(RESOLVED) Game errors when repacking

[l77l]

Hello guys.

I've recently tried to start a TL for a visual novel called "Natsumelo". It uses HXP files with a Him5 signature. I've created a repacker and the repacker seems to work correctly. (https://github.com/iHeq/him5-repacker). 
Now when I open a script (for instance the first one), and I simply change the text from japanese to something in english, the game throws two errors when starting a new game.

The errors in question

Is this an encryption error? Or something with the text format? Does anyone know how to fix this?

https://www.swisstransfer.com/d/3bf46403-7631-482e-a053-e5bea5312011
^ here is the original archive (natsuscn_or) and my repackaged file (natsuscn) for reference.

Edited November 24, 2024 by l77l

[Entai2965]

Does the error appear or change when using the full width versions of the ascii characters including full width japanese spaces? Try checking quickly here https://dencode.com/en/string/character-width

What about when using half width ascii characters + full width japanese spaces?

If the error stays exactly the same, then that likely indicates an encryption/packaging error. If the error changes, or it loads normally, then that indicates a script syntax error.

Another thing to try to figure out what is happening is to repackage the script using the original unmodified text. Then if it works, modify it by shortening the first line a few characters.

Edited November 22, 2024 by Entai2965

[l77l]

I tried it like this, still the same error throws. Also I tried removing a few characters from the file and repackaging without adding anything, the error throws again.
It is weird, since I tried to repackage without any changes and the game loads in without any issues.

Is there an issue in my repackager? Feel free to check the code in my first post.
I personally think that it is either a unicode or signature error, I can't tell though...

Edited November 22, 2024 by l77l

[Entai2965]

If the game loads without any changes to the script files, then it is not an issue with how Fushigi-Tools repacks the files. Fushigi-Tools is working correctly for that archive. The issue is how to extract and insert strings into the .him files correctly.

For that, you can either

• Write your own unpacker/repacker for the .him binary encoded shift-jis scripts based upon your efforts of trying to reverse engineer it, which likely involves looking at the .him files in a hex editor that supports shift-jis.
• Create a new post in the script extraction thread, since that is where we narrowed down the issue for this game. People more knowledgeable about script reverse engineering than me read stuff there sometimes.
• Create a new issue asking support for that format to be added to existing dedicated string extraction/insertion tool like SacanaWrapper or SExtractor.

Edited November 22, 2024 by Entai2965

[l77l]

So after playing around with a Hexeditor I managed to change some things here and there. Obviously transalting a VN in a Hexeditor is basically impossible, so I don't really know where to go from here. Also I still don't understand why editing the files in a texteditor and then repackaging them breaks the game...
After comparing the original and the edited version I saw that some Hexvalues stay the same, while others change. So I'd need someone to help me with this please...

[l77l]

I have since identified the Engine being Himauri Script Engine v2.0 (Him5). Is there any tool available that makes it easier to translate games using this engine?

[Anonym271]

This behaviour is acutally to expect. When you edited the texts in the HEX editor you probably did not change the length of the texts because you just replaced characters. This is most likely what caused your earlier attempts to fail: the game has stored the length of each line (in bytes) somewhere in the script, probably just before the text itself, and if you change the actual length but don't update this information the game will crash.

Now the question is: is it enough to just update the stored length whenever you change the length of a text? If yes, then it should be quite easy to write a simple editor script. But there are script engines that use file offsets to jump between chapters in the script. If this is the case it will not be enough to just update the text and its length because now all pointers to script data behind the edited text will be wrong. The only real solution in this case would be to write a full script disassembler and re-assembler which can be an insane amount of work, depending on the complexity of the script system.

[leticiel_]

As Anonym271 mentioned, the script files of this engine use pointers to locate text.

[l77l]

5 hours ago, Anonym271 said:

 

The next the question is: is it enough to just update the stored length whenever you change the length of a text? If yes, then it should be quite easy to write a simple editor script. But there are script engines that use file offsets to jump between chapters in the script. If this is the case it will not be enough to just update the text and its length because now all pointers to script data behind the edited text will be wrong.

Is there a way to test this? I am really new to VN hacking and I‘d be happy if someone could help me.

I have attached the original dumps of the script in my first post, so if you‘d like you can change the length of the first dialogue there and I could test it in-game, or you could explain how to test it and I‘d do it by myself.

If contacting me through discord is easier, feel free to add me if you want to help (l77l).

[leticiel_]

In this example, you need to update the file size (01 0D 72) and the pointers (0A25, 0A70, 0ADB, 0B60, etc.).

[l77l]

@leticiel_ I don't really understand what you mean sorry... (im not very technical in regards to editing binaries lol)

If noticed that before the linebreak (5C 6E) and the text, there is always a sequence of "01 00 01" followed by the \n and then comes the text. I don't know if this can be helpful, just something I noticed.

So basically the format seems to be the following for text: FF 01 00 01 5C 6E (text bytes) 00 00

Edited November 23, 2024 by l77l

[l77l]

Correct me if I'm wrong, but I don't see any indication of the game checking the lenght of the text, the format just seems to be 

FF 01 00 01 5C 6E (text bytes) 00 00 0A 0D 33

 

[l77l]

A tool has been created:
https://github.com/FritzTom/himauri-tools