.FLP File Format – Data chunk

FL Studio 11.5 to 12 project

The data chunk follows the header at offset 14. Its ID is FLdt, and its length covers every remaining byte of the file: the whole stream of events that makes up the project.

00000000  46 4C 68 64 06 00 00 00 00 00 10 00 60 00 46 4C  FLhd........`.FL
00000010  64 74 3A 9C 01 00 C7 0C 32 30 2E 38 2E 33 2E 32  dt:.....20.8.3.2
The data chunk ID and a length of 105,530 bytes, then the start of the event stream. The bytes come from an FL Studio 20.8.3 file; versions 11.5 to 12 lay out the chunk the same way.

Fields

OffsetSizeTypeNameDescription
144ASCIImagicAlways FLdt (46 4C 64 74).
184u32lengthThe number of bytes of events that follow, little-endian.
22lengthbyteseventsThe event stream, one event after another to the end of the file.

Checking the length

The header and the data chunk's own ID and length take 22 bytes, and nothing follows the events. So in a complete file:

file size = data chunk length + 22
The size check for a complete FLP file.

A file that fails this check was cut short or has extra bytes on the end. Reading the events stops at the end of the chunk, so a reader can still recover every event that is complete.