[linux-audio-user] Re: [Jackit-devel] What is a 'delay exceeds' vs. and xrun - BIG MISSES - AND SOLUTIONS!

[Mark Knecht]

Jack O'Quin wrote:
> Mark Knecht <markknecht at gmail.com> writes:
> 
> 
>>   In terms of better testing I now need to concentrate on finding an
>>application that run without creating xruns within the application
>>itself. At higher latency values (p=256 for instance) alsaplayer -r -o
>>jack runs pretty well, but as I move to lower latencies I find that
>>alsaplayer deterministically creates xruns at the transistion between
>>every song on a CD. I also tried alsaplayer playing wave files from
>>disk, but I see xruns as it goes from one file to the next also.
>>
>>   I want to try using chrt to see if alsaplayer is really getting
>>real-time access, etc. Maybe there are things still not right with the
>>way I'm running it on my box.
> 
> 
> I sometimes see problems with alsaplayer at low latencies, too.
> Generally below -p128 or so.

So -p8 -n2 qualifies as 'low latencies', right? ;-)

> 
> 
>>   Is there any other simple app that could play a wave file from, for
>>instance, memory without this sort of problem?
> 
> 
> I've had good luck with hydrogen.  Play one of the demo drum patterns.

I had Ardour on the machine already so I fired it up. It's running fine 
playing 'Drums on Demand' loops which I very quickly imported into a new 
Ardour session. No xruns in the last 20 minutes, although this time I'm 
using QJC which doesn't seem to let me start any faster than -p64. I can 
live with sub 3mS. (for now...)

All this with updatedb running in the background. This could make me 
heady, if it holds up. Much testing needed.

> 
> 
>>   So, the good news is my Gentoo system is not broken, and that I've
>>hopefully learned a bit and contributed just a little bit more along
>>the way. That said I still have a long ways to go.
> 
> 
> Good work.

And to you to for doing the realtim-lsm stuff. One thing I am seeing 
which I don't quite understand is with realtime-lsm loaded it seems that 
apps default to somewhere other than my home account the first time I 
open a file menu. They are either going to / or /root. Not sure if 
that's by design or some sort of limitation, but it seems a bit off to me.

Thanks,
Mark