FluidSynth is a cross-platform, real-time software synthesizer based on the Soundfont 2 specification.
FluidSynth generates audio by reading and handling MIDI events from MIDI input devices by using a SoundFont. It is the software analogue of a MIDI synthesizer. FluidSynth can also play MIDI files.
The central place for documentation and further links is our wiki here at GitHub:
If you are missing parts of the documentation, let us know by writing to our mailing list. Of course, you are welcome to edit and improve the wiki yourself. All you need is an account at GitHub. Alternatively, you may send an EMail to our mailing list along with your suggested changes. Further information about the mailing list is available in the wiki as well.
Latest information about FluidSynth is also available on the web site at https://www.fluidsynth.org/.
The source code for FluidSynth is distributed under the terms of the GNU Lesser General Public License, see the LICENSE file. To better understand the conditions how FluidSynth can be used in e.g. commercial or closed-source projects, please refer to the LicensingFAQ in our wiki.
Building from source
For information on how to build FluidSynth from source, please refer to our wiki.
FluidSynth's Home Page, https://www.fluidsynth.org
FluidSynth's wiki, https://github.com/FluidSynth/fluidsynth/wiki
FluidSynth's API documentation, https://www.fluidsynth.org/api/
Why did we do it
The synthesizer grew out of a project, started by Samuel Bianchini and Peter Hanappe, and later joined by Johnathan Lee, that aimed at developing a networked multi-user game.
Sound (and music) was considered a very important part of the game. In addition, users had to be able to extend the game with their own sounds and images. Johnathan Lee proposed to use the Soundfont standard combined with intelligent use of midifiles. The arguments were:
Wavetable synthesis is low on CPU usage, it is intuitive and it can produce rich sounds
Hardware acceleration is possible if the user owns a Soundfont compatible soundcard (important for games!)
MIDI files are small and Soundfont2 files can be made small thru the intelligent use of loops and wavetables. Together, they are easier to downloaded than MP3 or audio files.
Graphical editors are available for both file format: various Soundfont editors are available on PC and on Linux (Smurf!), and MIDI sequencers are available on all platforms.
It seemed like a good combination to use for an (online) game.
In order to make Soundfonts available on all platforms (Linux, Mac, and Windows) and for all sound cards, we needed a software Soundfont synthesizer. That is why we developed FluidSynth.
The synthesizer was designed to be as self-contained as possible for several reasons:
It had to be multi-platform (Linux, macOS, Win32). It was therefore important that the code didn't rely on any platform-specific library.
It had to be easy to integrate the synthesizer modules in various environments, as a plugin or as a dynamically loadable object. I wanted to make the synthesizer available as a plugin (jMax, LADSPA, Xmms, WinAmp, Director, ...); develop language bindings (Python, Java, Perl, ...); and integrate it into (game) frameworks (Crystal Space, SDL, ...). For these reasons I've decided it would be easiest if the project stayed very focused on its goal (a Soundfont synthesizer), stayed small (ideally one file) and didn't dependent on external code.