I have some general questions about compression.

I don't know much about different platforms. Is the .zip format accessible
on all platforms? I always zip all my scene files before I upload them to my
website, but does that exclude some people from using them?

If .zip is universally supported I have a question about mesh compression:
what is the reason for the compression used by pcm and mesh2? Zipping a mesh
file is more efficient than using any of those formats, and a zipped regular
mesh is even smaller than a zipped pcm or mesh2.

I have two guesses myself:
1) Zip is not universally supported.
2) The file size while sending the mesh over the net is not the reason for
compression, but rather the file size on the local HD.

Ignorantly,

Rune
--
\ Include files, tutorials, 3D images, raytracing jokes,
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Rune wrote:
> 
> I have some general questions about compression.
> 
> I don't know much about different platforms. Is the .zip format accessible
> on all platforms? I always zip all my scene files before I upload them to my
> website, but does that exclude some people from using them?
> 

I think ZIP is quite universal, don't know about Macs, but DOS, Windows,
OS/2 and most unix'es are ok.  C-source for ZIP is available, so there
should be some version on most platforms.  TGZ (.tar.gz) is also widely
supported, but it's much less common on the Windows platforms, so it would
not be such a good idea.  BTW, it's much more efficient when packing a lot
of smaller files.  

I personnaly don't see much need to compress single pov code files, since
otherwise you can directly view them and have less work when downloading.

Christoph

-- 
Christoph Hormann <chr### [at] gmxde>
IsoWood include, radiosity tutorial, TransSkin and other 
things on: http://www.schunter.etc.tu-bs.de/~chris/

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Rune wrote:

> If .zip is universally supported I have a question about mesh compression:
> what is the reason for the compression used by pcm and mesh2?

Pcm and mesh2 are text formats, not binary, which makes them portable and
editable, which are too good reasons. I also guess that zip support is not
royaltee-free (I could be wrong).

G.

--

**********************
http://www.oyonale.com
**********************
Graphic experiments
Pov-ray gallery

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There is shareware for the Mac that can open .zip files.

Josh

Christoph Hormann wrote:

> Rune wrote:
> >
> > I have some general questions about compression.
> >
> > I don't know much about different platforms. Is the .zip format accessible
> > on all platforms? I always zip all my scene files before I upload them to my
> > website, but does that exclude some people from using them?
> >
>
> I think ZIP is quite universal, don't know about Macs, but DOS, Windows,
> OS/2 and most unix'es are ok.  C-source for ZIP is available, so there
> should be some version on most platforms.  TGZ (.tar.gz) is also widely
> supported, but it's much less common on the Windows platforms, so it would
> not be such a good idea.  BTW, it's much more efficient when packing a lot
> of smaller files.
>
> I personnaly don't see much need to compress single pov code files, since
> otherwise you can directly view them and have less work when downloading.
>
> Christoph
>
> --
> Christoph Hormann <chr### [at] gmxde>
> IsoWood include, radiosity tutorial, TransSkin and other
> things on: http://www.schunter.etc.tu-bs.de/~chris/

--
Josh English -- Lexiphanic Lethomaniac
eng### [at] spiritonecom
The POV-Ray Cyclopedia http://www.spiritone.com/~english/cyclopedia/

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I beleive you're talking about two differnet compression needs. ZIP compresses
text files and encodes them in a way that is smaller than usual. Mesh
Compression, as I understand it, determines if a mesh has useless triangle and
removes them from the mesh, replacing them with larger triangles that fit the
job. So if a mesh was a grid of triangles that formed a flat square, it would
get replaced by two or three triangles.

More importantly, yes ZIP is a great method of making big files small, I don't
think POV-Ray can read the contents of a zip archive and use the code.

