Hacking ROM Hack LZ77 and Huffman Compression tools

TwoSpikedHands

TwoSpikedHands

Member
OP
Newcomer
Level 1
Joined
Jul 21, 2017
Messages
13
Trophies
0
Age
27
XP
99
Country
United States
Does anyone happen to know of any tools that can compress data in a 1-1 ratio with the GBA? So far I have been using these tools by CUE (which are AMAZING) - but if I decompress data then recompress it (without modifying it) the data somehow is not exactly the same

Here's a bit of context:

Below on the left is some data that was decompressed using ONLY huffman algo
Below on the right is data that was decompressed with both huffman, then lz77, unmodified, then recompressed using lz77

COMPARISON.png



To my knowledge this should be the exact same data since the decompressed data using the same huffman and lz77 compression tools looks exactly the same as it does in game:

COMPARISON2.png


There's likely something I'm overlooking at the moment, does anyone happen to know what I'm missing? I know for a fact that the decompression tools are working perfectly, it just appears that when I try to re-compress that same exact data is when I start to get issues... I don't know a whole lot about what I'm doing but I've tried quite a few things, including compressing it back with each and every single parameter possible within the command - but nothing is able to replicate the same exact data back. It's always SIMILAR, but the re-compressed data is never the same, and is typically longer than the original huffman decompressed data

A link to the tool I am using to compress/decompress is here:
https://www.romhacking.net/utilities/826/
 
Last edited by TwoSpikedHands,

Site & Scene News

Go to forum More news

Popular threads in this forum

EZ Flash Parallel MicroSD Card Compatibility

What Japanese proxy service should i use to buy gameboys?

ROM Hack  Mario & Luigi: Can I apply the superstar saga (Cartridge Rumble Patch) to Korean ROM?

GBA Homebrew game  Demons of Asteborg DX, a new game for the GBA !

SuperFW: a (very much WIP) supercard firmware

EZ-FLASH OMEGA Definitive Edition (REV. B) FREEZES when clean boot ROMS.

Software for generic Flash Card

Hacking GBA Translation  Codes on EZ-Flash Omega D.E in chinese???

General chit-chat
Help Users
  • No one is chatting at the moment.
  • BakerMan @ BakerMan:
    i said i was sleeping...
  • BakerMan @ BakerMan:
    sleeping with uremum
  • K3Nv2 @ K3Nv2:
    Even my mum slept on that uremum
  • TwoSpikedHands @ TwoSpikedHands:
    yall im torn... ive been hacking away at tales of phantasia GBA (the USA version) and have so many documents of reverse engineering i've done
  • TwoSpikedHands @ TwoSpikedHands:
    I just found out that the EU version is better in literally every way, better sound quality, better lighting, and there's even a patch someone made to make the text look nicer
  • TwoSpikedHands @ TwoSpikedHands:
    Do I restart now using what i've learned on the EU version since it's a better overall experience? or do I continue with the US version since that is what ive been using, and if someone decides to play my hack, it would most likely be that version?
  • Sicklyboy @ Sicklyboy:
    @TwoSpikedHands, I'll preface this with the fact that I know nothing about the game, but, I think it depends on what your goals are. Are you trying to make a definitive version of the game? You may want to refocus your efforts on the EU version then. Or, are you trying to make a better US version? In which case, the only way to make a better US version is to keep on plugging away at that one ;)
  • Sicklyboy @ Sicklyboy:
    I'm not familiar with the technicalities of the differences between the two versions, but I'm wondering if at least some of those differences are things that you could port over to the US version in your patch without having to include copyrighted assets from the EU version
  • TwoSpikedHands @ TwoSpikedHands:
    @Sicklyboy I am wanting to fully change the game and bend it to my will lol. I would like to eventually have the ability to add more characters, enemies, even have a completely different story if i wanted. I already have the ability to change the tilemaps in the US version, so I can basically make my own map and warp to it in game - so I'm pretty far into it!
  • TwoSpikedHands @ TwoSpikedHands:
    I really would like to make a hack that I would enjoy playing, and maybe other people would too. swapping to the EU version would also mean my US friends could not legally play it
  • TwoSpikedHands @ TwoSpikedHands:
    I am definitely considering porting over some of the EU features without using the actual ROM itself, tbh that would probably be the best way to go about it... but i'm sad that the voice acting is so.... not good on the US version. May not be a way around that though
  • TwoSpikedHands @ TwoSpikedHands:
    I appreciate the insight!
  • The Real Jdbye @ The Real Jdbye:
    @TwoSpikedHands just switch, all the knowledge you learned still applies and most of the code and assets should be the same anyway
  • The Real Jdbye @ The Real Jdbye:
    and realistically they wouldn't

    be able to play it legally anyway since they need a ROM and they probably don't have the means to dump it themselves
  • The Real Jdbye @ The Real Jdbye:
    why the shit does the shitbox randomly insert newlines in my messages
  • Veho @ Veho:
    It does that when I edit a post.
  • Veho @ Veho:
    It inserts a newline in a random spot.
  • The Real Jdbye @ The Real Jdbye:
    never had that i don't think
  • Karma177 @ Karma177:
    do y'all think having an sd card that has a write speed of 700kb/s is a bad idea?
    trying to restore emunand rn but it's taking ages... (also when I finished the first time hekate decided to delete all my fucking files :wacko:)
  • The Real Jdbye @ The Real Jdbye:
    @Karma177 that sd card is 100% faulty so yes, its a bad idea
  • The Real Jdbye @ The Real Jdbye:
    even the slowest non-sdhc sd cards are a few MB/s
  • Psionic Roshambo @ Psionic Roshambo:
    https://www.youtube.com/watch?v=SjCivnt5t50
  • Karma177 @ Karma177:
    @The Real Jdbye it hasn't given me any error trying to write things on it so I don't really think it's faulty (pasted 40/50gb+ folders and no write errors)
  • DinohScene @ DinohScene:
    run h2testw on it
  • DinohScene @ DinohScene:
    when SD cards/microSD write speeds drop below a meg a sec, they're usually on the verge of dying
    DinohScene @ DinohScene: when SD cards/microSD write speeds drop below a meg a sec, they're usually on the verge of dying