Add live mode detection in WebM MediaSource parser.

The live mode is indicated by presense of DateUTC element and unknown
segment duration and size.

BUG=338529

Review URL: https://codereview.chromium.org/231283005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@266452 0039d316-1c4b-4281-b951-d872f2087c98

media/base/demuxer.h

@@ -44,6 +44,12 @@ class MEDIA_EXPORT DemuxerHost {
 
 class MEDIA_EXPORT Demuxer {
  public:
+  enum Liveness {
+    LIVENESS_UNKNOWN,
+    LIVENESS_RECORDED,
+    LIVENESS_LIVE,
+  };
+
   // A new potentially encrypted stream has been parsed.
   // First parameter - The type of initialization data.
   // Second parameter - The initialization data associated with the stream.
@@ -92,6 +98,9 @@ class MEDIA_EXPORT Demuxer {
   // a null Time is returned.
   virtual base::Time GetTimelineOffset() const = 0;
 
+  // Returns liveness of the stream, i.e. whether it is recorded or live.
+  virtual Liveness GetLiveness() const = 0;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(Demuxer);
 };

media/base/mock_filters.h

@@ -40,6 +40,7 @@ class MockDemuxer : public Demuxer {
   MOCK_METHOD1(GetStream, DemuxerStream*(DemuxerStream::Type));
   MOCK_CONST_METHOD0(GetStartTime, base::TimeDelta());
   MOCK_CONST_METHOD0(GetTimelineOffset, base::Time());
+  MOCK_CONST_METHOD0(GetLiveness, Liveness());
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MockDemuxer);

media/base/stream_parser.cc

@@ -11,7 +11,8 @@ namespace media {
 
 StreamParser::InitParameters::InitParameters(base::TimeDelta duration)
     : duration(duration),
-      auto_update_timestamp_offset(false) {
+      auto_update_timestamp_offset(false),
+      liveness(Demuxer::LIVENESS_UNKNOWN) {
 }
 
 StreamParser::StreamParser() {}

media/base/stream_parser.h

@@ -60,6 +60,9 @@ class MEDIA_EXPORT StreamParser {
     // Indicates that timestampOffset should be updated based on the earliest
     // end timestamp (audio or video) provided during each NewBuffersCB.
     bool auto_update_timestamp_offset;
+
+    // Indicates live stream.
+    Demuxer::Liveness liveness;
   };
 
   // Indicates completion of parser initialization.

media/filters/chunk_demuxer.cc

@@ -974,6 +974,7 @@ ChunkDemuxer::ChunkDemuxer(const base::Closure& open_cb,
       log_cb_(log_cb),
       duration_(kNoTimestamp()),
       user_specified_duration_(-1),
+      liveness_(LIVENESS_UNKNOWN),
       splice_frames_enabled_(splice_frames_enabled) {
   DCHECK(!open_cb_.is_null());
   DCHECK(!need_key_cb_.is_null());
@@ -1064,6 +1065,10 @@ base::Time ChunkDemuxer::GetTimelineOffset() const {
   return timeline_offset_;
 }
 
+Demuxer::Liveness ChunkDemuxer::GetLiveness() const {
+  return liveness_;
+}
+
 void ChunkDemuxer::StartWaitingForSeek(TimeDelta seek_time) {
   DVLOG(1) << "StartWaitingForSeek()";
   base::AutoLock auto_lock(lock_);
@@ -1508,6 +1513,17 @@ void ChunkDemuxer::OnSourceInitDone(
     timeline_offset_ = params.timeline_offset;
   }
 
+  if (params.liveness != LIVENESS_UNKNOWN) {
+    if (liveness_ != LIVENESS_UNKNOWN && params.liveness != liveness_) {
+      MEDIA_LOG(log_cb_)
+          << "Liveness is not the same across all SourceBuffers.";
+      ReportError_Locked(DEMUXER_ERROR_COULD_NOT_OPEN);
+      return;
+    }
+
+    liveness_ = params.liveness;
+  }
+
   // Wait until all streams have initialized.
   if ((!source_id_audio_.empty() && !audio_) ||
       (!source_id_video_.empty() && !video_)) {

media/filters/chunk_demuxer.h

@@ -159,6 +159,7 @@ class MEDIA_EXPORT ChunkDemuxer : public Demuxer {
   virtual DemuxerStream* GetStream(DemuxerStream::Type type) OVERRIDE;
   virtual base::TimeDelta GetStartTime() const OVERRIDE;
   virtual base::Time GetTimelineOffset() const OVERRIDE;
+  virtual Liveness GetLiveness() const OVERRIDE;
 
