[MEncoder-users] Problem with -ss

[James Hastings-Trew]

According to the manual, -ss <sec> should skip forward to that number of 
seconds in the playback or encoding of a file. However, if I perform the 
following:

mplayer -vf cropdetect -nosound -frames 10 -ss 5415 %source%

I do not arrive 5415 seconds into the video. I end up at about 8 minutes 
and 25 seconds in. If I try it in hour:mins:sec format I get the same 
result:

mplayer -vf cropdetect -nosound -frames 10 -ss 1:30:25 %source%

So... what am I doing wrong?