Synthesis Voice Control

Low-level access to synthesis voices.

Functions

`fluid_synth_alloc_voice()`

fluid_voice_t * fluid_synth_alloc_voice(fluid_synth_t *synth, fluid_sample_t *sample, int channum, int key, int vel)

Allocate a synthesis voice.

Parameters:

Name	Description
`synth`	FluidSynth instance
`sample`	Sample to assign to the voice
`chan`	MIDI channel number (0 to MIDI channel count - 1)
`key`	MIDI note number for the voice (0-127)
`vel`	MIDI velocity for the voice (0-127)

Returns: Allocated synthesis voice or NULL on error

This function is called by a SoundFont's preset in response to a noteon event. The returned voice comes with default modulators and generators. A single noteon event may create any number of voices, when the preset is layered.

Note

Should only be called from within synthesis thread, which includes SoundFont loader preset noteon method.

`fluid_synth_get_voicelist()`

void fluid_synth_get_voicelist(fluid_synth_t *synth, fluid_voice_t *buf[], int bufsize, int ID)

Get list of currently playing voices.

Parameters:

Name	Description
`synth`	FluidSynth instance
`buf`	Array to store voices to (NULL terminated if not filled completely)
`bufsize`	Count of indexes in buf
`id`	Voice ID to search for or < 0 to return list of all playing voices

Note

Should only be called from within synthesis thread, which includes SoundFont loader preset noteon methods. Voices are only guaranteed to remain unchanged until next synthesis process iteration.

`fluid_synth_start()`

int fluid_synth_start(fluid_synth_t *synth, unsigned int id, fluid_preset_t *preset, int audio_chan, int midi_chan, int key, int vel)

Create and start voices using an arbitrary preset and a MIDI note on event.

Using this function is only supported when the setting synth.dynamic-sample-loading is false! Parameters:

Name	Description
`synth`	FluidSynth instance
`id`	Voice group ID to use (can be used with `fluid_synth_stop()`).
`preset`	Preset to synthesize
`audio_chan`	Unused currently, set to 0
`chan`	MIDI channel number (0 to MIDI channel count - 1)
`key`	MIDI note number (0-127)
`vel`	MIDI velocity number (1-127)

Returns: FLUID_OK on success, FLUID_FAILED otherwise

Note

Should only be called from within synthesis thread, which includes SoundFont loader preset noteon method.

`fluid_synth_start_voice()`

void fluid_synth_start_voice(fluid_synth_t *synth, fluid_voice_t *voice)

Activate a voice previously allocated with fluid_synth_alloc_voice().

Parameters:

Name	Description
`synth`	FluidSynth instance
`voice`	Voice to activate

This function is called by a SoundFont's preset in response to a noteon event. Exclusive classes are processed here.

Note

Should only be called from within synthesis thread, which includes SoundFont loader preset noteon method.

`fluid_synth_stop()`

int fluid_synth_stop(fluid_synth_t *synth, unsigned int id)

Stop notes for a given note event voice ID.

Parameters:

Name	Description
`synth`	FluidSynth instance
`id`	Voice note event ID

Returns: FLUID_OK on success, FLUID_FAILED otherwise

Note

In FluidSynth versions prior to 1.1.0 FLUID_FAILED would be returned if no matching voice note event ID was found. Versions after 1.1.0 only return FLUID_FAILED if an error occurs.