Time signal analysis and derivation of scale factors

US7181079B2 · kind B2 · utility

Assignee

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

Inventors

• Juergen Herre · Erlangen, DE
• Martin Dietz · Nuremberg, DE
• Thomas Sporer · Ergolding, DE
• Michael Schug · Erlangen, DE
• Wolfgang A. Schildbach · Nuremberg, DE

Key dates

• Filing date: Feb 16, 2001
• Grant date: Feb 20, 2007
• Expiry date: Nov 1, 2022

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04N19/60
• WIPO field: Audio-visual technology
• WIPO sector: Electrical engineering

Abstract

Analyzing an analysis time signal that has been generated from encoding and decoding and original time signal according to an encoding algorithm. The encoding block raster underlying the analysis time signal used by the encoding algorithm is determined. The analysis time signal is converted from its timely representation of analysis spectral coefficients to a spectral representation by using the established encoding block raster. At least two analysis spectral coefficients are grouped. The greatest common divisor of the analysis spectral coefficients are calculated, corresponding to the quantization step width used when quantizing the encoding algorithm or an integer multiple of it. In the case of an audio signal, the scale factor can easily be established for this group of spectral coefficients, i.e., for a scale factor band, from the quantization step width. All parameters used for the quantization of the original time signal are known; full iteration loops need not be performed.