This document has the same layout as the manpage, but it contains links to other pages for more information: FluidFeatures and FluidSettings.

FluidSynth - a SoundFont synthesizer

fluidsynth [options] [soundFonts] [ midifiles ]

FluidSynth is a real-time MIDI synthesizer based on the SoundFont® 2 specifications. It can be used to render MIDI input or MIDI files to audio. The MIDI events are read from a MIDI device. The sound is rendered in real-time to the sound output device. See FluidFeatures for a comprehensive list of features implemented and working.

The easiest way to start the synthesizer is to give it a SoundFont on the command line: fluidsynth output.sf2. FluidSynth will load the SoundFont and read MIDI events from the default MIDI device using the default MIDI driver. Once FluidSynth is running, it reads commands from stdin. There are commands to send MIDI events manually, to load or unload SoundFonts, and so forth. Available commands are discussed below.

FluidSynth can also be used to play a list of MIDI files. Simply run FluidSynth with the SoundFont and the list of MIDI files to play. In this case, you might not want to open the MIDI device to read external events. Use the -n option to deactivate MIDI input. You may also want to deactivate the shell causing FluidSynth to quit as soon as all MIDI files have been played. Start FluidSynth with the -i option to do so:

fluidsynth -ni soundfont.sf2 midifile1.mid midifile2.mid

Run FluidSynth with the --help option to check for changes in the list of options.

For some scenarios, it might be useful to execute certain shell commands right upon starting FluidSynth, e.g. to do some custom default initialization of the synth, change the default audio driver in use, etc. This can be achieved with a configuration file as described below. If no such file is provided via the -f command-line argument, FluidSynth tries to load a user-specific configuration file (as given by fluid_get_userconf()). If that fails, it tries to load a system-wide configuration file (as given by fluid_get_sysconf()).

FluidSynth accepts the following options (call FluidSynth with the --help option to get most up-to-date information):

-a, --audio-driver=[label]

The audio driver to use. "-a help" to list valid options

-b, --bank-offset=[num]

A positional flag that specifies the bank-offset for any Soundfonts following that flag. Can be specified multiple times. Example:

fluidsynth A.sf2 -b 1 someTune.mid B.sf2 C.sf2 -b 2 D.sf2

Would cause A.sf2 to be loaded with a bank-offset of zero, B.sf2 and C.sf2 loaded with bank-offset=1, and D.sf2 loaded with bank-offset=2.

-C, --chorus

Turn the chorus on or off [0|1|yes|no, default = on]

-c, --audio-bufcount=[count]

Number of audio buffers

-d, --dump

Dump incoming and outgoing MIDI events to stdout

-E, --audio-file-endian

Audio file endian for fast rendering or aufile driver ("-E help" for list)

-f, --load-config

Right upon starting, load and execute a configuration file containing fluidsynth related shell commands as described in the Section below.

-F, --fast-render=[file]

Render MIDI file to raw audio data and store in [file]

-G, --audio-groups

Defines the number of LADSPA audio nodes

-g, --gain

Set the master gain [0 < gain < 10, default = 0.2]

-h, --help

Print out this help summary

-i, --no-shell

Don't read commands from the shell [default = yes]

-j, --connect-jack-outputs

Attempt to connect the jack outputs to the physical ports

-K, --midi-channels=[num]

The number of midi channels [default = 16]

-L, --audio-channels=[num]

The number of stereo audio channels [default = 1]

-l, --disable-lash

Don't connect to LASH server

-m, --midi-driver=[label]

The name of the midi driver to use [oss,alsa,alsa_seq,...]

