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/base/timestamp_constants.h"
  13 #include "media/formats/webm/webm_cluster_parser.h"
  14 #include "media/formats/webm/webm_constants.h"
  15 #include "media/formats/webm/webm_content_encodings.h"
  16 #include "media/formats/webm/webm_info_parser.h"
  17 #include "media/formats/webm/webm_tracks_parser.h"
  18
  19 namespace media {
  20
  21 WebMStreamParser::WebMStreamParser()
  22     : state_(kWaitingForInit),
  23       unknown_segment_size_(false) {
  24 }
  25
  26 WebMStreamParser::~WebMStreamParser() {
  27 }
  28
  29 void WebMStreamParser::Init(
  30     const InitCB& init_cb,
  31     const NewConfigCB& config_cb,
  32     const NewBuffersCB& new_buffers_cb,
  33     bool ignore_text_tracks,
  34     const EncryptedMediaInitDataCB& encrypted_media_init_data_cb,
  35     const NewMediaSegmentCB& new_segment_cb,
  36     const base::Closure& end_of_segment_cb,
  37     const scoped_refptr<MediaLog>& media_log) {
  38   DCHECK_EQ(state_, kWaitingForInit);
  39   DCHECK(init_cb_.is_null());
  40   DCHECK(!init_cb.is_null());
  41   DCHECK(!config_cb.is_null());
  42   DCHECK(!new_buffers_cb.is_null());
  43   DCHECK(!encrypted_media_init_data_cb.is_null());
  44   DCHECK(!new_segment_cb.is_null());
  45   DCHECK(!end_of_segment_cb.is_null());
  46
  47   ChangeState(kParsingHeaders);
  48   init_cb_ = init_cb;
  49   config_cb_ = config_cb;
  50   new_buffers_cb_ = new_buffers_cb;
  51   ignore_text_tracks_ = ignore_text_tracks;
  52   encrypted_media_init_data_cb_ = encrypted_media_init_data_cb;
  53   new_segment_cb_ = new_segment_cb;
  54   end_of_segment_cb_ = end_of_segment_cb;
  55   media_log_ = media_log;
  56 }
  57
  58 void WebMStreamParser::Flush() {
  59   DCHECK_NE(state_, kWaitingForInit);
  60
  61   byte_queue_.Reset();
  62   if (cluster_parser_)
  63     cluster_parser_->Reset();
  64   if (state_ == kParsingClusters) {
  65     ChangeState(kParsingHeaders);
  66     end_of_segment_cb_.Run();
  67   }
  68 }
  69
  70 bool WebMStreamParser::Parse(const uint8* buf, int size) {
  71   DCHECK_NE(state_, kWaitingForInit);
  72
  73   if (state_ == kError)
  74     return false;
  75
  76   byte_queue_.Push(buf, size);
  77
  78   int result = 0;
  79   int bytes_parsed = 0;
  80   const uint8* cur = NULL;
  81   int cur_size = 0;
  82
  83   byte_queue_.Peek(&cur, &cur_size);
  84   while (cur_size > 0) {
  85     State oldState = state_;
  86     switch (state_) {
  87       case kParsingHeaders:
  88         result = ParseInfoAndTracks(cur, cur_size);
  89         break;
  90
  91       case kParsingClusters:
  92         result = ParseCluster(cur, cur_size);
  93         break;
  94
  95       case kWaitingForInit:
  96       case kError:
  97         return false;
  98     }
  99
 100     if (result < 0) {
 101       ChangeState(kError);
 102       return false;
 103     }
 104
 105     if (state_ == oldState && result == 0)
 106       break;
 107
 108     DCHECK_GE(result, 0);
 109     cur += result;
 110     cur_size -= result;
 111     bytes_parsed += result;
 112   }
 113
 114   byte_queue_.Pop(bytes_parsed);
 115   return true;
 116 }
 117
 118 void WebMStreamParser::ChangeState(State new_state) {
 119   DVLOG(1) << "ChangeState() : " << state_ << " -> " << new_state;
 120   state_ = new_state;
 121 }
 122
 123 int WebMStreamParser::ParseInfoAndTracks(const uint8* data, int size) {
 124   DVLOG(2) << "ParseInfoAndTracks()";
 125   DCHECK(data);
 126   DCHECK_GT(size, 0);
 127
 128   const uint8* cur = data;
 129   int cur_size = size;
 130   int bytes_parsed = 0;
 131
 132   int id;
 133   int64 element_size;
 134   int result = WebMParseElementHeader(cur, cur_size, &id, &element_size);
 135
 136   if (result <= 0)
 137     return result;
 138
 139   switch (id) {
 140     case kWebMIdEBMLHeader:
 141     case kWebMIdSeekHead:
 142     case kWebMIdVoid:
 143     case kWebMIdCRC32:
 144     case kWebMIdCues:
 145     case kWebMIdChapters:
 146     case kWebMIdTags:
 147     case kWebMIdAttachments:
 148       // TODO(matthewjheaney): Implement support for chapters.
 149       if (cur_size < (result + element_size)) {
 150         // We don't have the whole element yet. Signal we need more data.
 151         return 0;
 152       }
 153       // Skip the element.
