As you can see I released the first preliminary version of GByeBye, it's a program I develop with the help of my friend Fallen_Soul that allows you to decompress Gameboy Advance LZ77 in seconds, specifically, data called from the GBA BIOS routines. In future maybe I can add the LZ compressor - RL decompressor/compressor and huffman decompressor/compressor.

GBB is freeware, writed in Python Programming Language, so, you need the Python interpreter installed on your machine, in future I'll release Windows Binaries for people that don't like to install the interpreter only to run a few simple tasks.

For now I'm working on a GTK based GUI, but the program it's already functional, you must only gets the address of compressed data and write in the file config.xml like in the example I put in this file ([GBA]Advance Wars 1.1), GBB does the rest!

Here the results you can get running the exemple config.xml:

         

If anyone has question about how to proceed, feel free to ask, it's the purpose of this topic.

Well, if I can ever get the Python Programming thing to run on Windows ME, I'll love it. If not, Boo. 

Seriously though, that certainly opens up the options for ALOT more GBA hacking around here. Nice job.

~DS

There are already several LZ unpackers for GBA, what's missing though is one for Huffman! I'd wish people would work on that.

You can open with any tile editor, in the image I use Tile molester with the codec 4bpp-reverse, the codec used in Advance Wars.


I know about other lz unpacker, I think it's called unlLZ-gba, you've to search the data... because he stop at any 0x10, the flag for LZ, you'll loose a several time to found what you need.

In GBB the user has to inform the address, editing the file config.xml, and he gain time with this.

The problem with Huffman is know where the lookup table is, when the time comes, I'll study to see if this address is standarized.

And we cannot forget there's another standart compression in GBA, a RL variant (RLE + map byte).

So this extracts stuff, right? Does it compress stuff too? (Sorry, I'm dumb.)

There is also the excellent GBA Multi DeCompressor. You can give it a vba swi log and it will automatically extract all data which was called by the game. And you can of course extract specific addresses. Recompression is there too.
I guess this program is totally unknown since it comes from the Italian scene. I only know of it thanks to Gemini. We don't have it here either, I'll upload it right away.

Don't get me wrong, I don't want to downtalk your program. I'm happy for every GBA tool I just wanted to point out the lack of Huffman tools so far for the GBA.

By the way, the Huffman function from the Bios is fully standardized. Take a look at http://nocash.emubase.de/gbatek.htm#biosdecompressionfunctions
r0 will point to header data followed by the huffman tree. It should be easy to extract with a similar approach as GBAMdC by feeding a vba swi-log.

Should any of these utilities be added to the database?

I'm certain Parasyte's awesome GBA compression tool isn't in the archive, i found it on acmlm board a few years ago then it sort of disappeared from there aswell.

It decompresses all the bios compression formats and compresses 2 out of 3, only missing Huffman recompression, and it works great for everything I've used it for.