[Jackit-devel] Re: [PD-announce] Re: [linux-audio-dev] ANN: k_jack v0.0.0.5 and Mammut v0.15

Paul Davis paul at linuxaudiosystems.com
Fri Jan 24 10:22:01 UTC 2003


>> period_size: 64
>> buffer_size: 1728
>
>So I guess this explains a lot. This equals to running jackd 
>with "-p 64 -n 27" (and not as root or otherwise it will throw clients
>out if they miss one 64 frame deadline). 
>
>I'm quite sure you get much more reliable performance this way, although
>JACK doesn't take advantage of multip-period buffer configurations very
>well.  And this has its reasons. With a setup like shown above, you either
>get a huge latency (64*1728/44100*1000=2500ms), or you get latency jitter

not that large. you don't multiply the period size by the buffer size
and the 1000 is extraneous too. the maximum latency is 1728/44100 =
39ms, i think. i don't of any h/w that has a 2.5 second buffer!!

this is still pretty long, and as you note, pd is not subject to
per-period time limits with this configuration. it can take too long
on up to 26 of 27 periods before there is an xrun.

this configuration is not even vaguely equivalent to the one JACK is
typically run with. its not a similar test at all.

--p



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