| 摘要 |
The present invention makes efficient use of a storage section while protecting needed video. A processing section 42 causes a storage section 28 to cyclically overwrite and store video data that is sequentially input, a PING variation amount acquisition section 38 periodically sends a survival confirmation request (packet according to a PING command) to an external device 18 and detects a response to the packet according to the PING command from the external device 18, and an overall control section 40 carries out control such that, in a case in which the response is not detected a predetermined number of times, a time point going back in time by a set time period is designated as a first initiation time point at which protection of the video data excluded from a target over which the video data that has been input is overwritten is initiated, and such that, in a case in which the response to the packet according to the PING command from the external device 18 has been detected a predetermined number of times after protection of the video data has been initiated, the video data that has been input after the response was detected the predetermined number of times is removed from the protection target. |
