Game file detection: hash and correct filename needed?

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adventurefan
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Joined: Sat Mar 25, 2023 12:18 pm
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Game file detection: hash and correct filename needed?

Post by adventurefan »

Quick question - I always wondered about this: are the required game files detected purely by the (file-) hash or does the naming also play a role? Or is it both (hash value and file name)?

The reason I ask is that I was wondering when adding my “Indy 4 Atlantis” FM-Towns CD files: for some reason, the sound file I have from that CD is “MONSTER.SOU”, while the ScummVM Wiki lists “INDY4.SOU” as required from the FM-Towns CD version.

Can I or do I need to rename the sound file in that case or does it not matter because only the file hash is evaluated when detecting the game files?

In my example, ScummVM detects it correctly even when not using the “INDY4.SOU” name, so I assume it’s only the hash regardless of the filename. ... But I’m just curious and do not know for sure. 8)

Thanks a ton!
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criezy
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Re: Game file detection: hash and correct filename needed?

Post by criezy »

For most engines, including scumm, the detection uses the hash (only on part of the file and not the full file), name, and file size.
However the detection doesn't use all the game files and only a minimum set sufficient to identify the game. For example I think for the FM-Town version of Indiana Jones and the Fate of Atlantis, the detection only looks at the indy4.000 file.
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adventurefan
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Re: Game file detection: hash and correct filename needed?

Post by adventurefan »

Thanks Thierry! Good to know that I do not need to worry about the naming of the sound file in that case.

What I would be interested in is, if the soundfile hash of the Indy 4 Atlantis FM-Towns CD ("INDY4.SOU") and the regular DOS-CD Version of Indy 4 ("MONSTER.SOU") are 100% identical. Can someone confirm or deny that?
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