I'm not exactly sure what You have in mind, but if You mean "New Trailers" module from our demo than it uses whatever was embeded in K2 media section. If You will provide a player and an embed code suitable to be a standalone feature than it will play videos from Your server directly.
Yes I mea New Trailers module. the popup opening with video preview works ONLY with external video, I'm not able to see preview with video uploaded directly into site's server. How can I use it with on-site videos ? Is it possibile ?