An encoder includes circuitry and memory coupled to the circuitry. In operation, the circuitry determines whether or not a current video to be processed is a progressive video. When it is determined that the current video is a progressive video, the encoder encodes, into a bitstream, one syntax element indicating a chroma location type which is information indicating locations of chroma samples relative to luma samples for a frame included in the current video. When it is determined that the current video is not a progressive video, the encoder encodes two syntax elements into the bitstream, each of which indicates the chroma location type for a different one of fields of two types included in the current video.