Frequency domain postfiltering for quality enhancement of coded speech
US7124077B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 28, 2005 |
| Grant date | Oct 17, 2006 |
| Priority date | — |
| Expiry date | Mar 26, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L21/0364
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and system of performing postfiltering in the frequency domain to improve the quality of a speech signal, especially for synthesized speech resulting from codecs of low bit-rate, is provided. The method comprises LPC tilt computation and compensation methods and modules, a formant filter gain computation method and module, and an anti-aliasing method and module. The formant filter gain calculation employs an LPC representation, an all-pole modeling, a non-linear transformation and a phase computation. The LPC used for deriving the postfilter may be transmitted from an encoder or may be estimated from a synthesized or other speech signal in a decoder or receiver. The invention may be implemented in a linked decoder and encoder. A separate LPC evaluation unit that is responsible for processing and or deriving the LPC may be implemented within the invention.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.