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.

Features:

- Multi-track audio and MIDI sequencing and recording.
- Developed on pure Qt4 C++ application framework (no Qt3 nor KDE dependencies).
- 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 linsndfile).
- Standard MIDI files support (SMF 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 file.
- Point-and-click, multi-select, drag-and-drop interaction (drag, move, drop, cut, copy, paste, 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 VST and LV2 plug-ins support.
- Unlimited number of plug-ins per track or bus.
- Plug-in presets, programs and chunk/configurations support.
- Audio/MIDI clip fade-in/out (linear, quadratic, cubic).
- Audio/MIDI clip gain/volume, normalize and export.
- Audio clip time-stretching (WSOLA-like or via librubberband), pitch-shifting (also 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.
- MIDI clip editor (matrix/piano roll).
- MIDI instrument definitions (a-la Cakewalk(tm)).
- MIDI controller mapping (mixer).
- JACK transport sync master.
- MMC control surface enabled.
- MIDI Song Position cueuing support.
- Configurable keyboard shortcuts.

0.4.5 2010-01-23 A Friskier Demivierge.

- 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# 565860@bugs.debian.org).
- MIDI clip editor (aka piano-roll) multiple selection has been fixed (again) re. move/paste-snapping consistency.


0.4.4 2010-01-16 The Frisky Demivierge

- For all the DSSI plugins that have output control ports, a host feedback/update process cycle is now being finally provided: all output control ports are now marshaled to their respective GUI process, rather often and when found open/visible.
- MIDI clip editor (aka piano-roll) snap-to-beat behavior on edit mode is now kind of more like 'filling-in-the-blanks' (as Frank Neumann et al. wishes ;)
- Fixed MIDI clip editor mistake when reverting to initial clip length, before closing and discard changes (thanks to Frank Neumann, for spotting this one).
- LADISH Level 1 support has been added: SIGUSR1 signal trap just makes it a shortcut to File/Save.
- Avoid parameter value flickering, due to duplicate command invocation, most evident when changing values massively on native Linux VSTi plugin editor GUIs (thanks to a detailed report on this odd behavior, from Mike of linuxDSP.co.uk).
- Another TODO item bites the dust: MIDI event list editor, now accessible from the MIDI clip editor menu (View/Events)
- Last used session directory is now made current on startup only when no filename is given on the command line (solving bug #2920244).
- Current snap-to-beat setting (time quantization) now affects the anchor event only, while dragging, moving and/or pasting multiple events over the MIDI clip editor (aka piano-roll).
- Make anti-glitch audio clip micro fade-in/outs independent from current buffer size as much as possible.
- Audio/MIDI engine drift correction gets really sophisticated, with the help of (now old) ALSA MIDI tempo skew facility.
- Edit/Clip/Import... menu option is now available for expedite clip insertion from audio and MIDI file requesters.
- Set default session directory effective to file's location.
- Audio track/clip recording process has been target to special re-factorization across the internal audio engine process cycle, in a late attempt to get self-bounce/recording effective and working consistently for all track layouts.
- All session related dialogs are now set to window modality, (were set to default application modality before) allowing for continued input focus and interaction on all plugin/tool windows.
- An off-by-one nasty old bug fixed in audio clip drawing, was causing instant crashes on certain zoom levels of the main track view.
- Graphical MIDI clip representation regarding note/pitch range is now kept as much as possible across clip edits (cut, copy, paste, drag, move, delete, etc.)
- LV2 plug-in hosting has finally come into actual implementation; only some and the most basic LV2 plug-in features are supported at the moment; probably there's no big advantage against the old LADSPA ones; there's some support for external UIs though; also, LV2 MIDI/Event bare-bones support is included but chances are it won't build nor work right on most of the setups out there. It's a WIP host implementation anyways, as is the whole LV2 spec. for that matter ;)
- Connections filter is now reset when widget is shown through the View/Connections main menu or toolbar button.
- Audio bus auto-connection option is now applied when creating or updating, newer or existing buses, respectively.
- Global configuration state is now explicitly saved/committed to disk whenever View/Options... dialog changes are applied or when a session is loaded or saved.
- Audio ramping spin-locking makes its smooth stuff, in an attempt to reduce glitching and crackling when editing (due to its own pseudo spin-locking) and toggling playback states.
- JACK Transport, MMC Device, and MIDI Song Position pointer (SPP) control modes are now made optional (View/Options...), allowing for discretionary configuration: None/Disabled, Slave/Input, Master/Output or Full/Duplex (default).
- Session files may now be dragged and dropped over the main track view and get loaded for business as usual (once quietly ignored).
- In an attempt to mitigate potential stack corruption and sudden crashes, old commented out session pseudo-locks are now back in business while executing clip editing commands (cut, paste, drag, move, insert, delete) and playback is currently rolling.
- Adjusted first-time application window size to fit into 800x600 screen size and with reasonable initial dock-ables layout.
- Avoid duplicate snap-to-grid effect when changing the length of MIDI clip editor events across non-zero clip offsets (after a glitch reported by Ralf Mardorf).
- Late audio track processing optimization, suppressing all plugin, mixer and monitor pass-through activity when given track is muted, either explicitly or implicitly (ie. other track is in solo state).
- Entering System Exclusive events (SysEx) on the MIDI clip editor (aka matrix/piano-roll widget), yet something not fully supported anyway, even though allowed in edit mode, doesn't crash the whole damn thing anymore, while saving the clip to a file.
- Strict aliasing avoidance, with plain and demanded use of 'union', as much as to stop nagging warnings from gcc >= 4.4.1 (last seen on src/qtractorMidiEvent.h hackery).
- Visual correct play-head position while changing zoom levels, applicable to both main track and MIDI clip editor views.


0.4.3 2009-10-05 The Fussy Doula
0.4.2 2009-06-04 The Flaunty Demoness
0.4.1 2009-04-04 The Funky Dominatrix
0.4.0 2009-03-13 The Foxy Dryad
0.3.0 2008-12-25 The Fluffy Doll
0.2.2 2008-10-05 The Flirty Ditz
0.2.1 2008-08-30 The Fainty Diva
0.2.0 2008-07-18 The Frolic Demoiselle
0.1.3 2008-05-02 The Frugal Damsel
0.1.2 2008-03-23 The Frantic Dame
0.1.1 2008-02-16 The Futile Duchess
0.1.0 2008-01-05 The Frivolous Debutante