Josh
Rune wrote:

> I have some general questions about compression.
>
> I don't know much about different platforms. Is the .zip format accessible
> on all platforms? I always zip all my scene files before I upload them to my
> website, but does that exclude some people from using them?
>
> If .zip is universally supported I have a question about mesh compression:
> what is the reason for the compression used by pcm and mesh2? Zipping a mesh
> file is more efficient than using any of those formats, and a zipped regular
> mesh is even smaller than a zipped pcm or mesh2.
>
> I have two guesses myself:
> 1) Zip is not universally supported.
> 2) The file size while sending the mesh over the net is not the reason for
> compression, but rather the file size on the local HD.
>
> Ignorantly,
>
> Rune
> --
> \ Include files, tutorials, 3D images, raytracing jokes,
> / The POV Desktop Theme, and The POV-Ray Logo Contest can
> \ all be found at http://rsj.mobilixnet.dk (updated January 6)
> / Also visit http://www.povrayusers.org

--
Josh English -- Lexiphanic Lethomaniac
eng### [at] spiritonecom
The POV-Ray Cyclopedia http://www.spiritone.com/~english/cyclopedia/

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The .zip file format seems pretty universal...the preferred Mac format 
is StuffIt (.sit), but StuffIt Expander can open .zip files, and there 
are other shareware/freeware programs to decompress them. Linux and Unix 
systems also have software to open them.

However, they serve different needs...compressed meshes are just a file 
format that takes up less space while storing the same data, .zip files 
are archived files packed into a single file, usually for storage, 
backup, or transfer to another system, not for general use. Your 
question is similar to asking why there is a PNG or compressed TGA 
format when you can simply .zip up a PPM or plain TGA.

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><

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> I don't know much about different platforms. Is the .zip format accessible
> on all platforms? I always zip all my scene files before I upload them to
my
> website, but does that exclude some people from using them?

if your going toi use compression - and your should - zip is probably your
best bet, its about the closest there is to a 'standard'

much better to use zip than say RAR or ACE...


--
Rick

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Rune wrote:
> 
> I have some general questions about compression.
> 
[snip]

These are two different things.
The mesh compressor is specifically optimized for meshes; I believe it does
things like store coplanar faces as one larger face and maybe keep a separate
list of faces and vertices so coincident vertices are not duplicated (all this
is just my guess, of course).
ZIP and similar compressors use a generic algorithm; it basically looks for
recurring "patterns" in the input file and replaces the duplicates with pointers
to a "library of phrases".
POV can (with appropriate macros) read PCM files directly. ZIP files must first
be unpacked. I suppose it might be possible to make POV unpack and read zipped
files internally; and it shouldn't create serious portability issues. Whether or
not it would be worth the effort, I don't know.
Anyway, if you really want the smallest possible file size, first pass the mesh
through the mesh compresson and then zip it - you'll have the best of both
worlds.

-- 
Margus Ramst

Personal e-mail: mar### [at] peakeduee
TAG (Team Assistance Group) e-mail: mar### [at] tagpovrayorg
Home page http://www.hot.ee/margusrt

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"Margus Ramst" wrote:
> The mesh compressor is specifically optimized for meshes;
> ZIP and similar compressors use a generic algorithm;

But my point was that zip is far more effective.

> POV can (with appropriate macros) read PCM files directly.
> ZIP files must first be unpacked.

Yes, I think this is the real reason that PCM files are better.

> Anyway, if you really want the smallest possible file size,
> first pass the mesh through the mesh compresson and then zip
> it - you'll have the best of both worlds.

No, actually a zipped regular mesh is quite a bit smaller than a zipped PCM.
The reason is the separate lists of faces and vertices, which means that
there's less repeats of data for the zipper to work with.

Thanks you all for the replies!

Rune
--
\ Include files, tutorials, 3D images, raytracing jokes,
/ The POV Desktop Theme, and The POV-Ray Logo Contest can
\ all be found at http://rsj.mobilixnet.dk (updated January 6)
/ Also visit http://www.povrayusers.org

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Rune <run### [at] inamecom> wrote:
> I have some general questions about compression.
>
> I don't know much about different platforms. Is the .zip format accessible
> on all platforms? I always zip all my scene files before I upload them to
my
> website, but does that exclude some people from using them?
>
> If .zip is universally supported I have a question about mesh compression:
> what is the reason for the compression used by pcm and mesh2? Zipping a
mesh
> file is more efficient than using any of those formats, and a zipped
regular
> mesh is even smaller than a zipped pcm or mesh2.
>
> I have two guesses myself:
> 1) Zip is not universally supported.
> 2) The file size while sending the mesh over the net is not the reason for
> compression, but rather the file size on the local HD.

