LZO 0.28 -- a real-time data compression library

LZO 0.28 -- a real-time data compression library

Post by Oberhumer Marku » Wed, 05 Mar 1997 04:00:00



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 ============================================================================
 LZO -- a real-time data compression library
 ============================================================================

 Author  : Markus Franz Xaver Johannes Oberhumer

           http://www.infosys.tuwien.ac.at/Staff/lux/marco
 Version : 0.28
 Date    : 22-Feb-1997

 Abstract
 --------
 LZO is a portable lossless data compression library written in ANSI C.
 It offers pretty fast compression and very fast decompression.
 Decompression requires no memory.

 In addition there are slower compression levels achieving a quite
 competitive compression ratio while still decompressing at
 this very high speed.

 LZO is distributed under the GNU General Public License.

 Availability
 ------------
 ftp://hpv17.infosys.tuwien.ac.at/pub/mfx/lzo/lzo-0.28.tar.gz
 ftp://sunsite.unc.edu/pub/Linux/Incoming/lzo-0.28.tar.gz
 ftp://sunsite.unc.edu/pub/Linux/libs/lzo-0.28.tar.gz         (soon)
 ftp://tsx-11.mit.edu/pub/linux/sources/libs/lzo-0.28.tar.gz  (soon)
 ftp://ftp.elf.stuba.sk/pub/pc/pack/lzo028.zip

 Archive size is about 161 kB.

 What's new since 0.27
 ---------------------
 - new algorithm LZO1Y: LZO1Y-999 and LZO1Y decompressor
 - added lzo1x_optimize() and lzo1y_optimize()
 - minor speedup in assembler decompressors (i386+gcc)
 - lzo_test.c rewritten

 I want to release version 1 in the near future - please read
 the section 'Feedback' in the documentation.

 Introduction
 ------------
 LZO is a data compression library which is suitable for data
 de-/compression in real-time. This means it favours speed
 over compression ratio.
 I named it LZO standing for Lempel-Ziv-Oberhumer.

 LZO is written in ANSI C. Both the source code and the compressed
 data format are designed to be portable across platforms,
 and LZO should work on each architecture that has at least
 32 bit integers. Somewhat limited support for 16 bit
 MSDOS is implemented as well (using 'huge' pointers).

 LZO implements a number of algorithms with the following features:
  - Decompression is simple and *very* fast.
  - Requires no memory for decompression.
  - Compression is pretty fast.
  - Requires 64kB of memory for compression.
  - Allows you to dial up extra compression at a speed cost in the
    compressor. The speed of the decompressor is not reduced.
  - Includes compression levels for generating pre-compressed
    data which achieve a quite competitive compression ratio.
  - Algorithm is thread safe.
  - Algorithm is lossless.

 Design criteria
 ---------------
 LZO was designed with speed in mind. Decompressor speed has been
 favoured over compressor speed. Real-time decompression should be
 possible for virtually any application. The implementation of the
 LZO1X decompressor in optimized 80x86 assembler code runs about at
 the third of the speed of a memcpy() - and even faster for some files.

 Portability
 -----------
 I have built and tested LZO successfully on a variety of
 platforms including:

   i486 - Linux 1.2.6 - gcc 2.6.3
   i586 - Linux 2.0.20 - gcc 2.7.2
   i486 - MSDOS - djgpp v2 + gcc 2.7.2
   i486 - MSDOS - emx + gcc 2.7.2
   i486 - MSDOS - Watcom C32 10.5 (32 bit)
   i486 - MSDOS - Borland C 4.0 (16 bit)
   i586 - MSDOS - Microsoft C 7.0 (16 bit)

 LZO is also reported to work under HP-UX, AIX, IRIX, ConvexOS and Solaris.

 For more information point your browser at:
 -------------------------------------------
 http://www.infosys.tuwien.ac.at/Staff/lux/marco/lzo.html

- --
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