Q:"Is there a way to crop a video in QuickTime Player?" - From Quora

Possibly, there will be times when you need to crop some of the unnecessary surrounding frame from your video, remove irrelevant image area that you would like to conceal or make a video compatible to view in a frame device. Wonder how to crop video in QuickTime but still find no way? Happily, you just have to take a moment in this post to learn the full steps below. In case you are confused by the complexity of the procedure, we have also specially prepared an alternative to QuickTime Player for you to crop on Mac.