Icecast Streaming Media Server

[dezerver]

Hello there.

Im a german student and about to write my diploma thesis about audio and video streaming. I have a question about the transfer of the metadata in an mp3 or ogg streams with the icecast server to the clients. How does it work?

I could not find anything about this subject in the internet. I could suggest that there ist an Field responsible in the streamingprotokolls like RTSP/RTMP, but im not sure! I know there ist no ID3 Tag inside...

Please help me.

deZerver

[karlH]

For ogg, comments are maintained in a comment packet within in the stream, for vorbis, it's in the 2 packet of a logical stream. MP3 has no comment block but players can request metadata to be inserted on a regular basis which breaks the codec format so the player has to filter it out before decoding. search for shoutcast metadata, it's not hard to understand how it works

karl.

[dezerver]

Thanks for your answer.

Ok, i found a pretty nice example for Shoutcast Metadata.

http://www.smackfu.com/stuff/programming/shoutcast.html

The include of metadata differs from the kind of streaming format and the streaming server, it is rigth? I thougth there is an uniform mechanism with the protocols like rtmp or rtsp.

It is terrifying that there is no documentation about metadata in streams... Especially ther is no docu in german! -.-

deZerver

[jaddle]

I've been wrestling with this topic lately too - it's confusing, because mp3 streams have nothing to do with the usual id3 tags.

What happens is that when the client connects to the server, it can *optionally* request the metadata, which then gets embedded into the stream at regular intervals.

The client has to request the metadata specifically when it connects, because, unlike an id3 tag, the metadata is right in the middle of the audio data, so if the player doesn't understand it, you'll get audio glitches.

I've been trying to get at the metadata through flash players in web pages, and have been running into trouble because flash just doesn't request the metadata! Apparently there are ways to do it, but you basically have to go around the built-in mp3 streaming in flash. I'll write another post about this though, since it's not really related to this.