Variable length decoding using lookup tables
US5253053A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 31, 1990 |
| Grant date | Oct 12, 1993 |
| Priority date | — |
| Expiry date | Dec 31, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/91
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for decoding a variable length codeword (VLC) by reading a VLC, the VLC having a maximum length of X bits. The VLC is used as an index into a first table, wherein the first table contains decoded values for all possible VLC's with Y bits not equal to any value in a first set of values. Y is typically less than X and comprises, in the preferred embodiment, the most significant bits of the VLC. If the first Y bits of the VLC are not equal to any value in a first set of values then a second value is returned from the first table. If the first Y bits of the VLC are equal to any value in a first set of values, then a pointer to a second table is returned from the first table. The VLC is used as an index into the second table, and a third value is returned from the second table.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.