Custom Compression Files and Hidden Assets in Danganronpa v3 Demo

[Rentarou]

Like with Pokemon Sun and Moon's demo, it's come to light that there are a metric f***ton of assets in the Danganronpa V3 demo - unpacking the .cpk files will get you more models, sprites, and textures than are present in the full SuperDanganronpa 2



Only problem is... they're compressed in a custom SPC format(Not Spectrum or PKCS7, a new format just for the game)

Now, not ALL the files in Danganronpa V3's demos were compressed in the custom SPC format - sound, voice, and music files were able to be extracted right after unpacking the .cpk. These were in .vis and .awb format - easily extractable by many tools.

https://i.sli.mg/XDpJV2.png

But the juicy stuff, the scripts, images, - it's all behind the SPC compression. Proof of that is from a former programmer for Project Zetsobou, a fan translation group of Danganronpa 1 and 2 for the PSP. In addition to being the first to say there were assets in the demo, the programmer posted this image on their twitter (No nudity, still mildly unsafe for work)http://www.bdh.moe/uploads/stand_014_019a.jpg - as you can see from the file name, it's "stand_014_019a.jpg"

stand_014_019a probably corresponds to an SPC file of a similiar name - stand_014_019.SPC - found in the "chara" subfolder of the "model" subfolder. Here - take a look.



In addition to seeing how a .jpg of a character model shares a similiar name to the SPC file, from the index you can see that the .cpk files all unpacked correctly, so this SPC file definitely seems like compression rather than encryption - which is what the former Project Zetsoubou progammer said to begin with

However, though PZ Programmer knows how to decompress the custom SPC format, they're not too eager to share that knowledge I've been banging my head against the wall trying to figure it out - at one point I tried using a modification of the "Unknown Format" quickbms to try and just bruteforce it.

I'm a bit out of my element here, so any tips on how to proceed would be appreciated. I've shared a link to the stand_014_019.SPC file - the one associated with the leaked JPG file at the botom. If you saw anything in the screenshots that you'd like me to upload I can provide more links - but I imagine if we can decompress this one Custom Compression file we can decompress them all

https://mega.nz/#!h1Q3nJDB!lJZMM9CjTgTZ ... zNXNqXb3UY

NOTE: Windows might say the .SPC file is a pkcv7 file, but it's a false positive. It's not encrypted.

[aluigi]

Even if the compression algorithm looks very simple, it's not available in quickbms so my compression scanner found no matching results.
Luckily the format is ok and I have added its support in my existent script:
http://aluigi.org/bms/danganronpa.bms

[Keph]

Hi!

I saw you did some things with the Danganronpa V3 files and now i'm looking for help with the graphics. I'm doing the translation of the demo to spanish and the tool i have isn't working as we expect since it doesn't repack the graphics the right way and while yeah, they are in the game, they just look weird, causes random glitches to the screen and so...

That's why i've been wondering if you could take a look to they format a little more and see if you can create a script or whatever to import graphics back, all that i know of how it works is that the .srd file it's like an index and the .srdv file have the graphic information. All those file all stored on the .spc. (The tool i've been using is Spiral)

Would be awesome if you can help us with that because is the last part we need to finish the translation!

Thank you!

[aluigi]

I don't think I can help.
I just analyze the formats and make the script.
The one for this game is there but that compression is not available as reported in my last update.
If yours is the same game/version, I don't have updates.