Two-dimensional inverse discrete cosine transform processor
AssigneesUnited Microelectronics Corp., National Cheng Kung University
InventorsJar-Ferr Yang, Shih-Chang Hisa, Chyou-Hsiung Hwang, Zhi-Hsien Chen
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Abstract
A two-dimensional inverse discrete cosine transform (2-D IDCT) processor comprises cosine angle index generators, pipelined multipliers and a symmetrical kernel. The 2-D IDCT processor of the invention has a five-stage pipelined structure for carrying out a coefficient-by-coefficient 2-D IDCT algorithm and can be operated at a clock rate of more than 50 MHz to achieve a pixel rate of about 400 MHz.
Claims16
A data processor which carries out a two-dimensional inverse discrete cosine transform (IDCT) for transforming data representing an N.times.N matrix into N.times.N transformed data, said processor comprising:
- a pipelined multiplier for multiplying a non-zero input coefficient of said N.times.N matrix with ROM data determined by coordinate parameters of said input coefficient;
- a cosine angle index generator for generating a positive angle index and a negative angle index from said coordinate parameters;
- a mapping module receiving said positive angle index and said negative angle index for generating one-coefficient-only results based on said positive and negative angle indices and output data from the pipelined multiplier;
- ##EQU29## adders for summing said one-coefficient-only results;
- an accumulator for accumulating data from said adders and generating said N.times.N transformed data.
Dependencies are inferred from the claim text.