I want to make a DVD+R copy of a DVD9 that has about 2h of video with LPCM audio on it. Since the whole DVD9 is to big to fit on a DVD+R I want to convert the existing LPCM audio into less place consuming AC3 2-channel audio. I don't want to lose the menus from the original DVD. I've ripped the entire disc to my HD. Is there a way to extract the LPCM audio from the VOB files, convert them to AC3 2-channel (with AC3machine) and than re-insert the AC3 audio somehow in the original VOB files?