Vector adaptive predictive coder for speech and audio
US4969192A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 6, 1987 |
| Grant date | Nov 6, 1990 |
| Priority date | — |
| Expiry date | Apr 6, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L2019/0014
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A real-time vector adaptive predictive coder which approximates each vector of K speech samples by using each of M fixed vectors in a first codebook to excite a time-varying synthesis filter and picking the vector that minimizes distortion. Predictive analysis for each frame determines parameters used for computing from vectors in the first codebook zero-state response vectors that are stored at the same address (index) in a second codebook. Encoding of input speech vectors s.sub.n is then carried out using the second codebook. When the vector that minimizes distortion is found, its index is transmitted to a decoder which has a codebook identical to the first codebook of the decoder. There the index is used to read out a vector that is used to synthesize an output speech vector s.sub.n. The parameters used in the encoder are quantized, for example by using a table, and the indices are transmitted to the decoder where they are decoded to specify transfer characteristics of filters used in producing the vector s.sub.n from the receiver codebook vector selected by the vector index transmitted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.