it seem the -ss ( mplayer / mencoder ) doesn't jump to the correct position, ex : -ss 500 ( on a dvd stream.dump ), start at 1280sec, 86% !! ( get from a modified mplayer version, values are ok ). ok, playing must start at a keyframe, but it's seem little far... ( deal is the use of -ss -endpos mb for slitting a steam.dump into several divx )