[dfox]

IIRC IceCast essentially extends/abuses HTTP/1.1 chunked encoding to frame such metadata. The original Nullsoft's ShoutCast protocol simply multiplexes fixed size blocks of mp3 data with length prefixed metadata packets. In both cases you can pretty easily strip the metadata out.

[grishka]

Back when di.fm was an actual online radio and gave you a stream URL to play in a player of your choice, it was dead simple. I don't know what protocol it used, but there was no chunked encoding and no content-length, simply a 200 OK HTTP response and then an endless MP3 "file" with ID3 tags inserted every now and then. You could play it with Android's MediaPlayer in like 3 lines of code.

Oh and by the way. For this exact purpose, ID3v2 has a flag called "unsynchronized" that means all 0xFF bytes in that field are replaced with 0xFF00, so that players won't play the wrong thing. You're supposed to replace them back when parsing the tag. A very hacky solution.