MSE: Signal new coded frame group more aggressively

media/filters/frame_processor.h

 // Copyright 2014 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.
 
 #ifndef MEDIA_FILTERS_FRAME_PROCESSOR_H_
 #define MEDIA_FILTERS_FRAME_PROCESSOR_H_
 
 #include <map>
 
 #include "base/callback_forward.h"
@@ skipping 134 matching lines @@
   AudioDecoderConfig current_audio_config_;
   base::TimeDelta sample_duration_;
 
   // The AppendMode of the associated SourceBuffer.
   // See SetSequenceMode() for interpretation of |sequence_mode_|.
   // Per http://www.w3.org/TR/media-source/#widl-SourceBuffer-mode:
   // Controls how a sequence of media segments are handled. This is initially
   // set to false ("segments").
   bool sequence_mode_ = false;
 
-  // Flag to track whether or not the next processed frame is a continuation of
-  // a coded frame group. This flag resets to false upon detection of
-  // discontinuity, and becomes true once a processed coded frame for the
-  // current coded frame group is sent to its track buffer.
-  bool in_coded_frame_group_ = false;
+  // Tracks whether or not the next processed frame is a continuation of a coded
+  // frame group (see https://w3c.github.io/media-source/#coded-frame-group).
+  // Resets to kNoDecodeTimestamp() upon detection of 'segments' mode
+  // discontinuity, parser reset during 'segments' mode, or switching from
+  // 'sequence' to 'segments' mode.
+  // Once a processed coded frame is emitted for the current coded frame group,
+  // tracks the decode timestamp of the last frame emitted.
+  // Explicit setting of timestampOffset will trigger subsequent notification of
+  // a new coded frame start to the tracks' streams, even in 'sequence' mode, if
+  // the resulting frame has a DTS less than this.
+  DecodeTimestamp coded_frame_group_last_dts_ = kNoDecodeTimestamp();
 
   // Tracks the MSE coded frame processing variable of same name.
   // Initially kNoTimestamp(), meaning "unset".
   base::TimeDelta group_start_timestamp_;
 
   // Tracks the MSE coded frame processing variable of same name. It stores the
   // highest coded frame end timestamp across all coded frames in the current
   // coded frame group. It is set to 0 when the SourceBuffer object is created
   // and gets updated by ProcessFrames().
   base::TimeDelta group_end_timestamp_;
 
   UpdateDurationCB update_duration_cb_;
 
   // MediaLog for reporting messages and properties to debug content and engine.
   scoped_refptr<MediaLog> media_log_;
 
   // Counters that limit spam to |media_log_| for frame processor warnings.
   int num_dropped_preroll_warnings_ = 0;
   int num_dts_beyond_pts_warnings_ = 0;
 
   DISALLOW_COPY_AND_ASSIGN(FrameProcessor);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_FRAME_PROCESSOR_H_