Conversion between different projection formats of a 360-degree video may be performed in a uniform way. The geometric characteristics of the different projection formats may be considered when applying 3D-to-2D and 2D-to-3D mapping. Parameters reflective of the geometric characteristics of the different projection formats may be determined and used in the mapping and/or conversion. The parameters may include a normal vector that is perpendicular to a projection plane, a reference point in the projection plane, and/or unit vectors defined in the projection plane. An architecture with consolidated modules for handling the various projection formats may be provided.