BIFF file format
Applies to:
BG1, BG1: TotS, BG2, BG2: ToB, PST, IWD, IWD:HoW, IWD:TotL, IWD2
File versions
General Description
This file format is a simple archive format, used mainly both to simplify organization of the files by grouping logically related files together (especially for areas). There is also a gain from having few large files rather than many small files, due to the wastage in the FAT and NTFS file systems. BIF files containing areas typically contain:
The bitmaps are named xxxxxxHT.BMP, xxxxxxLM.BMP, xxxxxxSR.BMP and optionally xxxxxxLN.BMP.
- one or more WED files, detailing tiles and wallgroups
- one or more TIS files, containing the tileset itself
- one or more MOS files, containing the minimap graphic
- 3 or 4 bitmap files which contain one pixel for each tile needed to cover the region
The bitmaps are named xxxxxxHT.BMP, xxxxxxLM.BMP, xxxxxxSR.BMP and optionally xxxxxxLN.BMP.
- xxxxxxHT.BMP: Height map, detailing altitude of each tile cell in the associated wed file
- xxxxxxLM.BMP: Light map, detailing the level and colour of illumination each tile cell on the map. Used during daytime
- xxxxxxLN.BMP: Light map, detailing the level and colour of illumination each tile cell on the map. Used during night-time
- xxxxxxSR.BMP: Search Map, detailing where characters cannot walk, and the footstep sounds
Overall structure:
- Header
- File entries
- Tileset entries
- Data for the contained files, as described in the file and tileset entries
Note that the data of the contained files might be after the header, and the file/tileset entries after the contained files. The offset to the file entries and the offset to each contained file should be used to know the exact location of each.
| Offset | Size (data type) | Description |
|---|---|---|
| 0x0000 | 4 (char array) | Signature ('BIFF') |
| 0x0004 | 4 (char array) | Version ('V1 ') |
| 0x0008 | 4 (dword) | Count of file entries |
| 0x000c | 4 (dword) | Count of tileset entries |
| 0x0010 | 4 (dword) | Offset (from start of file) to file entries |
| Offset | Size (data type) | Description |
|---|---|---|
| 0x0000 | 4 (dword) | Resource locator NB: On disk, only bits 0-13 are matched. They are matched against the file index in the "resource locator" field from the KEY file resource entries which claim to exist in this BIFF. |
| 0x0004 | 4 (dword) | Offset (from start of file) to resource data |
| 0x0008 | 4 (dword) | Size of this resource |
| 0x000c | 2 (word) | Type of this resource |
| 0x000e | 2 (word) | Unknown |
| Offset | Size (data type) | Description |
|---|---|---|
| 0x0000 | 4 (dword) | Resource locator NB: On disk, only bits 14-19 are matched upon. They are matched against the tileset index in the "resource locator" field from the KEY file resource entries which claim to exist in this BIFF. |
| 0x0004 | 4 (dword) | Offset (from start of file) to resource data |
| 0x0008 | 4 (dword) | Count of tiles in this resource |
| 0x000c | 4 (dword) | Size of each tile in this resource |
| 0x0010 | 2 (word) | Type of this resource (always 0x3eb - TIS) |
| 0x0012 | 2 (word) | Unknown |
BIFC V1 file format
Overall structure:
Header
Compressed file data
This format is identical to the SAV file format, except for the signature and version fields. The data, once uncompressed, is formatted as a normal BIF file, as seen above. Note that the SAV files can hold more than one compressed file. It is unknown whether this occurs also in CBF files.
| Offset | Size (data type) | Description |
|---|---|---|
| 0x0000 | 4 (char array) | Signature ('BIF ') |
| 0x0004 | 4 (char array) | Version ('V1.0') |
| 0x0008 | 4 (dword) | Length of filename |
| 0x000c | (ASCIIZ char array) | Filename (length specified by previous field) |
| sizeof(filename)+0x000C | 4 (dword) | Uncompressed data length |
| sizeof(filename)+0x0010 | 4 (dword) | Compressed data length |
| sizeof(filename)+0x0014 | Variable (raw data) | Compressed data |
BIFC V1.0 file format
Overall structure:
The file is broken up into blocks (usually 8192 bytes each), which are compressed separately. Each block consists of an uncompressed size and a compressed size, and then the zlib compressed data.
The file is broken up into blocks (usually 8192 bytes each), which are compressed separately. Each block consists of an uncompressed size and a compressed size, and then the zlib compressed data.
| Offset | Size (data type) | Description |
|---|---|---|
| 0x0000 | 4 (char array) | Signature ('BIFC') |
| 0x0004 | 4 (char array) | Version ('V1.0') |
| 0x0008 | 4 (dword) | Uncompressed BIF size |
| Offset | Size (data type) | Description |
|---|---|---|
| 0x0000 | 4 (dword) | Decompressed size |
| 0x0004 | 4 (dword) | Compressed size |
| 0x0008 | varies (bytes) | Compressed data |