With the use of Studio, you can now fairly easily use videos in discussions. Check this tutorial (length: 4 minute and 18 seconds) for more information. We would like to thank Dr. Tim Sensing from the Graduate School of Theology for permission to use his instructions for illustration.
As mentioned in the video, it is a good idea to include a short tutorial video showing students how to comment with videos. Here is the URL to the video you could link to or embed in your course: