Method and apparatus for encoding video and method and apparatus for decoding video, based on hierarchical structure of coding unit

An apparatus for decoding video data, the apparatus comprising:

• a receiver which receives and parses a bitstream comprising encoded video data;
• an obtainer which obtains, from the bitstream, the encoded video data, split information of a coding unit, encoding information regarding the coding unit, and information regarding an operating mode of a coding tool, determined according to a size of the coding unit in a maximum coding unit;
• and
• a decoder which determines the coding unit which is hierarchically split from the maximum coding unit based on the split information, and decodes the coding unit in the maximum coding unit according to an operating mode of a coding tool, by using the encoding information regarding the coding unit, wherein the operating mode of the coding tool is determined corresponding to the size of the coding unit based on the information regarding an operating mode of a coding tool determined according to a size of the coding unit,
• wherein the image is split into a plurality of maximum coding units,
• the maximum coding unit 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, the coding unit of a current depth is split into four coding units of a lower depth, independently from neighboring coding units, and
• when the split information indicates a non-split for the lower depth, the coding unit of the lower depth is split into one or more prediction units.

A method of decoding video data, the method comprising:

• receiving and parsing a bitstream comprising encoded video data;
• splitting a image into one or more coding units of depths;
• extracting, from the bitstream, a quantization mode indicating which depth of coding unit contains a quantization parameter delta;
• determining the depth of coding unit containing the quantization parameter delta based on the quantization mode;
• obtaining the quantization parameter delta based on the determined depth of coding unit from the bitstream;
• and,
• performing inverse-quantization and inverse-transformation on transformation units included in the determined depth of coding unit using the quantization parameter delta,
• wherein:
• the image is split into a plurality of maximum coding units,
• the maximum coding unit 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 split information,
• when the split information indicates a split for the current depth, the coding unit of a current depth is split into four coding units of a lower depth, independently from neighboring coding units, and
• when the split information indicates a non-split for the lower depth, the coding unit of the lower depth is split into one or more prediction units.

A method of decoding video data, the method comprising:

• receiving and parsing a bitstream comprising encoded video data;
• splitting a image into variable more coding units;
• extracting, from the bitstream, information regarding relationship between sizes of the coding unit and a quantization mode, wherein the quantization mode indicates a size of the coding unit where a quantization parameter delta is applied to;
• obtaining the quantization parameter delta based on at least one of the relationship and the size of coding unit;
• and,
• performing inverse-quantization using the quantization parameter dalta,
• wherein:
• the image is split into a plurality of maximum coding units,
• the maximum coding unit 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 split information,
• when the split information indicates a split for the current depth, the coding unit of a current depth is split into four coding units of a lower depth, independently from neighboring coding units, and
• when the split information indicates a non-split for the lower depth, the coding unit of the lower depth is split into one or more prediction units.