[MEncoder-users] mencoder problems in going from vob to avi

[Mike Castle]

On Sun, Jun 6, 2010 at 10:57 PM, Reimar Döffinger
<Reimar.Doeffinger at gmx.de> wrote:
> On Sun, Jun 06, 2010 at 08:35:37PM -0700, Mike Castle wrote:
>> Recent version of mkvmerge started having with AVI files that mencoder
>> produces.  The mkvmerge folks did some analysis and have come to the
>> conclusion that the AVI file is malformed.
>
> Not really, MPlayer just tries to keep sync the best it can with copy,
> so it ends up dropping _encoded_ frames, which is going to work really
> badly. Are you actually sure the desync issue you noticed didn't
> exist with the AVI file? Because I am almost certain that the new

Yup.  Pretty sure.  If there is, mplayer is correcting it.  I'm not
seeing anything obvious in mplayer's output.

> mkvmerge behaviour is actually the correct one.
> Either way you lost quality due to dropped frames already before.
> The solution is to use -noskip (and probably also -mc 0) when using
> -ovc copy with compressed data.

Well, doing that does fix the issue with this test case.   Thank you.

> Suggestions on how to document this better are welcome (or maybe we should
> make -noskip default for -copy, not sure).

Well, is is necessary only for -ovc copy or -oac copy?  Since I'm
using copy for both in this case, I wasn't sure.

The encoding-guide says ``Therefore, using <option>-noskip</option> is
not in general recommended.''  In this doc, -mc 0 mildly suggests
-noskip, but in the man page, it pretty much suggests -mc 0 requires
-noskip.

So, that's why I probably avoiding it all of these years.

mrc