Method and system for determining video program system signals

摘要

A video program system (VPS) signal superimposed on a television signal is continuously stored in an input buffer (11). A determination process circuit (21) determines whether or not the VPS signal stored in the input buffer (11) is a normal signal. When the VPS signal stored in the input buffer (11) is a no-signal, a count value of a no-signal counter (14) is counted. When the count value of the no-signal counter exceeds a predetermined count value, the circuit (21) determines that the VPS signal detected from the television signal is the no-signal. When VPS signals corresponding to various programs are stored in the input buffer (11), a count value of an error counter (15) is counted. When the count value of the error counter (15) exceeds a pre­determined count value, the circuit (21) determines that the input state of the VPS signal detected from the television signal is unstable. When the same VPS signal is continuously stored in the input buffer (11), the circuit (21) determines that the VPS signal detected from the television signal is a normal signal.