Better archiver that LZX with small unarc tool

[Brian]

I'm searching for a better archiver than LZX with a small unarchive tool compatible with 68000 w/o FPU. I've looked into many options but they either don't compress as well as LZX or they compress better but their unarchive tool are huge and/or need huge library file(s) that the better compression doesn't compensate enough for (when it's data and compression tool that need to fit onto a single floppy).

Any suggestions or is LZX the best option?

[Brian]

http://aminet.net/package/util/arc/xz-utils

Main program with library is like 300K... not an option.

[Brian]

Then your only option is unrar.

http://aminet.net/package/util/arc/unrar-68k-amigaos-bin

Can't get RAR to compress better than LZX and the unrar executable is still too big.

[Brian]

Stupid question: Have you tried RAR's 'Create solid archive' option?

Also, try compressing executables and libraries with Power Packer to save more space.

To be hones probably not... if you could give me an compressionrate optimized command line sample for RAR I'd appreciate it.

I found Imploder (with merged library) to compress better than PowerPacker so used that to compress UnLZX ta about 13K but since LZX have best compression rate that these one the fly extraction options (and require no library) just about everything else get the LZX treatment.

Knowing LZX2 (.CAB) give better compression I had hoped to find a good implementation for the Amiga but still the extraction tool cabextract although it can be compressed to about 35K still require a 175KB library so the gain is lost.

[Brian]

Try crunching all everything in C: L: Libs: and Devs: with this.

http://aminet.net/package/util/shell/lzma-exe

Requiers 90KB program and a 215KB library to work... everything like that is already LZX compressed.

[Brian]

What are you trying to do exactly, and how much more space do you need? I assume everything must fit on a 880Kb formatted floppy? Perhaps it can still be done with just LZX.

Trying to fit something on a DD floppy that doesn't fit basicly so have skipped parts but am trying to minimze the amount of skipped parts as much as possible. It works as it is but if I could save some KB by using a different archiver I'd like to do that.

I know there are better compression out there but nothing seem to rival LZX with it comes to the size of it's extraction tool UnLZX Imploder compressed to 13KB with no external library needed and working on 68000 w/o FPU is impressive.

Basicly it's a question if I'm doing it right using LZX or if I have overlooked something (I don't think I have but would live to be proven wrong on this as it would meen freeing up some space for further improvements).

[Brian]

Indeed.  It would be useful to know exactly what he's trying to compress as one size does not fit all when it comes to compression.

Texts, pictures, executables etc... a general mix of things that LZX seem to to a good jobb of compress (about 60% i think). As said, I'm pleased with LZX's compression, I know LZX2 (.cab) compress it better by about 50KB but with extractiontool 4 times that it's not an option unless someone have 68000 compatible, library free, LZX2 extractor that takes less than 63KB.

[Brian]

7zip ?

Apart from the main program it also requier a 175KB library... not an option.

[Brian]

If you are only compresing for archiving/backup purposes why do you need to fit the unarchiver on the same floppy? You could create a single boot floppy with all the xad/xfd/xpk libs/decrunchers you need and use it to boot up and decrunch the stuff that is on your other disks.

Have you tried the '-3' argument with LHA btw?  Might shave of a few bytes here and there and be comparable to LZX.

Save your bitmaps as PNG, your photos as JPEG, your text and exes/libs/devices/handlers etc with XZ/NUKE/RAR/EPU (or whichever) and you should be able to fit a lot more on a floppy than just plain old LZX for everything.

It is not a question of backup purpose (but I don't want to alter the files). The project of mine require it to fit on a single self sustaining DD floppy.

So the question is simply if LZX is the best option (compression rate, extract tool size, CPU/NoLIB requirements)... looking at this thread I think I have that question answered but wanted to ask it to be sure.

[Brian]

Can you give us a bit more detail to work with then we might be able to provide better solutions for you.  i.e. What exactly is your project, what are it's goals/what are you trying to achieve as an end result?

I need an archiver optimized for compression rate (speed is not a priority) and need to work with mixed file types. The extraction tool has to work with just a 68000 w/o FPU and require no external libraries.

There is more data than actually fits unless the compression rate can somehow be increased. The data archived need to fit onto a single DD floppy together with the extraction tool hence the extraction tools size is a factor that has to be calculated with.

More info shouldn't really be necessary.

[Brian]

Yo, Brian - long time no see!

I assume you're unpacking something into RAM: and need something with a very small memory footprint in order to fit everything?

Hi!

Some is extracted to RAM: (startup files) so although small memory footprint is nice it isn't the biggest priority, compression rate is (together with extraction tool size).

[Brian]

Well obviously it is neccessary for me to know more so I can understand better or I wouldn't be asking would I?

Anyway, one thing you can try to increase the compression ratio is to first create a completely uncompressed archive with all the files you want inside it, then compress this single file at the highest compression rate with LZX.

It'll probably save you quite a few kilobytes. It's the same concept behind *.tar.gz on UNIX systems rather than gzipping each individual file.

Thanks for the suggestion, however since LZX support merging files it only saved me 1.2KB out of 1.7MB compared to letting LZX handle it all in one go, not worth it.

[Brian]

Try to increase the maximum merge size in LZX by using the -M option, like for example -M8000

Also make sure to use -3 compression as well.

If you create the archive on a Amiga with 68020 CPU or higher, you can also use the 68020 version of LZX which allows you to use -9 compression instead. This along with increasing the maximum merge size will give you the absolute max compression that can be achived with LZX.
The resulting archive can not be extracted with 68000 LZX since it doesn't support -9 (de)compression, but it will work fine with UnLZX

The above methods are the ones used on my Amiga911 disks.
http://amiga911maker.site11.com

Thanks for confirming these options are right. I'm use options "-e -f -F -m -M8000 -Qf -r -9" as I've found that to be the optimum options (yes I need empty archives), can you confirm these also (setting priority doesn't seem to change anything)?

Also compressing files from RAM: to RAM: seem to improve compression rate a bit, same goes for higher CPU speed (use WinUAE to get insane Mips/MFlops). Still LZX outputs size is a bit of a gamble... compressing same files a few times often result in different size archives. Removing files from the archive can sometimes result in a bigger archives etc.

[Brian]

StripHunk is only a valid option for uncompressed programs and libraries since the hunk structure seem to become invalid for crunchers after a strip.