[Icecast] restarting streamtranscoder w/ out killing listeners

[Josh Whiting]

> You could set up a fallback stream, redirecting people to a static file or
> a stream streamed by ezstream (for example) when the transcoder goes down.
> Obviously this will still interrupt the listeners, but it will not
> disconnect them and will automatically move them back to the main stream
> once it's up and running again.

Interestingly enough yesterday my friend & I devised a similar idea
where we setup two ST instances per format, (call them A and B,) each
set as a fallback for the other.  We then setup a cronjob to restart
A, then B, then A etc on an alternating schedule, so our listeners get
moved from A->B->A on a regular interval.  Quite a hack but at least
our stream is usable for now.

> BTW, we also use the streamTranscoder, and I found that increasing the
> internal buffer size greatly increased the stability (at the cost of
> slightly higher latency, but this was not an issue for us).
> 
> If you open transcurl.cpp and look for the comment "JCMOD, made this a lot
> larger" (should be in three places), you'll see a value defined as
> something multiplied by 20. I (rather arbitrarily) changed it to "*60" and
> recompiled and it worked so well I haven't felt the need to try other
> values :-)

Good tip there, I'll give that a try, thanks!

-jw