Audio decoder with an adaptive frequency domain downmixer
US6205430A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 21, 1999 |
| Grant date | Mar 20, 2001 |
| Priority date | — |
| Expiry date | Jun 21, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04H20/88
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for decoding a multi-channel audio bitstream in which adaptive frequency domain downmixer (3) is used to downmix, according to long and shorter transform block length information (17), the decoded frequency coefficients of the multi-channel audio (12,13,14,15) such that the long and shorter transform block information is maintained separately within the mixed down left and right channels. In this way, the long and shorter transform block coefficients of the mixed down let and right channels can be inverse transformed adaptively (4,5,6,7) according to the long and shorter transform block information, and the results of the inverse transform of the long and short block of each the left and right channel added together (8,9) to form the total mixed down output of the left and right channel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.