This is pretty much the case - ZIP may be an unofficial standard, but it's
not guaranteed to be available on all platforms, and to use the zipped file
you have to unzip it first (so the unzipped file plus the zipped file means
the disk space required while using the file is actually larger than the
uncompressed file!).

It was for these reasons that Warp first approached me with the idea of
creating a portable text format for meshes that could reduce the file size
without reducing functionality.  As it turned out, the format we eventually
developed offers *increased* functionality (deformations, hair growth,
subdivision surfaces, etc.) using the Compressed Mesh macros I and others
were able to create for the PCM format.

To clarify, Warp's Mesh Compressor does not (currently) reduce the number of
triangles in a mesh by replacing multiple, smaller faces with larger
triangles.  Instead it works like the ZIP format, reducing the amount of
repeated information in a file.  It does this firstly by removing common
elements (the triangle keyword, angled and curly brackets), and also by
searching for vertices shared by multiple triangles.

Certainly, it's not the most compact text format possible.  Warp and I
actually tried more compact forms, replacing digits with characters and
such, but found that parsing speed became unacceptably slow.  So, like many
things in POV, what we ended up with is a compromise that works at a
reasonable speed.

The mesh2 format works on the same principle as the PCM format, which (as I
understand it) is also found in other software that uses triangle mesh
surfaces.  In the end, the different compression formats have different
uses - if you have the disk space, an uncompressed mesh might the fastest
and easiest if you don't want to do anything fancy with it, whereas the PCM
gives you direct control over each vertex, and the mesh2 allows easy
conversion from other formats, such as UV-mapped models.

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Christoph Hormann wrote:

> I personnaly don't see much need to compress single pov code files, since
> otherwise you can directly view them and have less work when downloading.

Yeah, I hate when single small files are zipped up (some with little size benefit
anyway). Then I have to open explorer and unzip it, and PKZip for windows is
incredibly slow to load up and close. Sometimes it's used more as a packaging tool
than a compression tool, which is ok I guess, but if there's an alternative use
it. (Like TI calculator games, just make an .86g or .89g or whatever file).

--
David Fontaine  <dav### [at] faricynet>  ICQ 55354965
My raytracing gallery:  http://davidf.faricy.net/

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Gilles Tran wrote in message <3A5F7662.D8DFB100@inapg.inra.fr>...
>Pcm and mesh2 are text formats, not binary, which makes them portable and
>editable, which are too good reasons. I also guess that zip support is not
>royaltee-free (I could be wrong).


Zip support is free.

--
Mark

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On Fri, 12 Jan 2001 17:51:41 +0100, "Rune" <run### [at] inamecom>
wrote:

>I have some general questions about compression.
>
>I don't know much about different platforms. Is the .zip format accessible
>on all platforms? 

Yes. Well, on 16- and 32-bit platforms, that is :)

>I always zip all my scene files before I upload them to my
>website, but does that exclude some people from using them?

No.

>If .zip is universally supported I have a question about mesh compression:
>what is the reason for the compression used by pcm and mesh2? 

The file gets a) smaller b) better organised and c) readable by POV's
#read directive, which allows for some neat effects such as shown by
Chris' macros.

>Zipping a mesh file is more efficient than using any of those formats, 
>and a zipped regular mesh is even smaller than a zipped pcm or mesh2.

zip uses a Leimpfell-Ziff-Huffman compression algorithm very suitable
for text files. I don't recall if hash tables were a courtesy of LZW
but if not, this would be the explanation. A pcm file reorganises the
data into a more compact form with some data loss.

>I have two guesses myself:
>1) Zip is not universally supported.
>2) The file size while sending the mesh over the net is not the reason for
>compression, but rather the file size on the local HD.

Both guesses are off-the-point as the main purpose of the pcm file
format is to provide the POV parser with access to the mesh component
(vertices, faces, normals, uv indices etc.)


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] vipbg
TAG      e-mail : pet### [at] tagpovrayorg

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On Fri, 12 Jan 2001 23:10:30 -0000, "Rick [Kitty5]" <ric### [at] kitty5com>
wrote:

>if your going toi use compression - and your should - zip is probably your
>best bet, its about the closest there is to a 'standard'
>
>much better to use zip than say RAR or ACE...

