To improve user operability.
Provided is a Next change operating section that receives a changing operation on each item in a Next control data set being in a control state of a Next-use M/E of a switcher (vision mixer). When a changing operation is received in the Next change operating section, that is, when there is a changing operation, a control section changes contents of the Next control data set, and in accordance with the changed contents of the Next control data set, sends a control signal concerning the Next-use M/E to the switcher. A user can simply and easily change the contents of the Next control data set by operating the Next change operating section, and operability can be improved.