xpkBZP2.library

oliver@

.co.uk

xpkBZP2.library

Version: 1.7

Released: 4 March 2005

Download: xpkBZP2.lha (94K)

Block-sorting/huffman xpk compression library based on Julian Seward's bzip2 algorithms
(for 68K, OS4, MorphOS and WarpOS)

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.

Changes since 1.6:

PPC OS4 native version public release - rebuilt with GCC 3.4.3, now 10% faster at packing, and upto 30% faster unpacking
MorphOS and WarpOS versions recompiled with VBCC 0.8h, both now 2% faster at packing/unpacking and 6% faster unpacking for MorphOS

Benchmarks

The following benchmarks were generating after booting with no startup-sequence on my 50MHz 68060 and 240MHz 603e. The standard set of benchmark files was used in all cases, with the figures below being generated from the averages.

68k version
Mode	Ratio	Pack Speed	Unpack Speed	Pack Mem	Unpack Mem	Description
0..19	79.5%	107K/s	330K/s	1171K	488K	100K -1
20..29	80.2%	111K/s	326K/s	1953K	878K	200K -2
30..39	80.4%	109K/s	324K/s	2734K	1269K	300K -3
40..49	80.7%	106K/s	323K/s	3515K	1660K	400K -4
50..59	80.8%	104K/s	320K/s	4296K	2058K	500K -5
60..69	80.8%	102K/s	319K/s	5078K	2441K	600K -6
70..79	80.9%	103K/s	316K/s	5957K	2832K	700K -7
80..89	80.9%	103K/s	313K/s	6640K	3222K	800K -8
90..100	80.7%	103K/s	310K/s	7421K	3613K	900K -9

OS4 version
Mode	Ratio	Pack Speed	Unpack Speed	Pack Mem	Unpack Mem	Description
0..19	79.5%	227K/s	1231K/s	1171K	488K	100K -1
20..29	80.2%	239K/s	1130K/s	1953K	878K	200K -2
30..39	80.4%	235K/s	1089K/s	2734K	1269K	300K -3
40..49	80.7%	224K/s	1056K/s	3515K	1660K	400K -4
50..59	80.8%	217K/s	1021K/s	4296K	2058K	500K -5
60..69	80.8%	213K/s	996K/s	5078K	2441K	600K -6
70..79	80.9%	213K/s	985K/s	5957K	2832K	700K -7
80..89	80.9%	213K/s	878K/s	6640K	3222K	800K -8
90..100	80.7%	211K/s	964K/s	7421K	3613K	900K -9

WarpOS version
Mode	Ratio	Pack Speed	Unpack Speed	Pack Mem	Unpack Mem	Description
0..19	79.5%	201K/s	985K/s	1171K	488K	100K -1
20..29	80.2%	212K/s	928K/s	1953K	878K	200K -2
30..39	80.4%	208K/s	900K/s	2734K	1269K	300K -3
40..49	80.7%	199K/s	877K/s	3515K	1660K	400K -4
50..59	80.8%	195K/s	855K/s	4296K	2058K	500K -5
60..69	80.8%	191K/s	850K/s	5078K	2441K	600K -6
70..79	80.9%	191K/s	837K/s	5957K	2832K	700K -7
80..89	80.9%	191K/s	832K/s	6640K	3222K	800K -8
90..100	80.7%	190K/s	822K/s	7421K	3613K	900K -9

MorphOS version
Mode	Ratio	Pack Speed	Unpack Speed	Pack Mem	Unpack Mem	Description
0..19	79.5%	198K/s	971K/s	1171K	488K	100K -1
20..29	80.2%	208K/s	909K/s	1953K	878K	200K -2
30..39	80.4%	205K/s	885K/s	2734K	1269K	300K -3
40..49	80.7%	195K/s	861K/s	3515K	1660K	400K -4
50..59	80.8%	191K/s	840K/s	4296K	2058K	500K -5
60..69	80.8%	187K/s	834K/s	5078K	2441K	600K -6
70..79	80.9%	187K/s	824K/s	5957K	2832K	700K -7
80..89	80.9%	187K/s	819K/s	6640K	3222K	800K -8
90..100	80.7%	186K/s	810K/s	7421K	3613K	900K -9

Requirements

Kickstart 3.0 or higher
XPK compression package
At least 8Mb free ram to use maximum compression

68k version

68020 processor or higher (optimized versions included)

OS4 version

PPC accelerator card / AmigaOne
AmigaOS 4.0 pre-release or newer

WarpOS version

PPC accelerator card + 68040/060
WarpUp Release 4 (powerpc.library V15) or higher

MorphOS version

PPC accelerator card
MorphOS beta release 1 or higher