Short: Burrows-Wheeler Transform package Uploader: osterh00 marvin informatik uni-dortmund de (Andre Osterhues) Architecture: m68k-amigaos Author markn@tiny.com (Mark Nelson) Uploader: osterh00@marvin.informatik.uni-dortmund.de (Andre Osterhues) Type: util/pack Requires: ixemul v40.2 This is the Amiga port of the Burrows-Wheler Transform. It makes a given input file more compressible by sorting the input in a specific order. Combined with good compressors, it gives ratios mostly superior to GZIP/PKZIP. A Run Length Encoder, an Arithmetic Coder and a Move-To-Front Coder are also included to form a powerful compression package. A paper on the transform by Mark Nelson, the author, is to appear in Dr. Dobbs Journal, September 1996. The original HTML doc (including graphics and the source code) is also included in this archive for your convenience ;) The latest version can be downloaded from: http://web2.airmail.net/markn/articles/bwt/bwt.htm Installation: ------------- There are two drawers, one contains the plain 68000 versions, the other contains the 68020-68060 versions of the following programs: ari - Arithmetic Coder bwt - Burrows-Wheeler Transform mtf - Move-To-Front rle - Run Length Encoder unari - Arithmetic Decoder unbwt - Inverse Burrows-Wheeler Transform unmtf - Reverse Move-To-Front unrle - Run Length Decoder Install them anywhere you like, most preferably somewhere in your path (e.g. C:). Usage: ------ The compression procedure requires 5 steps: 1. rle output1 2. bwt output2 3. mtf output3 4. rle output4 5. ari output where output1...output4 are temporary files, which can be deleted afterwards. I suggest to use the extension .bwt for files compressed using these 5 steps. The decompression procedure also requires 5 steps: 1. unari output1 2. unrle output2 3. unmtf output3 4. unbwt output4 5. unrle output Like above, the files output1...output4 are temporary and can be deleted. Instead of using rle and ari, you can also use other compression programs. For comments, suggestions, bug reports, donations, etc. contact me: André Osterhues Meitnerweg 13/122 D-44227 Dortmund Tel.: 0231/7519501 email: osterh00@marvin.informatik.uni-dortmund.de www: http://sx1.hrz.uni-dortmund.de/~andre/