On Fri, Oct 02, 2009 at 06:07:22PM +0200, Etienne Buira wrote: > However, when I tried ac3 (-oac lavc -lavcopts acodec=ac3:abitrate=128), > the encoding worked, but everytime I seeked while playing the encoded > movie with mplayer, the sound track restarted from the very beginning. I > don't know if it is a known problem, or if it is a combination which is > not intented to work. It is not a known problem and it is supposed to work. If the issue exists with latest SVN version, a sample file and/or instructions how to reproduce are welcome. -demuxer lavf usually is worth a try with all kinds of issues.