What exactly is passed to XXH64 when creating hashes?

[Invader]

So, I wrote a script for Wiimm's tools to extract all the textures from Paper Mario: The Thousand Year Door, when JosJuice brought up this:

(10-06-2016, 02:10 AM)JosJuice Wrote: If the image data you get from this is identical to the image data you would get from Dolphin, it's possible to write a program that calculates image hashes in the same way as Dolphin.

So, what I want to know is what xxh64 sees when Dolphin passes the data to it. Also Is it using a seed when hashing? The only thing I could find was this: https://github.com/dolphin-emu/dolphin/blob/master/Source/Core/VideoCommon/ImageWrite.cpp#L27
From what I understand this states that the data should be 8-bit RGBA. I'm not fluent in C++ so I have no idea if the code reflects that comment. Tbh... not even sure what I'm saying makes sense.

I tested the go version and the python version of XXHash. The thing is I'm obviously doing something wrong because they're giving me different hashes for the same files!

I attached the python script and the xxhsum.exe (might require go to run, I have no idea).

Here's the .py script I wrote.

Code:

import os
import xxhash

path='' #placeholder for later
in_filename='test.rgba.data' #this should be changed to the input file
with open(in_filename, 'rb') as f:
   xxhash.xxh64(f.read()).hexdigest()

Sorry, if these questions sound really stupid. Never done any real coding in my life until now.

Any help would be appreciated.

[degasus]

Almost: https://github.com/dolphin-emu/dolphin/blob/master/Source/Core/VideoCommon/HiresTextures.cpp#L277 and https://github.com/dolphin-emu/dolphin/blob/master/Source/Core/VideoCommon/TextureCacheBase.cpp#L747

So it hashes the texture in the native GC format, which is tiled and often encoded in uncommon formats.

[Invader]

(10-08-2016, 08:46 AM)degasus Wrote: Almost: https://github.com/dolphin-emu/dolphin/blob/master/Source/Core/VideoCommon/HiresTextures.cpp#L277 and https://github.com/dolphin-emu/dolphin/blob/master/Source/Core/VideoCommon/TextureCacheBase.cpp#L747

So it hashes the texture in the native GC format, which is tiled and often encoded in uncommon formats.

Hashes match! Thanks a ton!