title: Dynamically using the first frame as poster in HTML5 video?
body: <p>I'm wondering if there's any straightforward way to achieve this effect, without needing backend code to extract a frame, save it as a jpg and database it somewhere.</p>
  
  <p>An effect whereby the first frame of the video just shows up as the poster when the video loads would be so helpful (it would only work if the browser can play back the video obviously, which might be a little different from how <code>poster</code> traditionally works, but that is not a concern.</p>