How to Add Video to Your PowerPoint 2013 Slides
Resize the movie if you want and drag it to a new location on the slide.
When you resize the movie, try to do it by using one of the corner handles. If you drag one of the side handles, you distort the image.
To play the movie while you’re working on the presentation in Normal View, double-click the movie. During a slide show, a single click does the trick, unless you set the movie to play automatically. In that case, the movie runs as soon as you display the slide.