Hover images and Videos

Hi all,

I got this code to show video loops on my blog. It’s working nicely.

Function.php

function catch_video() {
  global $post, $posts;
  $first_vid = '';
  ob_start();
  ob_end_clean();
  $output = preg_match_all('/<iframe.+src=[\'"]([^\'"]+)[\'"].*>/i', $post->post_content, $matches);
  $first_vid = $matches [1] [0];
  echo '<iframe width="100%" height="400" src="';
  echo $first_vid;
  echo '" frameborder="0" allowfullscreen></iframe>';
}

It is shown by the code in the loop: <?php catch_video();?>

Now, I would like that when it was posted a featured image instead of the video, it showed a code of mouse hover (I already have it ready), so I created this code but something is wrong with it:

<?php $blog = new WP_Query($args); ?>
<?php while( have_posts() ): the_post(); ?>

   <?php if(has_post_thumbnail()): ?>

   <!-- Hover Image -->
     <div class="image-wrapper-hover">
        <!-- hover-content -->
         <?php the_post_thumbnail('large');?>
     </div>
   <!-- close Hover Image -->	

   <?php else ?>

      <?php catch_video();?>

   <?php endif ?>

Anyone knows what is wrong?