Bitrate scalable speech coding and decoding apparatus and method
US7702504B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 9, 2004 |
| Grant date | Apr 20, 2010 |
| Priority date | — |
| Expiry date | Nov 8, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/12
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A coding apparatus including a base layer, a speech quality enhancement layer, and a multiplexer. The base layer filters an input speech signal using linear prediction coding and generates an excitation signal corresponding to the filtered speech signal through a fixed codebook search and an adaptive codebook search. The speech quality enhancement layer searches a fixed codebook using parameters obtained through the fixed codebook search in the base layer, or searches the fixed codebook using a target signal, which is obtained by removing a contribution of a fixed codebook of the base layer and a signal which is obtained by synthesizing and filtering a previous fixed codebook of the speech quality enhancement layer from a target signal for the fixed codebook search of the base layer. The multiplexer multiplexes signals generated by the base layer and the at least one speech quality enhancement layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.