After Effects prerenders so slow

[Its_Ariss]

I've been editing using After Effects CC 2018 since last year, and recently it's been rendering some clips really slow. I used make edits using clips I get from a game called Fortnite, and recently I switched to CS:GO and Call of Duty. Ever since I started to edit clips from CS:GO and COD (Call of Duty), my After Effects starts to freeze every time I move the blue line in the timeline, when i move a keyframe or when i move the clip. I think its because the clip I use to edit for CS:GO or COD is 300+ fps and the clips i used for Fortnite are mostly 60. Some are also 300 but never 600. The 300 ones lag sometimes too but not as much as COD or CS:GO. Is there any way I can reduce the amount of fps in the clips so they don't make AE lag as much? I've heard of Virtualdub but that only supports .avi and all the clips i use are .mp4 or .mov.

Specs:

[Mylenium]

Yeah, sure. Insane framerates make for lots of data and most game recording tools use variable stream data rates to boot. None of that bears any relation to professional video formats for which AE was designed in the first place. I'm afraid unless you mangle it through some MP4 conversion software to conform framerates and data rates this won't improve. Any ffmpeg-based encoder will do like good old Handbrake or whatever five million other tools... Next time simply use sensible recording settings.

Mylenium

[Its_Ariss]

Okay I am using Handbrake and I think I found out how to use it, but do you know the recommended settings for keeping the same quality and everything just changing the fps from 600 to 60 or 120?