How can I turn my HD-DVD that I ripped to my hard drive into a .mkv file with high quality? I've found a guide on one site but it's as if you need a computing engineer's degree to understand how to do the conversion! Is there a simple way to do this? I can't get good playback with the HD DVD and powerdvd it's too choppy, but I can play .mkv files perfectly on my system, please help!!