A system, comprising: a task distributor, configured to distribute video capturing tasks to a first plurality of video capturing devices; and the first plurality of video capturing devices, each of which including at least one camera (221, 222, 231, 232) configured to obtain a video when executing a video capturing task and a node server (210A, 210B) configured to control the at least one camera (221, 222, 231, 232) based on the video capturing tasks distributed by the task distributor, wherein the task distributor comprises: a first time information determination module, configured to determine first time information related to when a first video capturing task is to be executed, wherein the first video capturing task is to be assigned to the first plurality of video capturing devices; a video capturing devices selection module configured to determine a second plurality of video capturing devices from the first plurality of video capturing devices to distribute the first video capturing task based on a selection criterion relating to a workload of each of the first plurality of video capturing devices; a second time information determination module, configured to, for each of the second plurality of video capturing devices, determine second time information related to when at least one second video capturing task is to be executed by the video capturing device, wherein the at least one second video capturing task has been assigned to the video capturing device; a target video capturing device determination module, configured to determine a target video capturing device from the second plurality of video capturing devices based on the first time information, the second time information, and a load variance of each of the second plurality of video capturing devices; and an assigning module, configured to assign the first video capturing task to the target video capturing device. a task distributor, configured to distribute video capturing tasks to a first plurality of video capturing devices; and the first plurality of video capturing devices, each of which including at least one camera (221, 222, 231, 232) configured to obtain a video when executing a video capturing task and a node server (210A, 210B) configured to control the at least one camera (221, 222, 231, 232) based on the video capturing tasks distributed by the task distributor, wherein the task distributor comprises: a first time information determination module, configured to determine first time information related to when a first video capturing task is to be executed, wherein the first video capturing task is to be assigned to the first plurality of video capturing devices; a video capturing devices selection module configured to determine a second plurality of video capturing devices from the first plurality of video capturing devices to distribute the first video capturing task based on a selection criterion relating to a workload of each of the first plurality of video capturing devices; a second time information determination module, configured to, for each of the second plurality of video capturing devices, determine second time information related to when at least one second video capturing task is to be executed by the video capturing device, wherein the at least one second video capturing task has been assigned to the video capturing device; a target video capturing device determination module, configured to determine a target video capturing device from the second plurality of video capturing devices based on the first time information, the second time information, and a load variance of each of the second plurality of video capturing devices; and an assigning module, configured to assign the first video capturing task to the target video capturing device. a first time information determination module, configured to determine first time information related to when a first video capturing task is to be executed, wherein the first video capturing task is to be assigned to the first plurality of video capturing devices; a video capturing devices selection module configured to determine a second plurality of video capturing devices from the first plurality of video capturing devices to distribute the first video capturing task based on a selection criterion relating to a workload of each of the first plurality of video capturing devices; a second time information determination module, configured to, for each of the second plurality of video capturing devices, determine second time information related to when at least one second video capturing task is to be executed by the video capturing device, wherein the at least one second video capturing task has been assigned to the video capturing device; a target video capturing device determination module, configured to determine a target video capturing device from the second plurality of video capturing devices based on the first time information, the second time information, and a load variance of each of the second plurality of video capturing devices; and an assigning module, configured to assign the first video capturing task to the target video capturing device.