Video decoding method and apparatus, and video encoding method and apparatus

Abstract

Proposed is a video decoding method and apparatus which: in the process of video encoding and decoding, acquires chroma intra-prediction mode information on a current chroma block; when the chroma intra-prediction mode information indicates a DM mode, determines a luma block including a luma sample corresponding to a chroma sample located at the bottom-right of the center of the current chroma block; determines a chroma intra-prediction mode of the current chroma block on the basis of an intra-prediction mode of the determined luma block; and performs intra-prediction of the current chroma block on the basis of the determined chroma intra-prediction mode.