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

[Kai Vehmanen]

On Fri, 24 Jan 2003, Kjetil S. Matheussen wrote:

>> This means that you could be having small xruns all the time! Of course,
>> really long breaks are always audible, but shorter ones are sometimes
>> quite subtle. Still, you are losing audio data.
> I guess so. But its not necesarrily very import, at least not for (most
> kinds of) live performance. Is there a quick way to patch pd so that it
> detects xruns?

Yup, replace the set_stop_mode call with:

snd_pcm_sw_params_set_stop_threshold(handle, sw_params, XXX);

... where XXX is the buffersize (ie. 64*27=1728). 

The difference is definitely notable. I've just patched jackd to ignore
all xruns the way pd does, and yup, I can do all kinds of stuff as a
normal user (with ./jackd -p 64 -n 27). I'm currently running
ecasound+jackd+freqtweak+qjackconnect as a normal user, with the same
1.5->39ms latency as with pd, and while there are occasional audible
artifacts, it does indeed work!

Also more common jackd setups like 'jackd -d alsa -p 1024 -n 3' 
work more reliably this way. But of course, as I noted in my previous 
message, we are definitely losing samples even though no errors are 
reported.

--
 http://www.eca.cx
 Audio software for Linux!