Transmission device, transmitting method, reception device, and receiving method

A transmitting method comprising:

• a clock generation step to generate a clock of a first frequency synchronized with time information acquired from a time information server;
• a time information generation step to generate time information synchronized with time information acquired from the time information server and including frequency information of the clock of the first frequency generated in the clock generation step;
• an encoding step to encode a transmission medium;
• a packetizing step to fragment, in a predetermined unit, the transmission medium encoded in the encoding step, and generate a transmission media packet including each fragment;
• and
• a transmission step to perform transmission by carrying, on a broadcast wave, a stream that includes, on time division basis, the transmission media packet generated in the packetizing step, a packet having time information generated in the time information generation step, and a packet including a control signal.

A reception device comprising:

• a receiving unit configured to receive a broadcast wave carrying a stream that includes, on time division basis, a transmission media packet including a fragment obtained by fragmenting an encoded transmission medium, a time information packet including frequency information of a clock of a first frequency and having time information synchronized with time information acquired from a time information server, and a control signal packet having a control signal;
• a clock generation unit configured to generate a clock of the first frequency based on time information included in the time information packet;
• a time information generation unit configured to generate time information including frequency information of the clock of the first frequency generated in the clock generation unit and synchronized with time information acquired from the time information server;
• a time calculator configured to calculate a decoding time and a presentation time per presentation unit of the transmission medium based on period information inserted into the transmission media packet;
• and
• a processing unit configured to process, per presentation unit, an encoded transmission medium included in the transmission media packet received in the receiving unit based on the decoding time and the presentation time calculated in the time calculator and the time information generated in the time information generation unit.

A receiving method comprising:

• a receiving step to receive a broadcast wave carrying a stream that includes, on time division basis, a transmission media packet including a fragment obtained by fragmenting an encoded transmission medium, a time information packet including frequency information of a clock of a first frequency and having time information synchronized with time information acquired from a time information server, and a control signal packet having a control signal;
• a time calculation step to calculate a decoding time and a presentation time per presentation unit of the transmission medium based on period information inserted into the transmission media packet;
• a clock generation step to generate a clock of the first frequency based on time information included in the time information packet;
• a time information generation step to generate time information synchronized with time information acquired from the time information server and including frequency information of the clock of the first frequency generated in the clock generation step;
• and
• a processing step to process, per presentation unit, an encoded transmission medium included in the transmission media packet received in the receiving step based on the decoding time and the presentation time calculated in the time calculator and the time information generated in the time information generation step.