A server (101) streams data coded by inter-frame prediction. The server (101) comprises: a transmission data generator (116) for causing an independently decodable key frame to be added with at least one difference frame following the key frame to create data of one transmission unit, and generating a buffering key frame added with information on the data of one transmission unit, the information including a frame number; and an output unit (114) for transmitting, with transmission timing of the key frame, a buffering key frame generated with a key frame that should be transmitted with the transmission timing, and transmitting an arbitrary frame with transmission timing of the difference frame. This can reduce buffering time for switching a terminal to play a stream between a plurality of terminals, allowing the switching to be done smoothly.