DFF 3.0 File Format

Introduction

This page describes the DFF 3.0 file format, an open file format for structured binary data.

DFF 3.0 File Format

The DFF 3.0 file format is endian-agnostic: the endianness of all fields is determined by the endianness of the magic number at the beginning of the file.

A DFF 3.0 file starts with a magic number and an array of resource type records.

Type	Description	Notes
int32	magic	the magic number 0x25444633; the four-character constant (fcc) %DF3
int32	typeCount	the number of resource types
type[]	types	an array of resource type records
int64	type	the resource type; an eight-character constant (ecc)
int32	resourceCount	the number of resources of this type
int32	resourceTableOffset	offset from start of file to start of resource table

For each resource type, a resource table follows that consists of an array of resource records.

Type	Description	Notes
resource[]	resourceTable	an array of resource records
int32	id	the resource id
int16	dataType	an application-specific value
int16	attributes	Bit 0 (0x0001; readonly) indicates the resource is read-only. Bit 1 (0x0002; system) indicates the resource is used by the operating system. Bit 2 (0x0004; preload) indicates the resource should be loaded immediately. Bit 3 (0x0008; purgeable) indicates the resource may be paged out of memory. Bit 4 (0x0010; fromfile) indicates the resource represents a file. Bit 5 (0x0020; fromrsrc) indicates the resource represents a resource from another format. Bit 6 (0x0040; invisible) indicates the resource should not appear in a UI. Bit 7 (0x0080; disabled) indicates the resource should not be used for some meaning of "used." Bit 8 (0x0100; protected) is application-specific. Bit 9 (0x0200; fixed) indicates the resource should not be moved in memory. Bit 10 (0x0400; multilingual) indicates the resource contains several localized versions of the same data. Bit 11 (0x0800; compressed) indicates the resource data is compressed. Other bits are application-specific.
int32	nameOffset	offset from start of file to start of resource name
int48	dataOffset	offset from start of file to start of resource data
int48	size	length of resource data

Following the resource tables is the name table which consists of an array of Pascal strings encoded in UTF-8. No word alignment is used.

Type	Description	Notes
name[]	names	an array of resource names
int8	length	length of resource name
byte[]	name	resource name in UTF-8 encoding

Finally, the file ends with the data of each individual resource. No word alignment is used.

Empty DFF 3.0 File

An empty DFF 3.0 file consists of the magic number and a type count of zero.

0000:  25 44 46 33  00 00 00 00

Or the little-endian version:

0000:  33 46 44 25  00 00 00 00