Audio signal loudness measurement and modification in the MDCT domain
US8504181B2 · kind B2 · utility
7Cited by
87References
7Claims
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Key dates
| Filing date | Mar 30, 2007 |
| Grant date | Aug 6, 2013 |
| Priority date | — |
| Expiry date | Sep 23, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/0212
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Processing an audio signal represented by the Modified Discrete Cosine Transform (MDCT) of a time-sampled real signal is disclosed in which the loudness of the transformed audio signal is measured, and at least in part in response to the measuring, the loudness of the transformed audio signal is modified. When gain modifying more than one frequency band, the variation or variations in gain from frequency band to frequency band, is smooth. The loudness measurement employs a smoothing time constant commensurate with the integration time of human loudness perception or slower.
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