Patent ID: 7743400

Claim:
A video data transmission/reception system comprising a transmission-side apparatus and a plurality of reception terminals, the transmission-side apparatus transmitting video data that has been compressed using motion compensation interframe prediction, and the reception terminals receiving the video data and decoding the received video data, wherein the transmission-side apparatus includes: a first encoding unit consisting of a first DCT unit and a first quantization unit, the first encoding unit applying interframe encoding processing to a plurality of frames of moving image data, to generate only interframe frame data for the video data; a second encoding unit consisting of a second DCT unit and a second quantization unit, the second encoding unit applying in parallel with the encoding processing by the first encoding unit, intraframe encoding processing to a frame of the moving image data, to generate substitute I frame data for the video data; an encoded video data generation unit connected to the first encoding unit and the second encoding unit to combine the substitute I frame data and the interframe frame data to form the video data; and a transmission unit transmitting the video data and the substitute I frame data to the plurality of reception terminals, wherein when the transmission unit is to resume transmission of the video data to one of the reception terminals after temporarily interrupting transmission of the video data to the reception terminal, the transmission unit checks each of a plurality of frames to determine whether a reference frame for each of the plurality of frames to be transmitted after resuming transmission of the video data has been transmitted or not, and if the reference frame has not been transmitted, transmits the substitute I frame data to the reception terminal for each of the plurality of frames for which the reference frame has not been transmitted before resuming transmission of the video data, the reception terminal, when the transmission unit is to resume the temporarily interrupted transmission of the video data, receives the transmitted substitute I frame data, decodes the received substitute I frame data, and uses the decoded substitute I frame data as reference frame data to decode video data that is received after resumption of transmission, and wherein the first encoding unit and the second encoding unit are included in a same encoder which has one motion compensation unit and one predictive memory unit.