Method for the cascaded coding and decoding of audio data

US6101475A · kind A · utility

Assignee

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

Inventors

• Michael Keyhl · Heroldsbach, DE
• Harald Popp · Tuchenbach, DE
• Ernst Eberlein · Erlangen, DE
• Karl-Heinz Brandenburg · Erlangen, DE
• Heinz Gerhauser · Waischenfeld, DE
• Christian Schmidmer · Nuremberg, DE

Key dates

• Filing date: Aug 21, 1996
• Grant date: Aug 8, 2000
• Expiry date: Aug 21, 2016

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04B1/665
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

In a method for the cascaded coding and decoding of audio data the spectral components of the short-time spectrum associated with a data block are formed for each data block with a certain number of time input data, the coded signal is formed, by quantization and coding, on the basis of the spectral components for this data block and using a psycho-acoustic model to determine the bit distribution for the spectral components, whereupon time output data are obtained by decoding at the end of each codec stage. To prevent a deterioration in the sound quality in codec cascades with a plurality of stages, an identification code is added to the coded signal at an initial stage to mark the start of the data block; furthermore, the subsequent codec stages divide the data blocks to be coded on the basis of this identification code.