A video banner is a standard video with one exception, it’s height is less than the standard height. A standard HD video is rendered at 1280×720. A video banner is rendered at 1280×360 or 1280×240, allowing for the video to be placed at the top of a WordPress blog, if you’re using a theme that supports a Header widget. When Uploaded to YouTube, this is the way it displays as 640×360:
Once the OLD EMBED code is copied from the YouTube site and placed into a Header widget, the parameters are modified. This is the same video, with the height changed to 180. It could be set to autoplay and loop, but if there is audio, either music or music and voice, it’s best to NOT autoplay it.