Firefox, Chrome, Safari have grey background for mp4 html5 video

in my case it was only firefox with gray background and the problem after google it was with filter and brightness

am using Revolution Slider

so i added this code

 

.fullcoveredvideo video, .fullscreenvideo video {

filter: url("data:image/svg+xml;utf8,<svg xmlns=\'http://www.w3.org/2000/svg\'><filter id=\'brightness\'><feColorMatrix type=\'matrix\' values=\'1.2 0 0 0 0 0 1.2 0 0 0 0 0 1.2 0 0 0 0 0 1.2 0\'/></filter></svg>#brightness");
}