![]() ![]() For x86, this means that near jumps, calls and conditional jumps (but not short jumps and conditional jumps) are converted from the machine language "jump 1655 bytes backwards" style notation to normalized "jump to address 5554" style notation all jumps to 5554, perhaps a common subroutine, are thus encoded identically, making them more compressible. The LZMA SDK comes with the BCJ and BCJ2 preprocessors included, so that later stages are able to achieve greater compression: For x86, ARM, PowerPC (PPC), IA-64 Itanium, and ARM Thumb processors, jump targets are 'normalized' before compression by changing relative position into absolute values. 7-Zip contains a from-scratch DEFLATE encoder that frequently beats the de facto standard zlib version in compression size, but at the expense of CPU usage.Ī suite of recompression tools called AdvanceCOMP contains a copy of the DEFLATE encoder from the 7-Zip implementation these utilities can often be used to further compress the size of existing gzip, ZIP, PNG, or MNG files. Deflate is found in several file formats including ZIP, gzip, PNG and PDF. DEFLATE – Standard algorithm based on 32 kB LZ77 and Huffman coding.PPMd – Dmitry Shkarin's 2002 PPMdH (PPMII (Prediction by Partial matching with Information Inheritance) and cPPMII (complicated PPMII)) with small changes: PPMII is an improved version of the 1984 PPM compression algorithm (prediction by partial matching).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).
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