RedLZW | SuperCollider 3.13.0 Help

Description

See http://en.wikipedia.org/wiki/LZW and http://marknelson.us/1989/10/01/lzw-data-compression/

A dictionary look-up compressor that performs well with both highly repetitive data and repeating patterns e.g. [0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 3, 3, 3, 3, 3, 3, 3, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3].

NOTE: Only works with 8bit Integer (0-255) values.

Class Methods

RedLZW.compress(input)

Expects an array of 8bit integers. Returns an array of integers.

RedLZW.decompress(input)

Array of integers. Returns an array of 8bit integers.

Inherited class methods

Instance Methods

Inherited instance methods

Examples

a= [0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 3, 3, 3, 3, 3, 3, 3, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3];
b= RedLZW.compress(a);
b.size/a.size;    //compressed to 60%
c= RedLZW.decompress(b);
a==c

a= "TOBEORNOTTOBEORTOBEORNOT".ascii;
b= RedLZW.compress(a);
b.size/a.size;    //compressed to 66%
c= RedLZW.decompress(b);
a==c;

a= "/WED/WE/WEE/WEB/WET".ascii;
b= RedLZW.compress(a);
b.size/a.size;    //compressed to 63%
c= RedLZW.decompress(b);
a==c;

a= "JOEYNJOEYNJOEYJOEYNJOEYNJOEYJOEYNJOEYNJOEYJOEYNJOEYNJOEY".ascii;
b= RedLZW.compress(a);
b.size/a.size;    //compressed to 37.5%
c= RedLZW.decompress(b);
a==c;

a= "Man is distinguished, not only by his reason, but by this singular passion from other animals, which is a lust of the mind, that by a perseverance of delight in the continued and indefatigable generation of knowledge, exceeds the short vehemence of any carnal pleasure.".ascii;
b= RedLZW.compress(a);
b.size/a.size;    //compressed to 69%
c= RedLZW.decompress(b);
a==c;

a= "this_is_his_thing".ascii;
b= RedLZW.compress(a);
b.size/a.size;    //compressed to 76%
c= RedLZW.decompress(b);
a==c;

a= "abcabcabcabcabcabc".ascii;
b= RedLZW.compress(a);
b.size/a.size;    //compressed to 50%
c= RedLZW.decompress(b);
a==c;

helpfile source: /home/stefan/.local/share/SuperCollider/downloaded-quarks/redSys/HelpSource/Classes/RedLZW.schelp
link::Classes/RedLZW::

RedLZW : Object Extension