nlzss11

Library for data compression using Nintendo's variant of the lzss algorithm

Reference implementation: nlzss

Usage

nlzss11 can be installed with pip3 install nlzss11.

nlzss11.get_uncompressed_size(data)

Returns the size in bytes of the file if uncompressed or None if the bytes are not a valid Nintendo LZSS 11 compressed file.

nlzss11.decompress(data)

Decompresses nlzss11-compressed data from a bytes-like object data. Returns a bytes object containing the uncompressed data.

nlzss11.decompress_unsafe(data)

Decompresses nlzss11-compressed data from a bytes (not bytes-like) object data. Returns a bytes object containing the uncompressed data.

Unlike nlzss11.decompress, this function assumes that the input data is well-formed. In exchange for slightly improved performance, no sanity checks are performed. Warning: Do not use on untrusted data.

nlzss11.compress(data, level=7)

Compresses a bytes-like object data. Returns a bytes-like object containing the compressed data.

level is the compression level (6-9). 6 is fastest and 9 is slowest. Higher compression levels result in better compression. 7 is a good compromise between compression ratio and performance.

Project information

This project is a fork from the amazing syaz0 Project, just modified to match the algorithm found in The Legend of Zelda: Skyward Sword.

Building from source

Building nlzss11 from source requires:

• CMake 3.10+
• A compiler that supports C++17
• Everything needed to build zlib-ng
• pybind11 2.4+ (including CMake config files)
• setuptools

When no binary build is available, pip will automatically build from source during the install process.

To build and install from source run pip3 install ..

Building for manylinux

• Use the manylinux docker container in this directory:
  docker run -v $PWD:/home/build/nlzss11 -ti quay.io/pypa/manylinux2010_x86_64 bash
• Run bash build-on-manylinux.sh
• run setup.py bdist_wheel with every cpython version you want from /opt/python

Changelog

1,7

• recompress support for files > 0xFFFFFF (found in SSHD)

1.3

• decompress support for files > 0xFFFFFF (found in SSHD)

License

This software is licensed under the terms of the GNU General Public License, version 2 or later.