In detail, i must set as resolution, the resolution of the computer screen or the resolution of the weather IP webcam ?
it depends. probably screen resolution (presuming you are using Windows Capture?)
Are you using RTSP for IP feed from webcam to OBS Studio (VLC? or ??) and not re-framing/cropping, or otherwise adjusting video (other than adding an overlay?). As the overlay added using screen resolution, that is the base/canvas resolution I'd use.. maybe. actually I'd test both ways.
This is NOT an area of expertise, so please take others word on this over mine
as I think about this further, I think I'd
- Presuming webcam lower resolution that monitor screen, I'd be inclined to display webcam image at full (native webcam) resolution (ie, not enlarge/ no video/image re-scale)
- add overlays as appropriate
- OBS Studio Base Resolution/Canvas at webcam resolution
