Speech encoding at variable bit rate
US5933803A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 5, 1997 |
| Grant date | Aug 3, 1999 |
| Priority date | — |
| Expiry date | Dec 5, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/002
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The invention is related digital speech encoding. In a speech codec according to the invention, for modeling a speech signal (301) both prediction parameters (321, 322, 331) modeling a speech signal in a short term and prediction parameters (341, 342, 351) modeling a speech signal in a long term are used. Each prediction parameter (321, 322, 331, 341, 342, 351) is presented using a certain accuracy, in a digital system with a certain number of bits. In speech encoding according to the invention the number of bits used for presenting prediction parameters (321, 322, 331, 341, 342, 351) is adjusted based upon information parameters (321, 322, 331, 341, 342, 351) obtained from a short-term LPC-analysis (32) and from a long-term LTP-analysis (31, 34, 35). The invention is particularly suitable for use at low data transfer speeds, because it offers a speech encoding method of even quality and low average bit rate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.