Technique for encoding/decoding of codebook indices for quantized MDCT spectrum in scalable speech and audio codecs
US8515767B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 3, 2008 |
| Grant date | Aug 20, 2013 |
| Priority date | — |
| Expiry date | Nov 30, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/24
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Codebook indices for a scalable speech and audio codec may be efficiently encoded based on anticipated probability distributions for such codebook indices. A residual signal from a Code Excited Linear Prediction (CELP)-based encoding layer may be obtained, where the residual signal is a difference between an original audio signal and a reconstructed version of the original audio signal. The residual signal may be transformed at a Discrete Cosine Transform (DCT)-type transform layer to obtain a corresponding transform spectrum. The transform spectrum is divided into a plurality of spectral bands, where each spectral band having a plurality of spectral lines. A plurality of different codebooks are then selected for encoding the spectral bands, where each codebook is associated with a codebook index. A plurality of codebook indices associated with the selected codebooks are then encoded together to obtain a descriptor code that more compactly represents the codebook indices.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.