MSE: Log a warning if muxed AV media segment has no A or has no V block

media/filters/chunk_demuxer.cc

Index: media/filters/chunk_demuxer.cc
diff --git a/media/filters/chunk_demuxer.cc b/media/filters/chunk_demuxer.cc
index 224abc430b697570bc8d05545417da950c9d1b71..c03de799e4e310994b4186ca801e9d65cd6e8cbd 100644
--- a/media/filters/chunk_demuxer.cc
+++ b/media/filters/chunk_demuxer.cc
@@ -192,7 +192,7 @@ class SourceState {
   void OnNewMediaSegment();
 
   // Called by the |stream_parser_| at the end of a media segment.
-  void OnEndOfMediaSegment();
+  bool OnEndOfMediaSegment();
 
   // Called by the |stream_parser_| when new buffers have been parsed.
   // It processes the new buffers using |frame_processor_|, which includes
@@ -240,6 +240,12 @@ class SourceState {
   // Keeps track of whether a media segment is being parsed.
   bool parsing_media_segment_;
 
+  // Valid only while |parsing_media_segment_| is true. These flags are to
+  // enforce adherence to MSE spec's requirement of at least one frame for each
+  // A/V track in each media segment.
+  bool media_segment_contained_audio_frame_;
+  bool media_segment_contained_video_frame_;
+
   // The object used to parse appended data.
   scoped_ptr<StreamParser> stream_parser_;
 
@@ -277,6 +283,8 @@ SourceState::SourceState(scoped_ptr<StreamParser> stream_parser,
       timestamp_offset_during_append_(NULL),
       new_media_segment_(false),
       parsing_media_segment_(false),
+      media_segment_contained_audio_frame_(false),
+      media_segment_contained_video_frame_(false),
       stream_parser_(stream_parser.release()),
       audio_(NULL),
       video_(NULL),
@@ -825,12 +833,27 @@ void SourceState::OnNewMediaSegment() {
   DVLOG(2) << "OnNewMediaSegment()";
   parsing_media_segment_ = true;
   new_media_segment_ = true;
+  media_segment_contained_audio_frame_ = false;
+  media_segment_contained_video_frame_ = false;
 }
 
-void SourceState::OnEndOfMediaSegment() {
+bool SourceState::OnEndOfMediaSegment() {
   DVLOG(2) << "OnEndOfMediaSegment()";
   parsing_media_segment_ = false;
   new_media_segment_ = false;
+
+  const bool missing_audio = audio_ && !media_segment_contained_audio_frame_;
+  const bool missing_video = video_ && !media_segment_contained_video_frame_;
+  if (missing_audio || missing_video) {
+    MEDIA_LOG(ERROR, media_log_)
+        << "Media segment did not contain any "
+        << (missing_audio && missing_video ? "audio or video"
+                                           : missing_audio ? "audio" : "video")
+        << " coded frames, mismatching initialization segment";
+    return false;
+  }
+
+  return true;
 }
 
 bool SourceState::OnNewBuffers(
@@ -841,6 +864,9 @@ bool SourceState::OnNewBuffers(
   DCHECK(timestamp_offset_during_append_);
   DCHECK(parsing_media_segment_);
 
+  media_segment_contained_audio_frame_ |= !audio_buffers.empty();
+  media_segment_contained_video_frame_ |= !video_buffers.empty();
+
   const TimeDelta timestamp_offset_before_processing =
       *timestamp_offset_during_append_;