title: creating HTML5 video tile
body: <p>I am trying to implement a responsive video "collage" that display videos of various aspect ratios in a flexible grid. </p>
  
  <p>In each row, the videos have the same height, but they fill the horizontal width of a div. Since the width and the aspect ratio of each video are known, I think it's straightforward to calculate the height. Not sure how to implement it with CSS + Javascript. Anyone can help? Thank you very much.   </p>