Have you tried installing VLC?
VLC will play just about any multimedia file-type.
There is a VLC browser plugin available for Linux, but I can't remember if it is included in the installation of the main VLC player package or if it is a separate package. Best bet would be to take a look in your distros software repositories and see what VLC packages are available.
You could either do this graphically by opening up the GUI for your distros default package manager and set a search filter for vlc, or use the command line to search. So, for example if you were on a Debian based system you could use apt-cache search vlc on the command line to list all packages in the repositories related to vlc.