Abstract: A coupling device for coupling a videotelephone with a video generation device. The coupling device includes (i) a first device, for detecting at least one code word contained in a signal originating from the videotelephone, (ii) a second device, coupled with the first device, for generating a control signal in response to the detected code word, and (iii) a change-over device. The change-over device is coupled with the first device and with the second device. The change-over device receives, from the video generating device, both a first video signal, coded in a first manner, and a second video signal, coded in a second manner. The change-over device then feeds, in response to a control signal, coded video signals originating from one of a number of video generating devices to the first device via the change-over device. The coupling device is readily applicable in multicast environments.