Method and apparatus for downmixing decoded data streams in the frequency domain prior to conversion to the time domain
US5946352A · kind A · utility
71Cited by
7References
12Claims
0Family size
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Key dates
| Filing date | May 2, 1997 |
| Grant date | Aug 31, 1999 |
| Priority date | — |
| Expiry date | May 2, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/008
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A data processing device is programmed to decode and transform a stream of data representing a plurality of subband encoded channels of audio data into one or more channels of PCM encoded data for reproduction by a speaker subsystem. An improved method for decoding and transforming utilizes downmix matrices (1021 and 1022) to form downmixed frequency domain channels in buffers (1031-1034). Only two long DCT transform operations (1041 and 1042) and two short DCT transform operations (1043 and 1044) are needed to transform the downmixed frequency domain channels into a left PCM output (1071) and a right PCM output (1072).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.