.FLP

Introduction

An FLP file is a project saved by FL Studio, the music production software from Image-Line, first released as FruityLoops in 1997. It holds everything needed to rebuild the session: the channel rack and its instruments, patterns and their notes, the playlist arrangements, the mixer and its effects, plugin settings and the project details such as tempo, title and author.

The file holds no rendered audio. Samples are stored as paths to files on disk, and plugins as their saved state, so a project opens fully only where the same samples and plugins are installed.

Image-Line does not publish the format. The details on these pages come from community reverse engineering, and some fields are still unknown.

Software

• FL Studio (Windows, macOS)

Structure

An FLP file is two chunks, each a four-letter ID and a little-endian length. The header chunk FLhd gives the file type, the channel count and the timing resolution. The data chunk FLdt holds the rest of the project as one long stream of events.

Each event is an ID byte followed by its value. The ID sets the size of the value: one, two or four bytes, or a length-prefixed block of text or data. There is no nesting. A New event starts a channel, a pattern or an arrangement, and the events after it describe that item until the next one starts. The event reference lists every known ID by what it belongs to.

The order shown inside the stream is a rough guide. Events of different kinds can appear in other orders, and a reader should handle each event by its ID wherever it appears.