> I try to encode from a start position with -ss 120, the video begins > at 120 but audio from the begining of the file. There is 120 second > of A/V desyncro !! Folks can't help you if you don't tell us exactly what commands you use. I'm =guessing= you are attempting to do a 3 pass encode and have forgotten to add the -ss and its argument on the audio pass.