What's QjackCtl ?

QjackCtl is a simple Qt application to control the JACK sound server daemon, specific for the Linux Audio Desktop infrastructure.

Written in C++ around the Qt framework for X11, most exclusively using Qt Designer.

Provides a simple GUI dialog for setting several JACK daemon parameters, which are properly saved between sessions, and a way control of the status of the audio server daemon. With time, this primordial interface has become richer by including a enhanced patchbay and connection control features.

QjackCtl is free, open-source software, distributed under the terms of the GNU General Public License (GPL) version 2 or later.

Project page: https://sourceforge.net/projects/qjackctl

Weblog: https://www.rncbc.org

Screenshots

Click on image to see more screenshots...

Requirements

The software requirements for build and runtime are listed as follows:

Mandatory:

• Qt framework (core, gui, xml), C++ class library and tools for cross-platform application and UI development
  https://qt.io/
• JACK Audio Connection Kit
  http://jackaudio.org/

Optional (opted-in at build time):

• ALSA, Advanced Linux Sound Architecture
  https://www.alsa-project.org/

Downloads

Latest release

2021-02-07 - A Winter'21 Release.
qjackctl-0.9.1.tar.gz

• Graph Disconnect now applies to all selected ports and connections.
• Main window is now freely resizable, while keeping all the buttons stretched to the same aspect ratio.
• Warning to confirm application close is now back in business when functioning as client only (Active).
• Graph items are automatically raised when created or high-lighted (incremental z-value).
• Add a little but straight horizontal line-gap to the Graph connections.
• Customize the Graph zoom slider widget to reset upon mouse middle-button click.
• Add Clear preset button to Setup dialog.
• Use default values for most preset parameters: sample rate, frames/period (aka. buffer-size), periods/buffer, realtime priority, port maximum, client timeout, word length, wait time, channel maximum.
• Early preparations for the New Year develop(ment) cycle.

Previous and older releases, including the change log, are also available here. You may also check out from the latest bleeding edge development source tree, using Git.

You can browse all files available for download, including binary packages, at QjackCtl Files on SourceForge.net.

Installation

The installation procedure follows the standard for source distributions. In the extracted source directory, just do:

./configure [--prefix=prefix]

make

and optionally as root:

[sudo] make install

Just launch prefix/bin/qjackctl and you're off (hopefully). Note that the default installation path prefix is /usr/local .

Configuration

QjackCtl holds its settings and configuration state per user, in a file located as $HOME/.config/rncbc.org/QjackCtl.conf. Normally, there's no need to edit this file, as it is recreated and rewritten everytime qjackctl is run.

Bugs

Probably plenty still, QjackCtl maybe considered on beta stage already. It has been locally tested since JACK release 0.98.0, with custom 2.4 kernels with low-latency, preemptible and capabilities enabling patches. As for 2.6 kernels, the emergence of Ingo Molnar's Realtime Preemption kernel patch it's being now recommended for your taking benefit of the realtime and low-latency audio pleasure JACK can give.

Support

QjackCtl is open source free software. For bug reports, feature requests, discussion forums, mailling lists, or any other matter related to the development of this piece of software, please use the Sourceforge project page.

You can also find timely and closer contact information on my personal web site.

Acknowledgements

QjackCtl's user interface primordial layout (and the whole idea for that matter) was partially borrowed from Lawrie Abbott's jacko project, which was just taken from wxWindow/Python into the Qt/C++ arena.

Since 2003-08-06, QjackCtl has been included in the awesome Planet CCRMA software collection. Thanks a lot Fernando!

This project has also a freecode.com entry.
( formerly freshmeat.net )

Dated from 2004-06-08, an online article written by no one else but Dave Phillips, has been published on Linux Journal, introducing you to Qjackctl and also QSynth. Please have a read:

At the Sounding Edge: Using QSynth and QJackCtl.

It's not on every regular day that you get to see one piece of the trade pointing two of your creations right in the title, is it?

Thanks Dave! You rule!

Here are some people who helped this project in one way or another, and in fair and strict alphabetic order:

Alexandre Prokoudine Andreas Persson Arnout Engelen Austin Acton Ben Powers Chris Cannam Dan Nigrin Dave Moore Dave Phillips Dirk Jagdmann Dominic Sacré

Fernando Lopez-Lezcano Filipe Tomás Florian Schmidt Fons Adriaensen Geoff Beasley Jack O'Quin Jacob Meuser Jesse Chappell Joachim Deguara John Schneiderman Jussi Laako

Karsten Wiese Kasper Souren Ken Ellinwood Kjetil Matheussen Lawrie Abbott Marc-Olivier Barre Matthias Nagorni Mark Knecht Melanie Nedko Arnaudov Orm Finnendahl

Paul Davis Robert Jonsson Robin Gareus Roland Mas Sampo Savolainen Stéphane Letz Steve Harris Taybin Rutkin Wilfried Huss Wolfgang Woehl

A very special mention should go to the translators of QjackCtl:

Thanks to you all.