title: Responsive Tumblr videos not working
body: <p>I'm trying to make videos on my Tumblr theme responsive. I am using <code>fitvids.js</code> to resize Vimeo and YouTube embeds. However, it won't work with Tumblr's native video player.</p>
  
  <p>The Tumblr native video player uploads an iframe at a fixed width — I can change this, but then the formatting of the controls are very wonky (they must depend on the fixed height or width). </p>
  
  <p>Also, the iframe <code>src</code> is hidden (<code>about:blank</code>), and Tumblr must do something custom to replace it:</p>
  
  <pre><code>&lt;iframe width="500" height="281" src="about:blank" id="tumblr_video_iframe_87978936100" class="tumblr_video_iframe has_lightbox" data-origin="ckone-dev.tumblr.com" data-width="500" data-height="281" frameborder="0" scrolling="no" webkitallowfullscreen="" mozallowfullscreen="" allowfullscreen="" seamless="" style="display:block;background-color:transparent;overflow:hidden;"&gt;
  &lt;/iframe&gt;
  </code></pre>
  
  <p>Is there a solution to access an API for this video player, or at least change some of the contents of the iframe?</p>