For YouTube videos, just get their link, and copy it.
Than, select this button
(located above your post box), and paste the code in between the button's codes.
Other video sites, in the video page, they have the code which you have to copy and paste in the forum, and will automatically generate the video.
Remember though, not every forum here on TS has HTML (codes) allowed, so videos might not show in every forum.
Videos
Linear Mode
