What is JMA?

kieran_ · Post by **kieran_** » Thu Mar 10, 2005 7:08 pm

Because of this craziness, I am never using jma.

Post by **grinvader** » Thu Mar 10, 2005 7:18 pm

Kieran wrote:Because of this craziness, I am never using jma.

Your loss.

xamenus · Post by **xamenus** » Thu Mar 10, 2005 11:51 pm

Kieran wrote:Because of this craziness, I am never using jma.

Of course JMA's crazy. In fact, it's insane (and I mean that in a good way).

It's a compression format for those who want insane maximum compression for their SNES ROMs.

Starman Ghost · Post by **Starman Ghost** » Fri Mar 11, 2005 12:40 am

Kieran wrote:Because of this craziness, I am never using jma.

Moron.

kieran_ · Post by **kieran_** » Fri Mar 11, 2005 9:48 am

IceFox wrote:
Kieran wrote:Because of this craziness, I am never using jma.
Of course JMA's crazy. In fact, it's insane (and I mean that in a good way). It's a compression format for those who want insane maximum compression for their SNES ROMs.

Crazy.

aprad046 · Post by **aprad046** » Sat Mar 12, 2005 4:59 am

after using jma, four things happened
i) got a good copy of (almost) all my roms
ii)erased some of them which I didn't even know I had (Inspector gadget

) or I didn't have a reason for keping anymore(Mickey Mouse Magical Quest which downloaded once to amuse my 5-year old cousin)
iii) discovered what a neat little tool NSRT is
iv) saved about 15% more space (from 90 mb - 73 mb)

daft · Post by **daft** » Sat Mar 12, 2005 9:48 pm

Is there a quick way to mass convert like 2000 individually zipped roms each into .JMA format?

Bear with me, I'm new to this, but am interested in the benefits of better compression.

Post by **Nach** » Sat Mar 12, 2005 10:01 pm

Of course.

nsrt -savetype jma -ren83 -saveren *.zip

kieran_ · Post by **kieran_** » Sun Mar 13, 2005 5:44 pm

Nach wrote:Of course.

nsrt -savetype jma -ren83 -saveren *.zip

The -ren83 renames into 8.3 format, right? If I removed tha tag, would it mass convert, but using full filenames?

Malcster · Post by **Malcster** » Sun Mar 13, 2005 5:48 pm

You need an option that renames or moves files to recompress. Use -rename instead of -ren83if you want full filenames.

kieran_ · Post by **kieran_** » Sun Mar 13, 2005 5:48 pm

Thanks, Malcster.

Jipcy · Post by **Jipcy** » Mon Mar 14, 2005 3:08 am

kieran_ · Post by **kieran_** » Mon Mar 14, 2005 12:17 pm

bitcopy wrote:

Entire NSRT Log: http://www.geocities.com/sendads2me/nsrtlog.html

How fast is your pc?

Jipcy · Post by **Jipcy** » Mon Mar 14, 2005 5:13 pm

Kieran wrote:How fast is your pc?

AMD Athlon 1.1 Ghz
256 MB SDR SDRAM
250 gb Hitachi hard drive (can't remember model)

The JMA compression format doesn't seem quite polished yet. I realize that it can compress SNES roms (slightly) better than pretty much any other format, but I think the time it takes to compress ROMS is a large tradeoff. Compressing with ZIPs at max compression takes a fraction of the time that it takes to use JMA. Anyway, if Nach can tune and speed up compression time for JMA, it would be much more desirable.

kieran_ · Post by **kieran_** » Mon Mar 14, 2005 5:15 pm

The only reason that I want to use jma is that it will allow for Zsnes to open roms inside a solid state archive. This will happen, right?

Post by **Nach** » Mon Mar 14, 2005 5:19 pm

bitcopy wrote: The JMA compression format doesn't seem quite polished yet. I realize that it can compress SNES roms (slightly) better than pretty much any other format, but I think the time it takes to compress ROMS is a large tradeoff. Compressing with ZIPs at max compression takes a fraction of the time that it takes to use JMA. Anyway, if Nach can tune and speed up compression time for JMA, it would be much more desirable.

I'm working on it.

Kieran wrote:The only reason that I want to use jma is that it will allow for Zsnes to open roms inside a solid state archive. This will happen, right?

It already can.

Jipcy · Post by **Jipcy** » Mon Mar 14, 2005 5:21 pm

Kieran wrote:The only reason that I want to use jma is that it will allow for Zsnes to open roms inside a solid state archive.

I see the future: single NSRT complete solid JMA archive, available over all the usual channels. NO unpacking required. Just open with any emulator that supports the archive, and you see all your roms just like in a directory.

Maybe Nach can implement paths within the archive, divided by region or what have you.

