Abstract: A distribution apparatus for distributing content data items via multicast includes a transmitting and receiving unit and an error correction encoding unit. The transmitting and receiving unit receives reception status information regarding a reception status of the content data items in a receiving apparatus that receives the content data items. The error correction encoding unit generates recovery data used by the receiving apparatus to recover a content data item that is not successfully received among the content data items on the basis of reception status information received from the receiving apparatus that receives the content data items distributed via multicast. Subsequently, the transmitting and receiving unit distributes the generated recovery data together with the content data items via multicast.

Abstract: A control apparatus includes an obtaining unit configured to obtain information for obtaining first moving image data that is stored in a storage device, a reproduction unit configured to reproduce second moving image data of which at least one of a bit rate, a frame rate, and resolution has been converted from that of the first moving image data, a generation unit configured to generate an instruction to reproduce the first moving image data based on the information obtained by the obtaining unit, and a communication unit configured to transmit, via a network, the instruction generated by the generation unit to a reproduction control device that controls a display device to reproduce the first moving image data.

Abstract: A moving image reproducing apparatus which receives moving image data transmitted through a network and reproduces the moving image data includes an analysis unit adapted to analyze first moving image data stored in a storage unit and additional information of the first moving image data, a determination unit adapted to determine a storage destination on the network which is configured to acquire second moving image data following the first moving image data on the basis of the analysis result on the additional information, an acquisition unit adapted to acquire the second moving image data from the storage destination of the second moving image data, and a reproducing unit adapted to reproduce the second moving image data acquired by the acquisition unit concurrently with finishing reproduction of the first moving image data.

Abstract: An error pattern analysis unit specifies positions of discarded packets in continuously transmitted groups of packets. A QoS control unit estimates the cause of a communication error based on the specified positions of discarded packets, and performs QoS control based on the estimated cause of the communication error.

Abstract: A transmission apparatus is provided, including a combination determination unit configured to determine combinations of data packets so that when a data packet in a first frame is missed in transmission, a recover packet (FEC packet) for recovering the missing data packet is generated based on data packets in the first frame and data packets in a second frame, and an error correction coding unit configured to generate a recover packet based on the determination made by the combination determination unit.

Abstract: A data playback device comprising a data reader which reads out moving image data from a storage device that stores the moving image data, a speed detector which detects a reading speed of the moving image data from the storage device, a data rate detector which detects a data rate of the moving image data in playback, a playback speed designation acceptance unit which accepts designation of a playback speed of the moving image data and a controller which controls reading of the moving image data by the data reader on the basis of the reading speed, the data rate, and the designated playback speed.

Abstract: A method for transmitting moving image data that includes a plurality of frames each divided into a plurality of pieces of data includes setting a priority to each of the plurality of pieces of data based on a characteristic thereof, determining a transmission order of the plurality of pieces of data to transmit the plurality of pieces of data according to the set priority, wherein a transmission order of the plurality of pieces of data having a same priority is determined not to transmit data which is displayed at a same position in successive frames in a same transmission order, and transmitting the plurality of pieces of data in the determined transmission order.

Abstract: A communication apparatus which can communicate a data packet, a recovery packet used to recover a data packet that failed to be communicated, and a retransmit packet for the data packet that failed to be communicated, the communication apparatus includes a determining unit configured to determine, when a first packet of a plurality of packets that failed to be communicated is normally communicated, a packet that can be recovered, from among the plurality of the packets that failed to be communicated based on the first packet and the normally communicated recovery packet, and a retransmit determination unit configured to determine not to retransmit at least a part of the plurality of packets that can be recovered, when the first data packet is retransmitted which is determined to recover a plurality of data packets if it is normally communicated.

Abstract: A communication control apparatus includes a data acquiring unit configured to acquire data to be transmitted to a receiving apparatus, a packetizing unit configured to generate packets using the data acquired by the data acquiring unit, a determining unit configured to compute a possible data transmission delay time of the data packetized by the packetizing unit and determine a transmission interval of the packets based on a result of the computation, and a transmission unit configured to transmit the packets generated by the packetizing unit at intervals that are each within the transmission interval determined by the determining unit.

Abstract: A distribution apparatus for distributing content data items via multicast includes a transmitting and receiving unit and an error correction encoding unit. The transmitting and receiving unit receives reception status information regarding a reception status of the content data items in a receiving apparatus that receives the content data items. The error correction encoding unit generates recovery data used by the receiving apparatus to recover a content data item that is not successfully received among the content data items on the basis of reception status information received from the receiving apparatus that receives the content data items distributed via multicast. Subsequently, the transmitting and receiving unit distributes the generated recovery data together with the content data items via multicast.

