A video processing device connectable with a recorder includes a first receiver and a controller. The first receiver receives a main video signal containing two or more frames which are consecutive in time sequence, the main video signal produced by imaging two or more subjects including at least one moving subject. The controller generates one or more sub video signals produced by imaging a first subject of the plurality of subjects, from the main video signal. The controller generates main video data including the main video signal and first association information specifying the one or more sub video signals generated from the main video signal. Furthermore, the controller generates one or more sub video data including the one or more sub video signals and second association information specifying the main video signal from which the one or more sub video signals have been generated. The controller makes a recorder store the main video data and the one or more sub video data.