Method subband of coding and decoding audio signals using variable length windows

US5848391A · kind A · utility

Assignees

• Max-Planck-Gesellschaft zur Föderung der Wissenschaften e.V. · US
• Dolby Laboratories Licensing Corporation · US

Inventors

• Marina Bosi · Redwood City, US
• Grant A. Davidson · Burlingame, US
• Charles Q. Robinson · Piedmont, US
• Martin Dietz · Nuremberg, DE
• Uwe Gbur · Berlin, DE
• Oliver Kunz · Seßlach, DE
• Karlheinz Brandenburg · Erlangen, DE

Key dates

• Filing date: Jul 11, 1996
• Grant date: Dec 8, 1998
• Expiry date: Jul 11, 2016

Classification

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

Abstract

A method of encoding time-discrete audio signals comprises the steps of weighting the time-discrete audio signal by means of window functions overlapping each other so as to form blocks, the window functions producing blocks of a first length for signals varying weakly with time and blocks of a second length for signals varying strongly with time. A start window sequence is selected for the transition from windowing with blocks of the first length to windowing with blocks of the second length, whereas a stop window sequence is selected for the opposite transition. The start window sequence is selected from at least two different start window sequences having different lengths, whereas the stop window sequence is selected from at least two different stop window sequences having different lengths. A method of decoding blocks of encoded audio signals selects a suitable inverse transformation as well as a suitable synthesis window as a reaction to side information associated with each block.