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Diffstat (limited to 'README')
| -rw-r--r-- | README | 23 |
1 files changed, 15 insertions, 8 deletions
@@ -5,8 +5,9 @@ and decompression functions, including integrity checking of the decompressed data. The compressed data format used by the library is the lzip format. Lzlib is written in C. -The lzip file format is designed for long-term data archiving, taking -into account both data integrity and decoder availability: +The lzip file format is designed for data sharing and long-term +archiving, taking into account both data integrity and decoder +availability: * The lzip format provides very safe integrity checking and some data recovery means. The lziprecover program can repair bit-flip errors @@ -21,8 +22,8 @@ into account both data integrity and decoder availability: extract the data from a lzip file long after quantum computers eventually render LZMA obsolete. - * Additionally lzip is copylefted, which guarantees that it will - remain free forever. + * Additionally the lzip reference implementation is copylefted, which + guarantees that it will remain free forever. A nice feature of the lzip format is that a corrupt byte is easier to repair the nearer it is from the beginning of the file. Therefore, with @@ -45,6 +46,12 @@ until some data is read, even if you write a lot of data. If you want the data to be compressed in advance, just call the read function with a size equal to 0. +If all the data to be compressed are written in advance, lzlib will +automatically adjust the header of the compressed data to use the +smallest possible dictionary size. This feature reduces the amount of +memory needed for decompression and allows minilzip to produce identical +compressed output as lzip. + Lzlib will correctly decompress a data stream which is the concatenation of two or more compressed data streams. The result is the concatenation of the corresponding decompressed data streams. Integrity testing of @@ -62,9 +69,9 @@ elaborated way of finding coding sequences of minimum price than the one currently used by lzip could be developed, and the resulting sequence could also be coded using the LZMA coding scheme. -Lzip currently implements two variants of the LZMA algorithm; fast (used -by option -0) and normal (used by all other compression levels). Lzlib -just implements the "normal" variant. +Lzlib currently implements two variants of the LZMA algorithm; fast +(used by option -0 of minilzip) and normal (used by all other +compression levels). The high compression of LZMA comes from combining two basic, well-proven compression ideas: sliding dictionaries (LZ77/78) and markov models (the @@ -79,7 +86,7 @@ range encoding), Igor Pavlov (for putting all the above together in LZMA), and Julian Seward (for bzip2's CLI). -Copyright (C) 2009-2014 Antonio Diaz Diaz. +Copyright (C) 2009-2015 Antonio Diaz Diaz. This file is free documentation: you have unlimited permission to copy, distribute and modify it. |