Detection and phase lock of pull-down video

摘要

Certain aspects of the invention may comprise a plurality of algorithms and architectures capable of performing 3:2 pull-down cadence detection and reverse 3:2 pull-down of a received video signal. In one embodiment, a method of identifying a pull-down field in a pull-down video stream comprises generating one or more temporally sequential variances, correlating the one or more temporally sequential variances to one or more temporal variance patterns associated with the pull-down video, wherein each of the one or more temporal variance patterns is associated with one or more unique field phases. In one embodiment, a system for identifying a pull-down field in a pull-down video stream comprises a memory, a first circuitry capable of computing a first equation, a second circuitry capable of computing a second equation, a third correlation circuitry, one or more counters, and a fourth circuitry capable of selecting a field phase.

主权项

1. A method of identifying a pull-down field in a 3:2 pull-down video stream, comprising:
generating one or more temporally sequential variances using said 3:2 pull-down video stream; correlating said one or more temporally sequential variances to one or more temporal variance patterns associated with said 3:2 pull-down video stream, each of said one or more temporal variance patterns associated with one or more unique field phases; generating one or more correlation coefficients associated with each of said one or more temporal variance patterns; assessing whether said one or more correlation coefficients exceeds a first threshold value; incrementing one or more counters associated with said one or more correlation coefficients if said one or more correlation coefficients exceeds said first threshold value; assessing whether said one or more correlation coefficients is less than a second threshold value; decrementing said one or more counters associated with said one or more correlation coefficients if said one or more correlation coefficients is less than said second threshold value; determining if a counter of said one or more counters exceeds a third threshold; selecting said one or more unique field phases as a repeat field phase if said counter exceeds said third threshold; and identifying said pull-down field associated with said repeat field phase.