Abstract: A data-transmission device dividing video data into packets and transmitting the packet to a data-reception device requesting the video data includes a unit generating transmission packets based on the video data, a unit setting importance for each of the generated packets, a unit storing information about the set importance in a first storage unit, a communication unit transmitting the generated packet to the data-reception device and receiving a packet-retransmission request from the data-reception device, a unit saving the transmitted packet in a second storage unit, a unit calculating the packet-loss rate based on the received packet-retransmission request, a unit determining a packet retransmitted to the data-reception device based on the calculated packet-loss rate and the packet importance, and a retransmission unit reading the determined retransmission packet from the second storage unit and transmitting the retransmission packet to the data-reception device.

Abstract: A communication control apparatus includes a packetizing unit configured to generate packets based on coded data; a calculating unit configured to calculate, based on at least one of information regarding the amount of code of the coded data, reception state information indicating a reception state of a reception device serving as a transmission destination to which the packets are to be transmitted, information regarding the effective speed of a communication line to be used for transmission of the packets, and information regarding an available capacity of a communication channel that can be ensured for communication of the packets, the number of packets to be continuously transmitted; and a transmitting unit configured to continuously transmit, via the communication line to the reception device, packets corresponding to the number of packets calculated by the calculating unit.

Abstract: A data recording apparatus and a data recording method to record multimedia files are provided. The data recording apparatus is configured to record media data into a file on a fragment-by-fragment basis. At least one fragment of the data is deleted in chronological order, starting with the data for the oldest fragment, if an amount of data recorded exceeds a determined amount of data. When data recording is ended, data for the fragments is rearranged in chronological order.

Abstract: A transmission apparatus is provided, including a combination determination unit configured to determine combinations of data packets so that when a data packet in a first frame is missed in transmission, a recover packet (FEC packet) for recovering the missing data packet is generated based on data packets in the first frame and data packets in a second frame, and an error correction coding unit configured to generate a recover packet based on the determination made by the combination determination unit.

Abstract: A communication apparatus which can communicate a data packet, a recovery packet used to recover a data packet that failed to be communicated, and a retransmit packet for the data packet that failed to be communicated, the communication apparatus includes a determining unit configured to determine, when a first packet of a plurality of packets that failed to be communicated is normally communicated, a packet that can be recovered, from among the plurality of the packets that failed to be communicated based on the first packet and the normally communicated recovery packet, and a retransmit determination unit configured to determine not to retransmit at least a part of the plurality of packets that can be recovered, when the first data packet is retransmitted which is determined to recover a plurality of data packets if it is normally communicated.

Abstract: An error pattern analysis unit specifies positions of discarded packets in continuously transmitted groups of packets. A QoS control unit estimates the cause of a communication error based on the specified positions of discarded packets, and performs QoS control based on the estimated cause of the communication error.

Abstract: A method for transmitting moving image data that includes a plurality of frames each divided into a plurality of pieces of data includes setting a priority to each of the plurality of pieces of data based on a characteristic thereof, determining a transmission order of the plurality of pieces of data to transmit the plurality of pieces of data according to the set priority, wherein a transmission order of the plurality of pieces of data having a same priority is determined not to transmit data which is displayed at a same position in successive frames in a same transmission order, and transmitting the plurality of pieces of data in the determined transmission order.

Abstract: A communication control apparatus includes a packetizing unit configured to generate packets based on coded data; a calculating unit configured to calculate, based on at least one of information regarding the amount of code of the coded data, reception state information indicating a reception state of a reception device serving as a transmission destination to which the packets are to be transmitted, information regarding the effective speed of a communication line to be used for transmission of the packets, and information regarding an available capacity of a communication channel that can be ensured for communication of the packets, the number of packets to be continuously transmitted; and a transmitting unit configured to continuously transmit, via the communication line to the reception device, packets corresponding to the number of packets calculated by the calculating unit.

Abstract: A communication control apparatus includes a data acquiring unit configured to acquire data to be transmitted to a receiving apparatus, a packetizing unit configured to generate packets using the data acquired by the data acquiring unit, a determining unit configured to compute a possible data transmission delay time of the data packetized by the packetizing unit and determine a transmission interval of the packets based on a result of the computation, and a transmission unit configured to transmit the packets generated by the packetizing unit at intervals that are each within the transmission interval determined by the determining unit.

Abstract: A data-transmission device dividing video data into packets and transmitting the packet to a data-reception device requesting the video data includes a unit generating transmission packets based on the video data, a unit setting importance for each of the generated packets, a unit storing information about the set importance in a first storage unit, a communication unit transmitting the generated packet to the data-reception device and receiving a packet-retransmission request from the data-reception device, a unit saving the transmitted packet in a second storage unit, a unit calculating the packet-loss rate based on the received packet-retransmission request, a unit determining a packet retransmitted to the data-reception device based on the calculated packet-loss rate and the packet importance, and a retransmission unit reading the determined retransmission packet from the second storage unit and transmitting the retransmission packet to the data-reception device.