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Topic: Better Zip Compression (Read 39352 times) previous topic - next topic
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Better Zip Compression

A program, distributed under the GNU LGPL, called 7-zip can compress to zip at higher ratio - www.7-zip.org.

cdcopy.zip - 2178181 bytes - original downloaded from www.cdcopy.sk
cdcopy.zip - 2123019 bytes- packed using 7-zip
cdcopy.7z - 1834760 bytes*- in 7z format
cdcopy.exe - 1906952 bytes* - SFX 7z format

cdex_150b7_enu.zip - 1815979 bytes
cdex_150b7_enu.zip - 1808502 bytes
cdex_150b7_enu.7z - 1779701 bytes*
cdex_150b7_enu.exe - 1851893 bytes*

Conclusion: 7z format is best, ZIP created by 7-zip is smaller than zip created with any other program. SFX 7z is sometimes smaller than normal ZIP.

If you want to publish many *.ZIP files on slow, popular server (e.g. rarewares) use 7-zip ZIP and consider switching to 7z format.

* - You can increse compression ratio by changing value of special parameters like dictionary size for LZMA, number of fast bytes for LZMA etc.

PS. For UPX users: use latest UPX 1.24 from http://upx.sourceforge.net/ with "--best" setting.

UPX forum: http://upx.sourceforge.net/phpBB/index.php

Better Zip Compression

Reply #1 –
I been using this program for awhile now, but its hard to get the 7z format widely supported. But I recommend you Zip with the 7z program cause it saves some space and since bandwidth is valuable on the net.
-=MusePack... Living Audio Compression=-

Honda - The Power of Dreams

Better Zip Compression

Reply #2 –
Can it be decoded with winzip?

How does it compare to ACE?

Better Zip Compression

Reply #3 –
The Zip portion can be decoded by WinZip, but the 7z function cannot. You need to use its own decoder program.

I don't know if it is better than ACE compression though, I never used 7z or ACE compression extensively.
-=MusePack... Living Audio Compression=-

Honda - The Power of Dreams

Better Zip Compression

Reply #4 –
ACE 2.X and RAR 3.X are always better than any ZIP.
7zip has better compression ratio than RAR or ACE, but not always.

7-zip can use multiple compression methods. One of loseless WAV compressors will be added to 7-zip. Author of 7-zip told me, that he can`t use Monkeysaudio - it`s not GNU compatible, but he found another good compressor. We`ll see...

Better Zip Compression

Reply #5 –
02/09/24  11:23 AM        1,692,185 cdex_150b7_enu.rar
02/09/24  11:30 AM        1,485,313 cdcopy.rar

Better Zip Compression

Reply #6 –
RAR's all the way bebe!

Better Zip Compression

Reply #7 –
Improving zip using an incompatible format with very small compression advantage is pretty much pointless.

Using a different (widely available) format with even better compression ratios would be the way to go.

Just look how bz2 outperforms zip on source code.

Better Zip Compression

Reply #8 –
7-Zip is indeed impressive...

cdcopy.ace: 1 468 274 bytes
cdcopy.7z : 1 378 688 bytes

cdex_150b7_enu.ace: 1 717 443 bytes
cdex_150b7_enu.7z : 1 677 803 bytes

Free program and beats the competitors, nice.

Better Zip Compression

Reply #9 –
zip compression:

  1-cdcopy.zip - 2178181 bytes - original downloaded from www.cdcopy.sk
  2-cdcopy.zip - 2123019 bytes - packed using 7-zip (using Maximum preset)
  3-cdcopy.zip - 2121786 bytes - packed using 7-zip (with extra setting..)
        just copy/paste this into parameters:  fb=255 pass=4
  4-cdcopy.zip - 2121686 bytes - repacked using ADVZIP.exe (based on 7-zip zip..)
        this is done for stage 3

RAR compression:
  5-cdcopy.rar - 1488192 bytes - packed with v3.0

ACE compression:
  6-cdcopy.ace -1458702 bytes - packed with v2.22

CAB compression:
  7-cdcopy.cab -1526889 bytes - packed with mscab.exe v0.61

7z  compression:
  8-cdcopy.7z  -1378661 bytes - packed with 7-zip (using maximum preset)
  9-cdcopy.7z  -1342416 bytes - packed with 7-zip with extra settings..
        just copy/paste the following into parameters:

0=BCJ2 1=LZMA 2=LZMA 3=LZMA b0:1 b0s1:2 b0s2:3 1fb=255 2fb=255 3fb=255

so you can see that 7z win easily .. don't forget that 7-zip has extra parameters for users that need more compression (of course advanced users..)

the zip implementation in 7-zip has provided more reduction in any format that uses zip-compression.. for example (zip,png,mng,tiff,....)

For now there is tools for using 7-zip (zip) implementation for:
1-zip  (advzip.exe)
2-png  (advpng.exe)
3-mng (advmng.exe)

for these tools go here http://advancemame.sourceforge.net/scan-readme.html
...

Better Zip Compression

Reply #10 –
sorry i've forget a small thing..

when using 7-zip (7z) format always let "solid archive" ON so it can work better..all my tests included that..

BTW: winace, winrar uses SOLID ARCHIVE by default..

Better Zip Compression

Reply #11 –
Compression is fun.

I hadn't tried 7-zip since it performed so badly on the ACT test suite.  Perhaps it's worth a try now.

-h

Better Zip Compression

Reply #12 –
Quote
sorry i've forget a small thing..

when using 7-zip (7z) format always let "solid archive" ON so it can work better..all my tests included that..

BTW: winace, winrar uses SOLID ARCHIVE by default..

