[MEncoder-users] Skipping frames while copying video [BUGREPORT]
digulla at hepe.com
Mon Aug 7 20:19:47 CEST 2006
>> The key point: It doesn't. By skipping frames, I end up with more
>> audio than video.
> Well I could have said "trying to maintain sync", but I assumed that
> would be clear. Most importantly, did you try disabling it by adding
> "-mc 0" (with/without -noskip)? You did not mention what effect
> it had, if any.
-mc 0 solved the problem and I ended up with a video where the audio and
the video had exactly the same "length".
> You said it was also duplicating frames, so it's not (just) shortening
> the video. Do you know audio was exactly the same length as video in
> all your source files to begin with?
The source material should have the same length for both streams; that's
why I was wondering why mencoder would want to drop/duplicate frames.
And it's dropping much more frames than it's duplicating.
>> Maybe this is a bug. Do you want to have a look at the input material?
>> I could upload a small file (4MB) which doesn't work.
> Always a good idea.
I uploaded a demo video as "copy-loosing-sync.mov" on the FTP server.
It's about 9MB and contains many skips and two duplicates.
The command I used to copy from Quicktime to an AVI container:
mencoder -ovc copy -oac pcm -o test.avi copy-loosing-sync.mov
Afterwards, I have 8.9s video and 9.5s audio. With "-mc 0", I get no
dropped or duplicated frames and the video and audio streams have the
I would expect mencoder not to drop or duplicate any frames while simply
copying a stream into a new container type.
Aaron "Optimizer" Digulla a.k.a. Philmann Dark
"It's not the universe that's limited, it's our imagination.
Follow me and I'll show you something beyond the limits."
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