http://glennji.com/content/streaming-audio-with-mpd-and-icecast
Haven't tried this yet.
Quoting in case the source goes away:
sudo aptitude install mpd
sudo aptitude install icecast
Now edit the /etc/mpd.conf file and add the following audio_output (leave any existing audio_output sections alone.
audio_output {
type “shout”
name “Icecast Stream”
host “localhost”
port “8000?
mount “/mpd.ogg”
password “youricecastpassword”
bitrate “96?
format “44100:16:1?
}
Now edit the icecast configuration at /etc/icecast2/icecast.xml.