Control which app Firefox uses to handle MMS streams
Here is how to control which application Firefox uses to handle MMS streams:
Type about:config Firefox address bar.
Right-click on any text in there and select “New” and then “String”.
In the first dialog box, as preference name, type network.protocol-handler.app.mms.
In the second dialog box, as string value, type in vlc (or the path to your favorite media player)