Code amount control device and encoding apparatus using the same
US6438167B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 1998 |
| Grant date | Aug 20, 2002 |
| Priority date | — |
| Expiry date | Nov 12, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/146
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An encoding apparatus including a block forming unit for dividing an input signal into blocks each consisting of a plurality of sample values, an orthogonal conversion unit for orthogonally converting the input signal blocks, a detection unit for detecting the characteristic of each block in accordance with orthogonal conversion coefficients obtained by the orthogonal conversion unit, a selection unit for selecting optimal quantization parameters which can realize a constant code amount obtained when the input signal blocks are encoded in a unit consisting of a plurality of input signal blocks, a changing unit for changing the quantization parameters selected by the selection unit in accordance with an output from the detection unit, and an encoding unit for encoding the orthogonal conversion coefficients from the orthogonal conversion unit using the quantization parameters changed by the changing unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.