RAR is available for DOS, Windows, Mac and *x. What more is there? :)


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] vipbg
TAG      e-mail : pet### [at] tagpovrayorg

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David Fontaine wrote:
> 
> Yeah, I hate when single small files are zipped up (some with little size benefit
> anyway). Then I have to open explorer and unzip it, and PKZip for windows is
> incredibly slow to load up and close. Sometimes it's used more as a packaging tool
> than a compression tool, which is ok I guess, but if there's an alternative use
> it. (Like TI calculator games, just make an .86g or .89g or whatever file).
> 

A fast solution for expanding ZIP with the windows explorer is to
associate them with a small batch file invoking regular unzip.exe.  I have
two menu items in the context menu, one for viewing, one for expanding in
a subdirectory named filename.zip.out 

Christoph

-- 
Christoph Hormann <chr### [at] gmxde>
IsoWood include, radiosity tutorial, TransSkin and other 
things on: http://www.schunter.etc.tu-bs.de/~chris/

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"Peter Popov" wrote:
> Both guesses are off-the-point as the main purpose of the
> pcm file format is to provide the POV parser with access
> to the mesh component (vertices, faces, normals, uv indices
> etc.)

I was not asking for the reason for the file format itself, but for the
compression used by that file format, so I think my second guess is not so
much off-the-point after all.

Thanks for the reply anyway. :)
Nice to know that .zip can be used by everybody.

Rune
--
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"Chris Colefax" wrote:
> Rune wrote:
> > what is the reason for the compression used by pcm and mesh2?
> >
> > I have two guesses myself:
> > 1) Zip is not universally supported.
> > 2) The file size while sending the mesh over the net is not
> >    the reason for compression, but rather the file size on
> >    the local HD.
>
> This is pretty much the case - ZIP may be an unofficial standard,
> but it's not guaranteed to be available on all platforms, and to
> use the zipped file you have to unzip it first (so the unzipped
> file plus the zipped file means the disk space required while
> using the file is actually larger than the uncompressed file!).

Thank you for clarifying that.

> an uncompressed mesh might the fastest and easiest if you don't
> want to do anything fancy with it, whereas the PCM gives you
> direct control over each vertex, and the mesh2 allows easy
> conversion from other formats, such as UV-mapped models.

I've been experimenting with my own mesh macros, but I've encountered some
problems. The biggest one is about the uv_vectors in mesh2. See p.u.p.

My idea is to create a new format that combines the best from PCM and mesh2.
(It would not support bicubic_patches though.)

Rune
--
\ Include files, tutorials, 3D images, raytracing jokes,
/ The POV Desktop Theme, and The POV-Ray Logo Contest can
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I would like to add something to Chris' comments:

  The advantage of the PCM and mesh2 formats over a zipped mesh format is
that the formers can be directly read from the file itself.
  In order to read a mesh inside a zip file you would have to first
decompress the zip file. This is even worse than just having the uncompressed
version: You don't only have the uncompressed version of the mesh, but you
also have the zipped version, thus requiring more disk space.
  With the PCM/mesh2 format you don't need any extra disk space since you
can directly read the file into povray (with a macro in the first case
and directly in the second case).

  The advantage of mesh2 over PCM is that reading a mesh2 is a lot faster
(it's even faster than reading a mesh).
  The advantage of the PCM format is that you get extra functionality
(such as those mentioned by Chris).

-- 
char*i="b[7FK@`3NB6>B:b3O6>:B:b3O6><`3:;8:6f733:>::b?7B>:>^B>C73;S1";
main(_,c,m){for(m=32;c=*i++-49;c&m?puts(""):m)for(_=(
c/4)&7;putchar(m),_--?m:(_=(1<<(c&3))-1,(m^=3)&3););}    /*- Warp -*/

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Rune <run### [at] inamecom> wrote:
: My idea is to create a new format that combines the best from PCM and mesh2.

  We have been planning for an extended PCM format which will support
uv-mapping and per-triangle/per-vertex texturing (and even texture definitions
inside the PCM file).
  The format is quite finished, but I have been "coding" support for it into
the compressor for the last half year (that is, I haven't done anything ;) ).

