Device and method for postprocessing spectral values and encoder and decoder for audio signals

US8321207B2 · kind B2 · utility

Assignee

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

Inventors

• Bernd Edler · Hannover, DE
• Ralf Geiger · Erlangen, DE
• Christian Ertel · Eckental, DE
• Johannes Hilpert · Nuremberg, DE
• Harald Popp · Tuchenbach, DE

Key dates

• Filing date: Sep 28, 2007
• Grant date: Nov 27, 2012
• Expiry date: Jan 20, 2030

Classification

• Technology area (CPC G): Physics
• CPC primary: G10L19/265
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

For postprocessing spectral values which are based on a first transformation algorithm for converting the audio signal into a spectral representation, first a sequence of blocks of the spectral values representing a sequence of blocks of samples of the audio signal are provided. Hereupon, a weighted addition of spectral values of the sequence of blocks of spectral values is performed in order to obtain a sequence of blocks of postprocessed spectral values, wherein the combination is performed such that for calculating a postprocessed spectral value for a frequency band and a time duration a spectral value of the sequence of blocks for the frequency band and the time duration and a spectral value for another frequency band or another time duration are used, wherein the combination is further performed such that such weighting factors are used that the postprocessed spectral values are an approximation to the spectral values as they are obtained by converting the audio signal into a spectral representation using a second transformation algorithm which is different from the first transformation algorithm. The postprocessed spectral values are in particular used for a difference format…