Trying to fix MIME issue of video

Author: nimisha-chaturvedi

_includes/headers/expanded.html

@@ -15,7 +15,7 @@ <h1>Advancing AI/data mining for extremely large and diverse data for Europe and
                        rel="noopener">Watch on YouTube.com</a>
 
                     <video controls muted autoplay>
-                        <source src="https://d25jew5a8evv5b.cloudfront.net/intro.mp4" type="video/mp4">
+                        <source src="https://d25jew5a8evv5b.cloudfront.net/intro.mp4" type="video/mp4; codecs='avc1.42E01E, mp4a.40.2'">
                     </video>
                 </div>
             </div>