An apparatus for decoding video data, the apparatus comprising: a receiver configured to receive a bitstream comprising encoded video data; a parser configured to obtain 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 (para. 79-80, 276); and, a decoder configured to perform inverse-quantization and inverse-transformation, 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, wherein for a coding unit of the current depth: the parser further determines whether the quantization parameter delta is to be used in the coding unit of the current depth, based on the information on said relationship, 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 obtained from the coding unit of the current depth, and the decoder performs inverse-quantization 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 performs inverse-transformation on the transformation units. a receiver configured to receive a bitstream comprising encoded video data; a parser configured to obtain 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 (para. 79-80, 276); and, a decoder configured to perform inverse-quantization and inverse-transformation, 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, the parser further determines whether the quantization parameter delta is to be used in the coding unit of the current depth, based on the information on said relationship, 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 obtained from the coding unit of the current depth, and the decoder performs inverse-quantization 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 performs inverse-transformation on the transformation units.