| 摘要 |
A composite video decoder that separates digitized composite video signals into luminance and chrominance, demodulates the chrominance signal to its R-Y and B-Y components, removes time base errors, synchronizes the output to the station reference signal and converts three parallel digital signals to a serial digital output signal. A three dimensional digital comb filter (3), an interpolation circuit for time base correction (8), a sync error detector circuit (158), a noise measurement circuit (157) and a means of using the noise measurement level to adapt the other circuits for best operation at various noise levels of the video input signal provide high quality translation from a composite video input to a serial digital interface output (SDI). A digital line recursive filter is used to extract the horizontal synchronizing signal whether the signal is clean or masked by a very high noise level riding on the video signal.
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