MSE: Update DTS by the same delta as PTS during partial append window trimming

media/filters/frame_processor.cc

 // 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.
 
 #include "media/filters/frame_processor.h"
 
 #include <cstdlib>
 
 #include "base/stl_util.h"
 #include "media/base/buffers.h"
@@ skipping 370 matching lines @@
     DVLOG(1) << "Truncating buffer which overlaps append window start."
              << " presentation_timestamp " << buffer->timestamp().InSecondsF()
              << " frame_end_timestamp " << frame_end_timestamp.InSecondsF()
              << " append_window_start " << append_window_start.InSecondsF();
 
     // Mark the overlapping portion of the buffer for discard.
     buffer->set_discard_padding(std::make_pair(
         append_window_start - buffer->timestamp(), base::TimeDelta()));
 
     // Adjust the timestamp of this buffer forward to |append_window_start| and
-    // decrease the duration to compensate.
+    // decrease the duration to compensate. Adjust DTS by the same delta as PTS
+    // to help prevent spurious discontinuities when DTS > PTS.
+    base::TimeDelta pts_delta = append_window_start - buffer->timestamp();
     buffer->set_timestamp(append_window_start);
-    buffer->SetDecodeTimestamp(
-        DecodeTimestamp::FromPresentationTime(append_window_start));
+    buffer->SetDecodeTimestamp(buffer->GetDecodeTimestamp() + pts_delta);
     buffer->set_duration(frame_end_timestamp - append_window_start);
     processed_buffer = true;
   }
 
   // See if a partial discard can be done around |append_window_end|.
   if (frame_end_timestamp > append_window_end) {
     DVLOG(1) << "Truncating buffer which overlaps append window end."
              << " presentation_timestamp " << buffer->timestamp().InSecondsF()
              << " frame_end_timestamp " << frame_end_timestamp.InSecondsF()
              << " append_window_end " << append_window_end.InSecondsF();
@@ skipping 290 matching lines @@
     DCHECK(group_end_timestamp_ >= base::TimeDelta());
 
     return true;
   }
 
   NOTREACHED();
   return false;
 }
 
 }  // namespace media