Fraunhofer-gesellschaft Zur Foerderung Der Angewandten Forschung E.v.

Hartmut Schott

Ernst Eberlein

Harald Popp

Dieter Seitzer

Heinz Gerhauser

Karlheinz Brandenburg

Albert Heuberger

Rainer Perthold

Christian Neubauer

Heinz Gerh&auml;user

Rolf Kapust

Roland Plankenb&uuml;hler

Karl Heinz Brandenburg

In a coding method and a coder for introducing a non-audible data signal into an audio signal, the audio signal is first transformed to a spectral range and the masking threshold of the audio signal is determined. A pseudo-noise signal and a data signal are provided and multiplied with each other so a to provide a frequency-spread data signal. The spread data signal is weighted with the masking threshold, and thereafter the audio signal and the weighted data signal are superimposed. In a method and a decoder for decoding a data signal introduced into an audio signal in non-audible manner, the audio signal is first sampled and thereafter the sampled audio signal is filtered in non-recursive manner. The filtered audio signal is subsequently compared to a threshold value so as to retrieve the data signal.

Coding process for inserting an inaudible data signal into an audio signal, decoding process, coder and decoder

A digital adaptive transformation coding method for the transmission and/or torage of audio signals, specifically music signals, wherein N scanned values of the audio signal are transformed into M spectral coefficients, and the coefficients are split up into frequency groups, quantized and then coded. The quantized maximum value of each frequency group is used to define the coarse variation of the spectrum. The same number of bits is assigned to all values in a frequency group. The bits are assigned to the individual frequency groups as a function of the quantized maximum value present in the particular frequency group. A multi-signal processor system is disclosed which is specifically designed for implementation of this method.

Digital adaptive transformation coding method

Apparatus for checking audio signal processing systems

Growing community of inventors

Erlangen, Germany

Hartmut Schott