Best Compression I have ever seen - How did they do this?

[qualia787]

I discovered something strange when downloading the free MOPY screensaver
from HP. (you can Google it yourself and test it out)

The download file is only 1.30MB (it was originally made to be easily distributed
on FLOPPY (yes Floppy) disks) and uncompressing takes a long time (for such
a small screensaver..) but it unpacks to over 8MB!

Now when I try to COMPRESS the MOPYFISH folder back again with the
compression utilities below I get nothing remotely NEAR the compression
level of the original distribution.

MOPYFISH folder 8.85MB
MOPYFISH.zip - 4381KB
MOPYFISH.rar - 4009KB
MOPYFISH.7z - 3671KB


How is it possible they packed the whole thing in only 1.30MB? Is this a
special tool they wrote specifically for the program and if so why can't
we use such an algorithm to pack all programs might tighter??

 

[quikah]

I just downloaded it, a 1.3MB setup.exe, open the setup.exe archive with 7zip showsme a few exe's and dll's totaling about 1.9MB. Most likely the setup program creates some data when it installs.

 

[agr8man]

Do you know KGB archiver? it really takes much time to decompress but it compresses a 300 mb file to some 2 or 3 mb.
Here is the link- http://kgbarchiver.net/
But you shud have a good system configuration with atleast 512 mb RAM

 

[Soundmanred]

Originally posted by: agr8man
Do you know KGB archiver? it really takes much time to decompress but it compresses a 300 mb file to some 2 or 3 mb.
Here is the link- http://kgbarchiver.net/
But you shud have a good system configuration with atleast 512 mb RAM

It states on their page that using the best compression, you can get the file to 20% of its original size, so a 300MB file would be compressed to ~60MB, not 2 or 3 MB.

 

[0roo0roo]

no magic, you have to have some incredibly compressible data to pull off high compression. the screensaver program is probably procedurally generating some kind of files.
famous example
http://en.wikipedia.org/wiki/Kkreiger
http://en.wikipedia.org/wiki/Procedural_generation
http://www.bit-tech.net/gaming..._Textures_Future_Gam/1