-- 
char*i="b[7FK@`3NB6>B:b3O6>:B:b3O6><`3:;8:6f733:>::b?7B>:>^B>C73;S1";
main(_,c,m){for(m=32;c=*i++-49;c&m?puts(""):m)for(_=(
c/4)&7;putchar(m),_--?m:(_=(1<<(c&3))-1,(m^=3)&3););}    /*- Warp -*/

Post a reply to this message

Josh English <eng### [at] spiritonecom> wrote:
: Mesh
: Compression, as I understand it, determines if a mesh has useless triangle and
: removes them from the mesh, replacing them with larger triangles that fit the
: job.

  My compressor doesn't do this (you'll have to use a SSS variant if you
want that functionality). It just writes a mesh in a more compact format,
that's it. It preserves all the triangles (well, it can remove degenerate
triangles if asked).

-- 
char*i="b[7FK@`3NB6>B:b3O6>:B:b3O6><`3:;8:6f733:>::b?7B>:>^B>C73;S1";
main(_,c,m){for(m=32;c=*i++-49;c&m?puts(""):m)for(_=(
c/4)&7;putchar(m),_--?m:(_=(1<<(c&3))-1,(m^=3)&3););}    /*- Warp -*/

Post a reply to this message

Peter Popov <pet### [at] vipbg> wrote:
: RAR is available for DOS, Windows, Mac and *x. What more is there? :)

  I have zip, rar, lha, gzip and bzip2 (and other less known)
compression/decompression and arj decompression software in this machine
(I think they are all generic unix programs).
  I think that's mostly enough.

  (Btw, bzip2 compresses better in almost every case and faster in most
cases than any of the other compression softwares; I wonder why it isn't
more popular in Windows systems...)

-- 
char*i="b[7FK@`3NB6>B:b3O6>:B:b3O6><`3:;8:6f733:>::b?7B>:>^B>C73;S1";
main(_,c,m){for(m=32;c=*i++-49;c&m?puts(""):m)for(_=(
c/4)&7;putchar(m),_--?m:(_=(1<<(c&3))-1,(m^=3)&3););}    /*- Warp -*/

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Christoph Hormann wrote:

> A fast solution for expanding ZIP with the windows explorer is to
> associate them with a small batch file invoking regular unzip.exe.  I have
> two menu items in the context menu, one for viewing, one for expanding in
> a subdirectory named filename.zip.out

I thought you meant that that could be done with pkzip for windows. Time to go
redownload pkunzip DOS...

--
David Fontaine  <dav### [at] faricynet>  ICQ 55354965
My raytracing gallery:  http://davidf.faricy.net/

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David Fontaine wrote:
> 
> I thought you meant that that could be done with pkzip for windows. Time to go
> redownload pkunzip DOS...
> 

no, just plain unzip, for example:

ftp://ftp.info-zip.org/pub/infozip/WIN32/

Christoph

-- 
Christoph Hormann <chr### [at] gmxde>
IsoWood include, radiosity tutorial, TransSkin and other 
things on: http://www.schunter.etc.tu-bs.de/~chris/

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Christoph Hormann wrote:

> > I thought you meant that that could be done with pkzip for windows. Time to go
> > redownload pkunzip DOS...
> >
>
> no, just plain unzip, for example:
>
> ftp://ftp.info-zip.org/pub/infozip/WIN32/

Tnx, but I've already dl'ed pkzip dos 2.50 and made the batch file and set it to
default action. Too fast for ya. ;)

--
David Fontaine  <dav### [at] faricynet>  ICQ 55354965
My raytracing gallery:  http://davidf.faricy.net/

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David Fontaine wrote:
> 
> Tnx, but I've already dl'ed pkzip dos 2.50 and made the batch file and set it to
> default action. Too fast for ya. ;)
> 

Well, it is probably slower and cannot handle long filenames...

