Patent ID: 8059716

Claim:
A method of transcoding MPEG (moving picture experts group)-2 data into H.264 data, the method comprising: dequantizing the MPEG-2 data to generate a DCT (discrete cosine transform) coefficient; approximating a 4Ã—4 H.264 integer transform matrix as a 4Ã—4 DCT matrix, and transforming the DCT coefficient into an integer transform coefficient using the 4Ã—4 DCT matrix; and quantizing the integer transform coefficient to generate the H.264 data; wherein the transforming of the DCT coefficient includes, changing an 8Ã—8 DCT matrix into a product of a first diagonal matrix and a plurality of matrices and changing the 4Ã—4 H.264 integer transform matrix into a product of a second diagonal matrix and the 4Ã—4 DCT matrix, changing a combination matrix expressed as a combination of some of the plurality of matrices and the 4Ã—4 DCT matrix into a product of a third diagonal matrix and a coefficient transform matrix having a symmetric structure, performing primary scaling on the DCT coefficient using the first diagonal matrix, two-dimensionally transforming the primarily scaled data using a product of the coefficient transform matrix and remaining ones of the plurality of matrices except the some of the plurality of matrices, and performing secondary scaling on the two-dimensionally transformed data using the second diagonal matrix and the third diagonal matrix to generate the integer transform coefficient.