An apparatus and a method for processing auxiliary data included in a video signal, in particular auxiliary data included in the vertical blanking interval of a television signal. The present invention recognizes that comb filtering of a television signal before processing the auxiliary data included in the television signal may cause corruption of the data. The present invention overcomes the problems associated with the data corruption by placing the takeoff point for the auxiliary data at a point in the signal path prior to the comb filtering. In an exemplary embodiment, the present invention also provides for switching between one of a plurality of signal sources while ensuring that the signal provided to an auxiliary data processor corresponds to the displayed signal and minimizing the additional hardware and software required with regard to prior art arrangements.