Apparatus and a method for calculating a number of spectral envelopes

US8296159B2 · kind B2 · utility

Assignee

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

Inventors

• Max Neuendorf · Nuremberg, DE
• Bernhard Grill · Lautenbächle, DE
• Ulrich Kraemer · Stuttgart, DE
• Markus Multrus · Nuremberg, DE
• Harald Popp · Tuchenbach, DE
• Nikolaus Rettelbach · Nuremberg, DE
• Frederik Nagel · Nuremberg, DE
• Markus Lohwasser · Hersbruck, DE
• Marc Gayer · Erlangen, DE
• Manuel Jander · Hemhofen, DE
• Virgilio Bacigalupo · Nuremberg, DE

Key dates

• Filing date: Jan 11, 2011
• Grant date: Oct 23, 2012
• Expiry date: Jan 11, 2031

Classification

• Technology area (CPC G): Physics
• CPC primary: G10L19/20
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

An apparatus calculates a number of spectral envelopes to be derived by a spectral band replication (SBR) encoder, wherein the SBR encoder is adapted to encode an audio signal using a plurality of sample values within a predetermined number of subsequent time portions in an SBR frame extending from an initial time to a final time, the predetermined number of subsequent time portions being arranged in a time sequence given by the audio signal. The apparatus has a decision value calculator for determining a decision value, the decision value measuring a deviation in spectral energy distributions of a pair of neighboring time portions. The apparatus further has a detector for detecting a violation of a threshold by the decision value and a processor for determining a first envelope border between the pair of neighboring time portions when the violation of the threshold is detected.