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Re: [PATCH] add pkzip support for gzio
From: |
Robert Millan |
Subject: |
Re: [PATCH] add pkzip support for gzio |
Date: |
Mon, 11 Aug 2008 23:29:01 +0200 |
User-agent: |
Mutt/1.5.13 (2006-08-11) |
On Mon, Aug 11, 2008 at 07:22:53PM +0200, Marco Gerards wrote:
> Hi,
>
> "y.volta" <address@hidden> writes:
>
> > i've made a little patch for pkziped ( deflate mode ) file. by
> > using this, we can have both gunzip and pkunzip supported: they have
> > only header different with the same file. ;-)
> >
> > please note, if your file is too small, pkzip will not compress it
> > but store the orginal data to the output file.
>
> Isn't this patented?
According to Wikipedia [1], the usual compression algorithm in ZIPs is the
deflate, same as gzip. I believe older variants use the LZW algorithm, but
the patents [2] for these have expired (at least in the US), and we happen
to be using it already in our LZMA (and LZO?) code.
[1] http://en.wikipedia.org/wiki/ZIP_(file_format)
[2] http://en.wikipedia.org/wiki/LZW#Patents
--
Robert Millan
The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and
how) you may access your data; but nobody's threatening your freedom: we
still allow you to remove your data and not access it at all."