Hi! So, for your query, you could take a look at tools like Avidemux or HandBrake. Each one has different filters and ways to make your video look better in full HD. Avidemux is easy to use, and HandBrake lets you do more by yourself.

Also, if you think about hardware, you should check out the Elgato HD60 S. It lets you record and scale videos as they happen. It may cost more, but the better picture quality is really worth it!