DCT/IDCT processor

An inverse discrete cosine transform processor, for use of a discrete cosine transform/inverse discrete cosine transform (DCT/IDCT) processor, having standardization and round-off means for standardizing and rounding off discrete-cosine transformed matrix data, a transpose buffer for transposing the matrix data outputted from the standardization and round-off means, and final standardization and round-off means for standardizing and rounding off finally inverse-discrete cosine transformed matrix data, said processor comprising:

• first data selection means for selecting and outputting one out of said matrix data and matrix data transposed by said transpose buffer;
• a first pre/post scaler for prescaling or postscaling the matrix data outputted from the first data selection means;
• second data selection means for selecting one out of a DCT coefficient and an IDCT coefficient in response to an external signal deciding a DCT and an IDCT, and outputting the coefficient as the matrix data;
• a matrix multiplier for multiplying the matrix data provided from said second data selection means by DCT or IDCT correlation coefficients selectively, accumulating its result matrixes, and controlling a path of discrete-cosine transformed or inverse-discrete cosine transformed matrix data in response to the external signal deciding the DCT and the IDCT;
• a second pre/post scaler for prescaling or postscaling the matrix data outputted from the matrix multiplier, and transferring the data to said first data selection means;
• and
• output path deciding means for deciding an output path of the matrix data outputted from the matrix multiplier.