The video encoding/decoding apparatus includes a video encoder for encoding macroblocks by each of prediction basic unit candidates, determining prediction basic units based on encoding costs for each of the prediction basic unit candidates, and generating a bitstream including image data encoded in determined prediction basic units, information on a prediction type for each of the determined prediction basic units, and prediction data depending on the prediction type; and a video decoder for extracting information on the prediction type for each of the prediction basic units, prediction data depending on the prediction type, and encoded image data from the bitstream, and generating a reconstructed image by decoding the encoded image data depending on the prediction type for each of the prediction basic units.