DECODING APPARATUS FOR PERFORMING INVERSE QUANTIATION AND INVERSE TRANSFORM IN H.264/AVC DECODER AND DECODING METHOD USING DECODING APPARATUS

摘要

The present invention relates to a decoding apparatus for performing inverse quantization and inverse transform in an H.264/AVC decoder and a decoding method using the same, wherein the decoding apparatus can reduce the complexity of control by performing inverse quantization and then performing inverse transform regardless of a direct current (DC) coefficient and an alternate current (AC) coefficient, which are included in compressed image information received from an encoder, and can reduce the complexity of calculation by processing an inverse quantization operation using a common operator. The decoding apparatus according to the present invention comprises: an inverse quantization (IQ) operator for restoring a DC coefficient and an AC coefficient in the quantized frequency component; an inverse transform (IT) operator for inverse-transforming the frequency component restored by the inverse quantization operator; a rounding part for removing a rounding error prevention coefficient, which is multiplied when the inverse quantization operator performs inverse quantization operation; and a decoding controller for controlling the order of macro block scanning of an input image, determining the presence or absence of inverse Hadamard transform, and controlling the timing of inverse quantization and inverse transform, according to the DC coefficient or AC coefficient. [Reference numerals] (100) Inverse quantization (IQ) operator; (200) Inverse transform (IT) operator; (300) Rounding part; (400) Decoding controller