English Amiga Board - View Single Post

leonard · 13 September 2021, 22:24

Hi!

I recently released my LDOS Amiga trackload demo toolchain ( https://github.com/arnaud-carre/ldos ). Since my Atari version I always used Arj -m7 as data packer. It has very good packing ratio and reasonable depacking speed (can depack at floppy disk bandwidth)

This packer is maybe 20 years old now and I was investigating other packers to find a better one. But it seems I failed ( Please note I'm not talking about arithmetic coding packers like packfire-lzma or crinckler. Both are excellent packers (and awesome packing ratio) but decoding speed doesn't suit for LDOS. So I'm talking about all LZxx packers family.)

I tested:

UPX ( nrv2b )

apLib ( using apultra packing library to get best packing ratio )

nrv2x ( by Ross from this forum )

These three packers has almost the same packing ratio, sometimes better than arjm7 but sometimes worst. So as a test, I'm using my "shrinked on a floppy to death" demo: AmigAtari ( https://www.pouet.net/prod.php?which=85276 ). I also tested to re-build De Profundis demo ( https://www.pouet.net/prod.php?which=81081 ). And for both demos, all three packers have worst packing ratio than arjm7. ( for instance AmigAtari demo can't fit on floppy with any of these 3 packers)

So my question: any of you knows another packer I could test to replace Arjm7?

(btw Arjm7 is nice, my issue is that no one have the packer source code, so I would prefer to have integrated compression code in my toolchain )

13 September 2021, 22:24	#1
leonard Registered User Join Date: Apr 2013 Location: paris Posts: 133	Is there a better packer than arjm7? Hi! I recently released my LDOS Amiga trackload demo toolchain ( https://github.com/arnaud-carre/ldos ). Since my Atari version I always used Arj -m7 as data packer. It has very good packing ratio and reasonable depacking speed (can depack at floppy disk bandwidth) This packer is maybe 20 years old now and I was investigating other packers to find a better one. But it seems I failed ( Please note I'm not talking about arithmetic coding packers like packfire-lzma or crinckler. Both are excellent packers (and awesome packing ratio) but decoding speed doesn't suit for LDOS. So I'm talking about all LZxx packers family.) I tested: UPX ( nrv2b ) apLib ( using apultra packing library to get best packing ratio ) nrv2x ( by Ross from this forum ) These three packers has almost the same packing ratio, sometimes better than arjm7 but sometimes worst. So as a test, I'm using my "shrinked on a floppy to death" demo: AmigAtari ( https://www.pouet.net/prod.php?which=85276 ). I also tested to re-build De Profundis demo ( https://www.pouet.net/prod.php?which=81081 ). And for both demos, all three packers have worst packing ratio than arjm7. ( for instance AmigAtari demo can't fit on floppy with any of these 3 packers) So my question: any of you knows another packer I could test to replace Arjm7? (btw Arjm7 is nice, my issue is that no one have the packer source code, so I would prefer to have integrated compression code in my toolchain )