1. A time synchronization information computation device comprising: a plurality of video acquisition units for acquiring videos; a plurality of visual event detection units provided corresponding to the plurality of video acquisition units for analyzing the videos acquired by the plurality of video acquisition units to detect visual events, and generating visual event detection information including information on when the visual events are detected; and a visual event integration unit for integrating the visual event detection information generated by the plurality of visual event detection units, and generating time synchronization information for synchronizing the times of the videos acquired by the plurality of video acquisition units.