pybcj

======================================= BCJ(Branch-Call-Jump) filter for python

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.. image:: https://img.shields.io/conda/vn/conda-forge/pybcj :target: https://anaconda.org/conda-forge/pybcj

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In data compression, BCJ, short for Branch-Call-Jump, refers to a technique that improves the compression of machine code of executable binaries by replacing relative branch addresses with absolute ones. This allows a LZMA compressor to identify duplicate targets and archive higher compression rate.

BCJ is used in 7-zip compression utility as default filter for executable binaries.

pybcj is a python bindings with BCJ implementation by C language. The C codes are derived from p7zip, portable 7-zip implementation. pybcj support Intel/Amd x86/x86_64, Arm/Arm64, ArmThumb, Sparc, PPC, and IA64.

Development status

A development status is considered as Beta state.

Installation

As usual, you can install pybcj using python standard pip command.

.. code-block::

pip install pybcj

Alternatively, one can also use conda:

.. code-block::

conda install -c conda-forge pybcj

WARNING

• When use it on MSYS2/Mingw64 environment, please set environment variable SETUPTOOLS_USE_DISTUTILS=stdlib to install.

License

• SPDX-License-Identifier: LGPL-2.1-or-later
• SPDX-URL: https://spdx.org/licenses/LGPL-2.1-or-later.html

• Copyright (C) 2020-2025 Hiroshi Miura
• Copyright (C) 1999-2010 Igor Pavlov