Introduction

FluidSynth is a software real-time synthesizer based on the Soundfont 2 specifications.

FluidSynth reads and handles MIDI events from the MIDI input device. It is the software analogue of a MIDI synthesizer. FluidSynth can also play midifiles using a Soundfont.

Information on the web

The place to look if you are looking for the latest information on FluidSynth is the web site at http://www.fluidsynth.org/.

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 an intelligent use of midifiles. The arguments were:

• Wave table 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.

Design decisions

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 environements, 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 focussed on it's goal (a Soundfont synthesizer), stayed small (ideally one file) and didn't dependent on external code.

Links

Home Page

• http://www.fluidsynth.org

Documentation

• Introduction to SoundFonts, by Josh Green, http://smurf.sourceforge.net/sfont_intro.php

• Soundfont2 Documentation, http://www.synthfont.com/SFSPEC21.PDF (if it moved, do a search on sfspec21.pdf).

• Soundfont.com FAQ, http://www.soundfont.com/faqs.html

• The MIDI Manufacturers Association has a standard called "Downloadable Sounds (DLS)" that closely ressembles the Soundfont Specifications, http://www.midi.org/about-midi/dls/abtdls.htm

Software SoundFont Synthesizers:

• LiveSynth Pro DXi and Crescendo from LiveUpdate (Win), http://www.livesynth.com/lspro.html

• Unity DS-1 from Bitheadz (Win & Mac), http://www.bitheadz.com/

• QuickTime 5 from Apple (Win & Mac), http://www.apple.com/quicktime/

• Logic from eMagic, http://www.emagic.de

Soundfont Editors

• Project SWAMI by Josh Green (Linux), http://www.swamiproject.org/

• Vienna SoundFont Editor by Creative Technology Ltd. (Win)

• Alive Soundfont Editor by Soundfaction (Win), http://www.soundfaction.com/alive/index.htm

• Polyphone, http://polyphone-soundfonts.com/en/

  Note: We cannot recommend using Audio Compositor for creating or editing Soundfonts, as it generates files that violate the Soundfont2 spec (specifically the order of generators as defined in section 8.1.2) and are therefore unusable with fluidsynth!

Conversion Tools

• CDxtract from CDxtract (Win), http://www.cdxtract.com

• ReCycle from Propellerhead Software (Win & Mac), http://www.propellerheads.se/products/recycle/

• Translator from Rubber Chicken Software (Win & Mac), http://www.chickensys.com/translator

Soundfont Databases

• HammerSound, http://www.hammersound.net