Method and apparatus for generating and encoding projection-based frame with 360-degree content represented in projection faces packed in segmented sphere projection layout

A video processing apparatus comprising:

• a conversion circuit, arranged to receive an omnidirectional content corresponding to a sphere, and generate a projection-based frame according to the omnidirectional content and a segmented sphere projection (SSP) format, wherein the projection-based frame has a 360-degree content represented by a first circular projection face, a second circular projection face, and at least one rectangular projection face packed in an SSP layout, a north polar region of the sphere is mapped onto the first circular projection face, a south polar region of the sphere is mapped onto the second circular projection face, at least one non-polar ring-shaped segment between the north polar region and the south polar region of the sphere is mapped onto said at least one rectangular projection face, and the conversion circuit comprises:
• a padding circuit, arranged to generate at least one padding region;
• and
• a video encoder, arranged to encode the projection-based frame to generate a part of a bitstream;
• wherein the SSP layout further comprises said at least one padding region, said at least one padding region comprises a first padding region, the first padding region connects with one boundary of a first projection face that is one of the first circular projection face, the second circular projection face and said at least one rectangular projection face;
• and
• wherein the padding circuit is arranged to derive pixel values of pixels included in the first padding region from duplication of pixel values of pixels included in the first projection face.