Our webpage is using WordPress 4.2.1 running Virtue - Premium theme.
When I insert a video using visual editor, e.g.
[video width="1280" height="720" mp4="http://F6tech.com/wp-content/uploads/../../test.mp4"][/video]
There is no preview on the webpage. It just shows a black video screen with an arrow.
Is it possible to display a still from the tenth second of the video instead?