Adaptive digital audio encoding system
US5649052A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 29, 1994 |
| Grant date | Jul 15, 1997 |
| Priority date | — |
| Expiry date | Dec 29, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/665
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An encoding system employing a novel perceptual spectrum difference estimation device improves the coding efficiency and audio quality of a digitized audio signal. The system comprises M number of encoding means arranged in parallel for encoding the input digital audio signal of a current frame, respectively; M number of decoding means arranged in parallel for decoding each of the encoded digital audio signals; a first estimator for estimating a power density spectrum for a difference signal between the input digital audio signal and each of the decoded digital audio signals; a second estimator for estimating a power density spectrum for the input digital audio signal of the current frame and for determining a masking threshold therefor based on the power density spectrum for the input digital audio signal; a third estimator for estimating a set of perceptual spectrum distances based on the power density spectrum for each of the difference signals and the masking threshold; and a circuit for selecting an encoded digital audio signal having a smallest perceptual spectrum distance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.