   // Methods used by an external object to control this demuxer.
   //
@@ -366,6 +367,7 @@ class MEDIA_EXPORT ChunkDemuxer : public Demuxer {
   double user_specified_duration_;
 
   base::Time timeline_offset_;
+  Liveness liveness_;
 
   typedef std::map<std::string, SourceState*> SourceStateMap;
   SourceStateMap source_state_map_;

media/filters/ffmpeg_demuxer.cc

@@ -394,6 +394,7 @@ FFmpegDemuxer::FFmpegDemuxer(
       media_log_(media_log),
       bitrate_(0),
       start_time_(kNoTimestamp()),
+      liveness_(LIVENESS_UNKNOWN),
       audio_disabled_(false),
       text_enabled_(false),
       duration_known_(false),
@@ -506,6 +507,11 @@ base::Time FFmpegDemuxer::GetTimelineOffset() const {
   return timeline_offset_;
 }
 
+Demuxer::Liveness FFmpegDemuxer::GetLiveness() const {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+  return liveness_;
+}
+
 void FFmpegDemuxer::AddTextStreams() {
   DCHECK(task_runner_->BelongsToCurrentThread());
 
@@ -696,6 +702,14 @@ void FFmpegDemuxer::OnFindStreamInfoDone(const PipelineStatusCB& status_cb,
 
   timeline_offset_ = ExtractTimelineOffset(format_context);
 
+  if (max_duration == kInfiniteDuration() && !timeline_offset_.is_null()) {
+    liveness_ = LIVENESS_LIVE;
+  } else if (max_duration != kInfiniteDuration()) {
+    liveness_ = LIVENESS_RECORDED;
+  } else {
+    liveness_ = LIVENESS_UNKNOWN;
+  }
+
   // Good to go: set the duration and bitrate and notify we're done
   // initializing.
   host_->SetDuration(max_duration);

media/filters/ffmpeg_demuxer.h

@@ -155,6 +155,7 @@ class MEDIA_EXPORT FFmpegDemuxer : public Demuxer {
   virtual DemuxerStream* GetStream(DemuxerStream::Type type) OVERRIDE;
   virtual base::TimeDelta GetStartTime() const OVERRIDE;
   virtual base::Time GetTimelineOffset() const OVERRIDE;
+  virtual Liveness GetLiveness() const OVERRIDE;
 
   // Calls |need_key_cb_| with the initialization data encountered in the file.
   void FireNeedKey(const std::string& init_data_type,
@@ -251,6 +252,9 @@ class MEDIA_EXPORT FFmpegDemuxer : public Demuxer {
   // time if the file doesn't have an association to Time.
   base::Time timeline_offset_;
 
+  // Liveness of the stream.
+  Liveness liveness_;
+
   // Whether audio has been disabled for this demuxer (in which case this class
   // drops packets destined for AUDIO demuxer streams on the floor).
   bool audio_disabled_;

media/formats/webm/webm_stream_parser.cc

@@ -20,6 +20,7 @@ namespace media {
 
 WebMStreamParser::WebMStreamParser()
     : state_(kWaitingForInit),
+      unknown_segment_size_(false),
       parsing_cluster_(false) {
 }
 
@@ -150,6 +151,9 @@ int WebMStreamParser::ParseInfoAndTracks(const uint8* data, int size) {
       return result + element_size;
       break;
     case kWebMIdSegment:
+      // Segment of unknown size indicates live stream.
+      if (element_size == kWebMUnknownSize)
+        unknown_segment_size_ = true;
       // Just consume the segment header.
       return result;
       break;
@@ -190,6 +194,15 @@ int WebMStreamParser::ParseInfoAndTracks(const uint8* data, int size) {
 
   params.timeline_offset = info_parser.date_utc();
 
+  if (unknown_segment_size_ && (info_parser.duration() <= 0) &&
+      !info_parser.date_utc().is_null()) {
+    params.liveness = Demuxer::LIVENESS_LIVE;
+  } else if (info_parser.duration() >= 0) {
+    params.liveness = Demuxer::LIVENESS_RECORDED;
+  } else {
+    params.liveness = Demuxer::LIVENESS_UNKNOWN;
+  }
+
   const AudioDecoderConfig& audio_config = tracks_parser.audio_decoder_config();
   if (audio_config.is_encrypted())
     FireNeedKey(tracks_parser.audio_encryption_key_id());
@@ -205,7 +218,6 @@ int WebMStreamParser::ParseInfoAndTracks(const uint8* data, int size) {
     return -1;
   }
 
-
   cluster_parser_.reset(new WebMClusterParser(
       info_parser.timecode_scale(),
       tracks_parser.audio_track_num(),

media/formats/webm/webm_stream_parser.h

@@ -76,6 +76,8 @@ class WebMStreamParser : public StreamParser {
   base::Closure end_of_segment_cb_;
   LogCB log_cb_;
 
+  bool unknown_segment_size_;
+
   // True if a new cluster id has been seen and its end has not yet been parsed.
   bool parsing_cluster_;