Patent ID: 8918829

Claim:
A communication system comprising: a source device configured to output video contents, a sink device configured to input the video contents, and a cable including a control transmission line and a video transmission line both connecting with the source device and the sink device to transmit data therebetween via the control transmission line and the video transmission line, with the source device including a control data I/O unit that inputs and outputs control data via the control transmission line, a video data output unit that outputs video data via the video transmission line, a control feature corresponding memory unit that stores correspondence of control data that can be input and output via the control data I/O unit, and a control unit that controls input and output of the control data via the control data I/O unit and that controls output of the video data from the video data output unit; and with the sink device including a control data I/O unit that inputs and outputs control data via the control transmission line, a video data input device that inputs video data via the video transmission line, a control feature corresponding memory unit that stores correspondence of control data that can be input and output via the control data I/O unit, and a control unit that controls input and output of the control data via the control data I/O unit and that controls input of the video data from the video data input unit; wherein upon connecting the cable between the source device and the sink device, one of the control units of the source device and sink device, as a first device, reads out correspondence information of the control data stored on the control feature corresponding memory unit in the other device, as a second device, via the control transmission line, the first device compares the correspondence information with information stored on the control feature corresponding memory unit in the first device, determines compliant control data that can be output to the second device via the control data I/O unit in the first device based on the resulting comparison, and stores the compliant control data in a database in the respective control feature corresponding memory unit of the first device, and the determined compliant control data controls an operational function of the second device according to a process of: (1) a user requesting a command for the operational function of the second device through a user operation performed on the first device, (2), upon receiving the command through the user operation, the first device queries the database to determine whether a database match exists between the command and the compliant control data stored in the database in the respective control feature corresponding memory unit of the first device, and (3), when a determination by the first device indicates that there is the database match for the command, the first device transmits the command to the second device via the control transmission line.