FST File Format: FL Studio mixer preset

Introduction

A mixer preset is what FL Studio saves for one mixer insert: its colour and name, the effect plugins in its slots and the mixer settings, such as volume, pan and routing. FL Studio 5 ships a few, such as the Chorus send, Flanger send and Reverb send inserts.

The file is an FLP project reduced to one insert: the FLhd and FLdt chunks, a file type of 64 in the header, then the events of the slot plugins and of the insert.

Five mixer presets are in FL Studio 5’s Patches/Mixer presets folder, four saved by version 3.6.5 and one by 4.5.2, read with the FruityLoops 1 to FL Studio 5 layout. 17 more are in PyFLP’s test assets, saved by FL Studio 20.8.4 and read with the FL Studio 20 layout. In those the header’s channel count is 18, and the events are 199 159 28 37 149 204 236 98 × 10 225: the version, build, licensed flag, 37, the colour and name, the insert flags (236), ten slot closers (98) and the 387-byte mixer parameters.

Structure

The header is the 14 bytes of any FLP file with the file type 40 00 (64); the channel count in the five files is 4. The events, as the five files have them:

Event	Name	Holds
199	Version	The FL Studio version as text.
201, 212, 203, 213	A slot’s plugin	Plugin internal name, wrapper settings, the name shown (203, in one file) and the plugin’s state. Absent in the Default preset, which has no effect; twice in Dual joypad control, which has two plugins.
149	Insert colour	The insert’s colour, 4 bytes.
204	Insert name	The insert’s name, such as “Chorus”.
225	Mixer parameters	The insert’s mixer settings, as 12-byte records of a location and a value: 28 records (336 bytes) in the send presets, 32 (384 bytes) in Default and Dual joypad control.

Event 212 records which insert and slot the plugin sat in (insert 65, slot 1 in the Chorus send), but the file holds the plugin for that slot only. Each event’s value is laid out as on the FLP mixer events page. The explorer adds a Preset section, the plugin events table, and the Mixer table of the insert the parameters give.

Worked example

The start of Chorus send.fst, 503 bytes long:

00000000  46 4c 68 64 06 00 00 00 40 00 04 00 60 00        FLhd, length 6, type 64, 4, PPQ 96
0000000e  46 4c 64 74 e1 01 00 00                          FLdt, length 0x01E1 = 481
00000016  c7 06 33 2e 36 2e 35 00                          199 version "3.6.5"
0000001e  c9 0e 46 72 75 69 74 79 20 43 68 6f 72 75 73 00  201 plugin "Fruity Chorus"
0000002f  d4 34 ...                                        212 wrapper, 52 bytes

Its last three events are 149 (colour), 204 (the name “Chorus”) and 225 (336 bytes of mixer parameters).

Not described

This page is partial. What it leaves out, and what the explorer does not do:

Item	Reference	Viewer
FL Studio 20 presets with effect plugins	Not described: the PyFLP presets have empty slots, so how filled slots look in version 20 was not seen.	Reads the plugin events with the FL Studio 20 layout; unchecked on such a preset.
Mixer parameters (event 225)	Only as the FLP mixer page lists them.	Shows the insert as the FLP viewer does; anything the FLP page lacks stays numbers.
Event 37 and other unknown events	Meaning unknown.	Shows them as numbers or bytes.
Plugin states that are not native layouts	Not described.	Shows them as bytes.
Versions 6 to 20.7, and FL Studio 21 on	No mixer preset from these versions was seen; the layout is assumed from the FLP pages.	Reads them with those layouts; unchecked.
Header channel count	Explained only as PyFLP defines it (the rack size of the source project).	Shows the number; does not use it.
Editing	Not applicable.	Read-only.

Also used for

OpenFst transducer – OpenFst’s binary finite-state transducer: a header and symbol tables, then the states.

Variants

FL Studio channel preset – file type 32: one channel with its sample or plugin
FL Studio plugin preset – file type 48: one plugin’s name and saved state
FL Studio mixer preset – file type 64: one mixer insert and its effect

.FST File Format

Introduction

Structure

Worked example

Not described

Also used for

Variants

Links

Software

Reference