Patent free video is in a strange space. I recently looked into just using old formats. To be super safe. With audio we have mp3 which is good enough for a lot of cases and seems to be patent free.
But for mpeg2 (used on DVD) even though it is really old (1995?) it is still patent encumbered in some places until 2035?
https://en.wikipedia.org/wiki/MPEG-2