Icecast Streaming Media Server

[Anonymous]

Hello all,

We are presently running Icecast 2.3.1 with MP3 sources (nearly all our DJs are running SAM3 or SAM4), and ezstream 0.4.1 as our fallback relay. We're considering switching to OGG. SAM handles OGG seamlessly and it's higher quality for lower size so it seems like a natural.

I figured out on my own that my source mountpoint needs a .ogg extension on it for SAM to log into Icecast successfully. I'm presently listening to my OGG stream with Winamp connected directly to my mountpoint with beautiful results.

Now to try this on the station's mountpoint. Nothing. When I log into my stream, Icecast merrily continues on playing the fallback. The stats page says that I'm streaming OGG, the fallback is streaming MP3, and the main mountpoint is streaming the fallback.

I cannot experiment with reconfiguring things further than this at the moment, with the station in production. However, I have a couple of ideas, and maybe you could advise me as to the credibility of these ideas.

* For some reason, ezstream running an MP3 stream as the fallback is preventing me from taking over. Perhaps reconfiguring ezstream to reencode as OGG would clear things up. I have no basis for this belief, as I assumed that the mere presence of a stream on a mountpoint should be enough to override the fallback.j

* In addition to the above, everything, including the fallback and the primary mountpoint /cyg1_hi, requires an .ogg file extension. That is, Icecast only works properly with relays if everyone is running the same audio format with the right extension on things. If so, I cannot find reference to this in the Icecast docs and I don't see any mention of it in any forum articles.

Or perhaps the issue is something else I haven't thought of at all.

What do you think?


David V

[karlH]

Whenever you have the possibility of moving listeners between mountpoints like in the case of a fallback then you need the two formats to be the same. Similarly you will want the settings of those two streams to be the same, no changes in channels or samplerate. Icecast will prevent listeners from being moved if the two formats are different, so ogg -> mp3 is out of the question. While technically, icecast could allow it, the problem is that every player would get confused in the change, typically they would stop playback until it found another ogg page or mp3 frame (depending on which the player started with).

Changes to the stream settings like samperate or channels may work on a small number of setups but is best avoided. Bitrate differences will probably be treated like VBR streams, so vorbis is ok (although huge changes could lead to buffering issues) but mp3 can be an issue for some players like wmp. If override is enabled then the listeners are moved from the fallback at the time the primary mountpoint connects. There is no automatic checking after that although you can manually move listeners via the admin interface.

Icecast can handle any combination of handled formats, provided they are on separate mountpoints, so 3 ogg streams and 3 mp3 streams is fine. Icecast does not enforce much on the naming of mountpoints, obviously /admin is not allowed. The issue with the .ogg extension is not an icecast one, but one often used by players to determine the codec to use for decoding. Icecast uses the content type header so naming is not a factor but players like winamp still require an .ogg extension. It is possible to use a fallback ogg stream that does not have a .ogg extension and the players will work because they never see the fallback mountpoint directly.

karl.

[Anonymous]

[karlH]