I wonder how this is done since I don't really see an option in the widget, unless you can upload any of the supported formats and SF will convert them on upload, or on the fly.
RadMediaPlayer works with files of any HTML5-supported format, including WebM, Ogg, MP4 and WAVE. In browsers not supporting HTML5 the control falls back to Flash.Because not all modern browsers support the same formats, the control allows you to specify different formats of the file to automatically match the user’s browser with the right format.
PS: I think the youtube stuff could have been exposed better for endusers. Button add youtube video browse to video and enter.