usb adapter?

Adapters vary a lot in what the can play, what they cost, and what they can connect to. As you have given no information about your TV and videos it is not possible to advise.

You have posted your question in the audio section. You have not said anything about what your TV is capable of or what sort of video formats you want to play.

(1) You need to ask in the TV section of this site to obtain the best possible audience
(2) When you ask you need to state what connectors your tv has
(3) When you ask you need to state the make and model or your TV
(4) When you ask please give details about the format of the video files you want to play. If you do not know the format then state where you obtained them from as this may give a clue to others about the format.

Neil S
February 2014