[FFmpeg-trac] #424(undetermined:open): A/V desync on transport stream

FFmpeg trac at avcodec.org
Mon Sep 12 18:56:16 CEST 2011


#424: A/V desync on transport stream
-------------------------------------+-------------------------------------
             Reporter:  cehoyos      |                    Owner:
                 Type:  defect       |                   Status:  open
             Priority:  normal       |                Component:
              Version:  git-master   |  undetermined
             Keywords:               |               Resolution:
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  0
-------------------------------------+-------------------------------------
Changes (by mjs973):

 * status:  new => open


Comment:

 I looked at this sample running the latest videolan git code, downloaded
 2011-09-10. For me, ffprobe does show dts/pts timestamps in the file, but
 the PTS timestamps shown by ffprobe are wrong. The PTS values displayed
 are multiplied by approximately 2.

 I confirmed this pts corruption is being done by compute_pkt_fields(), as
 my previous comment guessed. The line that changes pts to the wrong value
 is line 1044 in libavformat/utils.c:

     pkt->pts = pkt->dts + pc->pts_dts_delta * num / den;

 No time to debug this further right now.

-- 
Ticket URL: <http://avcodec.org/trac/ffmpeg/ticket/424#comment:4>
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