Well I want to play movies on my HDTV using my new Samsung Home theater player. I burned movies with the extension .mp4. When I inserted the disc, my dvd player read it but it did not play the movie with the file extension saying, "format not supported". Again when I burned a movie with the file extension .avi, it played. So, what video format should I use in order for my home theater to play avi file movies? XviD or DivX? thanks very much.