I'm looking for a way to restore pixelated (aritfacted?) older videos.

[Ein0r]

Hi, I got tasked with repairing some old video files, but I don't know how. They are .mp4 and .mov files.

 

The videos are short dance instructions, 5-10 years old, and look like the ones I attached. They worked fine in the past though.

 

I put one of the videos into Da Vinci Resolve 17 and Vegas 15, hoping a fresh render would help, but it didn't even render in DaVinci. When I went through the video frame by frame it started to give me a "Media Offline" warning for some of the frames. The render fails with a warning that some parts of the video could not get properly decoded. I could render it just fine in Vegas 15, but that obviously didn't fix my problem and it came out the same. 

 

Are there tools out there, preferably free, that can help me with repairing those videos, or do I have to say goodbye because of whatever file rot has befallen those poor little tutorial videos?