Combine demo lumps into one lump?

[fawtytoo]

As Doom 2 only supports 3 demo lumps, is there a way to combine demos into one lump? I have 21 demos, and would like to combine 7 into 1 lump, thus giving 3 demo lumps overall.

I'm guessing there could be some bytes I could add to the end of the first demo to dismiss the intermission and go straight to the next demo.

Possible?

[Grazza]

You can combine the data, but the resulting demo almost certainly won't play back correctly.

The reason is that many in-game events are determined by the state of the pseudo random number generator (PRNG). If you append a demo to the end of another, it will get different random numbers than if it starts from scratch. This will very quickly throw events out of sync.

[40oz]

You could probably play a few maps in succession in one demo lump, but for the demos you have I doubt you'll have any luck getting them to play right.

What's the purpose of have 21 demos anyway if you don't mind me asking?

[TimeOfDeath]

I'd say either use 40oz's idea of recording a single demo of multiple maps at once, or include all the demos in the wad zipfile (not in the wad itself).

[Memfis]

In prboom-plus it is possible to record a demo where the player uses "load game" function. I guess you could switch between the levels this way. I don't know how it works exactly but it happened to me one time when I saved during the recording.

[fawtytoo]

40oz said:

You could probably play a few maps in succession in one demo lump, but for the demos you have I doubt you'll have any luck getting them to play right.

What's the purpose of have 21 demos anyway if you don't mind me asking?

I simply have 21 demos for 21 maps. I found some demos for Chex Quest 1 which has several levels in one demo. Just wondered how it was done.

I'll go back to my original idea: 7 wads with 3 demos each. Then load a demo wad at random using a script.

[Grazza]

fawtytoo said:

I found some demos for Chex Quest 1 which has several levels in one demo. Just wondered how it was done.

They were recorded as a single demo. They weren't recorded separately and then added together.