Input/output device, relay device for transmitting contents to external apparatus and methods thereof

An input or output device is disclosed. The apparatus, connected to an external source available at least one input-output port, an external device capable of communicating with a wireless interface, for performing encoding, the encoder and at least one being an external source connected to the input and output ports is the content reconstructed from an external source and input and output ports If the received on, and a processor for transmitting the content to the external device over the air interface. The processor, after the content is a still image as sent to the external device, and if the content is video encode video and transmits it to an external device. In this way, without the need for the connection line to the display device, it is possible to provide a content efficiently.