When I backup dvds, sometimes the audio is really ahead of the movie, sometimes it isn't. I have to re-encode the movie at 29.97 fps, instead of 23.976. The problem is I don't know if there is a sync problem until i have completed the rip. Please don't tell me to use flask mpeg (i hate it). I was just wondering if there is a way to detect which fps i should use before i encode the movie. Thanks!