RINGS Fast Bit Compressor.

[Bulat Ziganshin]

btw, in russian compression forum grzip author described idea of extra-fast bwt compression: http://forum.compression.ru/viewtopic.php?t=1948

[Black_Fox1]

msufsort also seems quite good

[Piotr Tarsa]

bulat:
that's non deterministic algorithm. the output is usually not valid due to hash collisions. therefore it's not used in practice.

black_fox:
i know about it. afair divsufsort is currently faster than msufsort.


on my system szip -o4 has almost identical speed as rings and szip also uses bwt (of limited order - it's called shindler transform).

rings is more modern so it has better compression (of about 2 - 3 % with same block size).

on 64- bit computers it would be possible to do szip -o8 or -o7 with same speed. it would then have better compression.

[Bulat Ziganshin]

donkey7, we know that's ST

[Piotr Tarsa]

so why are you pointing to full bwt solutions? st works best with simple one- pass quicksort.

[Bulat Ziganshin]

because Nania said about bwt. and i'm not sure that simple sorting may be used for fast ST4 algorithms. afaik, grzip use itw own algorithm

[Piotr Tarsa]

well, i'm partially mistaken. i thought that st4 doesn't need stable sorting algo. but there is a workaround - make uint64 by:

[4 bytes of context] << 32 + [3 bytes of index] << 8 + [1 byte of last column - st4 output]

and then apply simple sort on uint64s.

[Bulat Ziganshin]

the problem is that some sorting procedure specialized for ST4 may run faster and definitely will use less amount of memory

[Nania Francesco]

RINGS 1.5 released

- UNREAL COMPRESSION!
Warning: Only for testing
Copyright ® 2007 by Nania Francesco Antonio (Italy).
All rights reserved.
link:
http://www.winturtle.netsons.org/rings.zip

[LovePimple]

Thanks Francesco!

Mirror: Download

[LovePimple]

Quick test...

RINGS c 9

A10.jpg > 819,150
AcroRd32.exe > 1,493,652
english.dic > 566,326
FlashMX.pdf > 3,752,097
FP.LOG > 486,886
MSO97.DLL > 1,872,766
ohs.doc > 884,912
rafale.bmp > 799,867
vcfiu.hlp > 716,177
world95.txt > 527,124

Total = 11,918,957 bytes

ENWIK8 > 21,848,093 bytes


Compression speed is still quick!

[Christian]

Very good results Francesco! Now, text compression is really great - thanks to its BWT nature I think.
Can you confirm that your "fast BWT" is using limited key lengths? Have you extended the length limit with each version?

[Nania Francesco]

Christian
Yes ! but for I apply only now it to some types of file (txt,log,bin) but an a little slower has become!

[Nania Francesco]

RINGS 1.5b released

- More stable !
- Corrected more bugs!
Warning: Only for testing
Copyright ® 2007 by Nania Francesco Antonio (Italy).
All rights reserved.
link:
http://www.winturtle.netsons.org/rings.zip

[Christian]

Corrected more bugs!

I tested it on a couple of files. What was wrong?

[Nania Francesco]

the prototype of fast bwt coder that use on file of few byte goes to crash!

[Nania Francesco]

CREATED NEW

RINGS HOME PAGE

http://www.winturtle.netsons.org/RINGS/rings.htm

[LovePimple]

UNREAL!

Mirror: Download

[Nania Francesco]

RINGS 1.5c released
- Full compatible!
Warning: Only for testing
Copyright ® 2007 by Nania Francesco Antonio (Italy).
All rights reserved.
link:
http://www.winturtle.netsons.org/rings.zip

[LovePimple]

Thanks Francesco!

Mirror: Download

[LovePimple]

Quick test...

A10.jpg > 819,150
AcroRd32.exe > 1,493,652
english.dic > 566,326
FlashMX.pdf > 3,752,097
FP.LOG > 486,886
MSO97.DLL > 1,872,766
ohs.doc > 884,912
rafale.bmp > 799,867
vcfiu.hlp > 716,177
world95.txt > 527,124

Total = 11,918,957 bytes


ENWIK8 > 21,848,093 bytes

Compression time for ENWIK8 was 80.61s on my P3 @750MHz.


Compression speed is impressive even on my old P3 @750MHz machine.

[Nania Francesco]

Thanks LovePimple Hi! At moment rings is not entirely stable !

[LovePimple]

At moment rings is not entirely stable !

Why?

[Black_Fox1]

I guess "not stable" as in "still under heavy development"

[Nania Francesco]

YES ! still under heavy development ! HI !

[LovePimple]

still under heavy development

That statment covers almost ALL archivers and compressors.