Audio encoder, audio decoder, method for encoding and audio information, method for decoding an audio information and computer program using an optimized hash table

US8914296B2 · kind B2 · utility

Assignee

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

Inventors

• Guillaume Fuchs · Erlangen, DE
• Vignesh Subbaraman · Erlangen, DE
• Markus Multrus · Nuremberg, DE
• Nikolaus Rettelbach · Nuremberg, DE
• Matthias Hildenbrand · Erlangen, DE
• Oliver Weiss · Nuremberg, DE
• Arthur Tritthart · Erlangen, DE
• Patrick Warmbold · Emskirchen, DE

Key dates

• Filing date: Jan 18, 2013
• Grant date: Dec 16, 2014
• Expiry date: Jan 18, 2033

Classification

• Technology area (CPC G): Physics
• CPC primary: G10L19/02
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

An audio decoder includes an arithmetic decoder for providing decoded spectral values on the basis of an arithmetically encoded representation thereof, and a frequency-domain-to-time-domain converter for providing a time-domain audio representation. The arithmetic decoder selects a mapping rule describing a mapping of a code value onto a symbol code representing a spectral value, or a most significant bit-plane thereof, in a decoded form, in dependence on a context state described by a numeric current context value. The arithmetic decoder determines the numeric current context value in dependence on a plurality of previously decoded spectral values. It evaluates a hash table, entries of which define both significant state values amongst the numeric context values and boundaries of intervals of numeric context values, in order to select the mapping rule, wherein the hash table ari_hash_m is defined as given in FIGS. 22(1), 22(2), 22(3) and 22(4).