I suppose what's at the root of Dave's question is: What if you could somehow 'reconstruct' the scene which is outside the left and right boundaries of a portrait mode video.
I would suggest that it would be simpler just to equip the phone with sensor / lens coverage much wider than the field of view seen on the vertically oriented screen - the user would still hold the phone whichever way up they wanted to and compose the shot on what they see, but if played back on a landscape player the 'wider' recorded material would be seen.
The main argument against this is the amount of storage which would be wasted recording the unseen 'side' information when it might never be seen.
A better, and more practical idea: Automatically disable video recording on any mobile phone which is oriented vertically. ...Problem solved.
Rambo, I had to google VVS. It means different things in different contexts but I'm sure this is the one you had in mind.
https://www.urbandictionary.com/defi...deo%20syndrome