Audio signal encoder/decoder for use in low delay applications, selectively providing aliasing cancellation information while selectively switching between transform coding and celp coding of frames

US8630862B2 · kind B2 · utility

Assignee

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

Inventors

• Ralf Geiger · Erlangen, DE
• Markus Schnell · Nuremberg, DE
• Jérémie Lecomte · Santa Clara, US
• Konstantin Schmidt · Nuremberg, DE
• Guillaume Fuchs · Erlangen, DE
• Nikolaus Rettelbach · Nuremberg, DE

Key dates

• Filing date: Apr 19, 2012
• Grant date: Jan 14, 2014
• Expiry date: Apr 19, 2032

Classification

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

Abstract

An audio signal encoder includes a transform-domain path which obtains spectral coefficients and noise-shaping information on the basis of a portion of the audio content, and which windows a time-domain representation of the audio content and applies a time-domain-to-frequency-domain conversion. The audio signal decoder includes a CELP path to obtain a code-excitation information and a LPC parameter information. A converter applies a predetermined asymmetric analysis window in both if a current portion is followed by a subsequent portion to be encoded in the transform-domain mode or in the CELP mode. Aliasing cancellation information is selectively provided in the latter case.