:-)

Christoph

-- 
Christoph Hormann <chr### [at] gmxde>
IsoWood include, radiosity tutorial, TransSkin and other 
things on: http://www.schunter.etc.tu-bs.de/~chris/

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"Warp" wrote:
> Rune wrote:
> : My idea is to create a new format that combines the
> : best from PCM and mesh2.
>
>   We have been planning for an extended PCM format
> which will support uv-mapping and per-triangle/per-vertex
> texturing (and even texture definitions inside the PCM
> file).
>   The format is quite finished, but I have been
> "coding" support for it into the compressor for the
> last half year (that is, I haven't done anything ;) ).

I'd be very interested in more information about this format.
More specifically the new format definition.

Rune
--
\ Include files, tutorials, 3D images, raytracing jokes,
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Christoph Hormann wrote:
> 
> David Fontaine wrote:
> >
> > Tnx, but I've already dl'ed pkzip dos 2.50 and made the batch file and set it to
> > default action. Too fast for ya. ;)
> >
> 
> Well, it is probably slower and cannot handle long filenames...
> 

I haven't used pk(un)zip 2.50 in ages, but I seem to remember it did
handle long file names properly.

-- 
Francois Labreque | Unfortunately, there's no such thing as a snooze
    flabreque     | button on a cat who wants breakfast.
        @         |      - Unattributed quote from rec.humor.funny
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Francois Labreque wrote in message <3A6119BF.6F0D307F@videotron.ca>...

>I haven't used pk(un)zip 2.50 in ages, but I seem to remember it did
>handle long file names properly.


Except under Windows NT.

Post a reply to this message

Christoph Hormann wrote:

> > Tnx, but I've already dl'ed pkzip dos 2.50 and made the batch file and set it to
> > default action. Too fast for ya. ;)
> >
>
> Well, it is probably slower and cannot handle long filenames...

But it can. As for speed, right now the biggest time-consumer is having to close the
DOS window.

--
David Fontaine  <dav### [at] faricynet>  ICQ 55354965
My raytracing gallery:  http://davidf.faricy.net/

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On 13 Jan 2001 13:42:51 -0500, Warp <war### [at] tagpovrayorg> wrote:

>Peter Popov <pet### [at] vipbg> wrote:
>: RAR is available for DOS, Windows, Mac and *x. What more is there? :)

>  I have zip, rar, lha, gzip and bzip2 (and other less known)
>compression/decompression and arj decompression software in this machine
>(I think they are all generic unix programs).

>  I think that's mostly enough.

I meant, what more was there, OS-wise :)
I also have uc3, yac, ain, 

>  (Btw, bzip2 compresses better in almost every case and faster in most
>cases than any of the other compression softwares; I wonder why it isn't
>more popular in Windows systems...)

The best compressor I've seen, compression-wise, is yac (Yet Another
Compressor). It was incredibly slow to compress, though (decompression
speed was normal). It was designed for BBS mail (anyone remember Blue
Wave? :) ) as it could do successive archiving. It was great as it
could only send you the part of the archive that you didn't have and
would join it seamlessly with your archive, regardless if the data
inside was a single file which has changed or many little files. It
was great at tracking changes.

ZIP ruled the DOS world until ARJ came out. After that RAR and UC2
offered better compression and AIN was basically a fast ARJ (with a
bit lower compression). ZIP came back with the invasion of the
Internet and long file names and Winzip seems to rule the Windows
world now. RAR is still used for downloads but you will mostly find it
in crackz/warez sites (I don't know why). As of bzip2... well... bzip2
is best at text files (as is lha, I've never seen anything better that
lha for compressing large volumes of ASCII) so that might have
something to do with it. I am not sure if it needs a 32-it envoronment
or large amounts of memory (like 1MB for a hash table / dictionary)
but that would explain why it was mostly *x-only for a long time.


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] vipbg
TAG      e-mail : pet### [at] tagpovrayorg

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Peter Popov <pet### [at] vipbg> wrote:
: bzip2 is best at text files

  bzip2 is best at everything I have tried. I have tried text files,
executable binary files, etc, and bzip2 always compresses considerably
better than the others, and pretty fast.

-- 
char*i="b[7FK@`3NB6>B:b3O6>:B:b3O6><`3:;8:6f733:>::b?7B>:>^B>C73;S1";
main(_,c,m){for(m=32;c=*i++-49;c&m?puts(""):m)for(_=(
c/4)&7;putchar(m),_--?m:(_=(1<<(c&3))-1,(m^=3)&3););}    /*- Warp -*/

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Rune <run### [at] inamecom> wrote:
: I'd be very interested in more information about this format.
: More specifically the new format definition.

