Bug#399760: RFP: paq -- high compression ratio archiver
Package: wnpp
Severity: wishlist
* Package name : paq
Version : 8ja
Upstream Author : Matt Mahoney <matmahoney@yahoo.com>
* URL : Homepage: http://cs.fit.edu/~mmahoney/compression
* License : GPL
Programming Lang: C++
Description : high compression ratio archiver
PAQ is a series of open source data compression archivers that have
evolved through collaborative development to top rankings on several
benchmarks measuring compression ratio (although at the expense of
speed and memory usage).
- -
PAQ is a complete rewrite of PAQ6 and variants (PAQAR, PAsQDa).
Compression ratio is similar to PAQAR but 3 times faster. However it
lacks x86 and a dictionary, so does not compress Windows executables
and English text files as well as PAsQDa. It does include models for
color .bmp, .tiff, and .jpeg files, so compresses these files better.
The primary difference from older PAQs is it uses a neural network to
combine models rather than a gradient descent mixer.
Test results are shown on the Calgary corpus (14 individual files or
concatenated into a single file of 3,141,622 bytes). All options set
for maximum compression. Programs are ordered by increasing
compression on the concatenated corpus. For sources to many programs,
see <ftp://ftp.elf.stuba.sk/pub/pc/pack/>.
Program Options 14 files Seconds Concatenated
------- ------- -------- ------- ------------
gzip 1.2.4 -9 1,017,624 2 1,021,863
bzip2 1.0.0 -9 828,347 5 859,448
7zip 3.11 a -mx=9 822,059 20 821,872
winrar 3.20 b3 best, solid 754,270 7 760,953
PAQ8F -4 606,605 828*** 120 MB
-6 605,650 840*** 435 MB
***Tested on a 2.2 GHz AMD-64 (in 32 bit XP), adjusted times 4.17.
The above data is from PAQ homepage at
http://cs.fit.edu/~mmahoney/compression/
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