Search International and National Patent Collections

1. (WO2010121077) COMPUTING EVEN-SIZED DISCRETE COSINE TRANSFORMS

Pub. No.:    WO/2010/121077    International Application No.:    PCT/US2010/031314
Publication Date: Fri Oct 22 01:59:59 CEST 2010 International Filing Date: Fri Apr 16 01:59:59 CEST 2010
IPC: G06F 17/14
Applicants: QUALCOMM INCORPORATED
REZNIK, Yuriy
Inventors: REZNIK, Yuriy
Title: COMPUTING EVEN-SIZED DISCRETE COSINE TRANSFORMS
Abstract:
In general, techniques are described for computing even-sized discrete cosine transforms (DCTs). For example, a coding device may implement these techniques. The coding device includes a DCT-II unit that first determines whether a DCT-II to perform is a multiple of two, and in response to determining that the DCT-II to perform is a multiple of two, performs the DCT-II. To perform the DCT-II, the DCT-II unit computes a butterfly and reverses an order of a first sub-set of the outputs of the butterfly. The DCT-II unit then recursively subtracts the reverse-ordered first sub-set of the butterfly outputs. The DCT-II unit computes a sub-DCT-II for a second sub-set of the butterfly outputs and a sub-DCT-III for the recursively subtracted first set of butterfly outputs. The DCT-II unit reorders the outputs produced by the sub-DCT-II and sub-DCT-III to generate output values of the DCT-II.