How to improve video capture quality

Apart the obvious things (better source media and player, better cables etc.) I'd like to explore some different approaches:

average/median multiple capture (using the same media/player)

I tried several times, and it works really well - it delete noise and dropouts NOT present in the media/player

average/median multiple capture (using different media/player)

usually it delete noise and dropouts ALSO if present in the media/player

hardware TBC

it improves the quality of tape based media - like VHS or Video8

hardware Comb Filter

it improves the quality of composite based media - like VHS or Laserdisc

phase-inversion trick

it deletes completely any dot crawl in theory - never found the working way in real life, though... anyone who is aware of how to make it work, please post the info here, thanks!

component4all

found here - it seems it works well (apart the change in color)... further investigations and tests are needed!

Are you aware of any other technique? Please share it with the community!