For encoding externally input AV signal to MPEG-TS that enables quickly conversion from MPEG-TS to MPEG-PS, data unit (Multiplexing Unit) is defined which includes a plurality of packet and has data size corresponding to data amount of one pack in MPEG-PS, and MPEG-TS is encoded for each defined data unit. Furthermore, time stamp information (ATS) added to a packet of MPEG-TS which is converted to MPEG-PS and time stamp information (SCR) added to a packet of the converted MPEG-PS are correlated with a predetermined formula.