Nopes

You have to tick "solid archieve" in winrar to make it solid

btw does 7zip have context menu extraction ? i would hate to have to open a programs just to extract or compress
Sven Bent - Denmark

Better Zip Compression

Reply #13 –
Quote
Quote
sorry i've forget a small thing..

when using 7-zip (7z) format always let "solid archive" ON so it can work better..all my tests included that..

BTW: winace, winrar uses SOLID ARCHIVE by default..

Nopes

You have to tick "solid archieve" in winrar to make it solid

btw does 7zip have context menu extraction ? i would hate to have to open a programs just to extract or compress

yes it has contect menu options.

Better Zip Compression

Reply #14 –
7zip indeed does compress better than winrar, but imo its performance is unacceptable (on a p4 2.2 ghz).  Even the time on compressing a 30mb file is insane.  Winrar is a nice mix of speed and compression for most people.  7zip needs some more time in the oven before prime-time.

Better Zip Compression

Reply #15 –
Don't be ridiculous. 7zip does not compress better than RAR v3. Maybe only in rare cases such as this. And, RAR v3 has far better performence. (edited: check following posts )
Anyway, if you want to compress a text document to an AMAZINGLY AMAZING SMALL size, use RK. Damn... And also, RK is the best general compressor in the world, but has awful performence.
Audio compression for instance, using RK, is almost as good as Monkey's Audio, nearly identical, But again, bad performence.

http://compression.ca/act-sound.html a bit old though

Better Zip Compression

Reply #16 –
The 7z compressor is really damn cool.  Compression that can often beat rar and ace, and open source to boot!  Yes, it's slower than rar, but the 2.3 series is the first to offer 7z support.  2.2 and lower were "just" zip compressors.

sk1, the 7z compressor CAN compress better than rar 3.  For a good demonstration: hop over to Rarewares, and recompress everything with rar 3 and 7z.  Keep the smaller files.  You'll be tossing quite a few rar files.

If you want to see 7z handily spank lots of competition, test it on WinXP Visual Styles.  This appears to be more of a "When should I swich compression models?" issue than anything else, but the results are startling.

RK can really get stuff tighter than anything else out there, but you're really paying the price when it comes to time and RAM usage.  It's really scary when you go to decompress stuff later: it takes almost as long.

It'll be interesting to see how 7z does in the ACT.  (Note: The 2.0 version of 7-Zip that's in ACT now doesn't use 7z compression.)

Better Zip Compression

Reply #17 –
Yes, RK has HORRIBLE performence  i wouldn't recommend it for anything but text files.
And.. 7z, yes i guess i will check it out, maybe things have really changed since the last time i checked it out. I HOPE so..
Thanks.

Better Zip Compression

Reply #18 –
Quote
And.. 7z, yes i guess i will check it out, maybe things have really changed since the last time i checked it out. I HOPE so..

Holy fast moving thread Batman!

If you haven't tried the 2.3 betas: Yeah, it's changed a lot.

Now, if only it could get into a good GUI like PowerArchiver or UltimateZip.  QuickZip looks interesting, but every time I try t out, I can never get it to work quite the way I want to.

Better Zip Compression

Reply #19 –
I agree, the GUI is not nice at ALL . But i can live with that for one file format i guess . I'll still be using WinRAR for all other archives except for compressing zips.
And, yes, i've tested the 7z compression with some stuff and it actually is better than RAR. About audio i still don't know though, i don't think it'll beat RAR at audio compression.
The compression speed is pretty slow (edited: not pretty slow, more like annoyingly slow ), but who cares, the extraction is very reasonable!
So.. Things HAVE changed .
Moving to 7z. 7z from now on.

Better Zip Compression

Reply #20 –
Hey, I thought that I was the only one who used this program. I like it because its open-source and simple. What more do you need? I don't think that the 7z format is going to get too popular though. Maybe people could use the SFX 7zs though.

Better Zip Compression

Reply #21 –
I thought about doing this, but decided against it from the advice of another person. If using SFX make sure the archive are left on CD-Rs or on a totally secure system, because imagine if a virus managed to worm its way onto your system. Wouldn't that be the craps if your files were damaged! NOT HAPPY!

For personal backups 7z is fine, but when it comes to distribution of the files, it becomes a hassle.
-=MusePack... Living Audio Compression=-

Honda - The Power of Dreams

Better Zip Compression

Reply #22 –
Ardax:

Quote
Now, if only it could get into a good GUI like PowerArchiver or UltimateZip.


I'm perfectly happy with 7Zip's "GUI" (it's no real GUI as you know, it's just a modified Explorer window, and I like that). The only thing that annoys me is this bug - is anyone else experiencing this?

Also it would be nice if the view options were saved, so I can have a detailed view by default, and if the last used directory was saved. Apart from that, it's a nice program though. No mess, no fuss.

Better Zip Compression

Reply #23 –
I've been using 7zip for quite some time now, but only for the increased compression for .zip-files.

What would be interesting, is how it compares to tar+bzip2, which is also open-source. Like bzip2 vs 7z vs rar3 ?

Edit:

Did some tests: Packed my folder of Nero, uncompressed = 29 625 456 bytes.

10 363 306 NERO.RAR
10 365 307 NERO.7z
10 723 238 NERO.ACE

Command used for 7z was: 7zn a -r -t7z -mx NERO.7z
I don't know all the switches so 7z could probably do much better...

What worries me is this (stated in 7-Zip.chm):

Quote
Current version of 7z format is beta, so it is possible that format will be changed in future.

Better Zip Compression

Reply #24 –
tar+bzip2 lags pretty far behind rar