I only did a straight sudo apt-get install mplayer.
There is a graphical presentation that comes up after dbl-clk of
the avi file you wish to watch.
1. A large blue square with the mplayer wording.
2. At upper right of screen is some kind of clickers dealing with
audio and a showing of the avi file that was selected to view.
However there is no way to cause the selected item to play.
I clicked many combinations to no avail.