Method and apparatus for frequency-domain downmixing with block-switch forcing for audio decoding functions
US6931291B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 8, 1997 |
| Grant date | Aug 16, 2005 |
| Priority date | — |
| Expiry date | May 8, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/022
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An audio decoder solution is here provided where a reduction in computing power is required. The proposed method consists of forcing the multiple output channels to only one type of inverse transformation format. A format of long transform length is more suitable for input signals whose spectrum remains stationary or quasi-stationary. This provides a greater frequency resolution, improved coding performance and a reduction of computing power required. Another format of two or more short transform lengths, possessing greater time resolution, is more desirable for rapidly changing signals with time. The computer power required for two or more short transforms should be higher than for only one transformation. The time versus frequency resolution trade-off should be considered when selecting a transform block length. Advantage is taken of human hearing behaviour to reduce the computing power of a processing engine (e.g. DSP) when downmixing from an M-channel input to a P-channel output is required. The encoder provides spectral information concerning the transmitted audio signal frame. This information corresponds to signals which are stationary/quasi-stationary or changing rapidly wi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.