Patent ID: 6947096

Claim:
A video signal processing apparatus for converting a composite video signal to a digital component video signal, said apparatus comprising: first timing-signal generating means for extracting sampling points corresponding to the timing of a first virtual clock signal, from the sampling points in the composite video signal sampled with a system clock signal of a prescribed frequency, thereby to generate a first timing signal that is synchronous with the sampling points extracted; first interpolation means for interpolating signal levels at the sampling points in the first virtual clock signal, from the signal levels in the composite video signal sampled with the system clock signal, thereby to generate a composite video signal sampled with the first virtual clock signal, and for outputting the composite video signal sampled with the first virtual clock signal in synchronism with the first timing signal; Y/C dividing means for dividing the composite video signal sampled with the first virtual clock signal, into a luminance signal and a carrier color-difference signal, said luminance signal and said carrier color-difference signal having been sampled with the first virtual clock signal; chroma-decoding means for demodulating the carrier color-difference signal sampled with the first virtual clock signal, thereby to generate a color-difference signal sampled with the first virtual clock signal; second timing-signal generating means for extracting sampling points corresponding to a second virtual clock signal, from the sampling points in the first timing signal, thereby to generate a second timing signal that is synchronous with the sampling points extracted; second interpolation means for interpolating signal levels at the sampling points in the second virtual clock signal, from the signal levels in the luminance signal and the color-difference signal, both sampled with the first virtual clock signal, thereby to generate a luminance signal and a color-difference signal, both sampled with the second virtual clock signal, and for outputting the luminance signal and the color-difference signal, both sampled with the second virtual clock signal, in synchronism with the second timing signal; smoothing means for receiving the luminance signal and the color-difference signal, both sampled with the second virtual clock signal and input in synchronism with the second timing signal, and for outputting the luminance signal and the color-difference signal, by using an output clock signal which is synchronous with the second virtual clock signal; and frequency-changing means for changing the frequency of the first virtual clock signal in accordance with the type of the composite video signal input.