archiver : compression type dependent on filetype

[Alain]

Hi

Is there a freeware file archiver that changes it's "compression
effort" depending on the filetype?

I have a substantial amount of jpg's and rather not wait for
"compressing" those with 1%.

Of course best a "know format" zip64, 7zip, ... (or zip where the total
archive size can be more than 4Gb.)


Alain

 

[Onno Tasler]

Alain scribebat:

I have a substantial amount of jpg's and rather not wait for
"compressing" those with 1%.

You won't be able to compress JPEGs much further -- they are already
tensely compressed. If the original compression had not been done very
badly, you won't get more than 2 or 3 % off.

 

[Alain]

Alain scribebat:

You won't be able to compress JPEGs much further -- they are already
tensely compressed. If the original compression had not been done very
badly, you won't get more than 2 or 3 % off.

Yes I know, that's why I'm looking for an archiver that store's jpg's or
just does a very minimal compression on those.

Using a minimal compression has the advantage that the archiver can
learn all filetypes and learns from it's own errors (aka compress a file
only very lightly and still get a decent compression -> should have been
done more thorough).

Alain

 

[Onno Tasler]

Alain scribebat:

Yes I know, that's why I'm looking for an archiver that store's jpg's or
just does a very minimal compression on those.

For storage, TAR is a good choice. Most archivers can create it and it can
create extremely big archives.

Using a minimal compression has the advantage that the archiver can
learn all filetypes and learns from it's own errors

Well, you'd need a compression algorithm with an AI for that. I doubt that
such a thing exists. MP3 and JPEG, FLAC and PNG are already optimized
compression algorithms for certain purposes; and creating an optimized
compression for an already optimized compression seems quite odd.

 

[Alain]

Alain scribebat:

For storage, TAR is a good choice. Most archivers can create it and it can
create extremely big archives.

Basicly I want one that compresses most files good (aka makes a big
effort for it), but doesn't take time on filetypes that aren't going to
compress anyway (like gif,zip,png,jpg,7z etc)

Well, you'd need a compression algorithm with an AI for that. I doubt that
such a thing exists. MP3 and JPEG, FLAC and PNG are already optimized
compression algorithms for certain purposes; and creating an optimized
compression for an already optimized compression seems quite odd.

Nope I'm fully aware that those filetypes are almost not worth trying,
so I would like an archiver that doesn't spend -much- time on it. Isn't
that much AI. If a filetype compresses less than 10% use a fast
compressing option next time, lees that 5% use a very fast one. Can
even be a hardcoded list to compress with a fast version..

With zip levels : do a 9 on all files, execept certain filetypes --> use
only 1.


Alain

 

[Duddits]

Yes I know, that's why I'm looking for an archiver that store's jpg's or
just does a very minimal compression on those.

AFAIK, the only archiver that comes close to what you want is $ware Winrar
:-(

regards

Dud
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A Day in which you spend the entire day swimming upstream
only to get screwed and die in the end.