INVERSE DISCRETE COSINE TRANSFORMATION PROCESSOR AND MPEG DECODER

摘要

PROBLEM TO BE SOLVED: To reduce a circuit scale and to maintain a high data rate in a two-dimensional inverse discrete cosine transformation (IDCT) circuit having parallel processing paths using a distribution operation technology. SOLUTION: The parallel processing paths of DCT coefficient data are transformed into odd- and even-numbered processing paths 12. Partial IDCT circuit 105a and 105b execute first one-dimensional transformation in parallel in the parallel paths. DCT coefficient data becomes a parameter and it is transposed in an transposing part 150. The partial IDCT circuits 155a and 155b execute second one-dimensional transformation and the parameter becomes a picture element value. A parallel processing by the even and odd processing paths can be realized since the matrix of one-dimensional transformation can be dissolved into two smaller equations.