You can now insert and play your Google Drive videos in Google Slides, in addition to videos from YouTube.
Once you’ve added a Drive video to your presentation, you can choose when to start and end it, whether it should autoplay when presenting, and whether it should be muted or play with audio. Simply right-click on the video and select Video options.
If a person viewing your presentation doesn’t have permission to view a video embedded within it, they’ll be prompted to request access.
Note that while you can play Drive videos in Slides on the web and mobile, you can only insert them from the web application.