grtamayo

Gerald R. Tamayo's repositories

LZW-Algorithm

C implementations of the Lempel-Ziv-Welch (LZW) algorithm. Lzwg features optional bitsize (default=16) of dictionary string table size (default=65536). Lzwhc is a single file codec, via faster hashing. Note: lzwg uses maximum 1.7GB+ RAM and lzwhc uses maximum 2.4GB+ RAM @ 28-bit dictionary!

Language:C2 10

lzpgt

Fast LZP codec. Equivalent to "praq52 c1 infile outfile". Lzpgt decoder now faster! Compress output is more compact than ppp and lzp2. Output is a block of bits (1/0), then a block of mismatched bytes. Lzpgt6 now faster and lzpgt7 with optional guess table bitsize.

Language:C100

RLE

Sample program of Run-Length Encoding (RLE).

Language:C100

Algorithm-FGK

D. Knuth's adaptive or dynamic Huffman Coding named Algorithm FGK.

Language:C010

Algorithm-Vitter

Dynamic Huffman Coding II: Vitter's algorithm, also known as "Algorithm V". Vitc.c and vitd.c implement Vitter's algorithm. Vitz.c shows how you can have more than one "huffmodel" in one program. Vittz and vittzd use the simple functions encode_symbolVITTER() and decode_symbolVITTER() to encode and decode bytes respectively.

Language:C000

BWT

Sample code for the Burrows-Wheeler Transform (BWT).

Language:C000

Huffman-Coding

Sample program for static Huffman Coding.

Language:C000

lzhc

Lzhh rehashed without adaptive Huffman to output compression codes of lzuf2. Compiled with 128KB window. Uses an EOF_CODE, works on enwik10. :P

Language:C000

lzhhf

Golomb codes on the match_lengths, dynamic Huffman codes on the literals/offsets. Lzhhf3 and lzhhf4 single file coder/decoder.

Language:C010

lzuf62

Lzuf62 works on bigger files > 4GB like enwik10. Optional bitsize for sliding window implemented, WBITS = 12..20, default=17. Lzuf621 with optional bitsize of hash bucket search list (far_list_bits = 1..12), default=9. Lzuf622 and lzuf624 single file coder/decoder.

Language:C000

Move-To-Front

Simple file compressor using the MTF algorithm (2021). Your first data compressors (VLC + MTF), mtfc2 and mtfc3. :)

Language:C010

lzuf22

Corrected the decoding algorithm of lzuf2, actually using a previous simple working decoding algorithm. Note: ZIP is still better than lzuf22. :P

Language:C000

lzuf55

Lzuf55 starts with a small sliding window size to limit offset bitsize, but compression is not better than lzuf22. So in LZ77, big window size is king.

Language:C000

PRAQ

Sample code for LZ Prediction (LZP) algorithms.

Language:C000

praq4

This is a modification of praq3 from 2010 without using the ftell() function.

Language:C000

praq52

"PPP mode" now writes mismatched bytes as true raw bytes like in ppp compressor. Output is more compact than ppp and lzp2. As fast as ppp.

Language:C000

praq6

Essentially praq52 but using Golomb codes instead of the put_vlcode() function.

Language:C000

praq716

With lzpgt, these are what should have been the earliest versions of praq. Versions of transmitting LZP match_len and/or mismatched_len not just 1 bit per matched byte or mismatched byte. Actually less compression on mismatched_len.

Language:C000

Shannon-Fano-Coding

Sample code for Shannon Coding. Precursor to Huffman Coding?

Language:C000