Patent ID: 9071769
Filing Date: 2015-06-30
Classification: H04N

Abstract:
1. A method for determining a type of video signal to be output comprising: configuring different video output interface modes of a set-top box, wherein the set-top box comprises three digital-to-analog converter (DAC) ports, wherein one of the different video output interface modes uses the three DAC ports to output a luminance, blue color difference, and red color difference (YPbPr) video signal, and wherein another one of the different video output interface modes uses the same three DAC ports to simultaneously output a luminance and color (YC) video signal and a composite video broadcast signal (CVBS) video signal; outputting a detection signal in the one of the different video output interface modes using one of the three DAC ports; switching the set-top box from the one of the different video output interface modes to the another one of the different video output interface modes; outputting additional detection signals in the another one of the different video output interface modes using two of the three DAC ports; extracting the detection signal and the additional detection signals in the different video output interface modes, wherein the detection signal and the additional detection signals have different constant voltage values before and after a corresponding one of the three DAC ports is connected to a load; converting the extracted detection signal and the extracted additional detection signals into direct current voltage signals; comparing each of the direct current voltage signals with a voltage threshold to determine whether each of the direct current voltage signals is greater than or less than the voltage threshold; determining the type of video signal to be output based at least in part on which one or more of the direct current voltage signals is greater than the voltage threshold; recording a zero value for one of the three DAC ports when the direct current voltage signal is less than the voltage threshold; recording a one value for the one of the three DAC ports when the direct current voltage signal is greater than the voltage threshold; and performing an “OR” on recorded one and zero values for each of the three DAC ports to determine the type of video signal to be output.