Happy to help.
From another OBS thread where the customer had similar issues.
OEM kernel (per the Ubuntu guide).
sudo snap install obs-studio
Added my v4l2 source. Noted that it defaulted to YU12 which was like 5 FPS or something awful.
Controls were not immediately presented until I switched to YU12 (Emulated) (Test both entries as there may be two). Closed the properties box, reopened the proprieties box.
At the bottom of the image in the video preview, grabbed the little line that appears at the bottom of the image of me, and push up using my mouse to bring forward all of the v4l2 source settings.
Now for guvcview, it will differ here and the OSB settings will have different options.
Going to bold the parts I am not seeing in your post or the images.
For guvcview, Video controls tab, these are the recommended settings:
MJGP Motion Jpeg
60FPS
1920x1080
YU12 (Emulated) will give you super smooth video, you can even do 60 FPS.