Also, does anyone know, I extracted a single rom from a large RAR archive. The uncompressed rom size was about 4mb. Instead of WinRAR just quickly extracting the file, it started going through EVERY file in the archive, but it said "skipping" for those files. Then it finally got to the file I chose and extracted it. Is this behavior typical of solid archives? To extract a single file from a solid archive, does it need to read through the entire archive?

kieran_ · Post by **kieran_** » Mon Mar 14, 2005 5:22 pm

Sweet.
As for the speed issue, I would be really fucked, with a 333mhz PII. But if I compressed one letter at a time then it'd be all good.

bitcopy wrote:
Kieran wrote:The only reason that I want to use jma is that it will allow for Zsnes to open roms inside a solid state archive.
Also, does anyone know, I extracted a single rom from a large RAR archive. The uncompressed rom size was about 4mb. Instead of WinRAR just quickly extracting the file, it started going through EVERY file in the archive, but it said "skipping" for those files. Then it finally got to the file I chose and extracted it. Is this behavior typical of solid archives? To extract a single file from a solid archive, does it need to read through the entire archive?

As far as I know, Yes.

Also, can you only compress NSRT verifies roms, or could I make a solid-state archive of all of the Goodsnes variations of a rom?

Nightcrawler · Post by **Nightcrawler** » Mon Mar 14, 2005 6:23 pm

bitcopy wrote: Also, does anyone know, I extracted a single rom from a large RAR archive. The uncompressed rom size was about 4mb. Instead of WinRAR just quickly extracting the file, it started going through EVERY file in the archive, but it said "skipping" for those files. Then it finally got to the file I chose and extracted it. Is this behavior typical of solid archives? To extract a single file from a solid archive, does it need to read through the entire archive?

Yes.. The data in the file you're looking for can be based on previous data found in another file. It is necessary to decompress all data found before the file requested to be able to rebuild the file requested. That's an inherent trait of solid archiving.

Jipcy · Post by **Jipcy** » Mon Mar 14, 2005 6:32 pm

Nightcrawler wrote:Yes.. The data in the file you're looking for can be based on previous data found in another file. It is necessary to decompress all data found before the file requested to be able to rebuild the file requested. That's an inherent trait of solid archiving.

That's what I thought. If Nach is planning to allow ZSNES to look into a solid JMA archive, how will ZSNES decompress the single rom you want to play, without taking forever? Please correct me if I'm mistaken about anything here.

Oh, I just realized something. Few people would probably attempt to compress ALL their roms into a single solid JMA archive. Probably at most 10 or something, depending on the rom title and all its variations. So that wouldn't take too long. Still, I forsee performance issues.

Post by **Nach** » Mon Mar 14, 2005 8:09 pm

bitcopy wrote: If Nach is planning to allow ZSNES to look into a solid JMA archive

I already said ZSNES can.

bitcopy wrote: how will ZSNES decompress the single rom you want to play, without taking forever? Please correct me if I'm mistaken about anything here.

http://cvs.sourceforge.net/viewcvs.py/z ... ma/jma.cpp

The code is quite efficient.

I have a JMA with ~20 ROMs in it, and it took ZSNES for me ~4 seconds to load it.

kieran_ · Post by **kieran_** » Mon Mar 14, 2005 8:12 pm

Nach wrote:
bitcopy wrote: If Nach is planning to allow ZSNES to look into a solid JMA archive
I already said ZSNES can.

bitcopy wrote: how will ZSNES decompress the single rom you want to play, without taking forever? Please correct me if I'm mistaken about anything here.
http://cvs.sourceforge.net/viewcvs.py/z ... ma/jma.cpp

The code is quite efficient.

I have a JMA with ~20 ROMs in it, and it took ZSNES for me ~4 seconds to load it.

Just out of curiosity, what are your system specs? Also, does Nsrt only allow the creation of Solid State Jma's which only contain nsrt verified roms, or can you have a jma archive which contains any from from GoodSnes?

Post by **Nach** » Mon Mar 14, 2005 8:38 pm

Kieran wrote: Just out of curiosity, what are your system specs?

Athlon TB 1.4 GHz.
256 MB DDR RAM.
7200RPM 133 IDE drive.

Kieran wrote: Also, does Nsrt only allow the creation of Solid State Jma's which only contain nsrt verified roms

NSRT currently only JMAs ROMs it can rename.

Kieran wrote: or can you have a jma archive which contains any from from GoodSnes?

I can JMA whatever I want.

bohdy · Post by **bohdy** » Tue Mar 15, 2005 12:13 am

What is the point of telling us that Zsnes can handle solid multi-file JMA's if there is no way for us to make such JMA's?

Is there an ETA for this feature in NSRT? Preferably at least allowing the user to JMA all roms under each parent name together?

xamenus · Post by **xamenus** » Tue Mar 15, 2005 2:54 am

bohdy wrote:What is the point of telling us that Zsnes can handle solid multi-file JMA's if there is no way for us to make such JMA's?

Is there an ETA for this feature in NSRT? Preferably at least allowing the user to JMA all roms under each parent name together?

A stand alone JMA compresser, separate from NSRT and not yet released to the public, can put multiple files in a JMA. It can JMA any file you want, not just SNES ROMs.

BTW, as grinvader pointed out, JMA offers excellent compression for GBA ROMs. It'd be cool to see JMA support in VisualBoyAdvance.