[CentOS] Totem Can't Read .wmv Files

When I try to read a .wmv file, I get the error message:
           "Totem could not play 'file://tmp/F15.wmv'. You do not have a 
decoder installed to handle this file. You might need to install the 
necessary plugins.'
Granted that I am missing something, what is it, and where do I get it / 
install it?
Thanks in advance  --  Bob T.