Qtractor

Qtractor - An Audio/MIDI multi-track sequencer

Qtractor is an audio/MIDI multi-track sequencer application written
in C++ with the Qt framework [1]. Target platform is Linux, where the
Jack Audio Connection Kit (JACK) for audio [2] and the Advanced Linux
Sound Architecture (ALSA) for MIDI [3] are the main infrastructures
to evolve as a fairly-featured Linux desktop audio workstation GUI,
specially dedicated to the personal home-studio.

Website:

http://qtractor.org
https://qtractor.sourceforge.io
http://qtractor.sourceforge.net

Project page:

https://sourceforge.net/projects/qtractor

Git repos:

https://git.code.sf.net/p/qtractor/code
https://github.com/rncbc/qtractor.git
https://gitlab.com/rncbc/qtractor.git
https://bitbucket.org/rncbc/qtractor.git

Wiki:

https://sourceforge.net/p/qtractor/wiki/

• static rendering:
  http://qtractor.org/doc
  https://qtractor.sourceforge.io/doc
  http://qtractor.sourceforge.net/doc

• user manual & how-to's:
  https://download.sf.net/qtractor/qtractor-manual-and-howtos.epub
  https://download.sf.net/qtractor/qtractor-manual-and-howtos.pdf

Weblog:

https://www.rncbc.org

Qtractor is free, open-source software, distributed under the terms of
the GNU General Public License (GPL) [19] version 2 or later.

Features

• Multi-track audio and MIDI sequencing and recording.
• Developed on the Qt C++ application and UI framework [1].
• Uses JACK [2] for audio and ALSA [3] sequencer for MIDI
  as multimedia infrastructures.
• Traditional multi-track tape recorder control paradigm.
• Audio file formats support: OGG (via libvorbis [6]),
  MP3 (via libmad [7], playback only), WAV, FLAC, AIFF
  and many, many more (via libsndfile [4]).
• 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 [18]).
• LADSPA [5], DSSI [11], native VST [12] and LV2 [13] plug-ins support.
• Unlimited number of plug-ins per track or bus.
• Plug-in presets, programs and chunk/configurations support, including
  native VST FXB/FXP file support.
• Unlimited audio/MIDI effect send/return inserts per track or bus.
• Loop-recording/takes.
• Audio/MIDI clip fade-in/out, cross-fade (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 [9]),
  pitch-shifting (via librubberband [9]) and seamless sample-rate
  conversion (via libsamplerate [8]).
• Audio/MIDI track export (mix-down, render, merge, freeze).
• 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) [20]);
  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 [15].
• MMC control surface enabled.
• MIDI Clock, Song Position Pointer (SPP) support.
• Configurable PC-keyboard and MIDI controller shortcuts.

Requirements

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

Mandatory:

[1] Qt framework, C++ class library and tools for
cross-platform application and UI development
https://qt.io/

[2] JACK Audio Connection Kit
https://jackaudio.org/

[3] ALSA, Advanced Linux Sound Architecture
https://www.alsa-project.org/

[4] libsndfile, C library for reading and writing
files containing sampled sound
http://www.mega-nerd.com/libsndfile/

[5] LADSPA, Linux Audio Developer's Simple Plugin API
http://www.ladspa.org/

Optional (opted-in at build time):

[6] libvorbis (enc, file), Ogg Vorbis audio compression
https://xiph.org/vorbis/

[7] libmad, High-quality MPEG audio decoder
https://www.underbit.com/products/mad/

[8] libsamplerate, The secret rabbit code, C library
for audio sample rate conversion
http://www.mega-nerd.com/SRC/

[9] librubberband, Rubber Band Audio Time Stretcher,
an audio time-stretching and pitch-shifting library
https://breakfastquay.com/rubberband/

[10] liblo, Lightweight OSC implementation
(needed for DSSI GUI [11] and/or NSM support [16])
http://liblo.sourceforge.net/

[11] DSSI, An API for soft synth plugins with custom user interfaces
http://dssi.sourceforge.net/

[12] VST SDK, Steinberg's Virtual Studio Technology (see README.VST)
https://www.steinberg.net/

[13] LV2, Audio Plugin Standard, the extensible successor of LADSPA
http://lv2plug.in/

[14] liblilv, Lightweight LV2 host implementation stack
https://drobilla.net/software/lilv/
https://drobilla.net/software/sratom/
https://drobilla.net/software/sord/
https://drobilla.net/software/serd/

