for starts, QuickTime Pro has an export to iMovie setting, iMovie has an export to iDvd, and there are all sorts of complexities involved with hardware, OS configurations, and a variety of proprietary 'standards.'

Ripping quality video to cd and dvd's used to get more posts on the iMovie/iDvd forums than "awaiting sources" did here (I tried following the threads for a few months). They eagerly await OS and iLife upgrades the way new LW versions are anticipated here.