title: Adding an Overlay Using FFMPEG With Minimal Re-Encoding
body: <p>FFMPEG is really useful for cutting a part of a video, without re-encoding the video.</p>
  
  <p>I know it is also possible to use FFMPEG for adding an <strong>Overlay Image</strong> to a video, in a certain part of the video (for example from 10secs till 20secs).</p>
  
  <p>My question is: If I do this overlaying of an image, will the whole video get re-encoded because of that? Or just the relevant duration will be encoded?</p>
  
  <p>Also are there any options that I can use to make the re-encoding minimal?<br>
  The purpose if of course to keep the quality of the video like the original one..<br>
  (I would ask for no re-encoding at all, but I don't see how that might be possible...)</p>
  
  <p>Thank you</p>