I want to be able to parse the rtsp stream in order to extract data about the radio station, current playing song name, duration etc.
I have to do it manually – no libraries.
Preferred language is Java but I could work with something else too.
Welcome to the world of RFC 2326: Real Time Streaming Protocol (RTSP).
You’ll need to become a bit of an expert in the higher level structures and then code your own parser to extract the meta data.
You’d really save a lot of time by using a library. You should reconsider that decision.