Method and device for processing time-discrete audio sampled values

US7512539B2 · kind B2 · utility

Assignee

• Fraunhofer-Gesellschaft zur förderung der angewandten Forschung e.V. · DE

Inventors

• Ralf Geiger · Erlangen, DE
• Thomas Sporer · Ergolding, DE
• Karlheinz Brandenburg · Erlangen, DE
• Jürgen Herre · Buckenhof, DE
• Jurgen Koller · St. Blasien, DE

Key dates

• Filing date: May 28, 2002
• Grant date: Mar 31, 2009
• Expiry date: Mar 28, 2024

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F17/147
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

An integer transform, which provides integer output values, carries out the TDAC function of a MDCT in the time domain before the forward transform. In overlapping windows, this results in a Givens rotation which may be represented by lifting matrices, wherein time-discrete sampled values of an audio signal may at first be summed up on a pair-wise basis to build a vector so as to be sequentially provided with a lifting matrix. After each multiplication of a vector by a lifting matrix, a rounding step is carried out such that, on the output-side, only integers will result. By transforming the windowed integer sampled value with an integer transform, a spectral representation with integer spectral values may be obtained. The inverse mapping with an inverse rotation matrix and corresponding inverse lifting matrices results in an exact reconstruction.