Audio encoder, audio decoder, method for encoding an audio information, method for decoding an audio information and computer program using a region-dependent arithmetic coding mapping rule

US8612240B2 · kind B2 · utility

Assignee

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

Inventors

• Guillaume Fuchs · Erlangen, DE
• Vignesh Subbaraman · Erlangen, DE
• Nikolaus Rettelbach · Nuremberg, DE
• Markus Multrus · Nuremberg, DE
• Marc Gayer · Erlangen, DE
• Patrick Warmbold · Emskirchen, DE
• Christian Griebel · Nuremberg, DE
• Oliver Weiss · Nuremberg, DE

Key dates

• Filing date: Apr 19, 2012
• Grant date: Dec 17, 2013
• Expiry date: Apr 19, 2032

Classification

• Technology area (CPC G): Physics
• CPC primary: G10L19/0208
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

An audio decoder for providing a decoded audio information includes an arithmetic decoder for providing a plurality of decoded spectral values on the basis of an arithmetically-encoded representation of the spectral values and a frequency-domain-to-time-domain converter for providing a time-domain audio representation using decoded spectral values. The arithmetic decoder is configured to select a mapping rule describing a mapping of a code value onto a symbol code in dependence on a context state. The arithmetic decoder is configured to determine a numeric current context value describing the current context state in dependence on a plurality of previously decoded spectral values and also in dependence on whether a spectral value to be decoded is in a first predetermined frequency region or in a second predetermined frequency region. An audio encoder provides an encoded audio information on the basis of an input audio information.