[linux-audio-dev] mux concept paper

Lee Revell rlrevell at joe-job.com
Thu Feb 17 16:20:06 UTC 2005


On Thu, 2005-02-17 at 08:40 -0500, Paul Davis wrote:
> >complaining. But my experiences with jack are negative. First time I 
> >started looking at it I had huge expectations after all that I had read. 
> >   First problems, after a couple of second of running without any 
> >actual processing going on, strange noise artefacts kind of getting 
> >worse. I had a look at source code and realise that it bases its time 
> >calculation on cpu MHz in /proc/cpuinfo. I dont know about your machine, 
> >but on my machine(s) a) this is a float and b) it's slightly different 
> >every time I boot the machine.
> 
> this has nothing to do with your noise. JACK uses CPU Hz to provide a
> UST value. i am puzzled by the fact you are the 2nd person to think
> that JACK's timing is somehow based on system timers and so
> forth. JACK (in regular mode, using one of the normal backends) is
> driven 100% by the interrupt from your audio interface. whether or not
> the CPU Hz value is correct has (effectively) zero impact on audio
> generation and timing.

Besides, I wrote a patch to eliminate the /proc/cpuinfo hack, it's low
prio but should be in JACK eventually.  But like Paul says this has
absolutely nothing to do with the sound.

Lee




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