Patent ID: 7573500
Filing Date: 2009-08-11
Classification: H04N

Abstract:
1. A method of controlling a controllable video device configured to provide a video signal on a transmission medium, the method comprising: transmitting command data to the controllable video device over the transmission medium in a vertical blanking period of the video signal; receiving said command data at the controllable video device; and transmitting response data using the controllable video device over the transmission medium during the same vertical blanking period in response to said command data; wherein the command data and response data each comprise a plurality of bits encoded in a format wherein a first logic value is represented by presence of a transition during a bit period and a second logic value is represented by absence of a transition during said bit period, and said command data and said response data each comprise 8 bytes of data, and said command data is transmitted in four separate 2 byte portions, with each of said separate two byte portions being transmitted on one horizontal line in a first group of four associated consecutive horizontal lines in said vertical blanking period, and said response data is transmitted in four separate 2 byte portions, with each of said separate two byte portions being transmitted on one horizontal line in a second group of four associated consecutive horizontal lines in said vertical blanking period.