  This paper presents an efficient method for encoding common projection
formats in 360$^\circ$ video coding, in which we exploit inactive regions.
These regions are ignored in the reconstruction of the equirectangular format
or the viewport in virtual reality applications. As the content of these pixels
is irrelevant, we neglect the corresponding pixel values in ratedistortion
optimization, residual transformation, as well as inloop filtering and achieve
bitrate savings of up to 10%.
