Companding apparatus and method to reduce quantization noise using advanced spectral extension
US9947335B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Apr 1, 2014 |
| Grant date | Apr 17, 2018 |
| Priority date | — |
| Expiry date | Aug 25, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03G7/007
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Embodiments are directed to a companding method and system for reducing coding noise in an audio codec. A compression process reduces an original dynamic range of an initial audio signal through a compression process that divides the initial audio signal into a plurality of segments using a defined window shape, calculates a wideband gain in the frequency domain using a non-energy based average of frequency domain samples of the initial audio signal, and applies individual gain values to amplify segments of relatively low intensity and attenuate segments of relatively high intensity. The compressed audio signal is then expanded back to substantially the original dynamic range that applies inverse gain values to amplify segments of relatively high intensity and attenuating segments of relatively low intensity. A QMF filterbank is used to analyze the initial audio signal to obtain a frequency domain representation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.