Patent ID: 9161003
Filing Date: 2015-10-13
Classification: H04N

Abstract:
1. A time synchronization apparatus for synchronizing of a network camera and a network video recorder (NVR) connected to the network camera, the apparatus comprising: a data receiving unit receiving a data stream from the network camera, the data stream comprising timestamp information of the network camera; a noise determining unit determining whether time information input from the network camera is a noise based on a timestamp of the network camera contained in the timestamp information; and a setting control unit setting a timestamp of the NVR based on the determining of the noise determining unit, wherein the data stream comprises data obtained by the network camera and the timestamp information of the network camera which indicates a time when the data stream was transmitted from the network camera, wherein the apparatus further comprises an offset setting unit setting and adjusting an offset, which is a difference in reference time between the NVR and the network camera, by comparing the timestamp information of the network camera which is currently input and current time information of the NVR, and wherein the noise determining unit: determines whether a time difference between the currently input timestamp information of the network camera and previously input timestamp information of the network camera falls outside a threshold range, determines the currently input timestamp information as a potential noise if the time difference falls outside the threshold range; determines the potential noise as a time shift, which is not a noise, if a time difference between each subsequently input timestamp information of the network camera and previously input timestamp information continuously falls outside the threshold range for a predetermined time after determining that the currently input timestamp information is the potential noise; and determines the potential noise as a time spike, which is a noise, if the time difference between the each subsequently input timestamp information of the network camera and the previously input timestamp information does not continuously fall outside the threshold range for the predetermined time after determining that the currently input timestamp information is the potential noise.