[MPlayer-users] play or encode only range of frames

[piotr_sobolewski at o2.pl]

Hello,

I am new on this list. I subscribed it cause I have a question:
how can I play or encode only a range of frames? Yes, I know I can 
use -frames option, but I don't know how to start not from frame 0 
but (for instance) frame 157?
I know I can use -skip, but this option accepts only number of 
seconds, not number of frames. I know I can compute number of 
seconds if I know number of frames, but I'm afraid of unaccuracy - 
every frame is important for me, cause I am making a simple tool to 
cut and join movies which is using mencoder to do some operations.

Very thankful for your advices, wish you merry christmas,

Piotr Sobolewski