Qtractor An Audio/MIDI multi-track sequencer
What's Qtractor ?
Qtractor is an Audio/MIDI multi-track sequencer application written
in C++ with the Qt4 framework.
Target platform is Linux, where the Jack Audio Connection Kit
(JACK) for audio, and the Advanced Linux Sound Architecture
(ALSA) for MIDI, are the main infrastructures to evolve as a fairly-featured Linux desktop audio
workstation GUI, specially dedicated to the personal home-studio.
Qtractor is free, open-source software, distributed under the terms of the
GNU General Public License (GPL)
version 2 or later.
Project page: http://sourceforge.net/projects/qtractor
Click on image to see more screenshots...
- Multi-track audio and MIDI sequencing and recording.
- Developed on pure Qt4
C++ application framework.
- Uses JACK for audio
and ALSA sequencer for MIDI
as multimedia infrastructures.
- Traditional multi-track tape recorder control paradigm.
- Audio file formats support: OGG (via libvorbis),
MP3 (via libmad, playback only),
WAV, FLAC, AIFF and many, many more (via libsndfile).
- Standard MIDI files support (format 0 and 1).
- Non-destructive, non-linear editing.
- Unlimited number of tracks per session/project.
- Unlimited number of overlapping clips per track.
- XML encoded session/project description files (SDI).
- Point-and-click, multi-select, drag-and-drop interaction
(drag, move, drop, cut, copy, paste, paste-repeat, delete, split, merge)
- Unlimited undo/redo.
- Built-in mixer and monitor controls.
- Built-in connection patchbay control and persistence (a-la QjackCtl).
- LADSPA, DSSI, native VSTi and LV2 plug-in support.
- Unlimited number of plug-ins per track or bus.
- Plug-in presets, programs and chunk/configurations support.
- Unlimited audio effect send/return inserts per track or bus.
- Audio/MIDI clip fade-in/out (linear, quadratic, cubic).
- Audio/MIDI clip gain/volume, normalize, export.
- Audio/MIDI track and plugin parameter automation (dynamic curves,
sample&hold, linear and spline modes).
- Audio clip time-stretching (WSOLA-like or via librubberband), pitch-shifting (via librubberband) and seamless sample-rate conversion (via libsamplerate).
- Audio/MIDI track export (mix-down, merge).
- Audio/MIDI metronome bar/beat clicks.
- Unlimited tempo/time-signature map.
- Unlimited location/bar markers.
- MIDI clip editor (matrix/piano roll).
- MIDI instrument definitions (a-la Cakewalk(tm) (*.ins));
SoundFont (*.sf2) and MIDI Names XML (*.midnam) files also supported.
- MIDI controller mapping/learn/assignment (mixer and plug-in parameters).
- MIDI system exclusive (SysEx) setups.
- JACK transport sync master/slave.
- JACK session support.
- NSM (Non session management) support.
- MMC control surface enabled.
- MIDI Song Position cueing support.
- Configurable keyboard shortcuts.
The software requirements for build and runtime are listed as follows:
Optional (opted-in at build time):
- libvorbis (enc, file), Ogg Vorbis audio compression
- libmad, High-quality MPEG audio decoder
- libsamplerate, The secret rabbit code, C library
for audio sample rate conversion
- librubberband, Rubber Band Audio Time Stretcher,
an audio time-stretching and pitch-shifting library
- liblo, Lightweight OSC implementation
(needed for DSSI GUI and/or NSM support)
- DSSI, An API for soft synth plugins with custom user interfaces
- VST SDK, Steinberg's Virtual Studio Technology
- LV2, Audio Plugin Standard, the extensible successor of LADSPA
- liblilv, Lightweight LV2 implementation stack
- NSM, Non Session Management
Qtractor's already in some kind of beta stage of development and hence fully functional.
Though, the bleeding-edge development source tree is readily available from the sourceforge's public
2014-07-07 - The Boson Walk Beta
- Prevent linear and spline automation curve modes for all
integer valued subjects. Also, make sure those values are
rounded to the nearest integer away from zero.
- Fixed save of LV2 Presets for plugins with state files.
- A man page has beed added (making up Gürkan Sengün's work
on debian, thanks).
- When moving plugins by eg. drag-and-dropping across tracks,
automation curves were being left behind, maybe leading to
unpredictable mistaken behavior. Hopefully, not anymore.
- Translations install directory change.
- Automation curves are now automatically re-adjusted to tempo
map node changes (after a ticket by Holger Marzen, thanks).
- Audio/MIDI files or plugins found missing on session load
are now subject for an explicit modal warning message and
prompt for an immediate session backup salvage.
- Changing instrument plugin programs is now an undo/redo-able
command operation, especially for DSSI but also for plugins
that come with the LV2 Programs interface extension support
- Drawing, selecting and/or resizing of MIDI note events that
extend across tempo/time-signature changes is now made a bit
more correctly over the MIDI clip editor (aka. piano-roll),
especially regarding to current snap-to-beat setting (after
an outstanding ticket by yubatake, thanks).
- Once again, audio frame/MIDI time drift correction has been
slightly refactored to improve MIDI input monitor and timing.
- Discrete automation curve node values may now be edited via
a numerical entry floating spin-box on double-click (as yet
another request by AutoStatic aka. Jeremy Jongepier, thanks).
- Pressing shift/ctrl keyboard modifiers while double-clicking
on a plugin list entry now briefly reverses the current View
/Options.../Plugins/Editor/Open plugin's editor (GUI) by
default option preference.
- Fixed an old crash lurker when switching output buses that
implied a change on the number of audio channels, while on
tracks that have (auto-)monitor turned on and at least one
active plugin in chain (yet another ticket by AutoStatic
aka. Jeremy Jongepier, thanks).
- MIDI Controller assignment (aka MIDI learn) and/or automation
of plugins (de)activation state has been added (as requested
by AutoStatic aka. Jeremy Jongepier, thanks).
- LV2 UI Idle and Show interfaces support added.
- Allow the build system to include an user specified LDFLAGS
(patch by Alessio Treglia aka. quadrispro, thanks).
Previous and older pre-releases, including the change log,
are also available here.
You can browse all files available for download, including binary packages, at
Qtractor Files on SourceForge.net.
The installation procedure follows the standard for source distributions.
Once under the extracted source directory:
and optionally as root:
This procedure will end installing the following files:
Just launch prefix
/bin/qtractor and you're off (hopefully).
Note that the default installation path prefix is
Qtractor holds its settings and configuration state per user,
in a file located as
Normally, there's no need to edit this file, as it is recreated and
rewritten everytime qtractor is run.
Probably plenty still, Qtractor maybe considered on beta stage already.
Qtractor 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.
A new Qtractor quick start guide and user manual
has been updated for version 0.5.x by Seth Kenlon & Klaatu.
The older user manual for version 0.3.0 and before,
have been co-authored by James Laco Hines and Stephen Doonan.
Qtractor logo/icon is an original work of Andy Fitzsimon, borrowed from
the public domain openclipart.org gallery.
A special mention should also go to the translators of Qtractor, of course:
- Pavel Fric (cs)
- Guido Scholz (de)
- Yann Colette (fr)
- Massimo Callegari (it)
- Takashi Sakamoto (ja)
- Esteban Viveros (pt)
- Alexandre Prokoudine (ru)
This project has also a freecode.com entry.
( formerly freshmeat.net )
rncbc aka Rui Nuno Capela
rncbc at rncbc dot org