title: Save OpenGL Rendering to Video
body: <p>I have an OpenGL game, and I want to save what's shown on the screen to a video.<br>
  How can I do that? Is there any library or how-to-do-it?<br>
  I don't care about compression, I need the most efficient way so hopefully the FPS won't drop.</p>
  
  <p><strong>EDIT:</strong><br>
  It's OpenGL 1.1 and it's working on Mac OSX though I need it to be portable.</p>