A video processing method includes receiving an omnidirectional content corresponding to a sphere, generating a projection-based frame according to the omnidirectional content and a pyramid projection layout, and encoding, by a video encoder, the projection-based frame to generate a part of a bitstream. The projection-based frame has a 360-degree content represented by a base projection face and a plurality of lateral projection faces packed in the pyramid projection layout. The base projection face and the lateral projection faces are obtained according to at least projection relationship between a pyramid and the sphere.