A .NET library for reading and writing various FromSoftware file formats, targeting .NET 6 and 7.
Elden Ring, Dark Souls, Demon's Souls, Bloodborne, and Sekiro are the main focus, but other From games may be supported to varying degrees.
A brief description of each supported format can be found in FORMATS.md, with further documentation for some formats.

Forked from JKAnderson's repository, but also contains all the new changes from DS Map Studio (where it's currently maintained officially?). Sadly I have no option but to merge the changes manually — all credits go to the contributors there.

Additionally, I implement my own changes as well, mainly to the Headerizer class, which is used for deswizzling console textures (the most popular being PS4).

Objects for most formats can be created with the static method Read, which accepts either a Memory<byte>, or a file path. A very new addition to the library was to use Memory Mapped files, which reduces memory consumption, and is much faster due to unnecessary allocations.

BND4 bnd = BND4.Read(@"C:\your\path\here.chrbnd");

// or

var file = MemoryMappedFile.CreateFromFile(@"C:\your\path\here.chrbnd", FileMode.Open, null, 0, MemoryMappedFileAccess.Read);
var accessor = file.CreateMemoryAccessor(0, 0, MemoryMappedFileAccess.Read);
BND4 bnd = BND4.Read(accessor.Memory);

The Write method can be used to create a new file from an object. If given a path it will be written to that location with a stream, otherwise a byte array will be returned.

bnd.Write(@"C:\your\path\here.chrbnd");

// or

byte[] bytes = bnd.Write();
using FileStream stream = File.Create(@"C:\your\path\here.chrbnd");
stream.Write(bytes, 0, bytes.Length);
stream.Flush();

DCX (compressed files) will be decompressed automatically and the compression type will be remembered and reapplied when writing the file.

BND4 bnd = BND4.Read(@"C:\your\path\here.chrbnd.dcx");
bnd.Write(@"C:\your\path\here.chrbnd.dcx");

The compression type can be changed by either setting the Compression field of the object, or specifying one when calling Write.

BND4 bnd = BND4.Read(@"C:\your\path\here.chrbnd.dcx");
bnd.Write(@"C:\your\path\here.chrbnd", DCX.Type.None);

// or

BND4 bnd = BND4.Read(@"C:\your\path\here.chrbnd.dcx");
bnd.Compression = DCX.Type.None;
bnd.Write(@"C:\your\path\here.chrbnd");

Finally, DCX files can be generically read and written with static methods if necessary. DCX holds no important metadata so they read/write directly to/from byte arrays instead of creating an object.

Memory<byte> bndBytes = DCX.Decompress(@"C:\your\path\here.chrbnd.dcx");
BND4 bnd = BND4.Read(bndBytes);

// or

var file = MemoryMappedFile.CreateFromFile(@"C:\your\path\here.chrbnd.dcx", FileMode.Open, null, 0, MemoryMappedFileAccess.Read);
var accessor = file.CreateMemoryAccessor(0, 0, MemoryMappedFileAccess.Read);
Memory<byte> bndBytes = DCX.Decompress(accessor.Memory);
BND4 bnd = BND4.Read(bndBytes);

Writing a new DCX requires a DCX.Type parameter indicating which game it is for. DCX.Decompress has an optional out parameter indicating the detected type which should usually be used instead of specifying your own.

Memory<byte> bndBytes = DCX.Decompress(@"C:\your\path\here.chrbnd.dcx", out DCX.Type type);
DCX.Compress(bndBytes, type, @"C:\your\path\here.chrbnd.dcx");

// or

Memory<byte> bndBytes = DCX.Decompress(@"C:\your\path\here.chrbnd.dcx", out DCX.Type type);
Memory<byte> dcxBytes = DCX.Compress(bndBytes.Span, type);
using FileStream stream = File.Create(@"C:\your\path\here.chrbnd.dcx");
stream.Write(dcxBytes.Span);
stream.Flush();

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