Patent ID: 8169482

Claim:
A surveillance video accumulation system comprising a plurality of surveillance camera units and a video accumulation unit, the surveillance camera units and the video accumulation unit being capable of exchanging data with each other, wherein the surveillance video accumulation system further comprises: a selector operable to select one of the surveillance camera units that is currently shooting a subject; a selection information transmitter operable to transmit, to the surveillance camera units, selection information containing information indicating the one of the surveillance camera units selected by the selector; an accumulator operable to start receiving and accumulating video data from the one of the surveillance camera units when the selector selects the one of the surveillance camera units, the video data having been encoded according to a prediction encoding method; and a specifier operable to (i) specify, based on the video data from the selected one of the surveillance camera units, one or more of the surveillance camera units that (a) are different from the selected one of the surveillance camera units and (b) are expected to shoot the subject subsequently to the selected one of the surveillance camera units, and (ii) transmit, to the one or more of the surveillance camera units, specification information showing that each of the one or more of the surveillance camera units has been specified by the specifier, and wherein each of the surveillance camera units includes: a specification information receiver operable to receive the specification information; a selection information receiver operable to receive the selection information; an encoder operable to encode video data of the subject according to a prediction encoding method, the encoder (i) encoding the video data of the subject according to a prediction encoding method that uses either intra frame prediction or inter frame prediction until the specification information receiver has received the specification information, (ii) encoding the video data of the subject according to a prediction encoding method that uses only intra frame prediction when the specification information receiver receives the specification information, and (iii) encoding the video data of the subject according to a prediction encoding method that uses intra frame prediction and inter frame prediction when the selector performs the selection after the encoder has started encoding the video data of the subject when the specification information receiver receives the specification information; and a video data transmitter operable, when the surveillance camera unit is selected as the one of the surveillance camera units by the selector, to transmit the video data encoded by the encoder, in which at least a top frame has been encoded according to the prediction encoding method that uses only intra frame prediction, to the video accumulation unit.