[MPlayer-users] encode "n" frames every "p" ?

[OLIVIER LORILLU]

Is it possible to encode "n" frames every "p" frames with mencoder ?
If no, it would be great to implement this feature.

In fact, I want to do a "compressibility check" as the win$ GordianKnot 
program does. So I need to encode a part of a film (5 or 10 % is enough) 
and, in order have a good prediction of the kind of the whole film, this 
part of encoded film has to be not contiguous.

It would be a jump in quality levels since with "compressibility check" 
we can adapt the resolution more precisely.