Video encoding/decoding method and apparatus using a block transformation are disclosed. The apparatus encodes the video through predicting each pixel in a current block of the video by using one or more adjacent pixels, which are encoded prior to encoding the current block and have the closest proximity to the pixels respectively in a predetermined prediction direction, and wherein the current block is sized L×M with L being unequal to M. It has become possible to predict the pixels in the block starting from closest one of the pixels in the prediction direction in order to provide more accurate block predictions and then raise the compression efficiency that leaps to more efficient video encoding/decoding performance.