Carla and Cadence (Jack server problem)

[PrismaPhonic]

Hi guys,

I'm a Mastering engineer that lives in the bay area. I'm trying to get a linux system set-up for pro audio and I've found the tools you guys have made to be very helpful!

The one challenge I'm having is with Carla and Cadence. At least on my system Carla won't work unless it starts the Jack server. I'd like to start the Jack server with Cadence because I have far more control over the sample rate, bit depth and other settings for the Jack server there.

Simply put, how can I get Carla to recognize that Jack is already running so that I can start it with Cadence?

Thanks for the help!

[PrismaPhonic]

Yes, I have tried this. I started JACK up in cadence, and the server is running successfully. Then I start up Carla and Carla doesn't recognize that JACK is already running. it attempts to start JACK itself, but can't because JACK is already up and running.

This happens regardless of whether I start JACK up from Cadence or from qjackctl.

Here's the output I get in terminal if I launch Carla from terminal after successfully launching Jack server from Cadence:

Carla 1.9.6 (2.0-beta4) started, status:
Python version: 3.4.3
Qt version: 4.8.7
PyQt version: 4.11.4
Binary dir: /usr/lib/carla
Resources dir: /usr/share/carla/resources
libpng warning: iCCP: known incorrect sRGB profile
libpng warning: iCCP: known incorrect sRGB profile
libpng warning: iCCP: known incorrect sRGB profile
libpng warning: iCCP: known incorrect sRGB profile
libjack.so.0 loaded sucessfully!
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jackdmp 1.9.10
Copyright 2001-2005 Paul Davis and others.
Copyright 2004-2014 Grame.
jackdmp comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details
no message buffer overruns
no message buffer overruns
no message buffer overruns
JACK server starting in realtime mode with priority 10
self-connect-mode is "Don't restrict self connect requests"
audio_reservation_init
Failed to acquire device name : Audio0 error : Device reservation request with priority 2147483647 denied for "Audio0" via RequestRelease()
Audio device hw:PCH cannot be acquired...
Cannot initialize driver
JackServer::Open failed with -1
Failed to open server
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started

Carla does load up at this point. If I click on the Patchbay I see nothing at all in this window. If I click on "Engine" then I see the "Start" button available. Clicking this gives me:

Could not connect to Audio backend 'JACK', possible reasons:
Failed to create new JACK client

However, if Jack is not started up yet and I start up Carla, then Carla successfully will start Jack and input/outputs show up in the Patchbay for various Jack enabled programs.

To answer your question of:

Do you have the Cadence autostart jack option enabled?

I do not. I manually start Jack from Cadence.

[PrismaPhonic]

I tried that but it didn't fix the problem.

Carla is now working though if I start QjackCtl first. Perhaps I'll just use QJackCtl. One of the issues I've encountered with Cadence is that it can't automatically detect any of audio devices, however QJackCtl does this no problem. I had to manually input the HW number in Cadence to get the Jack server to start from there. Perhaps I should try compiling the git version of Cadence to see if that fixes the issue