[FFmpeg-trac] #4904(undetermined:new): Broken vp9 decoding after failed seek in webm file

FFmpeg trac at avcodec.org
Sat Oct 3 23:51:31 CEST 2015

#4904: Broken vp9 decoding after failed seek in webm file
             Reporter:  cehoyos      |                    Owner:
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:
              Version:  git-master   |  undetermined
             Keywords:  mkv vp9      |               Resolution:
  seek                               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |

Comment (by gjdfgh):

 Looking at this closer...
 - the file has only 1 index entry for video, pointing to the first packet
 - the video could indeed have only 1 keyframe (didn't check)
 - libavformat's demuxer "gives up" and does an *incorrect* seek (probably
 a fix for other broken files produced by lavf, I seem to remember a
 specific one)
 - the incorrect seek of course confuses the decoder, because the decoder
 only gets midstream packets
 - the correct behavior is seeking to the correct index entry, and decoding
 the video until the seek target is reached

 The latter is confirmed to work with lavfilters and mpv.

Ticket URL: <https://trac.ffmpeg.org/ticket/4904#comment:3>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker

More information about the FFmpeg-trac mailing list