mac geekery

Hi All,
I want to develop a player which can stream radio urls from shoutcast.com of aacplus codecs.Basically it is going to download the playlist file and play it.

At present I am able to play mp3 files but not able to play aacplus codec files.Is there any opensource where I can get the codecs and integrate with my code or how do I solve this issue.
thanks in advance
Arnab