[MPlayer-users] [mencoder] splitting big movies

[yardbird]

Hi all,
I want to split a big movie into two parts. I can create the first part with 
the -endpos switch:

mencoder big_movie.avi -oac copy -ovc copy -endpos 01:00:00 -o part1.avi

But when I create the second part with:

mencoder big_movie.avi -oac copy -ovc copy -ss 01:00:00 -o part2.avi

I get lots of errors in the output file. From DOCS it seems to me that this is 
a problem of the -ss switch, since I should start encoding from a time to 
which corresponds a key frame. How can I do this? Thanks for your assistance,

francesco