When a conventional audio video system is used, it is necessary to identify an input source of audio video information. For this reason, complicated operations and slow operation times have been a problem. A control apparatus (20) includes: an instruction receiving unit (201) for receiving an instruction to be provided to an audio video supplying apparatus (10a to 10c) which is an input source of audio video information currently outputted from an output apparatus (30) that outputs the audio video information; a determination unit (202) for determining one of the audio video supplying apparatuses (10a to 10c) to be the input source of the audio video information currently being outputted from the output apparatus (30); and a control information sending unit (205) for outputting control information to the audio video supplying apparatus (10a to 10c) determined by the determination unit (202), the control information corresponding to the instruction received by the instruction receiving unit (201) and being used for controlling the audio video supplying apparatus (10a to 10c).