 154       return result + element_size;
 155       break;
 156     case kWebMIdCluster:
 157       if (!cluster_parser_) {
 158         MEDIA_LOG(ERROR, media_log_) << "Found Cluster element before Info.";
 159         return -1;
 160       }
 161       ChangeState(kParsingClusters);
 162       new_segment_cb_.Run();
 163       return 0;
 164       break;
 165     case kWebMIdSegment:
 166       // Segment of unknown size indicates live stream.
 167       if (element_size == kWebMUnknownSize)
 168         unknown_segment_size_ = true;
 169       // Just consume the segment header.
 170       return result;
 171       break;
 172     case kWebMIdInfo:
 173       // We've found the element we are looking for.
 174       break;
 175     default: {
 176       MEDIA_LOG(ERROR, media_log_) << "Unexpected element ID 0x" << std::hex
 177                                    << id;
 178       return -1;
 179     }
 180   }
 181
 182   WebMInfoParser info_parser;
 183   result = info_parser.Parse(cur, cur_size);
 184
 185   if (result <= 0)
 186     return result;
 187
 188   cur += result;
 189   cur_size -= result;
 190   bytes_parsed += result;
 191
 192   WebMTracksParser tracks_parser(media_log_, ignore_text_tracks_);
 193   result = tracks_parser.Parse(cur, cur_size);
 194
 195   if (result <= 0)
 196     return result;
 197
 198   bytes_parsed += result;
 199
 200   double timecode_scale_in_us = info_parser.timecode_scale() / 1000.0;
 201   InitParameters params(kInfiniteDuration());
 202
 203   if (info_parser.duration() > 0) {
 204     int64 duration_in_us = info_parser.duration() * timecode_scale_in_us;
 205     params.duration = base::TimeDelta::FromMicroseconds(duration_in_us);
 206   }
 207
 208   params.timeline_offset = info_parser.date_utc();
 209
 210   if (unknown_segment_size_ && (info_parser.duration() <= 0) &&
 211       !info_parser.date_utc().is_null()) {
 212     params.liveness = DemuxerStream::LIVENESS_LIVE;
 213   } else if (info_parser.duration() >= 0) {
 214     params.liveness = DemuxerStream::LIVENESS_RECORDED;
 215   } else {
 216     params.liveness = DemuxerStream::LIVENESS_UNKNOWN;
 217   }
 218
 219   const AudioDecoderConfig& audio_config = tracks_parser.audio_decoder_config();
 220   if (audio_config.is_encrypted())
 221     OnEncryptedMediaInitData(tracks_parser.audio_encryption_key_id());
 222
 223   const VideoDecoderConfig& video_config = tracks_parser.video_decoder_config();
 224   if (video_config.is_encrypted())
 225     OnEncryptedMediaInitData(tracks_parser.video_encryption_key_id());
 226
 227   if (!config_cb_.Run(audio_config,
 228                       video_config,
 229                       tracks_parser.text_tracks())) {
 230     DVLOG(1) << "New config data isn't allowed.";
 231     return -1;
 232   }
 233
 234   cluster_parser_.reset(new WebMClusterParser(
 235       info_parser.timecode_scale(), tracks_parser.audio_track_num(),
 236       tracks_parser.GetAudioDefaultDuration(timecode_scale_in_us),
 237       tracks_parser.video_track_num(),
 238       tracks_parser.GetVideoDefaultDuration(timecode_scale_in_us),
 239       tracks_parser.text_tracks(), tracks_parser.ignored_tracks(),
 240       tracks_parser.audio_encryption_key_id(),
 241       tracks_parser.video_encryption_key_id(), audio_config.codec(),
 242       media_log_));
 243
 244   if (!init_cb_.is_null())
 245     base::ResetAndReturn(&init_cb_).Run(params);
 246
 247   return bytes_parsed;
 248 }
 249
 250 int WebMStreamParser::ParseCluster(const uint8* data, int size) {
 251   if (!cluster_parser_)
 252     return -1;
 253
 254   int bytes_parsed = cluster_parser_->Parse(data, size);
 255   if (bytes_parsed < 0)
 256     return bytes_parsed;
 257
 258   const BufferQueue& audio_buffers = cluster_parser_->GetAudioBuffers();
 259   const BufferQueue& video_buffers = cluster_parser_->GetVideoBuffers();
 260   const TextBufferQueueMap& text_map = cluster_parser_->GetTextBuffers();
 261
 262   bool cluster_ended = cluster_parser_->cluster_ended();
 263
 264   if ((!audio_buffers.empty() || !video_buffers.empty() ||
 265        !text_map.empty()) &&
 266       !new_buffers_cb_.Run(audio_buffers, video_buffers, text_map)) {
 267     return -1;
 268   }
 269
 270   if (cluster_ended) {
 271     ChangeState(kParsingHeaders);
 272     end_of_segment_cb_.Run();
 273   }
 274
 275   return bytes_parsed;
 276 }
 277
 278 void WebMStreamParser::OnEncryptedMediaInitData(const std::string& key_id) {
 279   std::vector<uint8> key_id_vector(key_id.begin(), key_id.end());
 280   encrypted_media_init_data_cb_.Run(EmeInitDataType::WEBM, key_id_vector);
 281 }
 282
 283 }  // namespace media