Extracting winzip11 archives



  • is it a known issue that files from winzip11 archives (compressed using the “optimized for best compression” option) cannot be extracted with PA 10.2 b4?

    it won’t even acknowledge the problem. if i ask it to test the archive, it tests only one file in it and report the archive is valid. it extracts only that file no matter what i do.



  • @yoniy0:

    compressed using the “optimized for best compression” option

    So what compression is it using?
    If Bzip2 or PPMD then PA does not support that compression format in a Zip file!


  • conexware

    yep, it wont work since it is not actually an zip archive. WinZip added their own formats to zip and it is not compatible with PKWARE standards.



  • @spwolf:

    yep, it wont work since it is not actually an zip archive. WinZip added their own formats to zip and it is not compatible with PKWARE standards.

    Actually, not true.

    The latest PK app note includes both PPMd and BZip2 as compression methods. Their latest software also supports BZip2 as a compression method. Although PPMd at this stage seems to be excluded.

    Sooner or later, your lack of support for these methods will begin to impact your product.


  • conexware

    @Razputin:

    Actually, not true.

    The latest PK app note includes both PPMd and BZip2 as compression methods. Their latest software also supports BZip2 as a compression method. Although PPMd at this stage seems to be excluded.

    Sooner or later, your lack of support for these methods will begin to impact your product.

    it is exactly what I said. They added their own formats to zip specifications to make everyone else incompatible.

    It is as if 7zip wasnt 7z, but author adding lzma compression to zip format. Would that be fine? I dont think so.

    p.s. isnt there also sound compression format in WZ as well? 🙂



  • @spwolf:

    it is exactly what I said. They added their own formats to zip specifications to make everyone else incompatible.

    It is as if 7zip wasnt 7z, but author adding lzma compression to zip format. Would that be fine? I dont think so.

    p.s. isnt there also sound compression format in WZ as well? 🙂

    Well actually, the zip specification does allow LZMA as a compression method just like it allows PPMd.

    It’s called progress.

    All the compression methods are documented and there is nothing stopping you from supporting them. Unless, of course the 3rd party compression engine that you are using, makes this difficult. It’s a competitive world out there, and unless you are happy with the proprietary WinRar format (PPMd based) becoming a standard, then you will have to get used to newer and better compression methods for zip emerging now and again.

    At least they are free to implement!


 

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