[PlanetCCRMA] Pd + PulseAudio?

Peter Kirn peter at createdigitalmedia.net
Wed Mar 24 12:04:05 PDT 2010

Right, I don't disagree, Niels ... but this still points the finger at
Pd. Why would Ardour running as a JACK client connect to JACK with no
problem, but Pd running with JACK would refuse to *connect to JACK* --
not to hw:Intel, but to JACK itself? It suggests that somehow JACK is
behaving differently with the two different interfaces in some way
that throws off Pd (though that shouldn't happen!)

There's no HDMI on this system, so that's not it.

Okay, using the launch parameters:
pd -rt -jack -inchannels 2 -outchannels 2

Instantly get some DIO errors, though only on launch:
audio I/O error history:
seconds ago	error type
     2.84	A/D/A sync
     2.99	unknown
     2.99	unknown

Ah-HAH! Sure enough, Fernando, you're right -- that fixes the problem.
Pd *instantly* autoconnects (those little glitches in the errorlog
show that is immediately tries to connect and succeeds), patches
properly to system out, the lot.

So what's going on here, exactly? Why does Pd work with the explicit
inchannels/outchannels flags but not without them? JACK shows up the
same way in the Pd GUI.

And why did the AK1 not have the same problem with its 4 outs, 2 ins?
(wouldn't it seem that'd be more likely to fail, not less, especially
since the AK1 lacks any alsamixer-visible parameters?)

Having blamed pulseaudio, the issues here seem to be related to Pd,
since once JACK is the audio system, PA is indeed out of the picture.

Also, Fernando, since I just manually started qjackctl and Pd, are
there any sort of scripts people tend to use to start JACK (maybe
without the GUI), then Pd configured properly? I'd love to be able to
recommend a solution for people, as I know a lot of people just give
up before they even get where I got -- and automating the process
would be part of the appeal of setting up a dedicated Linux config.

Cheers, and truly, thanks for your immense patience and help, Fernando
and Niels and everyone.

On Wed, Mar 24, 2010 at 2:49 PM, Niels Mayer <nielsmayer at gmail.com> wrote:
> On Tue, Mar 23, 2010 at 8:26 PM, Peter Kirn <peter at createdigitalmedia.net>
> wrote:
>> Looking at AlsaMixer as you suggest, I definitely see the HDA Intel
>> card. Master and PCM have volume levels; Headphone and Speaker show up
>> but do not have mixer values.
> ...
>> "control open "hw:intel" (No such device)
>> Cannot initialize driver"
> Hunches:
> Something is unexpectedly grabbing your hw:intel controls.
> Consider that X/Gdm launch pulseaudio, so you can have those cute noises
> when you mistype your password; it will therefore grab the hw:intel
> controls. By totally removing pulseaudio, this can't happen, ever.
> Consider also that these intel cards often include a semi-shared HDMI audio
> portion e.g.
> ##  1 [SB             ]: HDA-Intel - HDA ATI SB
> ##                       HDA ATI SB at 0xfb7f4000 irq 16
> ##  2 [HDMI           ]: HDA-Intel - HDA ATI HDMI
> ##                       HDA ATI HDMI at 0xfb9fc000 irq 19
> Perhaps also consider disabling the HDMI portion to prevent interference
> from that (as well as not loading extra drivers that you're not using).
> (from /etc/modprobe/*.conf: )
> alias snd-card-1 snd-hda-intel
> options snd-hda-intel index=1,2 enable=1,0
> As a half-step towards preventing problems, you can also even w/ pulse
> running, disable all system sounds and all error warning sounds. That causes
> a whole class of sound system lockups in and of itself. However, once you've
> gone that far, you might as well go all the way and follow my original
> suggestion: http://old.nabble.com/uninstall-pulseaudio-to-increase-audio-app-stability-across-updates-%28was-Re%3A-yum-update%29-tp27759501p27759501.html
> -- Niels
> http://nielsmayer.com

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