APPARATUS TO IDENTIFY VIDEO SIGNALS ACCORDING TO NORM AND OUT OF NORM.

摘要

A SOURCE (10) RESPONDING TO A COMPOSITE VIDEO INPUT SIGNAL (S1) PROVIDES A LINE AND SWEEP FREQUENCY RELATED TO THE SYNCHRONIZATION SIGNALS (FH, 4FSC). A MEASURING CIRCUIT (20) RESPONDING TO THE SYNCHRONIZATION SIGNALS PROVIDES MEASURING VALUES THAT TEND TO BE REPEATED WHEN THE VIDEO INPUT SIGNAL IS FROM A GIVEN COLOR TELEVISION DEVICE AND TENDS TO DISPLAY A PSEUDO RANDOM DISTRIBUTION OTHERWISE. A SIGNAL PROCESSOR (30, 40) PROVIDES A "HISTOGRAM" (FOR EXAMPLE, A FREQUENCY DISTRIBUTION) OF THE MEASURES THAT OCCUR WITHIN A GIVEN TIME INTERVAL AND PROVIDES AN OUTPUT SIGNAL THAT IDENTIFIES AN INPUT SIGNAL. STANDARD AND NOT STANDARD VIDEO BASED ON THE HISTOGRAM (FREQUENCY DISTRIBUTION) OF THE MEASURES.