Patent ID: 6549677
Filing Date: 2003-04-15
Classification: H04N

Abstract:
A data conversion apparatus for performing data conversion between first-format encoded data in which orthogonal transform coefficients are arranged in an order of DC components and AC components from a low spatial frequency order to a high spatial frequency order in each orthogonal transform block when compression encoding which includes orthogonal transform is applied to video data and second-format encoded data in which orthogonal transform coefficients are arranged in an order of DC components and AC components from a low spatial frequency order to a high spatial frequency order in each block assembly member formed of a plurality of orthogonal transform blocks when compression encoding which includes orthogonal transform is applied to video data, said data conversion apparatus comprising:decoding means for decoding the second-format encoded data to obtain orthogonal transform coefficients; conversion means for re-arranging the orthogonal transform coefficients of the second-format data obtained by said decoding means in the order of the DC components and AC components from a low spatial frequency order to a high spatial frequency order in each orthogonal transform block of the first format; and encoding means for encoding the orthogonal transform coefficients from said conversion means to form encoded data having the first format, wherein data of the first format includes a plurality of macroblocks having a plurality of luminance blocks and chrominance blocks, and wherein the DC components and AC components in each luminance block and in each chrominance block are arranged from the low spatial frequency order to the high spatial frequency order.