FluidPatcher

• Source Code
• Official Documentation

FluidPatcher is a lightweight Python toolkit for building playable FluidSynth-based instruments driven by MIDI events. It provides:

• A simple user-facing API for building applications/front-ends
• Rich YAML-based bank/patch file format for defining synth setups
• Support for multiple soundfonts, layered MIDI routing, and rules
• Built-in players (arpeggiators, sequencers, MIDI files, loopers)
• Optional LADSPA audio effects

FluidPatcher is designed for small systems such as Raspberry Pi but runs anywhere FluidSynth does.

Installation

System Requirements

• Python 3.10+
• PyYAML
• FluidSynth 2.2.0+

Install FluidPatcher

pip install fluidpatcher

Or install from source:

git clone https://github.com/GeekFunkLabs/fluidpatcher.git
cd fluidpatcher
pip install -e .

Configuration

FluidPatcher looks for config at FLUIDPATCHER_CONFIG if defined, or ~/.config/fluidpatcher/fluidpatcherconf.yaml. A default config is created if not found. The config file can be used to store/specify:

• Paths for soundfonts, bank files, MIDI files, LADSPA effects
• FluidSynth settings e.g. audio driver/device if other than default
• State information for specific programs

API Overview/Quick Start

import fluidpatcher

fp = fluidpatcher.FluidPatcher()
fp.load_bank("mybank.yaml")
fp.apply_patch("Piano")

Play notes on an attached MIDI controller to hear patches. By default, FluidSynth will automatically connect to MIDI devices.

Sample programs are in examples/, and can be run with

python -m fluidpatcher.examples.<example_name>

Banks & Patches

Users access all of FluidPatcher's features primarily by writing bank files. Bank files are a declarative, YAML-based format for describing synth patches. The underlying engine parses bank files and pre-loads required soundfonts so that different patches can be applied quickly in live performance.

View the Tutorials section in the docs and/or example banks (data/banks/tutorial/) for guided learning.

Status & Contributions

FluidPatcher is under active development. The goal is to keep the API minimalist and general, with most features/functionality implemented in bank files or external programs. Contributions, bug reports, and example banks are welcome.

Please open issues or pull requests on GitHub.

License

MIT. See LICENSE for details.

FluidPatcher uses the FluidSynth library (LGPL-2.1) via dynamic linking.