| 摘要 |
A discrete cosine transform (DCT) circuit providing DCT and inverse DCT results, receiving N input data and a selection signal, includes a first switch for selecting input data or accumulation data, a combining circuit transforming N input data into N/2 combination data, an adding/substracting circuit producing N subtraction and addition data from the combination data, a second switch for selecting one of the input data and the accumulation data, a permutation circuit producing permutated data based on the input data, a third switch for selecting one of the addition and subtraction data and the permutated data, a plurality of transforming circuits coupled to the third switch for transforming and accumulating data to produce the accumulation data, a fourth switch selecting one of the addition and substraction data and the permutated data and a selector circuit operatively coupled to the first and second switches for selecting the outputs of the transforming circuits in a predetermined order. According to one aspect of the invention one of a DCT result and an inverse DCT result are produced in the DCT circuit based on the selection signal. Both one and two dimension DCT results can be produced by the DCT circuit. A DCT circuit producing two-dimensional DCT results further includes a transposition memory device.
|