-n, --no-midi-in

Don't create a midi driver to read MIDI input events [default = yes]

-O, --audio-file-format

Audio file format for fast rendering or aufile driver ("-O help" for list)

-o

Define a setting, -o name=value ("-o help" to dump current values). See FluidSettings for details

-p, --portname=[label]

Set MIDI port name (alsa_seq, coremidi drivers)

-q, --quiet

Do not print welcome message or other informational output. (Windows only: also suppress all log messages lower than PANIC)

-Q, --query-audio-devices

Windows only, enumerate available WASAPI devices and their supported sample rates

-R, --reverb

Turn the reverb on or off [0|1|yes|no, default = on]

-r, --sample-rate

Set the sample rate

-s, --server

Start FluidSynth as a server process

-T, --audio-file-type

Audio file type for fast rendering or aufile driver ("-T help" for list)

-v, --verbose

Print out verbose messages about midi events (synth.verbose=1) as well as other debug messages

-V, --version

Show version of program

-z, --audio-bufsize=[size]

Size of each audio buffer

All the settings that can be passed with the -o flag to FluidSynth are known as FluidSettings. Refer to the wiki page for more details.

When starting FluidSynth an interactive shell opens. This section describes the most common commands.

• help
  Shows help topics (help TOPIC for more info)

• help help
  Shows a list of help topics (help <topic>)

• help all
  Prints help for all topics

• quit
  Quits the synthesizer

• source filename
  Loads commands from a file and executes them line by line

• echo arg
  Prints arg to output

• sleep duration
  Sleeps for duration milliseconds

• reset
  System reset (all notes off, all sound off, reset controllers, etc.)

• load filename [reset] [bankofs]
  Load a SoundFont onto the SoundFont stack. If reset is 1 (which is the implicit default), all currently in-use SoundFont presets will be re-evaluated with the newly loaded SoundFont taken into account. Optionally, you can specify a non-zero bank offset for the new SoundFont. For example the command load soundfont.sf2 0 10 will load the soundfont.sf2 with a bank offset of 10 without re-evaluating the presets.

• unload number [reset]
  Unload a SoundFont by its stack index (reset=1 default)

• reload number
  Reload the SoundFont by its stack index

• fonts
  List all loaded SoundFonts on the stack

• inst number
  Print available instruments for the SoundFont at given stack index

• channels [-verbose]
  Print out the presets of all channels. Use -verbose for more details.

• voice_count
  Prints the number of active synthesis voices

• noteon channel key velocity
  Send a note-on event

• noteoff channel key
  Send a note-off event

• pitch_bend channel offset
  Send a pitch bend event

• pitch_bend_range channel range
  Set pitch bend range for the MIDI channel

• cc channel ctrl value
  Send a control change MIDI event

• prog channel num
  Send a program change event

• select channel sfont bank prog
  Combination of bank-select and program-change

• gain value
  Set the master gain (0 < gain < 5)

• interp num
  Choose the interpolation method for all channels

• interpc channel num
  Choose the interpolation method for one channel

• basicchannels
  Prints the list of basic channels

• resetbasicchannels [chan1 chan2..]
  Resets all or some basic channels

• setbasicchannels [chan mode val...]
  Sets default, adds basic channels

• channelsmode [chan1 chan2..]
  Prints channel mode for specified/all channels

• legatomode [chan1 chan2..]
  Prints legato mode for specified/all channels

• setlegatomode chan mode [chan mode..]
  Set legato mode for channels

• portamentomode [chan1 chan2..]
  Prints portamento mode for specified/all channels

• setportamentomode chan mode [chan mode..]
  Set portamento mode for channels. The mode corresponds to the enum fluid_channel_portamento_mode, i.e.

