Audio codec using adaptive sparse vector quantization with subband vector classification
US6006179A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 28, 1997 |
| Grant date | Dec 21, 1999 |
| Priority date | — |
| Expiry date | Oct 28, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L25/18
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An audio coder/decoder ("codec") that is suitable for real-time applications due to reduced computational complexity, and a novel adaptive sparse vector quantization (ASVQ) scheme and algorithms for general purpose data quantization. The codec provides low bit-rate compression for music and speech, while being applicable to higher bit-rate audio compression. The codec includes an in-path implementation of psychoacoustic spectral masking, and frequency domain quantization using the novel ASVQ scheme and algorithms specific to audio compression. More particularly, the inventive audio codec employs frequency domain quantization with critically sampled subband filter banks to maintain time domain continuity across frame boundaries. The input audio signal is transformed into the frequency domain in which in-path spectral masking can be directly applied. This in-path spectral masking usually results in sparse vectors. The ASVQ scheme is a vector quantization algorithm that is particularly effective for quantizing sparse signal vectors. In the preferred embodiment, ASVQ adaptively classifies signal vectors into six different types of sparse vector quantization, and performs quantization a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.