updates

[ardax]

PowerArchiver Version: 11.50.49

I just got my first real .zipx file today…

…and I was unable to extract some of the files with a CRC error.

It turns out it was occurring on all the jpeg files. Opening the .zipx file up in PA and showing the “Method” column reveals “Unsupported” for all the jpeg files. I’m sure it has to do with the new compression method for jpeg files that WinZip added in 12.1. (I’m guessing it’s arithmetic coding, much like StuffIt added a while back?)

I ended up having to download the WinZip trial to unpack the files. Blech. Thank goodness for VirtualBox.

I can supply a sample archive, if you’d like.

[spwolf]

zipx jpeg algorithm extraction is still not in PA 2010… hopefully within a month we have that working as well. All we have to work off is pdf file for specs, to make it as hard as possible :)

[moles42]

you may or may not find this interesting…

http://expertester.wordpress.com/2009/07/02/winzip-winrar-7zip-winace-rematch/

[spwolf]

@moles42:

you may or may not find this interesting…

http://expertester.wordpress.com/2009/07/02/winzip-winrar-7zip-winace-rematch/

i can tell you a lot more info than some random person doing some random test :)

[spwolf]

like PA being only utility that can select different methods for 7zip compression in the same file at the same time (if it will compress text files with ppmd, other files with lzma).

Reason zip and zipx is worse, even if it has same actual algorithm support (lzma) is that it does not support solid archives, if it did, it would actually have better results than 7zip itself because it has dedicated wav and jpeg compression, together with ppmd and lzma that 7z uses.

[moles42]

useful info…thanks for the lesson boss…:)

[ViRi]

Is the ability to compress Jpg files Proprietary to Winzip or will PA have the ability as well?

Im slightly confused but Their 12.0 release had .Jpg compression and didnt change their format to zipx i believe. with 12.1 it was zipx if you compressed jpg without legacy or something?

[TBGBe]

@ViRi:

Is the ability to compress Jpg files Proprietary to Winzip or will PA have the ability as well?

Did you miss the first reply?
@spwolf:

zipx jpeg algorithm extraction is still not in PA 2010… hopefully within a month we have that working as well.

[spwolf]

change in extension to ZIPX is not due to new changes, just because people got confused with what exactly is ZIP as there are now 6-7 different compression algos inside.

[ViRi]

Sorry, i ment will PA be able to compress .Jpg the same way winzip does now as .zipx, at some point or just extract like .rar?

[spwolf]

@ViRi:

Sorry, i ment will PA be able to compress .Jpg the same way winzip does now as .zipx, at some point or just extract like .rar?

its doable, we will see, first we need to implement extract :)