title: Write video frames directly to file, bypassing screen rendering
body: <p>I am making a video out of a sequence of plots using <code>VideoWriter</code>.  It works mostly OK (after following advice in <a href="https://stackoverflow.com/a/8619687/133234">this SO answer</a>). However, it seems that Matlab tries to render all 3000 frames to screen sequentially after it's done animating, which causes my window manager to freak out and the computer to freeze for a few minutes.  </p>
  
  <p>Is there a way to write the video frames directly to disk, bypassing screen rendering?  It seems that <code>getframe</code> in <code>writeVideo(vid, getframe(f))</code> necessarily makes the figure visible; is there a way to avoid that?</p>