Opened 10 years ago

Last modified 10 years ago

#1416 new defect

asf mencoder a-v sync problem

Reported by: devik@… Owned by: reimar
Priority: normal Component: core
Version: HEAD Severity: normal
Keywords: Cc:
Blocked By: Blocking:
Reproduced by developer: Analyzed by developer:

Description

The file WMV3/WMA2 can be played with libavcodec without problems but can't me re-encoded (AV sync problem):

/tmp/mplayer-checkout-2009-02-24/mencoder -ovc lavc -oac lavc -lavcopts vcodec=mpeg4:acodec=ac3:abitrate=128 -o x.avi -vf scale=640:-11,harddup bad.wmv -ofps 30 -frames 250

When I change -oac lavc to -oac copy then it is ok. With -oac lavc
no combination of harddup,-mc x,-noskip works for me.
I looked into ASF, it has 33ms between video chunks, but audio
is interspersed at each ... say .. 400ms at different object
timestamps (than video is).

I uploaded it to the upload FTP as file devik_asf_encode_av.wmv

Change History (2)

comment:1 Changed 10 years ago by devik@…

I found that I can solve it by -of lavf. Thus avformat's AVI works, while mencoder's mpformat doesn't. I also compared resulting AVIs, there are a few differences in headers.

comment:2 Changed 10 years ago by compn

-demuxer lavf might help somewhat, remove -ofps tho

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