Reverse Engineering Jet Set Radio HD - Part 1

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Screw the last post, the Part 1 was a lie it is a now discontinued!

I was talking to my cousin about the speculation of JSRF HD with Hideki's tweet in response to being asked if he knew whether JSR HD sold well enough for SEGA to bother with recreating JSRF in HD (his response: "Yes. But it's a secret"). Now his response is in no way a clear indication as to what is happening in regards to my favourite game (not sure whether I prefer DOOM over it, I could go in a lengthy discussion about the two but I shan't... for the time being). BUT it gives the cult fanbase hope. We all want to play JSRF (and admittedly it is backwards compatible on the Xbox 360, though with framerate issues), but this new generation of consoles don't have backward compilatility. At least the Xbox One doesn't - I haven't been keeping up-to-date with them. Anyway I mentioned my excitement in reverse engineering the game in order to create a software which would allow users to manipulate parts of the game such as textures. So why not practice on JSR HD?

I'm not sure if I will get anywhere, but maybe it'll spur someone else to take the reigns and continue.

The first step is to locate the folder of JSR HD (for me): "C:\Program Files (x86)\Steam\steamapps\common\Jet Set Radio"

Roaming around we find the majority of the data is in "Jet Set Radio/DATA/JETRADIO", the larger files tend to have an AFS extension. Opening in notepad++ reveals a binary file (as expected). A quick Google search finds that the AFS file format is commonly used in games to store textures/models/etc all in one package (file), and I do believe the data is compressed from the Zlib compression algorithm (I'll keep this in mind as Java provides an easy implementation of this algorithm, which may be useful if I get to the software creation phase).

I found a download link to a piece of software called AFS Explorer 3.7 and it's hosted on GameSpot thus further indication that this is used for games.

ase of using toolsets as I imagine I will require multiple usage of AFS Explorer, I will create a Dropbox folder "Dropbox/Jet Set Reverse" - Jet Set Reverse is a name I thought of for this project! The Dropbox folder can easily be shared at a later stage allowing other people easy access to the tools used here)

The following is the results of my importing of a subset of the AFS files:

(Full Directory - allows me to copy and paste easily - C:\Program Files (x86)\Steam\steamapps\common\Jet Set Radio\DATA\JETRADIO)

STAGE1.AFS
st1dat.bin
st1txr.bin
Not sure what to with a binary file... Will try a Hex Editor later, if all files yield the same result

E_SEGALOGO.AFS
controlertxr.bin
instructiontxr.bin
logo_Stxr.bin
start_titletxr.bin
I'm assuming "txr" is "texture" abbreviated, so a Google Search for "binary textures" finds a program called BinTex made for Need For Speed to open .bin textures and convert them to .dds format, so let's see if it works here.

On using the program I'm told "dx8vb.dll" is missing, I'm thinking the VB stands for Visual Basic so my faith in this program is already dropping. Currently, I can't be bothered manually hunting the DLL down so I'll take my own approach to hacking open this bin file for now.

I export "start_titletxr.bin" to my Desktop, and change the file extension to some common ones. (Oh how I wish I was using a Unix CLI ;_; )

Neither BMP, PNG, JPG, TGA or DDS works, so I will delve into the file, see if there's any indication of specification.

No indication of specification, seems a custom format so I will try the NFS thingy. Which failed, even after the DLL was located - some ActiveX component error. Great. Time to do some digging around - Image2Graffiti and JSRFInside come to mind! If anyone has any ideas it would be great, but for now I have to decipher a custom image format without knowing the specification >_<

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