Provided is an apparatus that includes an inverse scanning unit configured to an inverse scan pattern to the quantized coefficient components to generate a quantized block, an inverse quantization unit configured to generate a quantization parameter and to inverse-quantize the quantized block to generate a transformed block, an inter prediction unit configured to derive motion information and to generate a prediction block, and an adder configured to generate a reconstructed block. The transform unit is larger than a 4×4 block, each of the quantized coefficient components are inversely scanned in the unit of subset to generate multiple subsets, and the multiple subsets are inversely scanned to generate the quantized block. Accordingly, the coding efficiency of the motion information is improved by including various motion vector candidates. Also, the amount of coding bits of the residual block is reduced by applying diagonal scan pattern to each subset.