I've got a G4 500 powerbook which can play DVD video just fine. However if I try an mp4 file it skips and jumps and is unwatchable. So far, the only way I have found of making video that plays reliably is by using a VIDEO TS folder through Apple DVD player. But this is a hassle and I'd much prefer a single file for each video. Quicktime? But what codec, and how can I convert to it? Any ideas?