mididings

A Python-based MIDI router and processor for Linux and macOS. Flexible, fast, and built for live performance. Route, filter, transform and split MIDI events using a clean Python DSL, with all processing handled in C++.

Supports ALSA and JACK MIDI. Available under the GNU GPL.

Why this fork?

The original mididings by Dominic Sacré has been unmaintained since 2015. This community fork provides full Python 3 support, a modern build system (Meson + pyproject.toml), updated dependencies, and unified fixes gathered from various forks. The API remains fully compatible with existing patches and scripts.

Features

MIDI routing and filtering

Filter events by type, channel, note, velocity, and more. Route freely between any number of input and output ports.

Modifying and converting MIDI events

Transpose notes, apply velocity curves, remap controller values and ranges, or convert events to any other MIDI event type. Includes a diatonic harmonizer, floating split points, latched notes, and more.

Seamless scene switching

Set up named scenes, each with its own routing and processing, and switch between them at any time while playing. No dropouts, no stuck notes.

Monitoring and side effects

Print MIDI events to the console for debugging. Trigger shell commands, OSC messages, or DBUS calls alongside MIDI output.

Installation

PyPI

Note: Ensure system dependencies (ALSA, JACK, Boost) are available before installing.

pip install mididings

With optional extras (OSC, MIDI files, DBUS, auto-restart):

pip install mididings[osc,smf,dbus,autorestart,xdg]

Available extras and their dependencies are listed in pyproject.toml.

Arch Linux

pacman -Syu mididings

From source

The recommended approach for development or testing a new version is a virtual environment:

python -m venv venv
source venv/bin/activate
pip install .

To verify the installation:

which mididings

To resume work in an existing environment:

source venv/bin/activate

System-wide installation

Requires scdoc and sphinx if building documentation.

meson build --prefix=/usr/local
meson compile -C build
meson install -C build

Packaging options

# Disable documentation
meson build -Ddocs=disabled -Dman=disabled

# Build documentation separately
meson setup build -Ddocs-only=true
meson compile -C build
cd build && meson install

Note: mididings must be installed before building docs with docs-only=true.

Dependencies

Required

• Python 3
• ALSA
• JACK
• Boost (Boost.Python, Boost.Thread)
• glib
• decorator

Optional

• pyliblo3: OSC send/receive
• pysmf: MIDI file read/write via process_file()
• dbus-python: DBUS messages
• watchdog: auto-restart on script change
• tkinter: livedings GUI
• pyxdg: XDG config file lookup

Build-time

• scdoc: man page generation
• sphinx: HTML documentation (see pyproject.toml for modules)

Documentation and support

• API documentation
• GitHub Wiki
• Community forum (Discourse)

Additional references:

• QJackCtl and the Patchbay
• The Python Tutorial
• Guide to the MIDI specification

License

mididings is available under the GNU General Public License, version 2 or later.

Example scripts in doc/examples are available under the GNU Free Documentation License 1.3 or later.