PURPOSE: To avert the deterioration in image quality generated by passing video signals plural times through decimation filters and (or) interpolation filters.

CONSTITUTION: A MAC encoder which encodes the video signals Y/Pb/Pr to a MAC format is provided with vertical sub-samplers 20, 24 which executes vertical sub-sampling of color difference signals Pb/Pr, vertical filters 18, 22 which vertically filter the color difference signals and limit the frequency vectors thereof to prescribed bands, a multiplexer 14 which generates a MAC format signal by multiplexing the filtered and sub-sampled color difference signals together with brightness information Y, and a marker detector 28 which prohibits the above-mentioned vertical filtering by responding to the video signals including the marker information indicating that the video signals are previously subjected to the MAC encoding.