A video transmission device comprising: an input processing unit configured to extract access units from a group-of-pictures (GOP) constituting a hierarchically encoded bit stream and impart a decoding time stamp to each extracted access unit; a GOP number imparting unit configured to detect a GOP head access unit of a base layer from among the extracted access units, impart a GOP number to the GOP head access unit of the base layer, further detect a GOP head access unit of an enhancement layer using a decoding time stamp of the GOP head access unit of the base layer and individual decoding time stamps of access units of the enhancement layer, and impart a GOP number to the GOP head access unit of the enhancement layer in accordance with a decoding time stamp of the GOP head access unit of the enhancement layer; and a hierarchical transmission control unit configured to transmit, hierarchically, access units of the base layer and access units of the enhancement layer using the GOP number imparted by the GOP number imparting unit; wherein the hierarchically encoded bit stream is input in MPEG-2 Transport Stream (TS) format; wherein the input processing unit is a TS processing unit that reconfigures a packetized elementary stream (PES) from the MPEG-2 TS and imparts a decoding time stamp (DTS) included in a header of the PES as the decoding time stamp to an access unit obtained from a payload of the PES; and wherein the hierarchical transmission control unit is an MMT transmission control unit that encapsulates the access units of the base layer and the access units of the enhancement layer in each of media processing units (MPUs) having different packet ids and transmits the MPUs according to an MPEG Media Transport (MMT) protocol. an input processing unit configured to extract access units from a group-of-pictures (GOP) constituting a hierarchically encoded bit stream and impart a decoding time stamp to each extracted access unit; a GOP number imparting unit configured to detect a GOP head access unit of a base layer from among the extracted access units, impart a GOP number to the GOP head access unit of the base layer, further detect a GOP head access unit of an enhancement layer using a decoding time stamp of the GOP head access unit of the base layer and individual decoding time stamps of access units of the enhancement layer, and impart a GOP number to the GOP head access unit of the enhancement layer in accordance with a decoding time stamp of the GOP head access unit of the enhancement layer; and a hierarchical transmission control unit configured to transmit, hierarchically, access units of the base layer and access units of the enhancement layer using the GOP number imparted by the GOP number imparting unit; wherein the hierarchically encoded bit stream is input in MPEG-2 Transport Stream (TS) format; wherein the input processing unit is a TS processing unit that reconfigures a packetized elementary stream (PES) from the MPEG-2 TS and imparts a decoding time stamp (DTS) included in a header of the PES as the decoding time stamp to an access unit obtained from a payload of the PES; and wherein the hierarchical transmission control unit is an MMT transmission control unit that encapsulates the access units of the base layer and the access units of the enhancement layer in each of media processing units (MPUs) having different packet ids and transmits the MPUs according to an MPEG Media Transport (MMT) protocol. <EOS>