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Qtractor 0.4.5 - A Friskier Demivierge is out!

SCNR ;) mostly yet another bug-fix-regression dot release, nuff said.

Qtractor 0.4.5 (friskier demivierge) is out!


  • Changing loop points while playback is rolling, with the play-head any near, was leaving audio clips out-of-sync.
  • MIDI event list view was missing some selected items with the very same onset time, now fixed.
  • When failing to detect a SSE enabled build, the CFLAGS variables are now properly restored to their previous sane state, preventing all subsequent dependency tests from false positives (bug#
  • MIDI clip editor (aka piano-roll) multiple selection has been fixed (again) re. move/paste-snapping consistency.


Project page:


Weblog (upstream support; oh wait...):


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

Cheers && Enjoy.


This is looking very cool. Great work.

To install the Ubuntu 9.10 (Karmic) package you need to also install these from the Lucid repository:

rncbc's picture


Didn't know about the librasqal2 in particular needing to be from Lucic repos. I thought it would be a direct and automatic dependency of librdf0 which you also need. However, librdf0 is available from Karmic repos. alright.

Anyway, thanks again.

Or install it from this PPA:



hi there,
it's good to see this software evolves :D.
i compiled last tarball (and svn) to get ladish level 1 support with no success.
when saving studio in gladish, the software keeps on exiting
any idea ? am i supposed to enable (i search configure --help output) ladish lv1 explicitly ?


rncbc's picture

Conforming to LADISH Level 1, an application should save its state in response to SIGUSr1 signal. That's what Qtractor >= 0.4.4 does. Try this:

kill -USR1 `pidof qtractor`

this should do the same as if you would have asked for File/Save from the main menu. Qtractor should NOT exit (provided you're running 0.4.4 or later).


Hejo ... noted that my release builds and svn builds showed different behaviour ... In the main, some odd bug where qtractor would crash trying to read templates (controller, us428) ... and so, I'm building from svn from now on ... will try to add more feedback ... great work!!!

Hejo, as to my last comment ... everything works really well ... 2 (or 4) audio tracks, midi control, live midi for a total or 3 to 5 tracks. control templates no problem, recording works well, control, playback, midi to internally loaded dssi, etc....

however, trying to open a saved session seg faults (same behaviour with last 2 realeases). This is with an svn build. AMD 64 bit debian ...

I could help with debugging (had it off, high hopes :) what's the best forum? This must be a simple bug.... or system dependent condition.


Hejo, ok, did a simple test based on some reading through this site and the source .... from within nautilus (gnome desktop with self-compiled compiz bummff) ... open qtr file in context with qtractor and PRESTO ... file opens properly. HOWEVER, i can't open qtractor at all now if I try to launch it normally (ie. desktop icon, alt-f2 works)

opening a document (recent menu) crash-o-rama ...

It seems to have to do with dbus? Could be that this only effects odd cases. I'm running a lenny with backports that had been a studio 64 box... Hmmm.

In any case, saving works just fine and re-opening in a context works too.


rncbc's picture


First, you can try moving the global configuration file away (~/.config/ It has been reported that starting from scratch is kind of a cure for most of similar faulty behavior.

Second, if the previous suggestion doesn't get you any better, you can try building from source without LV2 support (./configure --disable-lv2). Reasons for this are slight suspicions of a particular bad libslv2 delivery or/and one its dependencies (eg. librdf0). I've been told more than once that magic happens when switching one or all of those dependencies, specially on debian based systems.

Third, if you dare, you should still build from source with debug in mind (./configure --enable-debug). Watch then for stack-trace dumps whenever it segfaults and report back. It also helps if you turn off View/Options.../Display/Capture standard output, so that those segfault stack-traces get caught on the terminal console.


im back after some tests. qtractor DOES respond to SIGUSr1. but when calling save in gladish, it keeps on exiting. i'll have to deal with ladish dev for that. thx


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