[icecast] OT: OGG in the mainstream

Mark Casey mccasey at clara.co.uk
Tue Jul 15 14:27:25 UTC 2003

There is a big, big difference between cbr and vbr, btw. The machine in
question is a Pentium 3 700 oc'ed to 800, 512MB ram, win nt 5.1 (2k and xp
being nt) etc
In an earlier version the oddcast dsp ate up so much cpu time when set at
say 64kbps (for examples sake) 44.1kHz, stereo that the machine became
totally unusable and the winamp task had to be (slowly) ended with task
Now, currently on the same machine using CBR and so forth winamp with the
oddcast dsp eats between 70-90% cpu, it essentially prevents you from doing
anything since the machine in question was also used as a desktop machine
(purely testing purposes).
If I had this machine setup as say a Gentoo Linux machine dedicated for
realtime encoding I'm sure cpu usage wouldn't be so bad, but still its too
VBR is always a headache for streaming, hence why the majority of people use
And I was under the impression that OGG Vorbis was never designed for
samplerates other than 44.1kHz, sure it can encode at other bitrates but to
my knowledge it was always designed for lossy compression of samplerates at


<p>-----Original Message-----
From: owner-icecast at xiph.org [mailto:owner-icecast at xiph.org] On Behalf Of
Sent: 15 July 2003 07:40
To: icecast at xiph.org
Subject: Re: [icecast] OT: OGG in the mainstream

<p>On Tue, Jul 15, 2003 at 11:06:03AM +1200, Ross Levis wrote:
> Mark Casey wrote:
> > I think when the real-time cbr encoding issues are sorted
> > Vorbis (this is my experience with oddcast dsp, winamp and 
> > icecast 2 win32, big cpu hog) will start gaining more ground, 
> I can't use the managed bitrate option in OddCast on my K6II-500 CPU! 
> (Overclocked to 525, WinXP Pro,192MB RAM).  I would like to.  Normal 
> VBR uses about 90% CPU.  This seems too high.  Perhaps some work will 
> be done on reducing CPU requirements and/or utilizing some CPU 
> extensions in the future.

That's funny, because we're doing it all the time with Pentium 2's running
at 233mhz.

44100 samplerate, mono, 56k VBR.  ices2. pretty basic setup. no skips.

Prehaps it's an issue with your CPU having poor floating point, or prehaps
its OddCast, or prehaps it was compiled without CPU optimisations, etc.  But
we've been doing it for quite some time quite successfully with ices2.

furthermore, with my K62 450mhz I've successfully done 44100/stereo encoding
at 128k with ices2, it uses about 90% of the cpu but it's doable.  Dropping
to mono makes it much faster, dropping the bitrate (56k vs 128k) makes it
even faster.  Dropping to 22050 samplerate makes it dramatically faster.  

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