Audio coding device with two-stage quantization mechanism
US8019601B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 25, 2007 |
| Grant date | Sep 13, 2011 |
| Priority date | — |
| Expiry date | Jul 2, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/035
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An audio coding device that optimizes quantization parameters for fast convergence of iterations. A quantized bit counter calculates a codeword length representing the number of bits of a Huffman codeword corresponding to quantized values. The quantized bit counter also calculates a codebook number bit count representing how many bits are consumed for optimal Huffman codebook numbers, and a scale factor bit count representing how many bits are consumed for scale factors of each subband. In a first stage of quantization, the quantized bit counter accumulates lengths of Huffman codewords corresponding to quantized values of every nth subband. A bit count estimator calculates a total bit count estimate by adding up n times the accumulated codeword length, the codebook number bit count, and the scale factor bit count. A parameter updater updates quantization parameters if the total bit count estimate exceeds a bit count limit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.