Method and apparatus for encoding and decoding multiple audio channels at low bit rates using adaptive selection of encoding method
US5890125A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 16, 1997 |
| Grant date | Mar 30, 1999 |
| Priority date | — |
| Expiry date | Jul 16, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04S2420/03
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A split-band coding system combines multiple channels of input signals into various forms of composite signals and generates spatial-characteristic signals representing soundfield spatial characteristics in a plurality of frequency subbands. The spatial-characteristics signals may be generated in either or both of two forms. In a first form, the signal represents measures of signal levels for subband signals from the input channels. In a second form, the signal represents one or more apparent directions for the soundfield. The type of the spatial-characteristics signal may be adapted dynamically in response to a variety of criteria including input signal characteristics. Temporal smoothing and spectral smoothing of the spatial-characteristics signals may be applied in an encoder. Temporal smoothing and spectral smoothing may be applied to gain factors derived from the spatial-characteristics signals in a decoder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.