Versions tested: 0.6b
Optimal parameters: -mdp -m1
Authors: Uwe Herklotz
Algorithms: RLE, LZP+ARI, LZ+ARI, LZP+PPM, X86
Notable peformances: -


The following quotes are from the program documentation.

-m0..3 Set compression mode.

ALZ uses advanced LZ77 compression algorithm with arithmetic entropy coder. "-m1" is the fastest ALZ mode, sacrificing compression ratio to gain better speed. Mode "-m3" achieves best compression and needs most time. "-m2" is a compromise ratio/speed and is used as default mode. The decompression speed is nearly the same for all ALZ modes and it is much faster than compression.

PPM mode uses an order-4-2-1-0 model with preliminary LZP pass. In most cases this mode provides the best compression results.

LZP mode uses the same dictionary compression as in PPM mode but with much simpler order-1-0 literal model.

There are also two extra modes (may be not supported in future versions):

-md Set maximum dictionary size (in KB).

If dictionary is disabled, this setting has no effect. Valid sizes:

A one-character shortcut can be used instead of size number, e.g. "-mda" instead of "-md1" or "-mdk" instead of "-md1024".

Dictionary size selection:

  1. Using option "-mdn", UHARC will never select a dictionary size greater than n. If "-mdn" is not used, UHARC will try to use default dictionary (n=4096).
  2. If data stream size is smaller than n, UHARC will use the smallest dictionary size which is greater than the data stream.
  3. If there is not enough memory for current selection, UHARC will use the largest dictionary size which is possible with available memory.

-mm[-,+] Disable/enable built-in multimedia detection/compression.

UHARC multimedia detection/compression supports many data types (8/16-bit mono/stereo waveforms, 24-bit true color pictures and many other types using 8/16/24/32-bit record sizes). It's also possible to detect multimedia-like data in other file types (e.g. in executables). Therefore it's NOT RECOMMENDED to disable multimedia detection/compression unless the user knows, that there is absolutely no chance to use multimedia compression (e.g. compressing text only).
the program documentation


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Qualified configurations
Ver Rating CPR DPR S.E. R.E. Ratio C. kB/s D. kB/s
-mdp -m1
0.6b 154 164 90 57 39 4.169 1322 8617
-mdp -m2
0.6b 143 148 103 48 41 4.228 1056 8681
-mdp -m3
0.6b 134 136 110 43 41 4.258 916 8764
-mdp -mx
0.6b 121 205 20 31 51 4.416 1013 1209
-mdp -mz
0.6b 72 148 10 122 2 3.345 10393 8634
0.6b 0 0 0 1 0 1.203 40954 39466
0.6b 0 0 0 41 0 2.157 17252 22725

Version info

0.6b, tar: no, mode: 32-bit, crc32: d3ac4a9, decoder: 107 kB, tested: 2010 Apr 13
compression: uharc.exe a -r <args> <cfile> <src>
decompression: uharc.exe x <cfile>