PPMX 0.08 is here!

[encode]

Hello everyone!

As a New Year gift, please welcome a new version of PPMX!

What's new:

• Max model order is 6. PPMX uses order skip, so actual model set is an order-6-4-2-1-0-(-1)
• Heavily improved escape handling. Instead of a straight SEE, PPMX make use of "escape adjustment" tricks, based on previous escape history. My experiments shows that these tricks as efficient, in terms of compression, as SEE, being less computationally expensive, thus much faster.

New PPMX can be downloaded at my homepage:
encode.narod.ru


Quick testing results:

ENWIK9: 1000000000 -> 202868559 in 107.5 sec

ENWIK8: 100000000 -> 23204040 in 11.9 sec

bookstar: 35594240 -> 9641612 in 6.1 sec

osho.txt: 206908949 -> 36675241 in 14.5 sec

3200.txt: 16013962 -> 3891976 in 1.7 sec

world95.txt: 2988578 -> 514531 in 0.2 sec

calgary.tar: 3152896 -> 791883 in 0.4 sec


* Compression time is as shown by PPMX, thus it includes I/O time.
* Tested on Core i7-2600K @ 4.6GHz, 8GB DDR3 @ 1866MHz, 240GB Corsair Force GT SSD

[Matt Mahoney]

I tested it a year early (it is still 2011 here for a few hours). http://mattmahoney.net/dc/text.html#1936

[Vacon]

Hello everyone,

thank you
and Happy new year!

Best regards!

[encode]

I tested it a year early (it is still 2011 here for a few hours). http://mattmahoney.net/dc/text.html#1936

Thanks a lot!

ENWIK9 decompression: 202868559 -> 1000000000 in 127.2 sec

Memory usage on my machine is the same as you posted - 355,628 K

(and SEE improvements, not SSE )

[Shelwien]

http://nishi.dreamhosters.com/u/pmx08.htm

[m^2]

What's up with finn lst?

[encode]

PPMX is PPM, others are CM. If compare apple to oranges - PPMX uses only ONE highest context possible to encode a symbol. Of course order-6 is a bad idea to code a dictionary. Same thing happens with "english.dic" as example.

[Matt Mahoney]

Updated. http://mattmahoney.net/dc/text.html#1936