A method of decoding video data, the method comprising: receiving a bitstream comprising encoded video data; obtaining, from the bitstream, information on a relationship between a depth of a coding unit and a quantization mode, wherein the information on said relationship specifies a quantization mode, for each depth among a plurality of depths, that indicates whether a quantization parameter delta is to be used; wherein: an image is split into a plurality of maximum coding units, a maximum coding unit, among the plurality of 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 split information obtained from the bitstream, further comprising, for a coding unit of the current depth: determining, based on the information on said relationship, whether a quantization parameter delta is to be used in the coding unit of the current depth, when the split information indicates a split for the current depth, the 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, transformation units are determined from the coding unit of the current depth, inverse-quantization is performed on the transformation units using the result of the determination of whether the quantization parameter delta is to be used in the coding unit of the current depth and inverse-transformation is performed on the transformation units. receiving a bitstream comprising encoded video data; obtaining, from the bitstream, information on a relationship between a depth of a coding unit and a quantization mode, wherein the information on said relationship specifies a quantization mode, for each depth among a plurality of depths, that indicates whether a quantization parameter delta is to be used; an image is split into a plurality of maximum coding units, a maximum coding unit, among the plurality of 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 split information obtained from the bitstream, further comprising, for a coding unit of the current depth: determining, based on the information on said relationship, whether a quantization parameter delta is to be used in the coding unit of the current depth, when the split information indicates a split for the current depth, the 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, transformation units are determined from the coding unit of the current depth, inverse-quantization is performed on the transformation units using the result of the determination of whether the quantization parameter delta is to be used in the coding unit of the current depth and inverse-transformation is performed on the transformation units. determining, based on the information on said relationship, whether a quantization parameter delta is to be used in the coding unit of the current depth, when the split information indicates a split for the current depth, the 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, transformation units are determined from the coding unit of the current depth, inverse-quantization is performed on the transformation units using the result of the determination of whether the quantization parameter delta is to be used in the coding unit of the current depth and inverse-transformation is performed on the transformation units.