The 1st thing you’ll need is a stock video for your animated background.  A great site to find these is VideoHive.  The one used in this example is found here.

You’ll need to grab frames from the video and save them as individual files.  Most video players will allow you to save individual frames.  Save a frame, and move the playback head forward a bit to save another. You only need 5-10 frames per shot to make the animation look fluid.  In this example there’s only 2 shots so we’re using 20 background animation frames.  Too few frames and the animation will look jumpy.  Too many and it will take too long process.  Be careful to save your files in a sequential format and be sure to use 2 digits like 01.jpg02.jpg etc…

Each frame should be resized to 600×400 px as this is the final size of the animated GIF.

The next step is to enable animated GIFs in Social Booth as well as enabling Animated Backgrounds and select the folder where you saved your frames from the video.  Remember Animated Backgrounds require the use of Green screen so be sure to enable that as well.

If you can’t shoot on greenscreen and still would like a similar effect, you can use Animated Overlays instead.  It’s a similar concept, except the animation is being placed on top of the photos as opposed to behind them.