I got a request to block or allow specific YouTube videos in couple appliances, one of them is checkpoint NGFW.
The simple solution would be to use couple url filtering regex patterns and block/allow rules with SSL Inspection enabled on couple domains.
(^|.*\.)youtube\.com/watch\?v=##VID##'
(^|.*\.)youtu\.be/.*##VID##.*
(^|.*\.)ytimg\.com/.*/##VID##/
(^|.*\.)youtube.com/embed/##VID##
Since YouTube uses googlevideo.com as it's CDN for delivering the video and the content is served with a unique token it is pretty safe to just allow anything under googlevideo.com by default.
In my tests I have added more then 3k VIDS (which is more then 3.2 k regex) and it seems to work OK.
There is a tiny(10 minutes max) delay