  • Mode 0 - Portamento on every note (staccato or legato)
  • Mode 1 - Portamento only on legato notes
  • Mode 2 - Portamento only on staccato notes

• breathmode [chan1 chan2..]
  Print breath options for channels

• setbreathmode chan poly(1/0) mono(1/0) breath_sync(1/0) [..]
  Set breath mode for channels

• tuning name bank prog
  Create a tuning with name, bank, and program number

• tune bank prog key pitch
  Tune a key to a specific pitch

• settuning chan bank prog
  Set a tuning for a MIDI channel

• resettuning chan
  Restore default tuning for a MIDI channel

• tunings
  Lists available tunings

• dumptuning bank prog
  Print pitch details of the tuning

• set name value
  Set the value of a setting (must be real-time for immediate effect)

• get name
  Get the value of a setting

• info name
  Get information about a setting

• settings
  List all settings

Note: Before FluidSynth 2.0 custom reverb commands existed. Starting with 2.0 users are encouraged to set reverb parameters via the realtime FluidSettings as described below.

• set synth.reverb.active [0|1]
  Turn the reverb on or off

• set synth.reverb.room-size num__ Change reverb room size (i.e the reverb time) in the range [0 to 1.0] (default: 0.2)

• set synth.reverb.damp num
  Change reverb damping in the range [0.0 to 1.0] (default: 0.0)

  • When 0.0, no damping.
  • Between 0.0 and 1.0, higher frequencies have less reverb time than lower frequencies.
  • When 1.0, all frequencies are damped even if room size is at maximum value.

• set synth.reverb.width num
  Change reverb width in the range [0.0 to 100.0] (default: 0.5) num value defines how much the right channel output is separated of the left channel output.

  • When 0.0, there is no separation (i.e the output is mono).
  • When 100.0, the stereo effect is maximum.

• set synth.reverb.level num
  Change reverb output level in the range [0.0 to 1.0] (default: 0.9)

Note: Before FluidSynth 2.0 custom chorus commands existed. Starting with 2.0 users are encouraged to set chorus parameters via the realtime FluidSettings as described below.

• set synth.chorus.active [0|1]
  Turn the chorus on or off

• set synth.chorus.nr n
  Use n delay lines (default 3)

• set synth.chorus.level num
  Set output level of each chorus line to num

• set synth.chorus.speed num
  Set mod speed of chorus to num (Hz)

• set synth.chorus.depth num
  Set chorus modulation depth to num (ms)

• router_default
  Reload default MIDI routing rules

• router_clear
  Delete all MIDI routing rules

• router_begin [note|cc|prog|pbend|cpress|kpress]
  Start a new routing rule for an event type

• router_chan min max mul add
  Filter/map MIDI channels for the current rule

• router_par1 min max mul add
  Filter/map parameter 1 (key/ctrl nr) for the current rule

• router_par2 min max mul add
  Filter/map parameter 2 (vel/cc val) for the current rule

• router_end
  Commit the current routing rule

• player_start
  Start playing from the beginning of the current song

• player_stop
  Stop playing

• player_cont
  Continue playing

• player_seek num
  Move forward/backward in current song by +/-num ticks

• player_next
  Move to next song

• player_loop num
  Set loop number (-1 = loop forever)

• player_tempo_bpm num
  Set tempo to num beats per minute

• player_tempo_int [mul]
  Set internal tempo multiplied by mul (default 1.0)

• ladspa_effect <name> <library> [plugin] [--mix [gain]]
  Create a new effect from a LADSPA plugin

• ladspa_link <effect> <port> <buffer or host port>
  Connect an effect port to a host port or buffer

• ladspa_buffer <name>
  Create a LADSPA buffer

• ladspa_set <effect> <port> <value>
  Set the value of an effect control port

• ladspa_check
  Check LADSPA configuration

• ladspa_start
  Start LADSPA effects

• ladspa_stop
  Stop LADSPA effect unit

• ladspa_reset
  Stop and reset LADSPA effects

• profile
  Prints default profiling parameters

• prof_set_notes nbr [bank prog]
  Sets notes number and preset bank/program for profiling

• prof_set_print mode
  Sets the profiling print mode

• prof_start [n_prof [dur]]
  Starts n_prof profiling measures of duration dur (ms) each

Please check the AUTHORS and THANKS files for all credits

SoundFont® is a registered trademark of Creative Technology Ltd.