MSE: Warn when keyframe after track_buffer is significantly in future

media/filters/source_buffer_stream.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // SourceBufferStream is a data structure that stores media Buffers in ranges.
 // Buffers can be appended out of presentation order. Buffers are retrieved by
 // seeking to the desired start point and calling GetNextBuffer(). Buffers are
 // returned in sequential presentation order.
 
 #ifndef MEDIA_FILTERS_SOURCE_BUFFER_STREAM_H_
@@ skipping 356 matching lines @@
 
   // Pointer to the seeked-to Range. This is the range from which
   // GetNextBuffer() calls are fulfilled after the |track_buffer_| has been
   // emptied.
   SourceBufferRange* selected_range_;
 
   // Queue of the next buffers to be returned from calls to GetNextBuffer(). If
   // |track_buffer_| is empty, return buffers from |selected_range_|.
   BufferQueue track_buffer_;
 
+  // If there has been no intervening Seek, this will be true if the last
+  // emitted buffer emptied |track_buffer_|.
+  bool just_exhausted_track_buffer_;
+
   // The start time of the current media segment being appended.
   DecodeTimestamp media_segment_start_time_;
 
   // Points to the range containing the current media segment being appended.
   RangeList::iterator range_for_next_append_;
 
   // True when the next call to Append() begins a new media segment.
   bool new_media_segment_;
 
   // The timestamp of the last buffer appended to the media segment, set to
@@ skipping 26 matching lines @@
   // Indicates which of the splice buffers in |splice_buffer_| should be
   // handled out next.
   size_t splice_buffers_index_;
 
   // Indicates that all buffers before |pending_buffer_| have been handed out.
   bool pending_buffers_complete_;
 
   // Indicates that splice frame generation is enabled.
   const bool splice_frames_enabled_;
 
-  // To prevent log spam, count the number of splice generation warnings and
-  // successes logged.
+  // To prevent log spam, count the number of warnings and successes logged.
   int num_splice_generation_warning_logs_;
   int num_splice_generation_success_logs_;
+  int num_track_buffer_gap_warning_logs_;
 
   DISALLOW_COPY_AND_ASSIGN(SourceBufferStream);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_SOURCE_BUFFER_STREAM_H_