Fast inverse integer transform for video decoding
US8553762B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 2011 |
| Grant date | Oct 8, 2013 |
| Priority date | — |
| Expiry date | Oct 21, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/61
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In video decoding using the H.264/AVC standard, the computation of an inverse 4×4 integer transform of a coefficient matrix derived by variable length decoding may be carried out using data reduction techniques to reduce the computation load. If the index value of the highest-indexed nonzero coefficient in the matrix is three or higher, the transform is computed conventionally, using two 1D transform operations separated by a transpose operation, and followed by rounding and shifting. If the index value of the highest-indexed nonzero coefficient in the matrix is zero (including the case where there is no nonzero coefficient), the inverse integer transform operation includes only rounding and shifting of that coefficient. If the index value of the highest-indexed nonzero coefficient in the matrix is one or two, then the inverse integer transform operation can be performed using a single integrated 2D transform followed by rounding and shifting.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.