Patent ID: 7034894

Claim:
A multiple-format video encoder comprising: a luminance/color-difference signal generating circuit that receives digital RGB signals to be inputted in synchronism with clock pulses at a predetermined frequency and generates a luminance signal and a color-difference signal from the RGB signals; a memory that stores trigonometric function values covering a predetermined number of phases at each address thereof for each of the phases and outputs a trigonometric function value stored at a designated address; and an address calculating circuit that receives a setting signal for selecting a predetermined video format from among a plurality of video formats each having a different chrominance subcarrier frequency, the address calculating circuit calculates a value to be added based on the chrominance subcarrier frequency of the predetermined video format selected with the setting signal, the predetermined number of phases, and the predetermined frequency of the clock pulses, and the address calculating circuit designates a next address of the memory by adding the calculated value to be added to the designated address, wherein a composite color video signal of the predetermined video format selected with the setting signal is generated based on the color-difference signal, the luminance signal, and a trigonometric function value stored in an address designated by the address calculating circuit.