[LAU] Jack & pulse...knickers in a twist.

Mac macdroid53 at gmail.com
Mon Jun 4 21:15:21 CEST 2018


Ok, so I'm trying to set this up so I control things with a script file.

I have a script that sets various parameters with jack_control.

I was attempting to start my own paulse audio sink/source, but when I do I
get 2 sinks/sources, and (I'm guessing) pulse is confused as to the default
connections.
So, when, for example, I start a browser and youtube, it doesn't play.

I did some googling, but, none of the files they say to change are on this
system. So, where is the paulse auto start configured and started? It does
show up in ps aux, so something is doing it.

The script:

#!/bin/bash
jack_control start
jack_control ds alsa dps capture none dps playback none
jack_control dps device hw:PCH
jack_control dps rate 48000
jack_control dps nperiods 2
jack_control dps period 256

(the first line fails if I have already started, say patchage...)



On Mon, Jun 4, 2018 at 10:54 AM, Len Ovens <len at ovenwerks.net> wrote:

> On Mon, 4 Jun 2018, Mac wrote:
>
> On Sun, Jun 3, 2018 at 4:22 PM, Len Ovens <len at ovenwerks.net> wrote:
>>
>> Yes, I suspect that Qjackctl saved one of the many iterations I attempted
>> and the
>> settings were totally bogus.
>>
>>
>>       jack_control ds alsa dps capture none dps playback none
>>       jack_control dps device hw:0  dps rate 44100 dps period 128 dps
>>       nperiods 2 start
>>
>> Well that did indeed work.
>>
>> I didn't change the hw:0.
>>
>>  aplay --list-devices
>> **** List of PLAYBACK Hardware Devices ****
>> card 0: PCH [HDA Intel PCH], device 0: ALC892 Analog [ALC892 Analog]
>>
>> I'm assuming hw:0 somehow used PCH, it being card 0.
>>
>> How did you arrive at these values: dps period 128 dps nperiods 2
>>
>
> jackdbus and jackd work differently. Jackd saves the last used commandline
> and if used without any parameters will use that commandline. So using a
> new commandline kills the old one. Jackdbus is different. It stores all of
> the parameters and will reload them at next run. It will only change things
> that the user changes but the old values stay. With your other audio device
> you had set period to 64 in the past and I have found that is too small for
> many internal audio devices (I have one that using 64 crashes jack) so I
> went one up. If all you are doing is listening, I would suggest that you
> use 1024 as that would use less resources. In Qjackctl terms, period is the
> same as "Frames/Period" and nperiods is the same as "Periods/Buffer".
> Internal audio devices are designed for A) listening to games noise and
> youtube, B) for using skype. The outputs sound reasonably good... the mic
> inputs, not so much (good enough for skype). The design "low latency" for
> internal devices is 30ms. If they manage at least that low they are "good
> enough" anything lower is accidental.
>
> jackdbus stores device (for a device that is both input and output) as
> well as input device and output device. It seems that if all are set, odd
> things happen. So in any script I use to start jackdbus, I clear the ones I
> am not using. I am not sure what qjackctl does, but I get the idea that
> rather than use device, it gives the same device to both input and output.
> That way the same code can deal with both the same or different values for
> each. In your original output from jack_control I noticed that device as
> well as input and output were set, that is why the line that set them to
> none so that there would be no confusion.
>
> --
> Len Ovens
> www.ovenwerks.net
>
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