Video not playing on Android

I am using the plugin with a .mp4 video, it plays on firefox, ipad, chrome etc but has to play on android dolphin. When I view it on android it just shows a grey box with a film image silhoutted in the background. Any ideas what I can do to get the video to work on dolphin?

https://www.ads-software.com/extend/plugins/media-element-html5-video-and-audio-player/