[Icecast] elegant way of re-encoding?

[Geoff Shang]

kloschi wrote:

>> I've not used it, but Icecast now has the ability to execute a command
>> upon stream start, as well as upon stream stop.  You could use this
>> fascility to launch a streamTranscoder instance.
>
> I didn't find any docs on that, how to execute a command upon stream
> start/end?

As I say, I've not used it, but I think there are some comments or at least 
some examples in the sample config files which come with Icecast.  Note 
that this is either an Icecast 2.3 or 2.3.1 feature, it's pretty new.

> the docs on streamTranscoder are a little rare also ;)
> what exactly does streamTranscoder:
> serving one multiple bandwidth stream (like havong one stream on server
> and when client clicks on it it just measures bandwidth and serves the
> highest possible quality) in just one mountpoint?
> or
> serving multiple streams with multiple encoding & qualities, just as
> configured?

It transcodes according to how you configure it.  What you describe above 
would theoretically be possible once someone implements bitrate pealing in 
Vorbis.

> What bothers me most, is that streamTranscoder seems to connect to just
> one server getting the stream and delivering to the same.

No.  I've not used the latest version, but versions up to 1.2.x listen to a 
stream, encode to whatever you specify, then send it where you specify. 
That could be a different mountpoint on the same server, or somewhere else 
entirely.  It can even listen to your sound card, though I've not tried 
this either.  It does not send it back to the same place where it got it 
from, it can't anyway since it wouldn't be able to connect.

Note that versions I've used take one input stream and deliver one output 
stream only.  If you want more than one transcode of a stream, you need to 
use multiple instances.  Whether this has changed in recent versions I do 
not know.

Geoff.