Google has released a new update that will allow you to insert videos from Google Drive into Google Slides. Prior to this update you were limited to only inserting videos from YouTube. With this new update, you will have the option to be able to loop the video, start it and end it at a specific time, and mute the audio. To get these options, simply right click on the video.
I created a short animation on this new feature.
Click here to read the official G Suite for Education update blog post.