[MPlayer-users] Question on conversion of svq1 and wmv files

[RC]

On Thu, 17 Nov 2005 20:21:53 -0800
Dave Hayes <dave at jetcafe.org> wrote:

> >> Just out of curiosity, why would I do "-mc 0"?
> > To prevent MEncoder from attempting to change the A/V sync at all,
> > in case it's doing so mistakenly when it actually shouldn't.
> 
> May I usefully assume that is most always the case when transcoding
> from one video type to another (e.g. in my case wmv2 to flv or
> svq1 to flv)? 

No, that's certainly not true.  MPlayers a/v sync (-mc) usually works. 
It's only occasionally when you want to disable that with -mc 0.  

The only place I can think of that I always use it is when re-encoding
from an AVI file created by mencoder.  Other than that, it hurts more
often than it helps.

> Now the kicker: How do I know what codec family to use, 

Look at the output of mplayer or mencoder playing your file.  It will be
something like e.g. "VIDEO:  [SVQ1]".  Now you know what codec is needed
to decode the video, and you can look at the output of "mplayer -vc
help" to see which codecs can decode that format, and to which family
they belong.  

> when to use a family vs a singluar codec, 

It makes no difference.  The codec "family" is for convenience in
selecting a whole group of codecs to be tried before the defaults.  You
can use this if, for instance, you want to try the binary DLL codecs
before native decoders, or any other order you like.

I suggested -vfm qtvideo to you before, because often the Win32 DLLs are
more accurate, more stable, etc., although slower, and work only on x86
systems.