I was reading about how the last avatar anime was up-scaled to 720p and colour-corrected, but I have not figured out how to do it myself.
Or even Neat Video stand-alone or video edit plug-in can be used for
up-scaling and some digital noise reduction.
https://www.neatvideo.com/home
And then there is AVCHDcoder for simple BD menu-making of HD video and
audio.