So I am thinking of converting my mkv's to m4v for my atv, but I am going to just keep them in 1080p and what I want is to have something convert the dts to aac but also keep a copy of the dts, I know the file will get bigger but this way I can have the high quality of dts and still keep aac for use with my iTunes for the wife. Is there anything that can do this? And do it in batches? I am on a mac by the way.