Frequency-domain scalable coding without upsampling filters

US6370507B1 · kind B1 · utility

Assignee

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

Inventors

• Bernhard Grill · Lautenbächle, DE
• Bernd Edler · Hannover, DE
• Karlheinz Brandenburg · Erlangen, DE

Key dates

• Filing date: May 28, 1999
• Grant date: Apr 9, 2002
• Expiry date: May 28, 2019

Classification

• Technology area (CPC G): Physics
• CPC primary: G10L19/0204
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

In a method of coding discrete time signals (X1) sampled with a first sampling rate, second time signals (x2) are generated using the first time signals having a bandwidth corresponding to a second sampling rate, with the second sampling rate being lower than the first sampling rate. The second time signals are coded in accordance with a first coding algorithm. The coded second signals (X2c) are decoded again in order to obtain coded/decoded second time signals (X2cd) having a bandwidth corresponding to the second sampling frequency. The first time signals, by frequency domain transformation, become first spectral values (X1). Second spectral values (X2cd) are generated from the coded/decoded second time signals, the second spectral values being a representation of the coded/decoded time signals in the frequency domain. To obtain weighted spectral values, the first spectral values are weighted by means of the second spectral values, with the first and second spectral values having the same frequency and time resolution. The weighted spectral values (Xb) are coded in accordance with a second coding algorithm in consideration of a psychoacoustic model and written into a bit stream. W…