AuroraLib.Compression

AuroraLib.Compression is a high-performance, memory-efficient compression library providing a wide range of algorithms commonly used in video games and game engines. The library is written entirely in managed C# and supports multiple .NET versions without requiring external native dependencies.

The goal of AuroraLib.Compression is not to provide the fastest possible implementation of a single algorithm, but to offer a broad collection of compression formats while keeping the library lightweight, flexible, and easy to integrate.

Command line tool

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Benchmarks

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Supported Algorithms

AuroraLib.Compression

Core compression algorithms and widely used general-purpose formats.

Algorithm	Description
LZO	Lempel–Ziv–Oberhumer algorithm, focused on fast decompression speed
LZ4	Very fast LZ-based algorithm designed for high decompression speed.
LZ4Legacy	Legacy variant of the LZ4 compression format.
LZSS	Classic LZSS compression algorithm widely used.
GZip	GZip compression format based on the DEFLATE algorithm.
ZLib	ZLib compression format using the DEFLATE algorithm.
Brotli	Modern compression by Jyrki Alakuijala and Zoltán Szabadka. (.NET 6+)
FastLZ	Lightweight and fast compression algorithm by Ariya Hidayat.
aPLib	Compression algorithm designed for high compression ratios, by Jørgen Ibsen.
Snappy	Google's Snappy previously known as Zippy, focused on decompression speed.

AuroraLib.Compression.Nintendo

Compression formats used across Nintendo platforms such as GBA, DS, Wii, and more.

Algorithm	Description
LZ10	Nintendo LZ10 compression used in various GBA, DS and Wii games.
LZ11	Nintendo LZ11 compression used in various DS and Wii games.
LZ40	Nintendo LZ40 compression, mainly used in DS games.
LZ60	Nintendo LZ60 corresponds to LZ40 algorithm.
LZ77	Nintendo LZ77 based on LZ10 used in Wii games and data.
HUF20	Nintendo Huffman compression algorithm, mainly used in GBA and DS games.
RLE30	Nintendo RLE compression algorithm used in GBA games.
BLZ	Nintendo BLZ compression, mainly used on the 3ds games.
LZOn	Nintendo LZOn compression algorithm mainly used in DS Download Games.
Yay0*	Nintendo YAY0 compression used in some Nintendo 64 and GameCube games.
Yaz0*	Nintendo Yaz0 compression used in games from the N64 to Switch era.
Yaz1*	Identical to Yaz0 used for data on the N64DD.
MIO0*	Nintendo MIO0 compression mainly used in early Nintendo 64 games.
SMSR00	Nintendo SMSR00 compression, mainly used in Yoshi's Story.
Level5	Level5 compression algorithm, mainly used in Level5 3ds games.
Level5LZSS	Level5 SSZL algorithm base on LZSS, used in Inazuma Eleven 3.
LZHudson	A LZSS based compression algorithm used in Mario Party 4-7.
RLHudson	A RLE based compression algorithm used in Mario Party 4-7.
COMP	Based on LZ11 algorithm, used in some Puyo Puyo.
CXLZ	Based on LZ10 algorithm, used in some Puyo Puyo.
GCLZ	Based on LZ10 algorithm, used in Pandora's Tower.
LZ_3DS	based on LZ10 algorithm, used in some 3DS games.

* Both big-endian and little-endian variants are supported.

AuroraLib.Compression.Sega

Compression formats found in Sega games and platforms.

Algorithm	Description
PRS*	Sega PRS compression algorithm used in various Sega games.
AKLZ	A LZSS based algorithm used in Skies of Arcadia Legends.
CNX2	Sega CNX2 algorithm, used in some Puyo Puyo.
LZ00	Sega LZ00 is based on LZSS algorithm with encryption.
LZ01	Sega LZ01 based on LZSS algorithm, used in some Puyo Puyo.
LZSega	A LZSS based compression algorithm used in some Sega GameCube games.

* Both big-endian and little-endian variants are supported.

AuroraLib.Compression-Extended

Additional compression formats used by various game studios and engines.

