[linux-audio-dev] Still on usx2y

[Rui Nuno Capela]

Antonio "Willy" Malara wrote:
>
>> Both modes are perfectly legal but, with this later one, you can run on
>> much lower latency settings (e.g. -p64 -n2) without crackling your ears
>> :)
>
> [snip]

> Zeryn:/home/willy/Pacchi/jack-0.99.48-cvs20040122# jackd -dalsa -dhw:0,2
> -r44100 -p64 -n2 -S
> jackd 0.99.48
> [...]
> loading driver ..
> apparent rate = 44100
> creating alsa driver ...
> hw:0,2|hw:0,2|64|2|44100|0|0|nomon|swmeter|-|16bit
> control device hw:0
> ALSA/USX2Y: EXPERIMENTAL hwdep pcm device hw:0,2 (aka "rawusb")
> configuring for 44100Hz, period = 64 frames, buffer = 2 periods
> Couldn't open hw:0,2 for 16bit samples trying 24bit instead
> Couldn't open hw:0,2 for 24bit samples trying 32bit instead
> Sorry. The audio interface "hw:0,2" doesn't support any of the hardware
> sample formats that JACK's alsa-driver can use.
> ALSA: cannot configure capture channel
>
> i've tried with plug layer (-d plughw:0,2) and it worked, i get some
> xruns, but the audio is a loud continous noise.
>

What hardware is this?

Anyway, try some deffensive approaches:

  1) jackd -R -d alsa -d hw:0 -r44100 -p1024 -n2 -S

  2) jackd -R -d alsa -d plughw:0 -r44100 -p1024 -n2 -S

  3) repeat without nrpacks=1 parameter

>> Be advised however, that you get far better results if you're running
>> jackd in realtime mode (-R) *and* under the help of a RT capable kernel,
>> like 2.6.10-mm1 with Ingo's V0.7.34-01 realtime-preempt patch.
>
> unfortunately i cant compile realtime preempt patches, i've tried almost
> any version but they seems to be linux/x86 only. i keep searching some
> kind of lowlatency patches that i can apply succesfully
>

First thing you're missing is probably the realtime-lsm module. Without it
you can't run "jackd -R ..." as a regular user (only as root?).

Cheers.
-- 
rncbc aka Rui Nuno Capela
rncbc at rncbc.org