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QjackCtl 0.3.5 slipped away!

A classic needs no introduction.

QjackCtl 0.3.5 slipped away!


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Weblog (upstream support):


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


  • Late support for UTF-8 encoded client/port names.
  • Allow only one single patchbay connection to or from an exclusive socket (mitigating bug #2859119).
  • Automatic crash-dump reports, debugger stack-traces (gdb), back-traces, whatever, are being introduced as a brand new configure option (--enable-stacktrace) and default enabled on debug build targets (--enable-debug).
  • Probable fix on the audio connections with regard to client/port (re)name changes (an ancient bug reported by Fons Adriaensen).
  • Portaudio device selector is now available (after a patch handed by Torben Hohn and Stephane Letz).
  • A couple of primitive D-Bus interface slots have been introduced, giving the option to start/stop the jackd server from the system bus eg. via dbus-send --system / org.rncbc.qjackctl.start (.stop), (a nice addition supplied by Robin Gareus, thanks).
  • New command line option (-a, --active-patchbay=path) to specify and activate a given patchbay definition file (a simple patch sent by John Schneiderman, thanks).
  • Added one significant digit to DSP Load percentage status display.
  • Tentative support for netjack (slave) by adding the "net" driver to the existing backend driver options on the Setup/Settings section.
  • Converted obsolete QMessageBox forms to standard buttons.
  • New patchbay snapshot now raises the dirty flag and allows for the immediate salvage of patchbay definition profile.
  • Conditional build for JACK port aliases support (JACK >= 0.109.2).
  • Alternate icon sizes other than default 16x16, are now effective to the Connections widget (Setup/Dislay/Connections Window/Icon size).



Awesome helpful software, Thanks!
but... I am writing to ask for help clearing up my confusion about the difference in functionality between the Patchbay window that opens when you click the patchbay button, and the Connect button that opens the Connections window. When would one use patchbay versus connect to set up the desired connections? It seems to this newbie like they do almost the same thing but somewhat differently, and maybe the patchbay can persistently saved, but not so apparently for the connections. There is some inner logic clearly working to decide what items get displayed in the dropdown lists of both windows but I can't figure it out. I am also confused about what's an input and what's an output.

For example: I have a Yamaha WX5 wind controller. I want to hook it up to send MIDI in to my Creative Soundblaster card (which has a MIDI cable plugged into the joystick port with a split output cable for MIDI in and MIDI out, with an Ubuntu jaunty computer running jackd compiled for alsa. I have also got fluidsynth running, with two virtual synthesizer instances set up inside. I want to be able to play the MIDI controller, to a) cause the MIDI data to go to one or the other of the two Qsynths (and be able to easily change which Qsynth in performance) and b) send output to be played by the Soundblaster's audio out to my external speakers. Simultaneously I want c) the same MIDI data routed out the Soundblaster's MIDI-out port so I can send it to an external Yamaha TX7 synthesizer also.

So how do I use the interfaces for the patchbay and the connect windows to specifiy what connects to what to make the connections, what will be persistent if I save the patchbay as a file, and what is performance-changeable and non-persistent?
Again, thanks so much for your great work! I appreciate any lore for newbies you can give me, to facilitate my actually having a solid grip on things.
-Dave Britton

rncbc's picture

Aha. You may like to read all about it on QjackCtl and the Patchbay.



For some weeks now, I have tried to compile Qjackctl under Mac OS X "Snow Leopard" and with Qt 4.6 but unsuccessfully. Whatever the Qt version, I systematically obtain an error message claiming that my Qt version is older than 4.1 and I have no way to compile Qjackctl.

Some advice ?

Thanks a lot,


rncbc's picture

I have no expertise in OSX, whatsoever. If you know the directory where your Qt framework is installed, tell it to the configure script, like this:

./configure --with-qt=/path/to/qt/framework/whatever

Cheers && Hapy New Decade
the 00's are over

Thanks for your answer but I already tried this option. I really don't understand why it fails...

Cheers and happy new decade.

rncbc's picture

Maybe, just maybe, you have Qt 3 also installed and it is found on standard search include/library paths? Have an insider look on the config.log file.



I took a look on the log file. Actually, it seems there is a kind of mix-up between 32 and 64 bits regarding this excerpt from the log:

"/usr/local/Trolltech/Qt-4.6.0//include/Qt/qglobal.h:288:2: error: #error "You are building a 64-bit application, but using a 32-bit version of Qt. Check your build configuration."

I thought that Qt 4.6 for Snow Leopard was "naturally" 64 bit but maybe I am wrong.

I don't know what to do at this point.

Thank you for your help,


rncbc's picture

I don't know what to do at this point.
I guess it is now clear that the way to go is to install new Qt4 64bit version. Maybe you can install the 64bit version in co-existence to the current Qt4 32bit, but I'm afraid of ill-advising you to do something I don't know entirely and thus break your system loose. I'm sorry I can't help you more than this, if that's help at all. I'm just a complete Mac-OSX moron :)


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