.vtex_c files impossible to decompile

[Lemoncakes]

Does anyone know how to decompile .vtex_c files after the last patch? Up until now I've been able to decompile them properly using resourceinfo.exe with the command line:

resourceinfo.exe -i FILENAME.vtex_c -debug tga -mip -game

...But ever since the last patch, most of the .tga files extracted turn out corrupted and garbled. Here's one of the trophy icons I tried to extract today:

trophy.png

Some .vtex_c files could still be decompiled properly, like the new Fall 2015 chat badges. But the vast majority look like the one above.

Did Valve change something with the format? Am I not supposed to be extracting these? As you know, Dota 2 Wiki relies heavily on in-game assets and these new Source 2 formats are making things very difficult. Why couldnt you guys have just stuck with .png ;_;

[Toyoka]

Try using the latest version of Myll's ModKit tool. But yea, it might also be that something went wrong with the new patch.

[Selaya]

Results into the same thing. (Why would it result into anything different, anyways. The tool`s basically just typing these command line arguments for you.)
Volvo probably introduced yet another encoding scheme (there`s already some stuff using a weird CIELAB spinoff encoding).

[Lemoncakes]

Update: I've partially figured it out with the help of HMFD on the moddota.com forums

.vtex_c appears to be used to compile several different file formats:

1. Straight-up TGA

These are just normal .tga files that can be viewed after being extracted with the command line. Only a small number of vtex_c files contain this format now.

2. PNG files

These don't need to be extracted with the command line. You just have to open the vtex_c file in a hex or text editor, delete everything up to the PNG header, and resave as .png. This solved the problem with the trophy icon I posted above.

3. Weird TGA

These files can be extracted as .tga but show up all corrupted in image editors. The colors are off, there's blocky artifacts, and some weird stretching on the bottom.

2.png

Unfortunately, the vast majority of vtex_c files are of this type and I haven't figured out how to make them look right. Will post update if/when I do.

[Selaya]

Thesse should be the CIELAB (or CIELUV, these encodings seem to be pretty similar?) files I`ve mentioned. From what I`ve gathered, the Alpha layer represents the Lightness value, the B layer represents the transparency, and R and G somehow represent a and b. The Lightness` pretty accurate, and the transparency is pretty weird, but should be pretty straightforward, too. The a and b values were the ones giving me headaches. They`ve been pretty weird

[Lemoncakes]

Any idea how to make it work?

[Selaya]

Hm.
You`d probably need some algorithm to calculate what the a, b values`re exactly doing? It`s certainly possible, but I`ve been too lazy to research into that. I mean, the Lightness is pretty straightforward, and the Alpha value isn`t particularly interesting, but the a, b values which actually define the colors are, and they`re unorthodox from what I`ve seen.

[Selaya]

Bump. Any updates on this?

[arosian]

I'd like to know too. I've tried decompiling vtex_c files which I thought were .png, but actually aren't (there's no .png header even though the file has "png" in its name). Using both ModKit and s2dc didn't work.

ModKit just generated an empty folder using the "vtex_c -> tga" function. s2dc just locked up and never completed.

[DoctorGester]

https://github.com/SteamDatabase/ValveResourceFormat