I'm recording lots of cartoons on DVD-Rs to placate the kids at their grandmothers. Recording from Sky+ (a PVR) onto DVD-R leaves alot of space taken up with adverts. What's the best software to read the DVDs into my Macbook, edit the adverts out and burn a new, advert free, DVD-R? Is it something that iMovie/iDVD can do? Is there something better?