Encoder apparatus and method that perform preliminary signal selection for transform coding before main signal selection for transform coding
US9361892B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 5, 2011 |
| Grant date | Jun 7, 2016 |
| Priority date | — |
| Expiry date | Jul 4, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/20
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An encoder apparatus is provided that suppresses the quality degradation of encoding processes. An ultimate selection candidate limiting unit uses the spectrum of an input signal and a residual spectrum to designate a given number of pre-selected suppression factors to a CELP component suppressing unit, which uses the designated suppression factors to generate a suppressed spectrum. A CELP residual signal spectrum calculating unit, to which the suppressed spectrum is input, calculates a residual spectrum. A conversion encoding unit uses the residual spectrum to perform a second encoding process. A distortion evaluating unit determines one of the designated suppression factors by use of the spectrum of a second decoded signal generated by decoding a second code obtained by the second encoding process, and further by use of the suppressed spectrum and the spectrum of the input signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.