12.10: GNOME Sound Converter and MP3

GNOME Sound Converter need a plugin to convert MP3.

But there is no link for Ubuntu 12.10 in the URL that is given in
the properties dialog:

http://soundconverter.org/gstreamer-mp3-encoding-howto/

This worked for me, running as root:

apt-get install gstreamer0.10-plugins-ugly