Video quality degrades when uploading to YouTube with variable frame rate So I use OBS (latest ver) to record my gameplay on Windows 10. 

OBS settings are:


recording format: MP4
Recording quality: indistinguishable quality, large file size
Encoder: Software (x264 low CPU usage preset, increases file size)
Downscale filter: Lanczos (sharpened scaling, 32 samples)
FPS value for recording: 60
Base and output resolution are both the same, 1080P and my monitor is
1080p as well as my in-game resolution.


So when i'm recording from a less demanding games like the new Resident Evil 2 (RE2) the video file looks perfect, both on my computer (using VLC) and on YouTube they look great. I run the game on fixed 60 FPS using V-sync and ultra graphic settings.

the videos i'm talking about:


                
            


                
            

But, when I record from a more demanding game like Assassin's Creed Odyssey, I can't get a fixed 60 FPS, average is 45 FPS and it varies between 32 to 60 FPS.
after i finish recording i play the video file on VLC and it looks great, just like my gameplay, but when I upload it to YouTube, it looks awful, blurry and so much noise in it. 


                
            

My YouTube channel doesn't have so much subscribers (almost 200) so YouTube doesn't use VP9 to convert my videos, it only uses x264, I don't know it's relatable though.

so my question is, where is the problem exactly? is it YouTube's fault converting my videos so poorly? because they look fine on my computer when i play them.

Or

is it my fault and i'm doing something wrong in the settings? if so what should i change?

PS:

I've tried setting the recording FPS in OBS to 30 FPS but the gameplay looked so slow on YouTube and on my PC.
Not sure why YouTube would be degrading the video quality because of the lower framerate. Perhaps, after recording at the lower framerate, re-encode the videos using 60fps before uploading. It'll make the file bigger without the actual benefit of the higher framerate (just creates duplicate frames), but maybe worth it if it prevents video quality from degrading.

Edit: OBS uses FFmpeg, &amp; FFmpeg has some recommended settings specific for YouTube. If you are using the same settings for both videos, this is probably irrelevant.