This is a recent issue. I took a video from my camera as well as a different video from my web cam. Loaded them in to Movie Studio 17.0 Platinum and edited them. The raw video played fine. The edited version played fine on the preview panel. When I rendered the movie and saved it to the desk top the video had pixelated portions that would come in and out of focus.
There was a recent update to the program. Not sure that has anything to do with this. I just know that I have made a lot of videos and never had this problem. The only video that does not paly smoothly is the rendered version.
Any help would be apricated.