Maybe something like this would help?:
.secondary-navigation .current-menu-item > .sub-menu,
.secondary-navigation .current-menu-ancestor > .sub-menu {
position: relative;
visibility: visible;
opacity: 1;
height: auto;
left: 0;
right: 0;
width: auto;
float: none;
}
.secondary-navigation .current-menu-item:hover > .sub-menu,
.secondary-navigation .current-menu-item.sfHover > .sub-menu,
.secondary-navigation .current-menu-ancestor:hover > .sub-menu,
.secondary-navigation .current-menu-ancestor.sfHover > .sub-menu {
left: 0 !important;
width: 100% !important;
}
Not sure about video playback, unfortunately. I think that would need adjusting in your video editing software.