|Optimal parameters:||-mx -a -15m|
Zzip, a new compression tool still under development, can compress files with a very high compression ratio. Compared to WinZip 7.0, you can gain, at least, 15 %. Zzip has a lot of useful features (like support for file integrity tests, built-in multimedia detection/compression...).former website
With Zzlib, you can also use Zzip as a library (dll) in one of your program.
Source code of Zzip/Zzlib is released under the GNU LGPL.
Zzip compression algorithm is mainly based on the Burrows-Wheeler Transform method developed by Mike Burrows and David Wheeler. Here are the different steps :
- RLE packing if necessary
- some transformations for text, multimedia and win32 binary files (eol coding, delta-encoding,...)
- Burrows-Wheeler Transformation, it's a suffix sorting (Bentley-Sedgewick ternary sorting with initial bucket sorting)
- MTF like transformation
- arithmetic coding (two groups, ternary sequence & structured model)
the program documentation
- -... Block size (e.g. -3m,-3072k) + block size of 1 Mb : -1m + block size of 2347 kb : -2347k
- -a Adaptive block size reduction
- -mx MaXimum compression
- -mm MultiMedia compression
-mx gives the best compression ratio but compression is 15% slower
-a is useful with binary or tar files, it reduces the block size adaptively to give a better compression ratio, but compression is 5% slower
-mm enables a special algorithm for image and wav files, use it only for multimedia files since it can give a worse compression ratio for regular files
The program has following filters (quotes from the source code):
* Some phrase replacements.This replaces the following phrases with single byte codes:
the, you, for, and, hav, he, nd.
* some ASCII transformations: alphabet reordering, carriage-return tagging, upper-case letter tagging
The compressor is featured in the BWT comparison.
(Have info that should be added here? E-mail.)
Configuration '-a -16m' fails verify check on Game2.
|Ver||Rating||CPR||DPR||S.E.||R.E.||Ratio||C. kB/s||D. kB/s|
|-mx -a -15m|