Nintendo Switch Online NES App .XTX.Z files

[CosmicDreams]

So i managed to get a dump of the NSO NES app and a lot of the formats are just standard PNG's, WAV's, lua scripts, .nes roms etc etc.

But it seems like the game box art is stored in the .XTX format(which tools exist for), However they have an extra .Z extension, Opening it in a hex editor shows that the files are seemingly compressed, and im willing to bet the .Z means zlib or zstd.

I ran the file through TriD(http://mark0.net/onlinetrid.html)
And it showed a 100% match to zlib compressed data.
It could be wrong still but i thought i'd mention that.

Here's one of these files.
https://cdn.discordapp.com/attachments/419711036837330956/492673879484137482/CLV-P-NAACE.xtx.z
If my research was correct this should be the Super Mario Bros 3 cover art.
This is the only format that currently can't be tinkered with at the moment. Everything else is bog standard stuff.

[aluigi]

Code: Select all

comtype zlib_noerror
get SIZE asize
get NAME basename
clog NAME OFFSET SIZE SIZE

[CosmicDreams]

Thanks!
Works great but there's an issue that i don't think is related to the script


A dedicated XTX tool outputs something a little different.

Rather odd.

EDIT: https://github.com/aboood40091/XTX-Extractor
Here's the dedicated XTX tool i spoke of.

Also, how hard would it be to "reverse" the script to recompress?(For modding reasons)

[aluigi]

For recompression:

Code: Select all

comtype zlib_compress
get SIZE asize
get NAME filename
string NAME + ".z"
clog NAME 0 SIZE SIZE

[CosmicDreams]

Thanks again!
I'll try it.

I should really try learn BMS for myself lol

[bodyXY]

aluigi

Hey, can you please contact me? Im the dev of the Nintendo Online Game Autoinjector and need your help for compressing of xtx.z files.

thanks

[aluigi]

@bodyXY
It's just a simple zlib compressed file without any header, there is nothing else I can add.

[Acewell]

if you set the width to 375 it looks good to me