A family of Microsoft presentation graphics products that offer tools for creating presentations and adding graphic effects like multimedia objects and special effects with text.
Do not insert the video in the slide master. If you insert it there, it will re-start with every slide.
Insert your video on the first slide. Change the animation to "Play". Set it to play across slides. Then it will continue to play, if you change slides. BUT: You cannot display the text of the second slide in front of the video, it will be placed behind it. So this method works only for animated borders, not for full-size backgrounds.
Best,
Ute