user15878: I've been looking everywhere to try to figure this out. I am trying to figure out how to make a video transition where the background changes before everything else. Is this just done with a mask? 
https://instagram.com/p/BF-K-V5ges1/

user674: According to the comments on that page, it is rotoscoped - which is (from Wikipedia)

the technique of manually creating a matte for an element on a live-action plate so it may be composited over another background.


15878: <p>I've been looking everywhere to try to figure this out. I am trying to figure out how to make a video transition where the background changes before everything else. Is this just done with a mask? </p>

<p><a href="https://instagram.com/p/BF-K-V5ges1/" rel="nofollow">https://instagram.com/p/BF-K-V5ges1/</a></p>
 674: <p>According to the comments on that page, it is rotoscoped - which is (<a href="https://en.wikipedia.org/wiki/Rotoscoping" rel="nofollow">from Wikipedia</a>)</p>

<blockquote>
  <p>the technique of manually creating a matte for an element on a live-action plate so it may be composited over another background.</p>
</blockquote>
