This tutorial had some great information, but I commonly need to have a video run in a continuous loop. Unfortunately, as far as I know that's a function of the video player itself and not a feature you can add to the .mp4 file. The method shown in this tutorial works fine for a few repeats, but wouldn't be practical for an infinite loop because of file size and rendering time. Most social media sites will automatically loop short videos for you, but if you are presenting the video on a website the only way I've found to do it is to use HTML5 tags. If anyone is aware of another way to do it, please let me know! Here's an example:
<video width="1920" height="1080" loop="loop"autoplay><source src="movie.mp4" type="video/mp4"> </video>
