Thanks Nat for reply.
In the example I gave its even more complicated to fix screen in post as the video cameras are often hand held with no gimbals or steady cam type devices and often only standard HD 1920x1080 resolution. The resulting uploaded video is shaky up & down and left to right as well as rotation.
I first try to stabilize, then use the mask but still end up with a trapezoidal screen shape if I want the screen in proportion. If I then try to use scale I turn circles into ovals, heads become noticeable wider as I scale the screen linear wider to make it rectangular.
When I watch it thru I still have the on-screen action moving out side the screen. So the left to right movement of the camera is quit a lot and irregular.
About the only think that I can do is tight crop which is cutting too much out.
Everyone that films anything should use either a steady cam type device or a rest, if you really want to film the tv to post and show people and you don’t have a tripod just use a chair to rest your video camera on and point it straight in front of the tv and don’t touch it until the item on the tv finishes. Other wise if you hand hold the video camera you will make your audience sea sick with a jerky and rolling picture.
Various video editors do have tracking plug-ins, but even these are only good for scenes, locking on to something in the scene to center or other wise setting the screen frame.
There is also “tracker-pod” web camera software used in competition ballroom dancing to follow a particular couple around the ballroom floor.