Loudness measurement of immersive audio has been standardized in ITU BS 1770-4 Annex 3. This specifies a extension of the regular measurement method by explaining how to measure immersive audio with height channels. The extended method modifies the weighting coefficients according to both the azimuth and the elevation of the input channel. Loudness measurement as per BS 1770-4 with optional Dialog Intelligence of Dolby Digital Plus with Dolby Atmos is performed automatically during encoding of file-based (non-live) content.