Video-encoding method and video-encoding apparatus based on encoding units determined in accordance with a tree structure, and video-decoding method and video-decoding apparatus based on encoding units determined in accordance with a tree structure
Provided are a method and apparatus for encoding a video and a method and apparatus for decoding a video. The encoding method includes: splitting a picture of the video into one or more maximum coding units that are coding units having a maximum size; encoding the picture based on coding units according to depths which are obtained by hierarchically splitting each of the one or more maximum coding units according to depths in each of the one or more maximum coding units, determining coding units according to coded depths with respect to each of the coding units according to depths, and thus determining coding units having a tree structure; and outputting data that is encoded based on the coding units having the tree structure, information about the coded depths and an encoding mode, and coding unit structure information indicating a size and a variable depth of a coding unit.
1. A method of decoding a video, the method comprising:
receiving a bitstream with respect to an encoded video;
extracting, from the received bitstream, information about a size of a coding unit that is a data unit for decoding of a picture of the encoded video, a variable depth of the coding unit, split information and an encoding mode with respect to coding units having a tree structure of the picture;
determining a maximum size of the coding unit based on the information about the size and the variable depth;
splitting the picture into one or more maximum coding units based on the determined maximum size;
determining the coding units having the tree structure based on the split information, and
decoding the picture based on the determined coding units based on the encoding mode,
wherein the information about the size and the variable depth are extracted from a sequence parameter set of the bitstream,
a maximum coding unit, among the one or more maximum coding units, is hierarchically split into one or more coding units of depths including at least one of a current depth and a lower depth according to the split information,
when the split information indicates a split for the current depth, a coding unit of the current depth is split into four coding units of the lower depth, independently from neighboring coding units, and
when the split information indicates a non-split for the current depth, the coding unit of the current depth is split into one or more prediction units.