[vlc-devel] [PATCH] demux: mkv: add the first cluster position to seeker

[Zhao Zhili]

Otherwise SegmentSeeker::mkv_jump_to may miss the first cluster.
---
Missing the first cluster leads to blured screen for the sample
https://drive.google.com/open?id=1Tu8K2Y63mFnYCMaHo4KzvmKNkRCB3ewR
I think the seeker needs some kind of fix/cleanup but I don't know how.

 modules/demux/mkv/matroska_segment.cpp | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/modules/demux/mkv/matroska_segment.cpp b/modules/demux/mkv/matroska_segment.cpp
index ef89457..837a3b2 100644
--- a/modules/demux/mkv/matroska_segment.cpp
+++ b/modules/demux/mkv/matroska_segment.cpp
@@ -638,13 +638,17 @@ bool matroska_segment_c::Preload( )
 
             cluster = kc_ptr;
 
-            // add first cluster as trusted seekpoint for all tracks
-            for( tracks_map_t::const_iterator it = tracks.begin();
-                 it != tracks.end(); ++it )
+            if( sys.b_seekable )
             {
-                _seeker.add_seekpoint( it->first,
-                SegmentSeeker::Seekpoint( cluster->GetElementPosition(), -1,
-                                          SegmentSeeker::Seekpoint::TrustLevel::QUESTIONABLE ) );
+                _seeker.add_cluster_position( cluster->GetElementPosition() );
+                // add first cluster as questionable seekpoint for all tracks
+                for( tracks_map_t::const_iterator it = tracks.begin();
+                     it != tracks.end(); ++it )
+                {
+                    _seeker.add_seekpoint( it->first,
+                    SegmentSeeker::Seekpoint( cluster->GetElementPosition(), -1,
+                                              SegmentSeeker::Seekpoint::TrustLevel::QUESTIONABLE ) );
+                }
             }
 
             /* stop pre-parsing the stream */
-- 
2.9.5