Method and apparatus for introducing information into a data stream and method and apparatus for encoding an audio signal

US7454327B1 · kind B1 · utility

Assignee

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

Inventors

• Christian Neubauer · Nuremberg, DE
• Juergen Herre · Erlangen, DE
• Karlheinz Brandenburg · Erlangen, DE
• Eric A. Allamanche · Nuremberg, DE

Key dates

• Filing date: Oct 5, 2000
• Grant date: Nov 18, 2008
• Expiry date: Dec 31, 2022

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04B1/707
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

An inventive method for introducing information into a data stream including data about spectral values representing a short-term spectrum of an audio signal first performs a processing of the data stream to obtain the spectral values of the short-term spectrum of the audio signal. Apart from that, the information to be introduced are combined with a spread sequence to obtain a spread information signal, whereupon a spectral representation of the spread information is generated which will then be weighted with an established psychoacoustic maskable noise energy to generate a weighted information signal, wherein the energy of the introduced information is substantially equal to or below the psychoacoustic masking threshold. The weighted information signal and the spectral values of the short-term spectrum of the audio signal will then be summed and afterwards processed again to obtain a processed data stream including both audio information and information to be introduced. By the fact that the information to be introduced are introduced into the data stream without changing to the time domain, the block rastering underlying the short-term spectrum will not be touched, so that intro…