result;
 170       break;
 171     case kWebMIdInfo:
 172       // We've found the element we are looking for.
 173       break;
 174     default: {
 175       MEDIA_LOG(ERROR, log_cb_) << "Unexpected element ID 0x" << std::hex << id;
 176       return -1;
 177     }
 178   }
 179
 180   WebMInfoParser info_parser;
 181   result = info_parser.Parse(cur, cur_size);
 182
 183   if (result <= 0)
 184     return result;
 185
 186   cur += result;
 187   cur_size -= result;
 188   bytes_parsed += result;
 189
 190   WebMTracksParser tracks_parser(log_cb_, ignore_text_tracks_);
 191   result = tracks_parser.Parse(cur, cur_size);
 192
 193   if (result <= 0)
 194     return result;
 195
 196   bytes_parsed += result;
 197
 198   double timecode_scale_in_us = info_parser.timecode_scale() / 1000.0;
 199   InitParameters params(kInfiniteDuration());
 200
 201   if (info_parser.duration() > 0) {
 202     int64 duration_in_us = info_parser.duration() * timecode_scale_in_us;
 203     params.duration = base::TimeDelta::FromMicroseconds(duration_in_us);
 204   }
 205
 206   params.timeline_offset = info_parser.date_utc();
 207
 208   if (unknown_segment_size_ && (info_parser.duration() <= 0) &&
 209       !info_parser.date_utc().is_null()) {
 210     params.liveness = DemuxerStream::LIVENESS_LIVE;
 211   } else if (info_parser.duration() >= 0) {
 212     params.liveness = DemuxerStream::LIVENESS_RECORDED;
 213   } else {
 214     params.liveness = DemuxerStream::LIVENESS_UNKNOWN;
 215   }
 216
 217   const AudioDecoderConfig& audio_config = tracks_parser.audio_decoder_config();
 218   if (audio_config.is_encrypted())
 219     OnEncryptedMediaInitData(tracks_parser.audio_encryption_key_id());
 220
 221   const VideoDecoderConfig& video_config = tracks_parser.video_decoder_config();
 222   if (video_config.is_encrypted())
 223     OnEncryptedMediaInitData(tracks_parser.video_encryption_key_id());
 224
 225   if (!config_cb_.Run(audio_config,
 226                       video_config,
 227                       tracks_parser.text_tracks())) {
 228     DVLOG(1) << "New config data isn't allowed.";
 229     return -1;
 230   }
 231
 232   cluster_parser_.reset(new WebMClusterParser(
 233       info_parser.timecode_scale(),
 234       tracks_parser.audio_track_num(),
 235       tracks_parser.GetAudioDefaultDuration(timecode_scale_in_us),
 236       tracks_parser.video_track_num(),
 237       tracks_parser.GetVideoDefaultDuration(timecode_scale_in_us),
 238       tracks_parser.text_tracks(),
 239       tracks_parser.ignored_tracks(),
 240       tracks_parser.audio_encryption_key_id(),
 241       tracks_parser.video_encryption_key_id(),
 242       audio_config.codec(),
 243       log_cb_));
 244
 245   if (!init_cb_.is_null())
 246     base::ResetAndReturn(&init_cb_).Run(params);
 247
 248   return bytes_parsed;
 249 }
 250
 251 int WebMStreamParser::ParseCluster(const uint8* data, int size) {
 252   if (!cluster_parser_)
 253     return -1;
 254
 255   int bytes_parsed = cluster_parser_->Parse(data, size);
 256   if (bytes_parsed < 0)
 257     return bytes_parsed;
 258
 259   const BufferQueue& audio_buffers = cluster_parser_->GetAudioBuffers();
 260   const BufferQueue& video_buffers = cluster_parser_->GetVideoBuffers();
 261   const TextBufferQueueMap& text_map = cluster_parser_->GetTextBuffers();
 262
 263   bool cluster_ended = cluster_parser_->cluster_ended();
 264
 265   if ((!audio_buffers.empty() || !video_buffers.empty() ||
 266        !text_map.empty()) &&
 267       !new_buffers_cb_.Run(audio_buffers, video_buffers, text_map)) {
 268     return -1;
 269   }
 270
 271   if (cluster_ended) {
 272     ChangeState(kParsingHeaders);
 273     end_of_segment_cb_.Run();
 274   }
 275
 276   return bytes_parsed;
 277 }
 278
 279 void WebMStreamParser::OnEncryptedMediaInitData(const std::string& key_id) {
 280   std::vector<uint8> key_id_vector(key_id.begin(), key_id.end());
 281   encrypted_media_init_data_cb_.Run(EmeInitDataType::WEBM, key_id_vector);
 282 }
 283
 284 }  // namespace media