A .cdi file is a image file(not a movie file). You have to burn it to a cd
first in order to use/view it. You must use burning software that will burn
..cdi images to the disk into the correct movie format, then you can watch
the movie. Simply burning a data cd and putting the .cdi file on the cd
isn't going to work. It has to be converted during the burn process from the
image file to the movie file.