Video encoding device and video decoding device using high-precision skip encoding and method thereof

A video decoding method performed by a video decoding apparatus, the video decoding method comprising:

• obtaining, from a bitstream, a skip mode flag indicating whether a current block is predicted in a skip mode;
• in response to the skip mode flag indicating that the current block is not predicted in the skip mode, obtaining, from the bitstream, a merge mode flag;
• in response to determining whether the merge mode flag indicates that the current block is predicted in a merge mode or not, obtaining motion vector prediction mode information of the current block, from the bitstream;
• when the motion vector prediction mode information of the current block indicates a pre-set prediction mode, obtaining, from the bitstream, motion vector difference information and a first index indicating a prediction candidate from a first candidate list, determining the first candidate list including prediction candidates corresponding motion vectors of blocks adjacent to the current block, determining a first motion vector candidate indicated by the first index from the first candidate list, and determining a motion vector of the current block based on the first motion vector candidate and the motion vector difference information;
• when the motion vector prediction mode information of the current block does not indicate the pre-set prediction mode, obtaining, from the bitstream, a second index indicating a prediction candidate from a second candidate list, determining the second candidate list including prediction candidates corresponding to motion vectors of neighboring blocks of the current block, determining a second motion vector candidate indicated by the second index from the second candidate list, and determining the motion vector of the current block based on the second motion vector candidate, without using the motion vector difference information;
• in response to the skip mode flag indicating that the current block is predicted in the skip mode, obtaining, from the bitstream, a third index indicating a prediction candidate from a third candidate list and determining the motion vector of the current block based on a motion vector candidate indicated by the third index from the third candidate list;
• determining a predicted block of the current block indicated by the motion vector;
• determining a residual block of the current block by performing inverse transformation on transform coefficients of the current block;
• and
• determining a reconstructed block of the current block by combining a prediction block and the residual block,
• wherein the motion vector difference information comprises a sign information and a pixel distance of a motion vector difference, the motion vector difference comprises a single component among an x-axis component and a y-axis component, and the pixel distance is a value of a sub-pel unit or an integer-pel unit.