There is no way of recording the actual Video iChat session within iChat (this is a promised future feature though) maybe a screen capture program would work but I don’t have one to try. I know you can record yourself with the built-in iSight camera within QT Pro.
Google – ripping software for the mac. I use Cinematize but there are free software out there. Then you take the QT and then compress it to a web standard.
Connect video out of your dvd player to in video in of you camera, press play, press record.
MXF files will not playback in anything until they are transfer (in which they became QT files) or if you have software installed that can read MXF files, like Raylight.