Color subcarrier regenerator for slow down processor

摘要

Luminance and chrominance components of a video input signal are stored at one rate and recovered at a lesser rate, 1/N, by means of a frame store to effect video signal bandwidth reduction. Burst is not stored but rather is regenerated and added to the video output signal to conserve memory space. To avoid undesirable hue changes and the necessity of rephasing the regenerated burst signal when switching between different video sources, the burst regenerator includes means for forming a product signal from two signals. One signal is locked to incoming burst, and the other signal is derived from a reference source having a phase related to that of burst. The latter signal is reduced in frequency by a factor (N-1)/N prior to forming the product signal and phase shift is added to a signal path such that the resultant difference component of the product signal exhibits a phase relative to that of the recovered chrominance component which equals the chroma-burst phasing of the video signal supplied to the frame store by any of the video sources. The difference component is then added as a burst component to the recovered chrominance component to form a composite output signal.