This extension allows you to upload a video to your website and then play it in any layout you want. It is not based on youtube or any other video hosting website, it will play videos from your own hosting and website.
The extension uses HTML5 video player and as such inherits all its limitation. Tested video formats are MP4 and WEBM. Also, it relies on the php upload limit and transaction time, so make sure you modify those accordingly. If the file is too big or takes too long the extension will not work properly, this is not a limitation with the extension, this is a PHP thing.