Audio coding

US7729903B2 · kind B2 · utility

Inventors

• Gerald Schuller · Erfurt, DE
• Stefan Wabnik · Ilmenau, DE
• Marc Gayer · Erlangen, DE

Key dates

• Filing date: Jul 27, 2006
• Grant date: Jun 1, 2010
• Expiry date: Mar 1, 2029

Classification

• Technology area (CPC G): Physics
• CPC primary: G10L19/265
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

The central idea of the present invention is that the prior procedure, namely interpolation relative to the filter coefficients and the amplification value, for obtaining interpolated values for the intermediate audio values starting from the nodes has to be dismissed. Coding containing less audible artifacts can be obtained by not interpolating the amplification value, but rather taking the power limit derived from the masking threshold, for each node, i.e. for each parameterization to be transferred, and then performing the interpolation between these power limits of neighboring nodes, such as, for example, a linear interpolation. On both the coder and the decoder side, an amplification value can then be calculated from the intermediate power limit determined such that the quantizing noise caused by quantization, which has a constant frequency before post-filtering on the decoder side, is below the power limit or corresponds thereto after post-filtering.