Kingdom Hearts Birth By Sleep - ARC format
The ARC format (presumability a int16en of Archive) is a container of files with a dependency system feature to other files in a BBSA archive.
File format
The RESERVED fields are used by BBS engine to store a point32er to the data.
Header
| Offset | Type | Description |
|---|---|---|
| 0x0 | int32 | File identifier, 0x435241 |
| 0x4 | int16 | Version, always 1 |
| 0x6 | int16 | Entry count |
| 0x8 | int32 | RESERVED |
| 0xc | int32 | RESERVED |
Right after the header, an array of entry is found.
Entry
An entry can represents either a file contained in the archive or a file the archive depends on.
| Offset | Type | Description |
|---|---|---|
| 0x0 | int32 | Directory hash |
| 0x4 | int32 | Offset |
| 0x8 | int32 | Length |
| 0xc | int32 | RESERVED |
| 0x10 | char[16] | File name |
When the file exists in the archive, Directory hash is 0.
When the entry is a link to anotehr file, Directory hash has a value and Lenght is 0 while Offset value is ignored.
Additional info
Apparently the file arc/menu/01_race.arc from Birth By Sleep is corrupt and unreadable. It is unknown if the remastered actually uses that file; and if yes, how.