Audio encoding device using concealment processing and audio decoding device using concealment processing
US9129590B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 29, 2008 |
| Grant date | Sep 8, 2015 |
| Priority date | — |
| Expiry date | Dec 19, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/12
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Disclosed are an audio encoding device and an audio decoding device which reduce degradation of subjective quality of a decoding signal caused by power mismatch of a decoding signal which is generated by a concealing process upon disappearance of a frame. When a frame is lost, a past encoding parameter is used to obtain a concealed LPC of the current frame and a concealed sound source parameter. A normal CELP decoding is performed from the obtained concealed sound source parameter. Correction is performed by using a conceal parameter on the obtained concealed LPC and the concealed sound source signal. The power of the corrected concealed sound source signal is adjusted to match a reference sound source power. A filter gain of the synthesis filter is adjusted so as to adjust the power of a decoded sound signal to the power of a decoded sound signal during an error-free state. Moreover, a synthesis filter gain adjusting coefficient is calculated by using an estimated normalized residual power so that a filter gain of a synthesis filter formed by using a concealed LPC is a filter gain during an error-free state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.