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:

  https://qtractor.org

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:
  https://qtractor.org/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) [18] 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 [19]).
- LADSPA [5], DSSI [11], native VST(2), VST3 [12], LV2 [13]
  and CLAP [21] 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) [21]);
  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/New 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:

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

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

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

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

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

  Optional (opted-in at build time):

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

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

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

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

  - liblo [10], Lightweight OSC implementation
    (needed for DSSI GUI [11] and/or NSM support [15])
    http://liblo.sourceforge.net/

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

  - VST SDK [12], Steinberg's Virtual Studio Technology (see README.VST(3))
    https://www.steinberg.net/

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

  - liblilv [14], 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

  - libaubio [16], a library for real time audio labelling
    https://aubio.org

  - CLAP [21], CLever Audio Plugin
    https://github.com/free-audio/clap



Installation
------------

Unpack the tarball and in the extracted source directory:

    cmake [-DCMAKE_INSTALL_PREFIX=<prefix>] -B build
    cmake --build build [--parallel <Njobs>]

and optionally, as root:

    [sudo] cmake --install build

Note that the default installation path (<prefix>) is /usr/local .


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 free, Linux Audio [17] open source free software. For bug
reports, feature requests, discussion forums, mailing 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 (out)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
     https://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] Non Session Management (NSM) (legacy)
     http://non.tuxfamily.org/nsm/
     New Session Manager (NSM)
     https://new-session-manager.jackaudio.org/

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

[17] Linux Audio consortium of libre software for audio-related work
     https://linuxaudio.org

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

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

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

[21] CLAP, CLever Audio Plugin
     https://github.com/free-audio/clap


Enjoy && have (lots of) fun.
--
rncbc aka Rui Nuno Capela
rncbc at rncbc dot org
https://www.rncbc.org