we run a DAW (LMMS) with jack and would like to exploit multiple cores.
Currently, we have one jack process (using `jack_set_process_callback`)
and multiple other processes that share all the work. The problem is
that only the jack process has RT prio. Imagine the following example:
* 4 threads, of which one is the jack thread, 3 have lower priority
* 4 tasks (e.g. 4 instruments play one note each)
* the realtime process is finished quickly, the other threads get
preempted by the kernel
These are situations where using such non-realtime helper threads can
threaten realtime behaviour. What is the best practice?
* Is it possible/good to use multiple rtprio threads controlled by jack?
(multiple clients, or multiple threads in one client)
* Should we keep using our non-rt helper threads?
* Should we be single-threaded, to have a (probably) longer average
time, but a better worst-case time?
* Should we start with helper threads and only the last few jobs will
only be run by the realtime thread (to avoid problems like in the
Many thanks on advance!
I wanted to start a discussion of what kind of AVB connectivity makes the most sense for jack.
But please keep in mind what AVB is and isn't.
a) Fully functional Backend
b) Media Clock Backend with AVB jack clients
- the AVDECC connection management could be done seamlessly in a jack way
- out of the box avb functionality
- only one talker/listener, single audio interface
- huge programming effort
- no dynamic audio mapping
- multiple talkers/listeners with multiple audio interface using alsa api
- avoiding huge code addition to the backend, thus much easier to maintain
- AVDECC handling per client for dynamic audio mapping
- cpu load... price for multiple talkers/listeners
I'm excited to hear your opinions!
Diese Nachricht wurde von meinem Android-Gerät mit K-9 Mail gesendet.
Op di 25 jun. 2019 22:44 schreef <jack-devel-request(a)lists.jackaudio.org>:
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> Today's Topics:
> 1. Re: Korg nanoKONTROL2 and Native Instruments Komplete Audio 6
> MIDI issues (Brian Hechinger)
> Message: 1
> Date: Tue, 25 Jun 2019 16:21:58 -0400
> From: Brian Hechinger <wonko(a)4amlunch.net>
> To: jack-devel(a)lists.jackaudio.org
> Subject: Re: [Jack-Devel] Korg nanoKONTROL2 and Native Instruments
> Komplete Audio 6 MIDI issues
> Message-ID: <e8b019d8-4bcb-9981-9c62-01f1111633a3(a)4amlunch.net>
> Content-Type: text/plain; charset=utf-8; format=flowed
> Huh, telling the ASLA-MIDI bridge to Export HW Ports fixed everything.
> On 6/22/19 5:26 PM, Ralf Mardorf wrote:
> > On Sat, 22 Jun 2019 15:39:24 -0400, Brian Hechinger wrote:
> >> So if amidi can list them why don't they show up in Claudia? I'm
> >> confused.
> > I've got an Arch Linux and an Ubuntu install, but even for the Ubuntu
> > install I'm neither using UbuntuStudioControls nor Cadence.
> > https://help.ubuntu.com/community/UbuntuStudio/UbuntuStudioControls
> > https://kx.studio/Applications:Cadence
> > I would disable all autostarts and manually start one after the other by
> > command line, jackd 2 instead of jackdbus and then a2jmidid.
> > Keep in mind that issues are expected:
> > It was mentioned several times on the Ubuntu Studio mailing lists, that
> > there are problems with Ubuntu Studio in combination with kxstudio
> > repositories.
> > _______________________________________________
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> > Jack-Devel(a)lists.jackaudio.org
> > http://lists.jackaudio.org/listinfo.cgi/jack-devel-jackaudio.org
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> End of Jack-Devel Digest, Vol 155, Issue 8
On Sat, 22 Jun 2019 13:39:00 -0400, Brian Hechinger wrote:
>wonko@deepthought:~$ amidi -l
>Dir Device Name
>IO hw:0,0,0 nanoKONTROL2 MIDI 1
>IO hw:1,0,0 Komplete Audio 6 MK2 MIDI 1
>I'll try to reboot but I'll also try the USB power thing you mentione
In my experiences, if USB bus power is the culprit, amidi doesn't list
So my previous setup was a Creative Labs SB1095 and the nanoKONTROL2.
The nanoKONTROL was showing up via the ALSA-MIDI bridge and I was using
it to control Ardour.
I replaced the SB1095 with a Native Instruments Komplete Audio 6 and
now the nanoKONTROL no longer shows up as a MIDI device. The ALSA-MIDI
bridge is running because I get the passthrough device in Claudia. The
Audio6 doesn't show up as a MIDI device either.
The weird thing is when I first got the Audio6 I unplugged the SB and
plugged in the Audio6 and it did show up as a MIDI device. JACK
*really* dislikes having its audio device removed out from under it I
noticed so audio never worked again after that. :)
I kept the Audio6 plugged in and rebooted. I got audio working but MIDI
never came up on either the nanoKONTROL or the Audio6.
I'm completely stuck now and don't know what to do, please help!!
I want to suggest to add the aubio tools (https://aubio.org/) to the
utilities section on the jack applications page
The tools can be used for audio labbeling. I personally use aubiotrack
from the aubio-tools package (standard package in ubuntu) to sync music
to lights in realtime together with QLC+ using aubiotracks midi output.
Aubio comes with jack support.