Digital encoding process

US5579430A · kind A · utility

Assignee

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

Inventors

• Bernhard Grill · Lautenbächle, DE
• Karl-Heinz Brandenburg · Erlangen, DE
• Thomas Sporer · Ergolding, DE
• Bernd Kürten · Großenseebach, DE
• Ernst Eberlein · Erlangen, DE

Key dates

• Filing date: Jan 26, 1995
• Grant date: Nov 26, 1996
• Expiry date: Jan 26, 2015

Classification

• Technology area (CPC H): Electricity
• CPC primary: H03M7/42
• WIPO field: Basic communication processes
• WIPO sector: Electrical engineering

Abstract

A digital encoding process for transmitting and/or storing acoustical sigs and, in particular, music signals, in which scanned values of the acoustical signal are transformed by means of a transformation or a filter bank into a sequence of second scanned values, which reproduce the spectral composition of the acoustical signal, and the sequence of second scanned values is quantized in accordance with the requirements with varying precision and is partially or entirely encoded by an optimum encoder, and in which a corresponding decoding and inverse transformation takes place during the reproduction. An encoder is utilized in a manner in which the occurrence probability of the quantized spectral coefficient is correlated to the length of the code in such a way that the more frequently the spectral coefficient occurs, the shorter the code word. A code word and, if needed, a supplementary code is allocated to several elements of the sequence or to a value range in order to reduce the size of the table of the encoder. A portion of the code words of variable length are arranged in a raster, and the remaining code words are distributed in the gaps still left so that the beginning of a cod…