hi. thanks for the guide. i\'ve used it before successfully, but now i am having a problem. as this guide is old and avidemux has been updated since then, some of the dialogs are different, but i can still find the same options. ok, so i am trying to covert an xvid/dd5.1 ac3 file. when i open it, i get a message that there is a \"Packed Bitstream detected\" and i choose to unpack it. once that is finished, however, the option for the video is set to \"Copy\" and grayed out so i cannot change it. Plz help me!