you can try GBS-Control if you are in a budget, its gonna output max 1080p, but the upscaling of the original 480p will me better than your tvs, after that, the tv does the 1080p to 4k scalling.
/watch?v=fmfR0XI5czI&t=1
dont use 15:01 video feed in the left as a example, Bob probably made some...