the post from Anithen is the one to work with here,
went to http://www.linuxpackages.net/
went to http://www.slacky.eu/
went to http://rpm.pbone.net
and all 3 had me chasing my tail .....
in the post above from Anithen you will see the ref: to
the mplayer website,
on this page select "download" on the left hand side -
which is referenced by Anithen above -
choose the source download from http or
MPlayer v1.0rc2 source
it shows up as a bzipped file
unpack it as
tar xjf MPlayer-1.0rc2.tar.bz2
then cd into MPlayer-1.0rc2 and run
then su to root and run
the mplayer that runs will run .wmv natively i suspect
essential-amd64-20071007.tar.bz2 or whichever codec file
you need is suggested by the web authors, but when i
unpacked it and tried to run ./configure in "essential-amd64-20071007"
it would not run ...
at that point i don't know why but i tested mplayer without it
and it ran fine ....
hope this is helpful ...