Error message: "Totem could not play mms"

[Reg Clemens]

I have asked this question before, with no response,

When trying to play video clips from www.cnn.com, I get the
error message

     Totem could not play mms

are there codecs somewhere to upgrade Totem?
What about Mplayer?
I have no idea how to try to use Mplayer rather than Totem
in Firefox,- the option to change doesnt seem to be in 
preferences anywhere... Is it possible to change and would
it help?

-- 
                                        Reg.Clemens
                                        reg at dwf.com