Hello,
This is not readily available as the Video is hidden while it is getting resized to avoid jumps. However, we have tested the following code and it appears to be working fine:
<div class="swiper-slide dark">
	<div class="container">
		<div class="slider-caption slider-caption-center">
			<h2 data-animate="fadeInUp">Beautifully Flexible</h2>
			<p class="d-none d-sm-block" data-animate="fadeInUp" data-delay="200">Looks beautiful & ultra-sharp on Retina Screen Displays. Powerful Layout with Responsive functionality that can be adapted to any screen size.</p>
		</div>
	</div>
	<div class="swiper-slide-bg" style="background-image: url('images/videos/explore-poster.jpg');"></div>
	<div class="video-wrap">
		<video id="slide-video" poster="images/videos/explore-poster.jpg" preload="auto" loop autoplay muted>
			<source src='images/videos/explore.webm' type='video/webm' />
			<source src='images/videos/explore.mp4' type='video/mp4' />
		</video>
		<div class="video-overlay" style="background-color: rgba(0,0,0,0.55);"></div>
	</div>
</div>
Hope this Helps!
Let us know if we can help you with anything else or if you find any further issues.