Short: Bzip2 xpk compression library (WarpOS/PPC) V1.3 Author: oliver.roberts@iname.com (Oliver Roberts) Uploader: oliver.roberts@iname.com (Oliver Roberts) Version: 1.3 Type: util/pack Requires: OS 3.0+,xpkmaster.library,WarpUp Release 4 Julian Sadler's bzip2 compresses files using the Burrows-Wheeler block sorting text compression algorithm, and Huffman coding. Compression is generally considerably better than that achieved by more conventional LZ77/LZ78-based compressors, and approaches the performance of the PPM family of statistical compressors. xpkBZP2.library uses the same compression algorithm as bzip2, and allows you to compress files with the same high crunch factor as bzip2, but under the XPK interface. In summary, xpkBZP2.library offers generally a very high compression ratio, typically around 70-90%. Of course, there's no such thing as a free lunch, and the downside is that the compression routines require lots of memory, although there are modes available which use less memory, at the expense of compression efficiency. The compression library offers 9 different modes, which correspond directly to the -1...-9 switches in bzip2: Pack Unpack Pack Unpack Mode Ratio Speed Speed Mem Mem Description 0..19 79.5% 154K/s 898K/s 1171K 488K 100K -1 20..29 80.2% 153K/s 842K/s 1953K 878K 200K -2 30..39 80.4% 150K/s 817K/s 2734K 1269K 300K -3 40..49 80.7% 138K/s 798K/s 3515K 1660K 400K -4 (default) 50..59 80.8% 139K/s 777K/s 4296K 2050K 500K -5 60..69 80.8% 141K/s 771K/s 5078K 2441K 600K -6 70..79 80.9% 137K/s 760K/s 5957K 2832K 700K -7 80..89 80.9% 119K/s 754K/s 6640K 3222K 800K -8 90..100 80.7% 128K/s 743K/s 7421K 3613K 900K -9 ============================= Archive contents ============================= Original Packed Ratio Date Time Name -------- ------- ----- --------- -------- ------------- 2802 1848 34.0% 16-Apr-00 15:29:34 xpkBZP2.info 1300 634 51.2% 14-Apr-00 16:05:10 +Install_xpkBZP2 2024 1540 23.9% 16-Apr-00 15:30:10 +Install_xpkBZP2.info 48284 17501 63.7% 16-Apr-00 15:05:52 +xpkBZP2.library 6371 2843 55.3% 16-Apr-00 15:28:46 +xpkBZP2.guide 2924 2308 21.0% 16-Apr-00 15:30:10 +xpkBZP2.guide.info -------- ------- ----- --------- -------- 63705 26674 58.1% 17-Apr-100 19:37:04 6 files