Analysis-by-synthesis speech coding method with open-loop and closed-loop search of a long-term prediction delay
US5974377A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 14, 1997 |
| Grant date | Oct 26, 1999 |
| Priority date | — |
| Expiry date | Oct 14, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L25/93
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method comprising the steps of performing a linear prediction analysis of a speech signal digitized in a series of frames divided into sub-frames, in order to determine the parameters of a short-term synthesis filter; carrying out an open loop analysis to detect voiced signal frames and determine, for each voice frame, a degree of signal voicing and a long-term prediction delay search interval containing a number of delays depending on the degree of voicing; carrying out a closed-loop predictive analysis of the speech signal to select, for at least some sub-frames of the voiced frames, a long-term prediction delay contained in the search interval and constituting a long-term synthesis filter parameter; and determining a stochastic excitation for each sub-frame, to minimize a perceptually weighted deviation between the speech signal and the stochastic excitation filtered by the long-term and short-term synthesis filters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.