Frozen field detection of formerly encoded video signal

摘要

A method of detecting frozen fields in a video signal that has undergone analog encoding at some point along a transmission path acquires the video signal as a digital video signal. Every field of the digital video signal and its nth subsequent field are selected as a pair, where n is an integer multiple of the number of fields required for one cycle of color phasing in the analog encoding. The pairs of the selected fields are compared and, if the difference is essentially zero, a frozen field error is indicated.