Even if you click on the green button nothing productive happens. Firefox just complains that "No suitable plugins were found". Duh!
The solution is to install the mozilla-mplayer package.
rajudell:~# cat /etc/apt/sources.listAt the "Do you want to continue? [Y/n/?]" prompt, just press 'y' and then 'Enter'. Pressing 'Enter' alone will also work as 'Y' is the default here.
deb http://ftp.us.debian.org/debian/ etch main contrib non-free
deb-src http://ftp.us.debian.org/debian/ etch main contrib non-free
deb http://security.debian.org/ etch/updates main contrib non-free
deb-src http://security.debian.org/ etch/updates main contrib non-free
deb http://www.debian-multimedia.org etch main
rajudell:~# aptitude update
rajudell:~# aptitude install mozilla-mplayer
Once you do this, the videos embed nicely in firefox. The audio works fine too!