Installing MPlayer via apt

[Jason Stevens]

I would like to install MPlayer using apt, but haven't managed to figure
out the process. The package I want is located at:
http://ayo.freshrpms.net/yellowdog/3.0/ppc/RPMS.freshrpms
I have already tried to add this location to my apt source list by
running (as root) "pico /etc/apt/sources.list" and adding an entry for
the new location, but it failed to work. Instead, a new file named
"/etc/apt/sources.list" was created and running "apt-get install
mplayer" does not find the package.
Is there an easier way to install the package, or must I do something
differently to the sources list?