The video thumb is streched

To display the Video thumbnail in the DW Wallpress, take a look at the following solution:
1. Log in to Dashboard  > Appearance > Customize > Custom Code, add the following code to the “Header Code” section.

 <style>
.masonry .format-video .item-content iframe, .masonry .format-video .item-content embed {
    display: block;
}
</style>

 – Add the following code to the “Footer code” section:

  <script>
jQuery(function($){
 function responsiveIframe() {
   $('iframe').each(function(){
       if ( ! $(this).hasClass('twitter-tweet') ) {
           var iw = $(this).attr('width');
           var ih = $(this).attr('height');
           var ip = $(this).parent().width();
           var ipw = ip/iw;
           var ipwh = ih*ipw; 
           $(this).css({
               'width': ip,
               'height' : ipwh,
           });
       }
   });
 }

 $(document).ready(function(){
  responsiveIframe();
 });

 $(window).resize(function(){
  setTimeout(function(){
   responsiveIframe();
  },500);
 });
 $('.masonry').masonry('reload',function(){
  setTimeout(function(){
   responsiveIframe();
  },500);
 });
});
</script>

2. Open the functions.php file. Find the line 660 & line 661. Replace the following code:

 add_filter('the_excerpt', 'wallpress_strip_tags');
add_filter('the_content', 'wallpress_strip_tags');

With new code:

 //add_filter('the_excerpt', 'wallpress_strip_tags');
//add_filter('the_content', 'wallpress_strip_tags');

Hope this helps !

Hi Tamas,
Thanks for the additional info !
I checked your site and below is our suggestion:
The best solution to resolve the issue is to use iframe for embedded video instead of object. 
Try it and let us know the result,
my friend 😉