"shift +" while rendering in ffmpeg, how to undo? I was rendering a video in ffmpeg and accidentally pressed "shift" and "+", and the below started happening.

What is this doing and how do I stop it and is it creating something I need to delete or worry about? And what do I do to delete it if so?
Don't worry, all you did is increase verbosity. The Shift had no effect, but the + increased it. Press - to cycle back to a lower verbosity level.

Press ? to see a list of all available commands.

If you want to not worry about accidental keypresses, you can add -nostdin to the command. Don't do this if one of your inputs is a pipe.