  I'll write a detailed description (as always) when I have coded it... :)

-- 
char*i="b[7FK@`3NB6>B:b3O6>:B:b3O6><`3:;8:6f733:>::b?7B>:>^B>C73;S1";
main(_,c,m){for(m=32;c=*i++-49;c&m?puts(""):m)for(_=(
c/4)&7;putchar(m),_--?m:(_=(1<<(c&3))-1,(m^=3)&3););}    /*- Warp -*/

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On Sun, 14 Jan 2001 09:36:51 +0200, Peter Popov wrote:
>On 13 Jan 2001 13:42:51 -0500, Warp <war### [at] tagpovrayorg> wrote:
>
>>  (Btw, bzip2 compresses better in almost every case and faster in
>>most cases than any of the other compression softwares; I wonder why
>>it isn't more popular in Windows systems...)

What kind of data are you compressing? bzip2 is usually slower than zip
at compressing and about the same speed at uncompressing.

>ZIP ruled the DOS world until ARJ came out. After that RAR and UC2
>offered better compression and AIN was basically a fast ARJ (with a bit
>lower compression). ZIP came back with the invasion of the Internet

Zip is well-documented, patent-free, and there is an implementation with
a very lenient licence. This is probably the reason why it is used for
compression in almost all internet protocols and file formats of the
last few years. The fact that many Web servers are Unix machines and zip
is available on these machines, while other formats often are not, may
also have had some influence.

>As of bzip2... well... bzip2 is best at text files (as is lha, I've
>never seen anything better that lha for compressing large volumes of
>ASCII) so that might have something to do with it. I am not sure if
>it needs a 32-it envoronment or large amounts of memory (like 1MB for
>a hash table / dictionary) but that would explain why it was mostly
>*x-only for a long time.

bzip2 doesn't even exist for "a long time", AFAIK. It is certainly
younger than Windows95, so a 32-bit environment should not have been a
problem in in the Windows world.

	hp


-- 
   _  | Peter J. Holzer    | All Linux applications run on Solaris,
|_|_) | Sysadmin WSR       | which is our implementation of Linux.
| |   | hjp### [at] wsracat      | 
__/   | http://www.hjp.at/ |	-- Scott McNealy, Dec. 2000

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"Warp" wrote:
> Rune wrote:
> : I'd be very interested in more information about this format.
> : More specifically the new format definition.
>
> I'll write a detailed description (as always) when I have coded it... :)

But I *reeaally* want to know it now so I can come with comments and
suggestions in the development stage! :)

Rune
--
\ Include files, tutorials, 3D images, raytracing jokes,
/ The POV Desktop Theme, and The POV-Ray Logo Contest can
\ all be found at http://rsj.mobilixnet.dk (updated January 6)
/ Also visit http://www.povrayusers.org

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On Sat, 13 Jan 2001 22:37:54 -0600, David Fontaine wrote:
>Christoph Hormann wrote:
>
>> > Tnx, but I've already dl'ed pkzip dos 2.50 and made the batch file and set it to
>> > default action. Too fast for ya. ;)
>> >
>>
>> Well, it is probably slower and cannot handle long filenames...
>
>But it can. As for speed, right now the biggest time-consumer is having to close the
>DOS window.

Create a .pif file for it and associate your action with the pif file instead
of the bat file.

-- 
Ron Parker   http://www2.fwi.com/~parkerr/traces.html
My opinions.  Mine.  Not anyone else's.

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Ron Parker wrote:

> Create a .pif file for it and associate your action with the pif file instead
> of the bat file.

Yep. Way ahead of ya ;)

--
David Fontaine  <dav### [at] faricynet>  ICQ 55354965
My raytracing gallery:  http://davidf.faricy.net/

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Warp <war### [at] tagpovrayorg> writes:
>   bzip2 is best at everything I have tried. I have tried text files,
> executable binary files, etc, and bzip2 always compresses considerably
> better than the others, and pretty fast.

For the ultimate in comparisons... http://web.act.by.net/~act/

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