Re: lzma Vs lzip ?
Le dimanche 09 août 2009 23:09:20, owens@netptc.net a écrit :
> >---- Original Message ----
> >From: thomas.preudhomme@celest.fr
> >To: debian-user@lists.debian.org
> >Subject: Re: lzma Vs lzip ?
> >Date: Sun, 9 Aug 2009 16:28:34 +0200
> >
> >>Le dimanche 09 août 2009 15:07:52, Mark a écrit :
> >>> Thomas Preud'homme wrote:
> >>> > Dead list,
> >>>
> >>> I know I look like crap, but it's just an hangover.. I'm not dead
> >
> >yet :)
> >
> >>> > I've just discovered the package lzip whose description says:
> >
> >"Lzip is a
> >
> >>> > lossless data compressor based on the LZMA algorithm, with (..)
> >
> >a user
> >
> >>> > interface similar to the one of gzip or bzip2."
> >>> >
> >>> > I already have lzma installed, whose part of his description is:
> >
> >"This
> >
> >>> > package provides a gzip-like interface for the lzma program."
> >>> >
> >>> > So what is the difference between lzma and lzip ? Should I fill
> >
> >a bug
> >
> >>> > report with minor severity to ask a statement in long
> >
> >description about
> >
> >>> > differences between lzip and lzma ?
> >>>
> >>> You could file a bug-report regarding the description, but.. we
> >
> >are
> >
> >>> talking about two different packages. In the lzip description it
> >
> >says:
> >>> "based on". Only that is enough to either try the package and make
> >
> >up
> >
> >>> your mind.
> >>> If the description would be false, and the gip-like interface
> >
> >would not
> >
> >>> exist, it might be interesting to start a debate to sort the
> >
> >difference
> >
> >>> in opinion.
> >>>
> >>> But, then again.. it is your call. Personally, I am not bothered
> >
> >by this
> >
> >>> sales talk.
> >>>
> >>> ,Mark
> >>
> >>Ok I installed lzip and I'll try on a big file and compare time to
> >
> >compress and
> >
> >>decompress but I think it's the same algorithm. One difference I see
> >
> >is that
> >
> >>the default extension for compressed file in lzma is lzma and the
> >
> >default in
> >
> >>lzip is lz. IIRW, lz is the recommanded extension because lzma is
> >
> >for the
> >
> >>algorithme (like gzip / gz and bzip2 / bz).
> >>
> >>Best regards,
> >>
> >>Thomas Preud'homme
>
> IIRC the lzip is based on the original Lempel-Ziv algorithm (from
> 1977)and as do most follow-ons, purports to have a better compression
> ratio and more rapid decoding. Unfortunately as do all such
> algorithms, the efficiency and speed depend on the type and
> correlation of the data being (de)compressed, so trying it on a
> single large file will probably not give you any clear indication.
> Larry
Do you suggest that lzma is not based on Lempel-Ziv algorithm ?
Indeed I looked in the man and found this :
LZMA (Lempel-Ziv-Markov chain-Algorithm) is an improved version of famous LZ77
compression algorithm. It was improved in way of maximum increasing of
compression ratio, keeping high decompression speed and low memory
requirements for decompressing.
But they can still claimed to be based on the original Lempel-Ziv algorithm.
It has just been improved.
>
> listmaster@lists.debian.org
Thanks for the answer.
Thomas Preud'homme
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