[15] libsuil, Lightweight C library for loading and wrapping LV2 plugin UIs
https://drobilla.net/software/suil/

[16] Non Session Management (NSM)
http://non.tuxfamily.org/nsm/

[17] libaubio, a library for real time audio labelling
https://aubio.org

Installation

The installation procedure follows the standard for source distributions.
Unpack the tarball and in the extracted source directory:

./configure [--prefix=/usr/local]
make

and optionally as root:

make install

This procedure will end installing the following files:

${prefix}/bin/qtractor
${prefix}/share/applications/qtractor.desktop
${prefix}/share/icons/hicolor/32x32/apps/qtractor.png
${prefix}/share/qtractor/translations/qtractor_*.qm

Just launch ${prefix}/bin/qtractor and you're off (hopefully).

Note that the default installation path ${prefix} is /usr/local.

If you're checking out from Git, you'll have to prepare the
configure script just before you proceed with the above instructions:

./autogen.sh

Configuration

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

Bugs

Probably plenty still, Qtractor maybe considered on beta stage already.

Support

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 (https://sourceforge.net/projects/qtractor).

You can also find timely and closer contact information on my personal
web site (https://www.rncbc.org).

Acknowledgments

The dated Qtractor quick start guide and user manual for version 0.5.x
has been authored by Seth Kenlon & Klaatu.
(https://downloads.sourceforge.net/qtractor/qtractor-0.5.x-user-manual.pdf)

The older Qtractor user manual for version 0.3.0 and before, have
been co-authored by James Laco Hines and Stephen Doonan.
(https://downloads.sourceforge.net/qtractor/qtractor-0.3.0-user-manual.pdf)

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
(see TRANSLATORS) and of course, last but not least, to all the
past, present and future contributors of the Qtractor Wiki.
(https://sourceforge.net/p/qtractor/wiki/)

Thank you all.

References

[1] Qt framework, C++ class library and tools for
cross-platform application and UI development
https://qt.io/

[2] JACK Audio Connection Kit
https://jackaudio.org/

[3] ALSA, Advanced Linux Sound Architecture
https://www.alsa-project.org/

[4] libsndfile, C library for reading and writing
files containing sampled sound
http://www.mega-nerd.com/libsndfile/

[5] LADSPA, Linux Audio Developer's Simple Plugin API
http://www.ladspa.org/

[6] libvorbis (enc, file), Ogg Vorbis audio compression
https://xiph.org/vorbis/

[7] libmad, High-quality MPEG audio decoder
https://www.underbit.com/products/mad/

[8] libsamplerate, The secret rabbit code, C library
for audio sample rate conversion
http://www.mega-nerd.com/SRC/

[9] librubberband, Rubber Band Audio Time Stretcher,
an audio time-stretching and pitch-shifting library
https://breakfastquay.com/rubberband/

[10] liblo, Lightweight OSC implementation
(needed for DSSI GUI support)
http://liblo.sourceforge.net/

[11] DSSI, an API for soft synth plugins with custom user interfaces
http://dssi.sourceforge.net/

[12] VST SDK, Steinberg's Virtual Studio Technology (see README.VST)
https://www.steinberg.net/

[13] LV2, Audio Plugin Standard, the extensible successor of LADSPA
http://lv2plug.in/

[14] liblilv, Lightweight LV2 host implementation stack
(needed for LV2 support)
https://drobilla.net/software/lilv/
https://drobilla.net/software/sratom/
https://drobilla.net/software/sord/
https://drobilla.net/software/serd/

[15] libsuil, Lightweight C library for loading and wrapping LV2 plugin UIs
(needed for LV2 UI support)
https://drobilla.net/software/suil/

[16] Non Session Management (NSM)
http://non.tuxfamily.org/nsm/

[17] libaubio, a library for real time audio labelling
https://aubio.org

[18] QjackCtl - JACK Qt GUI Interface
https://qjackctl.sourceforge.io
http://qjackctl.sourceforge.net

[19] GNU General Public License
https://www.gnu.org/copyleft/gpl.html

[20] Cakewalk, powerful and easy-to-use tools
for Windows-based music and sound production
http://www.cakewalk.com/

Enjoy && have (lots of) fun.

rncbc aka Rui Nuno Capela
rncbc at rncbc dot org
https://www.rncbc.org