Locate and draw a box around the moving object. Value 'preview' makes Motion only draw a box on a saved preview jpeg image and not on the saved mpeg movie.
The value 'preview' only works when 'output_normal' is set to either 'first' or 'best'.
Locate and draw a box around the moving object. Value 'preview' makes Motion only draw a box on a saved preview jpeg image and not on the saved mpeg movie.