[MEncoder-users] cat /dev/video0 | mencoder - ...

[Reimar Döffinger]

On Tue, Jul 27, 2010 at 04:49:06PM -0400, Bob Tennent wrote:
> > What's the problem with mplayer /dev/video0 ?
> > Either way you'll probably want a large -cache value to avoid some issues.
> 
> I don't want to view the TV-card output (in real time); I want to save
> it but use x264 to compress it.
> 
>   cat /dev/video0 > file.mpg
>   mencoder file.mpg ... -o file.avi
> 
> works fine but
> 
>   cat /dev/video0 | mencoder - ... -o file.avi
> 
> does not.

What's the difference?
Why didn't you try
mencoder /dev/video0
?
or
mencoder - ... < /dev/video0
?
This really looks a lot like "useless use of cat".
Of course it will give different (possibly worse) results
if mplayer/mencoder tries to seek outside the cached data,
but that is also a hint as to where the problem might lie.