title: Trying to understand CMTime and CMTimeMake
body: <p>1) <code>CMTimeMake(1,10)</code> means duration of 1 second and timescale of 10, or 10 frames per second. This means 1s duration of video with 10 frames?</p>
  
  <p>2) </p>
  
  <pre><code>CMTime lastTime=CMTimeMake(1,10);
  CMTime frameTime=CMTimeMake(1, 10);
  CMTime currentTime=CMTimeAdd(lastTime, frameTime)
  </code></pre>
  
  <p>= (2, 10) ?</p>
  
  <p>2 seconds of video and with 10 frames per second of the currentTime?</p>