Transmission device, transmission method, reception device, reception method, and program

A transmission method comprising steps of:

• packetizing time stamps into a time stamp packet;
• encoding data associated with the time stamps;
• packetizing the coded data encoded by the encoding unit into a data packet;
• multiplexing the time stamp packet and the data packet, generating a multiplexed stream, and transmitting the multiplexed stream to a reception device, wherein
• in a process of the time stamp packetizing step for packetizing the time stamps into the time stamp packet,
• the time stamps are packetized into the time stamp packet on a group basis, the group including the data associated with the time stamps, and
• in a case where a change is made in a group configuration or the time stamps of the group, the changed group configuration or time stamps of the group is packetized into the time stamp packet, and
• in a process of the step for generating the multiplexed stream and transmitting the multiplexed stream to the reception device, the time stamp packet of the changed group configuration or time stamps of the group is retransmitted to the reception device at a timing so that the time stamp packet is received before the reception device starts to decode the coded data corresponding to the changed group configuration or time stamps of the group.

A non-transitory computer readable medium storing program code, the program code being executable by a computer to perform operations comprising:

• packetizing time stamps into a time stamp packet;
• encoding data associated with the time stamps to produce coded data;
• packetizing the coded data into a data packet;
• multiplexing the time stamp packet and the data packet, generating a multiplexed stream, and transmitting the multiplexed stream to a reception device;
• wherein packetizing the time stamps comprises packetizing the time stamps into the time stamp packet on a group basis, the group including the data associated with the packetized time stamps, and
• in a case where a change is made in a group configuration or the time stamp of the group, packetizing the changed group configuration or time stamps of the group into the time stamp packet;
• and
• retransmitting the time stamp packet of the changed group configuration or time stamps of the group to the reception device at a timing so that the time stamp packet is received before the reception device starts to decode the coded data corresponding to the changed group configuration or time stamps of the group.

A reception device that receives a multiplexed stream transmitted from a transmission device including:

• a time stamp packetizing unit configured to packetize time stamps into a time stamp packet;
• an encoding unit configured to encode data associated with the time stamps;
• a data packetizing unit configured to packetize the coded data encoded by the encoding unit into a data packet;
• and
• a multiplexing unit configured to multiplex the time stamp packet and the data packet, generate a multiplexed stream, and transmit the multiplexed stream to the reception device, wherein
• the time stamp packetizing unit
• packetizes the time stamps into the time stamp packet on a group basis, the group including the data associated with the plurality of time stamps, and
• in a case where a change is made in a group configuration or the time stamps of the group, packetizes the changed group configuration or time stamps of the group into the time stamp packet, and
• the multiplexing unit retransmits the time stamp packet of the changed group configuration or time stamps of the group to the reception device at a timing so that the time stamp packet is received before the reception device starts to decode the coded data corresponding to the changed group configuration or time stamps of the group,
• the reception device comprising:
• a separating unit configured to separate the multiplexed stream into the time stamps and the coded data associated with the time stamps;
• a time stamp storing unit configured to store the time stamps;
• an update management unit configured to manage an update of the time stamps stored in the time stamp storing unit;
• a decoding unit configured to decode the coded data associated with the time stamps, which is separated by the separating unit;
• and
• a synchronization control unit configured to control a timing to decode the coded data associated with the time stamps and a timing to show the decoded data associated with the time stamps, on the basis of information of the time stamps stored in the time stamp storing unit, wherein
• in a case where the retransmitted time stamp is transmitted, the update management unit updates the time stamps stored in the time stamp storing unit with the undecoded time stamp among the time stamps in the group based on the retransmitted time stamp and stores the time stamps, and
• the synchronization control unit controls the timing to decode the coded data associated with the time stamps and the timing to show the decoded data associated with the time stamps, on the basis of the time stamps updated and stored in the time stamp storing unit.

A reception method of a reception device that receives a multiplexed stream transmitted from a transmission device including:

• a time stamp packetizing unit configured to packetize time stamps into a time stamp packet;
• an encoding unit configured to encode data associated with the time stamps;
• a data packetizing unit configured to packetize the coded data encoded by the encoding unit into a data packet;
• and
• a multiplexing unit configured to multiplex the time stamp packet and the data packet, generate a multiplexed stream, and transmit the multiplexed stream to the reception device, wherein
• the time stamp packetizing unit
• packetizes the time stamps into the time stamp packet on a group basis, the group including the data associated with the time stamps, and
• in a case where a change is made in a group configuration or the time stamps of the group, packetizes the changed group configuration or time stamps of the group into the time stamp packet, and
• the multiplexing unit retransmits the time stamp packet of the changed group configuration or time stamps of the group to the reception device at a timing so that the time stamp packet is received before the reception device starts to decode the coded data corresponding to the changed group configuration or time stamps of the group,
• the reception method comprising steps of:
• separating, from the multiplexed stream, the time stamps and the data which is encoded and associated with the time stamps;
• storing the time stamps;
• managing an update of the stored time stamps;
• decoding the coded data which is separated by the separating unit and associated with the time stamps;
• and
• controlling a timing to decode the coded data associated with the time stamps and a timing to show the decoded data associated with the time stamps, on the basis of information of the stored time stamps, wherein
• in a case where the retransmitted time stamp is transmitted, in a process of the managing step for managing an update of the stored time stamps, the undecoded time stamp among the time stamps in the group is stored by updating the stored time stamps on the basis of the retransmitted time stamp, and
• in a process of the controlling step for controlling the timings, the timing to decode the coded data associated with the time stamps and the timing to show the decoded data associated with the time stamps are controlled on the basis of the updated and stored time stamps.

A non-transitory computer readable medium storing program code for controlling a reception device that receives a multiplexed stream transmitted from a transmission device, wherein the transmission device includes:

• a time stamp packetizing unit configured to packetize time stamps into a time stamp packet;
• an encoding unit configured to encode data associated with the time stamps;
• a data packetizing unit configured to packetize the coded data encoded by the encoding unit into a data packet;
• and
• a multiplexing unit configured to multiplex the time stamp packet and the data packet, generate a multiplexed stream, and transmit the multiplexed stream to the reception device, wherein
• the time stamp packetizing unit
• packetizes the time stamps into the time stamp packet on a group basis, the group including the data associated with the time stamps, and
• in a case where a change is made in a group configuration or the time stamps in the group, packetizes the changed group configuration or time stamps of the group into the time stamp packet, and
• the multiplexing unit retransmits the time stamp packet of the changed group configuration or time stamps in the group to the reception device at a timing so that the time stamp packet is received before the reception device starts to decode the coded data corresponding to the change group configuration or time stamps of the group,
• the program code being executable by a computer to perform operations comprising:
• separating the multiplexed stream into the time stamps and the coded data associated with the time stamps;
• storing the time stamps;
• decoding the coded data associated with the time stamps;
• controlling a timing to decode the coded data associated with the time stamps and a timing to show the decoded data associated with the time stamps, on the basis of information of the time stamps stored in the time stamp storing unit, wherein
• in a case where the retransmitted time stamp is transmitted, the time stamps that are stored are updated with the undecoded time stamp among the time stamps in the group based on the retransmitted time stamp and are stores the updated time stamps;
• and
• controlling the timing to decode the coded data associated with the time stamps and the timing to show the decoded data associated with the time stamps, on the basis of the updated time stamps updated that are stored.