An optical recording/reproducing apparatus comprising an audio and video (A/V) codec having a function for separating luminance and color components. A video decoder converts an analog video signal into a digital video signal; an A/V codec having a pre-compression processing unit separates luminance and color components from the converted digital video signal; an encoder compresses the digital video signal having the separated luminance and color components into a predetermined compression format; and a decoder decodes the digital video signal compressed in the predetermined compression format. A memory provides a storage space as the A/V codec carries out signal processing. Accordingly, the size and production cost of the video decoder may be reduced.