Algorithm	Description
ALLZ	Aqualead LZ compression algorithm used by a handful of games.
HWGZ*	Hyrule Warriors GZ compression format based on ZLib.
RareZip	Rareware Zip based on DEFLATE, used in Banjo-Kazooie.
ZLB	ZLB based on ZLib compression algorithm used in Star Fox Adventures.
RefPack	RefPack compression algorithm used in some EA games.
CRILAYLA	Algorithm by CRI Middleware, used in games built with the CRIWARE toolset.
MDB4	Sega MDB4 based on LZSS, used in Typing of the Dead for the PlayStation 2.
CNS	CNS compression algorithm, used in Games from Red Entertainment.
CLZ0	CLZ0 compression algorithm, used in Games from Victor Interactive Software.
FCMP	FCMP based on LZSS algorithm, used in Muramasa The Demon Blade.
LZ02	LZ02 compression algorithm used in Mario Golf: Toadstool Tour.
LZShrek	LZShrek compression algorithm used in Shrek Super Slam.
AsuraZlb	AsuraZlb based on ZLib compression algorithm used in Simpsons The Game.
HIG	High Impact Games WAD compression, similar to LZO.
MDF0	Konami MDF0 based on ZLib used in Castlevania: The Adventure ReBirth.
GCZ	Konami GCZ based on LZSS, mainly used in Konami/Bemani music games.
SDPC	TREVA Entertainment SDPC compression based on LZO.
SSZL	SynSophiaZip based on Zlib with Mersenne Twister xor encryption.
IECP	IECP algorithm based on LZSS, used in Fate/Extra.
ECD	Rocket Company ECD algorithm based on LZSS, used in Kanken Training 2.
WFLZ	WayForward's LZ algorithm, focused on decompression speed.
ZLWF	WayForward's LZ chunk header.

* Both big-endian and little-endian variants are supported.

How To Use

Decompress a File Using a Specific Algorithm

    using FileStream source = new("input.dat", FileMode.Open, FileAccess.Read, FileShare.Read);
    using FileStream destination = new("output.dat", FileMode.Create, FileAccess.ReadWrite, FileShare.None);
    new LZSS().Decompress(source, destination);

Compress a File Using a Specific Algorithm

    using FileStream source = new("input.dat", FileMode.Open, FileAccess.Read, FileShare.Read);
    using FileStream destination = new("output.dat", FileMode.Create, FileAccess.ReadWrite, FileShare.None);
    new LZSS().Compress(source, destination, CompressionSettings.Balanced);

Check If a File Matches a Specific Compression Algorithm

    using FileStream source = new("input.dat", FileMode.Open, FileAccess.Read, FileShare.Read);
    bool canDecompressed = LZSS.IsMatchStatic(source);

Configure an Compression Encoder

    Yaz0 encoder = new Yaz0
    {
        FormatByteOrder = Endian.Big,  // Use big-endian byte order
    };
	
    CompressionSettings settings = new CompressionSettings(
        quality: 10,  // 0 (fastest, lowest compression) to 15 (slowest, best compression)
        maxWindowBits: 12, // Maximum LZ window size (for LZ-based algos) 
        strategy: CompresionStrategy.CompatibilityMode // Enables compatibility features for older or simpler decoders.
    );
	
	encoder.Compress(source, destination, settings);

Automatically Detect and Decompress Using a Recognized Algorithm

This approach is useful when you don't know in advance which compression algorithm was used on a file.

    FormatDictionary formats = new FormatDictionary(new Assembly[] 
    { 
        typeof(LZSS).Assembly,    // Base algorithms assembly
        typeof(Yaz0).Assembly     // Nintendo algorithms assembly
    });

    using FileStream source = new("input.dat", FileMode.Open, FileAccess.Read, FileShare.Read);
    ReadOnlySpan<char> fileName = Path.GetFileName("input.dat");

    // Identify the compression format
    if (formats.Identify(source, fileName, out IFormatInfo format) && format.Class != null)
    {
     	// Create an instance of the detected format
        var decoder = format.CreateInstance();
		
        if (decoder is ICompressionDecoder compressionDecoder)
        {
            using Stream destination = compressionDecoder.Decompress(source);
            // Use the decompressed stream as needed
        }
    }

Credits

• LZ4 reference for LZ4 algorithm.
• Haruhiko Okumura reference his original C implementation of the LZSS algorithm.
• Oberhumer reference for the LZO algorithm.
• Google reference for the snappy algorithm.
• Ariya reference for the FastLZ algorithm.
• ibsensoftware Creator of aPLib.
• Daniel-McCarthy reference for MIO0, YAZ0, YAY0 algorithm.
• Nickworonekin Puyo Tools reference for CNX2, LZ00, LZ01, LZ10, LZ11, PRS algorithms.
• Kuriimu reference for HUF20 algorithm.
• Niotso.wiki reference for RefPack algorithm.
• Sukharah reference for CLZ0 algorithm.
• Gamemasterplc reference for LZHudson algorithm.
• KirbyUK reference for LZShrek algorithm.
• Brolijah reference for ALLZ algorithm.thm.
• CUE reference for LZ40 algorithm.
• hack64 reference for SMSR00 algorithm.
• RareZip reference for RareZip algorithm.
• ShaneYCG reference for WFLZ algorithm.
• UYA_pyTools reference for HIG algorithm.