To quickly process image data both in a predetermined studio and in another studio.

An MPEG video encoder 42A superimposes, on the elementary stream of encoded video data, Picture Order Information representing an encoding order and display order of a picture and transmits the elementary stream to an SDTI-CP network within the same studio via an SDTI-CP interface 46. When the elementary stream is received via SDTI-CP interfaces 46, 51, a TS MUX/DEMUX 61 extracts the Picture Order Information contained therein, generates a time stamp on the basis of the extracted information, superimposes the time stamp on a transport stream and transmits it to the other studio.