Remove logo or watermark from a video

Command line ffmpeg tool has a really powerful logo removal video filter. It is as simple as:

ffmpeg -i in.mp4 -strict -2 -vf "delogo=x=XX:y=YY:w=WW:h=HH:band=10" out.mp4

Replace the XX, YY, etc with the location of the logo in pixels, same for WW and HH for the dimensions.
You can make a screenshot of the video and get the parameters from Gimp beforehand. You can expect perfect result when the logo is above sky or other quite homogeneous part of the video, otherwise of course it's noticeable.
Play with the band parameter (specifies the thickness of the fuzzy edge of the rectangle) for the best outcome.