Scalable compression of audio and other signals
US6947886B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 21, 2003 |
| Grant date | Sep 20, 2005 |
| Priority date | — |
| Expiry date | Mar 6, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/24
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Disclosed are scalable quantizers for audio and other signals characterized by a non-uniform, perception-based distortion metric, that operate in a common companded domain which includes both the base-layer and one or more enhancement-layers. The common companded domain is designed to permit use of the same unweighted MSE metric for optimal quantization parameter selection in multiple layers, exploiting the statistical dependence of the enhancement-layer signal on the quantization parameters used in the preceding layer. One embodiment features an asymptotically optimal entropy coded uniform scalar quantizer. Another embodiment is an improved bit rate scalable multi-layer Advanced Audio Coder (AAC) which extends the scalability of the asymptotically optimal entropy coded uniform scalar quantizer to systems with non-uniform base-layer quantization, selecting the enhancement-layer quantization methodology to be used in a particular band based on the preceding layer quantization coefficients. In the important case that the source is well modeled as Laplacian, the optimal conditional quantizer is implementable by only two distinct switchable quantizers depending on whether or not the pr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.