Railpage supports auto-embedding of videos from a growing list of platforms. As of April 2016 we support videos hosted on Railpage in our Downloads module, as well as videos hosted on YouTube and Vimeo.
To insert a video into your post, it's as simple as pasting the URL of the video. You can get the URL of your video from the address bar - simply select the URL, copy, and paste into your forum post. Railpage will then automatically convert that link into a fully embedded video!