WinZip

[Demosthenes]

This might be a long shot, but hopefully someone is knowledgable.

It is my knowledge that WinZip uses a form of the LZW algorithm. But after the LZW, does it run a Huffman or any other algorithm? And, if not, do other compression programs such as WinRAR, WinACE, etc, which claim better compression ratios, utilize a second algorithm, like Huffman's?

Respectfully,

Demosthenes

[glc]

I think Winzip follows PKZIP conventions, whatever they are.

[doctorgonzo]

Apparently WinRAR uses an algorithm of their own making: http://www.rararchiver.com/winrar.html

[Statica]

http://www.compression.ca/act-index.html

[Demosthenes]

Wow, I missed that page in my searching, Statica, but a very nicely done page. Is anyone else interested in what winzip is doing?

Now, obviously it does not run all these algorithms on one file, so how does it decide? Does it compare file extensions and compare to a listing for best algorithm, does it run a preprocessing algorithm, and when and how does it know when to run a second algorithm? I will be looking, but perhaps you or someone will find these answers before me.

Respectfully,

Demosthenes