I want to download movies from internet and watch them on my set-top box, because I don't have a PC. How can I convert these files (in my case MP4) so I can play them on the set-top box. I know they are different format. I think it is TRP.
Set-top boxes are not made equal. So, list the model of your box, or contact your service provide' help desk for help.
As a last resort - $50 media player could be the easiest solution (and you could get a streaming one for like $70)