Migrating Videos

I need to migrate my videos from site-1 to site-2 - these videos are only embeded videos. Can someone specify what table(s) name where these videos links reside, and where the videos thumbnail pictures reside on the system ( path names ) so can I copy the videos links from the database along with their thumbnial pictures as well..

Please note, I tried to migrate some videos tables, but I am not sure if I missed anything because some videos titles shows questions mark like this  ?????????????? and when I click on them, I get a message "not found"

Please advice. Thank you.