ZDoom

[quote="InsanityBringer"]... all I can say at the moment is that [url=https://github.com/coelckers/gzdoom/blob/86551e53df40be2e850e6f1024a1e49a1794378c/src/version.h#L76]the current demo version is 0x221 (545 decimal)[/url][/quote]
That is all well and good and interesting, but kind of useless if there is no correlation to the GZDoom version used to record the demo.

okay but literally none of that is relevant to gzdoom? (vanilla does version demos, anyways, at least since [url=https://doomwiki.org/wiki/Demo]1.2[/url])

in any case, GZDoom does version demos, it needs to in order to determine if a demo can be played back. You'll need some sort of file viewer or hex editor to look at it though. you'll find a "ZDHD" marker in the file, followed by 4 bytes for the size, and then the next two bytes should be the version. A hex editor like xvi32 (and probably a million better ones, but frustratingly enough not hxd) will usually have an option to automatically convert that number into a readable base 10 number. The only trouble is that I don't fully know how demo versions map into game versions, all I can say at the moment is that [url=https://github.com/coelckers/gzdoom/blob/86551e53df40be2e850e6f1024a1e49a1794378c/src/version.h#L76]the current demo version is 0x221 (545 decimal)[/url]

In general, I do not believe that versioning was included in demo recordings.
So, that would be a bust.

However, the demo demo3.lmp of Ancient Aliens has this string at the end

[imgur]https://i.imgur.com/GZR2tP1[/imgur]

How that got embedded, I do not know. I never used PrBoom.

Other than that, the only thing I can suggest is to look at the timestamp of the demo and try to correlate with the GZDoom timestamp. But, I guess, you already tried that.

Well, that. Is there any way to know which version of GZDoom was used to record a demo? I found some that I recorded a couple years ago and I don't remember which version I used to record them. It seems a bit time consuming to go around downloading every single version and trying to play the demos with it. I figure the demo has that information somewhere, as it has to know somehow what version to expect to not show the desync warning message. Maybe a hex string?

Any help would be welcome, thanks!