One of the advantages of creating your own video assignment (over delivering a speech in person to a live audience) is that you can make a test recording first.  Be sure that you test the following: lighting, sound, reflections, obstructions, etc.  You can also record your video assignment as many times as you like before uploading it.  Take advantage of this opportunity.  You may even want to record practice speeches so that you get more comfortable in front of the camera.