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Author Topic: Strange PSX Compression  (Read 2374 times)

RoyalityKnight

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Strange PSX Compression
« on: March 24, 2018, 10:42:34 am »
I'm working onto a PSX translation, but when i have extracted the files of the game i have this



as far i'm concerned the game is compressed, but this format is similar to a fragmented file, also i have searched into a Hexadecimal editor and found something



Apparently, yes the game is compressed, but if it can be assambled it can display files (I suppose that there are files, but they are compressed) there is any way of extract them?

Jorpho

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Re: Strange PSX Compression
« Reply #1 on: March 24, 2018, 07:29:43 pm »
Your image links aren't working.  I tried to fix them, but this is all I can get.

Spoiler:


Quote
as far i'm concerned the game is compressed, but this format is similar to a fragmented file
I don't know what makes you think that.  What did you use to "extract the files of the game"?  It looks like they're all just .bin files.

Quote
Apparently, yes the game is compressed, but if it can be assambled it can display files (I suppose that there are files, but they are compressed) there is any way of extract them?
I don't know what makes you think that either.  The hex editor is showing references to files named "name.c" and "t_char.c", but that just suggests there's leftover debugging information in the game's code; there's probably no way to extract files named "name.c" and "t_char.c".
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RoyalityKnight

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Re: Strange PSX Compression
« Reply #2 on: March 24, 2018, 08:02:23 pm »
Sorry, probably i haven't expressed me well, most PSX games stores their files in different folders, but when i pulled them out from the image i only get the bin files, the images only shows the inner folder of the game


And this is what is inside the folder



And it goes on and on until 108.bin, probably just ideas of mine, but i can barely figure out something from them...

NERV Agent

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Re: Strange PSX Compression
« Reply #3 on: March 25, 2018, 12:35:05 am »
What game are you hacking? If you post what game you are hacking, someone might be knowledgeable in that game and inform you about the compression scheme.

For example, Final Fantasy VII uses GZIP and LZSS compression, and there are tools available for that.

FAST6191

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Re: Strange PSX Compression
« Reply #4 on: March 25, 2018, 06:45:10 am »
From the hex window that does not look like compression -- there an awful lot of large repeating fragments and runs in that. Even the most rudimentary schemes would catch a lot of those, and the PS1 was a bit beyond rudimentary schemes. I can't rule out the other files but that one at least does not look compressed.

Anyway what it sounds more like you are asking is what do I do with this game. The game devs were under no obligation to put things in nicely named files, extensions and folders and it appears they did not here.
You can manually document the files if you like -- certain formats might have fingerprints (magic stamps, certain structures, certain lengths...) that indicate what they are.
If you want something specific (the graphics, a song, the text...) then you can trace it. I am not sure what I feel about tracing on file system using games/devices -- on the one hand it is not usually quite as direct as the likes of the SNES or GBA or something but on the other once it all clicks it is somewhat nicer. That and PS1 debugging is not quite as developed as some other systems. If you want to do that for the various aspects of the game then you can build up a picture that way.
Corruption is a thing. I know it has fallen out of favour a bit around here but edit some of the files and play the game, if it crashes at a point or something loads that is far different to what it normally is then you have an idea of what it is.

I should also note some games on the PS1 and PS2 store things outside the file system. Square (Enix) were notorious for this.

If you want to check other regions for the game, if the same game is on other systems then those, or other games from the same dev then that might yield something. Or it might not.

RoyalityKnight

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Re: Strange PSX Compression
« Reply #5 on: March 25, 2018, 10:48:11 am »
So... i will need use a debbuger?
Alright, i guess that explain some things, thanks

weissvulf

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Re: Strange PSX Compression
« Reply #6 on: March 25, 2018, 03:28:02 pm »
You don't have to understand what all of those files are in order to translate a game. You just have to find where the text is and deduce how to edit it. The 'BIN' file extension is generic and irrelevant. Your picture with hex data shows a list of RAM addresses (C8880280 etc) and is not compressed.

A debugger usually isn't the right tool to discover where text is stored. This is Shin Megami Tensei If right? I see Roman letters in some of the screen shots so it may already have partial support for a translation.

The SLPM file is the exe; the menu text is often stored there. A fair number of PS1 games use Shift-JIS encoding, so the first thing I would do is look at the exe in a hex editor that supports Shift-JIS (like MadEdit). Check the PS1 utility section for scanning tools like TIMviewer or nana to find graphics. There are also scanning tools for video and sound formats.