Video Accessibility

<p><em>Select play to begin the video presentation.</em>
</p>
<div title="This is a video describing the System Safety Process. The play button will begin the video.">
  <video height="360" width="640" poster="../media/5114/WO57_02-poster.jpg" preload controls>
    <source src="../media/5114/WO57_02.mp4" type="video/mp4" /> 
    <source src="../media/5114/WO57_02.webm" type="video/webm" /> 
    <track default="" kind="captions" label="Captions" src="../media/5114/WO57_02.vtt" srclang="en" />
  </video>
</div>

<!-- 
This is the snippet. It's part of a training template used for interactive learning.
Client's technique to date has been to use a title attribute on the parent div. 
Screen reader reads the title attribute value when the user tabs throught the screen.

I'm building a new interface for future courses and I'm curious if this technique 
could/should be replaced with aria-describedby attributes.
-->