X-Authentication-Warning: delorie.com: mail set sender to djgpp-bounces using -f From: Rugxulo Newsgroups: comp.os.msdos.djgpp Subject: Gzip 1.2.4 "-9" hack (improved compression) / Unzip 6.0 Date: Mon, 25 May 2009 23:38:04 -0700 (PDT) Organization: http://groups.google.com Lines: 40 Message-ID: <26f4410e-07ea-4a16-87b2-269265674c39@m17g2000vbi.googlegroups.com> NNTP-Posting-Host: 65.13.115.246 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Trace: posting.google.com 1243319884 29666 127.0.0.1 (26 May 2009 06:38:04 GMT) X-Complaints-To: groups-abuse AT google DOT com NNTP-Posting-Date: Tue, 26 May 2009 06:38:04 +0000 (UTC) Complaints-To: groups-abuse AT google DOT com Injection-Info: m17g2000vbi.googlegroups.com; posting-host=65.13.115.246; posting-account=p5rsXQoAAAB8KPnVlgg9E_vlm2dvVhfO User-Agent: G2/1.0 X-HTTP-UserAgent: Opera/9.64 (Windows NT 6.0; U; en) Presto/2.1.1,gzip(gfe),gzip(gfe) To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com The ultimate .gz compressor is probably 7-Zip / p7zip, but it's very very slow. But if you want better compression without the huge speed penalty, you can compile Gzip 1.2.4 (only) with Ilia Muraviev's "-9" hack (two-byte lookahead or whatever). As he calls it, it's a five- minute hack, so it's not ported to 1.3.12 or Zlib. But hey, it improves the compression while still keeping older levels for fastest speed ratio. So, if you want a bit better speed, try his modified DEFLATE.C (and use -DNO_ASM and remove all mentions of match.S from the makefile, and fix the silly tab error, and it should compile and work correctly). And yes, it's 100% compatible output. Basically, it compresses better than typical Gzip "-9" but somewhat slower: enwik8 enwik9 gzip124hack -9 36,273,716 321,050,648 gzip 1.3.5 -9 36,445,248 322,591,995 http://www.encode.ru/downloads/gzip124hack.zip (original patched DEFLATE.C and Win32 binary) http://rugxulo.googlepages.com/gzhakwat.zip (311k, includes everything necessary, mainly full sources + patch + OpenWatcom DOS + Win32 compiles, this was before I knew why DJGPP wasn't byte identical, don't forget -DNO_ASM and don't use match.S !!!) P.S. Since I'm talking about compression, Info-Zip 6.0 was *finally* released last month (and Zip 3.0 last year and 3.1b beta srcs recently), default package includes MSC 16-bit and :-) DJGPPv2 :-) 32-bit .EXEs (with Bzip2 method support). Not sure why no default binaries for Zip 3.0, I did compile for them (minor bug on DR-DOS, MS- DOS 6.22 re: "-f", probably still unresolved, bah), but anyways, it's easy to build. http://www.info-zip.org http://www.sourceforge.net/projects/infozip ftp://ftp.info-zip.org/pub/infozip/msdos/unz600x3.exe ftp://ftp.info-zip.org/pub/infozip/src/