title: How do I know my youtube video has buffered sufficiently to play using api
body: <p>If I want to make a youtube video seek and then play, using the javascript api, I first need to wait until the video has buffered.  Sometimes the video appears with a circle in the middle going round and round for a while, and I assume that means its buffering.  </p>
  
  <p>Is there some event I can listen for that tells me that not only is the player loaded, but the player has buffered enough to seek?</p>
  
  <p>In addition, is there a way of knowing whether the player is in the middle of a seek, so I can wait for the seek to complete, before doing another seek?
  Thanks,</p>