Bzip2 uses two reversible transformations BWT, then Move to front with Huffman coding for symbol reduction (the actual compression element).

Bzip2 – The standard Burrows–Wheeler transform algorithm.

LZMA2 – modified version of LZMA providing better multithreading support and less expansion of incompressible data.

The LZ stage is followed by entropy coding using a Markov chain-based range coder and binary trees. LZMA – A variation of the LZ77 algorithm, using a sliding dictionary up to 4 GB in length for duplicate string elimination.The following compression methods are currently defined: The format's open architecture allows additional future compression methods to be added to the standard. to re-assemble an archive from a set of multi-part component files). Support for multi-part archives : e.g.Compression and encryption of archive headers.Support for solid compression, where multiple files of like type are compressed within a single stream, in order to exploit the combined redundancy inherent in similar files.Large file support (up to approximately 16 exbibytes, or 2 64 bytes).High compression ratios (depending on the compression method used).Open, modular architecture that allows any compression, conversion, or encryption method to be stacked.

The 7z format provides the following main features: There have been additional third-party attempts at writing more concrete documentation based on the released code.

The specification can be found in plain text format in the 'doc' sub-directory of the source code distribution. The official, informal 7z file format specification is distributed with 7-Zip's source code since 2015. The latest stable version of 7-Zip and LZMA SDK is version 22.01. The LZMA SDK 4.62 was placed in the public domain in December 2008. The 7-Zip program is publicly available under the terms of the GNU Lesser General Public License. The 7z format initially appeared as implemented by the 7-Zip archiver. Yes: GNU Lesser General Public License / Public domainħz is a compressed archive file format that supports several different data compression, encryption and pre-processing algorithms.

7zip converter