High definition video extender and method

摘要

An apparatus and method for extending high definition multimedia signals from a source to a display over long distances (e.g., up to 300 feet) using a single cable medium having a plurality of twisted pair conductors contained therein. The extender transparently supports HDMI and/or DVI signaling, which allows encrypted video content to be displayed at the remote display (or other sink device). Display data channel control (DDC) information is sampled and transferred in packet from the local unit to a remote unit to comply with high-bandwidth digital content protection (HDCP).

主权项

1. A method for extending high definition multimedia signals over a single twisted pair cable medium having a plurality of twisted pair conductors, the method comprising:
receiving a plurality of source differential multimedia signals and control information from a source at a local unit, wherein the plurality of source differential multimedia signals include a plurality of source video signals and a source clock signal; transmitting a plurality of local unit differential multimedia signals from the local unit to a remote unit, the plurality of local unit differential multimedia signals being based on the plurality of source differential multimedia signals, wherein the plurality of local unit differential multimedia signals include a plurality of local unit differential video signal pairs and a local unit differential clock signal pair; converting at least a portion of the control information into converted data display channel (DDC) information at the local unit for transmission to the remote unit, wherein the converted DDC information includes serial clock data and serial data that is sampled and transmitted in packet form at a rate sufficient to comply with high-bandwidth digital content protection (HDCP) and the converted DDC information is transmitted as a differential common mode signal; forming a first channel comprising a first pair of conductors and a second pair of conductors of the plurality of twisted pair conductors, wherein transmitting a plurality of local unit differential multimedia signals from the local unit to the remote unit comprises transmitting a first pair of local unit differential multimedia signals over the first pair of conductors and transmitting a second pair of local unit differential multimedia signals over the second pair of conductors; forming a second channel comprising a third pair of conductors and a fourth pair of conductors of the plurality of twisted pair conductors, wherein transmitting a plurality of local unit differential multimedia signals from the local unit to a remote unit comprises transmitting a third pair of local unit differential multimedia signals over the third pair of conductors and transmitting a fourth pair of local unit differential multimedia signals over the fourth pair of conductors, none of the local unit differential multimedia signals in the second channel being included in the local unit differential multimedia signals in the first channel; powering one of the local unit and the remote unit through the first and second channels, the first and second conductor pairs of the first channel being coupled to a first voltage and the third and fourth conductor pairs of the second channel being coupled to a second voltage, the second voltage being different than the first voltage; transmitting the converted DDC information as a common mode signal on the first channel; receiving the plurality of local unit differential multimedia signals and the converted DDC information at the remote unit; extracting the converted DDC information at the remote unit from the first channel; generating reconstructed DDC information at the remote unit from the converted DDC information; generating a plurality of remote unit differential multimedia signals at the remote unit based on the received plurality of local unit differential multimedia signals; transmitting return remote unit DDC information from the remote unit to the local unit over the first channel; outputting the plurality of remote unit differential multimedia signals and the reconstructed DDC information from the remote unit to an associated display based at least in part on the control information.