Music On Hold AAC Codec

Hi,
How can i capture live radio stream with AAC Codec? I am able to capture mp3 radio stream with mpg123
(http://www.voneto.com/blogger/2012/06/27/streaming-radio-music-on-hold-for-freepbx-and-asterisk/)
but how can i do that with an MPEG AAC audio stream ?
thanks
IN