Improving WebM video duration estimation.

media/filters/source_buffer_stream.cc

 // 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.
 
 #include "media/filters/source_buffer_stream.h"
 
 #include <algorithm>
 #include <map>
 #include <sstream>
 
@@ skipping 319 matching lines @@
         deleted_buffers.front()->GetDecodeTimestamp();
 
     DCHECK(track_buffer_.empty() ||
            track_buffer_.back()->GetDecodeTimestamp() < start_of_deleted)
         << "decode timestamp "
         << track_buffer_.back()->GetDecodeTimestamp().InSecondsF() << " sec"
         << ", start_of_deleted " << start_of_deleted.InSecondsF()<< " sec";
 
     track_buffer_.insert(track_buffer_.end(), deleted_buffers.begin(),
                          deleted_buffers.end());
+    DVLOG(3) << __FUNCTION__ << " Added " << deleted_buffers.size()
+             << " deleted buffers to track buffer. TB size is now "
+             << track_buffer_.size();
+  } else {
+    DVLOG(3) << __FUNCTION__ << " No deleted buffers for track buffer";
   }
 
   // Prune any extra buffers in |track_buffer_| if new keyframes
   // are appended to the range covered by |track_buffer_|.
   if (!track_buffer_.empty()) {
     DecodeTimestamp keyframe_timestamp =
         FindKeyframeAfterTimestamp(track_buffer_.front()->GetDecodeTimestamp());
     if (keyframe_timestamp != kNoDecodeTimestamp())
       PruneTrackBuffer(keyframe_timestamp);
   }
@@ skipping 467 matching lines @@
   const bool exclude_start =
       new_buffers.front()->splice_buffers().empty() &&
       prev_timestamp == next_timestamp &&
       SourceBufferRange::AllowSameTimestamp(prev_is_keyframe, next_is_keyframe);
 
   // Delete the buffers that |new_buffers| overlaps.
   DecodeTimestamp start = new_buffers.front()->GetDecodeTimestamp();
   DecodeTimestamp end = new_buffers.back()->GetDecodeTimestamp();
   base::TimeDelta duration = new_buffers.back()->duration();
 
-  if (duration != kNoTimestamp() && duration > base::TimeDelta()) {
+  // Set end time for remove to include the duration of last buffer. If the
+  // duration is estimated, use 1 microsecond instead to ensure frames are not
+  // accidentally removed due to over-estimation.
+  if (duration != kNoTimestamp() && duration > base::TimeDelta() &&
+      !new_buffers.back()->is_duration_estimated()) {
     end += duration;
   } else {
-    // TODO(acolwell): Ensure all buffers actually have proper
-    // duration info so that this hack isn't needed.
+    // TODO(chcunningham): Emit warning when 0ms durations are not expected.
     // http://crbug.com/312836
     end += base::TimeDelta::FromInternalValue(1);
   }
 
   RemoveInternal(start, end, exclude_start, deleted_buffers);
 
   // Restore the range seek state if necessary.
   if (temporarily_select_range)
     SetSelectedRange(NULL);
 }
@@ skipping 228 matching lines @@
     scoped_refptr<StreamParserBuffer>& next_buffer = track_buffer_.front();
 
     // If the next buffer is an audio splice frame, the next effective config id
     // comes from the first splice buffer.
     if (next_buffer->GetSpliceBufferConfigId(0) != current_config_index_) {
       config_change_pending_ = true;
       DVLOG(1) << "Config change (track buffer config ID does not match).";
       return kConfigChange;
     }
 
+    DVLOG(3) << __FUNCTION__ << " Next buffer coming from track_buffer_";
     *out_buffer = next_buffer;
     track_buffer_.pop_front();
     last_output_buffer_timestamp_ = (*out_buffer)->GetDecodeTimestamp();
 
     // If the track buffer becomes empty, then try to set the selected range
     // based on the timestamp of this buffer being returned.
     if (track_buffer_.empty())
       SetSelectedRangeIfNeeded(last_output_buffer_timestamp_);
 
     return kSuccess;
@@ skipping 476 matching lines @@
     return false;
 
   DCHECK_NE(have_splice_buffers, have_preroll_buffer);
   splice_buffers_index_ = 0;
   pending_buffer_.swap(*out_buffer);
   pending_buffers_complete_ = false;
   return true;
 }
 
 }  // namespace media