I recently shot a little video with my phone (SE w580i) and when I copied it over to my Debian Linux box I of course immediately realized I had no video players that would show a 3GP film. Or rather, they all showed it but none of them played the sound! It seems the phone uses the ‘amr_nb‘ codec for audio, which is a non-free thing that my “Debian unstable” players (not very surprisingly) don’t have built-in support for…
Anyway, if you close your eyes for the problems with closed proprietary evil, I got pointed to the cool site www.debian-multimedia.org and then I could add the following line to my /etc/apt/sources.list
deb http://www.debian-multimedia.org unstable main
… and do a plain plain “apt-get update” and “apt-get dist-upgrade” and wham, my mplayer could now show the 3gp video with sound.
The only slightly quirk remaining is that I didn’t manage to transcode the movie with audio nicely with mencode, but I didn’t really spend enough time to figure out why.