Patent attributes
An apparatus comprising a video decoder configured to receive a composite video signal modulated on a sub-carrier signal and having a luma component and a chroma component, the video decoder configured to perform a motion detection operation on the luma component and the chroma component in a plurality of frequency regions respectively. The video decoder includes variable threshold logic, coupled to the video decoder, and configured to provide a unique threshold value to the video decoder for each of the plurality of frequency regions respectively. The apparatus also includes a sub-carrier detection logic, coupled to the variable threshold logic, and configured to detect the sub-carrier signal by checking both spatial and temporal characteristics of the sub-carrier detection logic.