title: Add annotations to a web video
body: <p>I would like to implement a web application where you can <strong>upload a video</strong> (e.g. in mp4 format) and <strong>add custom messages</strong> to it or <strong>tag specific frames</strong>. I need to be able to determine the location, size and duration of the balloon containing the text. The interface should be easy enough to use and allow you to add a simple text or a link.  </p>
  
  <p>How could I implement this? Is there a platform I could use? Looking around I found this platform called <strong>WireWax</strong> which basically does everything I need, however there is no pricing section and I suspect that you have to contact them directly.</p>
  
  <p>Another interesting product that I found is <strong>Popcorn.js</strong> which allows you to add annotations to videos, but I would have to create from scratch the interface to add messages.</p>
  
  <p>Do you have any advice?</p>