Enhancing the performance of coding systems that use high frequency reconstruction methods
US7050972B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 15, 2001 |
| Grant date | May 23, 2006 |
| Priority date | — |
| Expiry date | Jul 7, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L21/038
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An apparatus for encoding an audio signal to obtain an encoded audio signal to be used by a decoder having a high frequency reconstruction module for performing a high frequency reconstruction for a frequency range above a crossover frequency includes, a core encoder for encoding a lower frequency band of the audio signal up to the crossover frequency, the crossover frequency being variable, and the core encoder being operable on a block-wise frame by frame basis, and a crossover frequency control module for estimating, dependent on a measure of the degree of difficulty for encoding the audio signal by the core encoder and/or a boarder between a tonal and a noise-like frequency range of the audio signal, the crossover frequency to be selected by the core encoder for a frame of a series of subsequent frames, so that the crossover frequency is variable adaptively over time for the series of subsequent frames.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.