Resources for those interested in the RefPack/QFS compression algorithm used in many EA games. Also maintains links to known implementations of the compression for easy reference.
RefPack is a compression algorithm based on the LZ77/LZSS compression written by Frank Barchard for use in games made by EA1. It can be found in games as early as FIFA International Soccer (1993)2. The algorithm uses different encoding schemes based on the length and position of the data that's being compressed, which allows it to achieve a higher compression ratio compared to other LZ-based algorithms.
The name QFS comes from a file format used in old Need for Speed games in which this algorithm was used. However, the actual name of the algorithm is RefPack1.
Niotso Wiki: Generic information on the compression algorithm.
Source Code: Official code released by EA as a part of the public release of the source code of Command and Conquer: Generals - Zero Hour.
Explanation of LZ77/LZSS Compression: RefPack is based on the LZ77 compression algorithm.
Explanation of zlib: zlib is a popular compression library and a lot of the techniques employed in zlib are also utilized in RefPack compression code.
List of known implementations of the compression algorithm organized by language and format and for easy reference. A lot of those are rewrites of the same code in another programming language. The quality varies from one implementation to another.
| Language/Format | EAC | EAC (w/ 32-bit size) | Maxis | Fusion |
|---|---|---|---|---|
| C | Denis Auroux | aluigi3 | ||
| C# | 0xC0000054 Venomalia rivit |
Venomalia GlitcherOG pljones & Tiger gibbed |
0xC0000054 Venomalia Afr0 ambertation |
AcK773 |
| C++ | EA Games OmniBlade KUDr J.M. Pescado |
benrg | ||
| Go | marcboudreau | |||
| Java | emd4600 | java_dwarf | ||
| JavaScript | sebamarynissen | |||
| Kotlin | DarkAtra3 | |||
| Pascal | Banshee3 | |||
| PHP | Delphy3 | |||
| Python | lingeringwillx4 lah7 |
yukinogatari3 | ||
| Rust | actioninja | actioninja | ||
| Scala | memo33 |
