Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V.

Juergen Koller

Juergen Herre

Ralf Geiger

Karlheinz Brandenburg

Gerald Schuller

Thomas Sporer

Niels Rump

Eric Allamanche

Joachim Deguara

For embedding binary payload in a carrier signal, which, for example, is an audio signal, a sequence of time-discrete values of the carrier signal is converted to the frequency domain by means of an integer transform algorithm to obtain binary spectral representation values. Bits of the binary spectral representation values with a valency less than signal limit valency are determined and set according to the payload. The signal limit valency for a spectral representation value is less than the valency of the leading bit of this spectral representation value, so that, with adequate distance, a psychoacoustic transparent insertion of information is achieved. Thus a modified spectral representation with inserted information is generated which is finally converted back to the time domain using an integer back transform algorithm. For extracting the payload, the time-discrete signal with the inserted information is again converted to a spectral representation with the integer forward transform algorithm. Furthermore, signal limit valency information is determined to identify the bits of the binary spectral representation values containing no information regarding the carrier signal, but information regarding the payload signal, to extract these bits. The inventive concept is simple in its implementation and may be scaled with respect to the data rate of the information to be inserted.

Device and method for embedding binary payload in a carrier signal

An apparatus for scalable encoding a spectrum of a signal including audio and/or video information, with the spectrum comprising binary spectral values, includes a means for generating a first sub-scaling layer and a second sub-scaling layer in addition to a means for forming the encoded signal, with the means for forming being implemented so as to include the first sub-scaling layer and the second sub-scaling layer into the encoded signal that the first and the second sub-scaling layer are separately decodable from each other. In contrast to a full-scaling layer, a sub-scaling layer includes only the bits of a certain order of a part of the binary spectral values in the band, so that, by additionally decoding a sub-scaling layer, a more finely controllable and a more finely scalable precision gain may be achieved.

Method and apparatus for scalable encoding and method and apparatus for scalable decoding

An apparatus for generating an encrypted data stream representing an audio and/or video signal comprises an encoder for encoding an input signal to generate a data stream with a predefined data stream syntax as output signal. The apparatus further comprises an encryption means coupled with the decoder in order to influence encoder internal data and/or the output signal of the encoder in a uniquely reversible manner based on a key such that the generated encrypted data stream comprises payload information differing from payload information of a data stream that would be generated by the apparatus without the presence of an encryption means and that the generated encrypted data stream comprises the predefined data stream syntax. Thereby, a flexible data stream encryption is achieved, wherein the degree of encryption can be freely selected such that the owner of a decoder who does not possess the key, still obtains a rough idea of the audio and/or video signal which might cause him to buy the key in order to hear or view the audio and/or video signal in its full quality. The encoder-specific encryption and decryption concept can be implemented into already existing encoders/decoders with little effort.

Device and method for producing an encoded audio and/or video data stream

A time-discrete audio signal is processed to provide a quantization block with quantized spectral values. Furthermore, an integer spectral representation is generated from the time-discrete audio signal using an integer transform algorithm. The quantization block having been generated using a psychoacoustic model is inversely quantized and rounded to then form a difference between the integer spectral values and the inversely quantized rounded spectral values. The quantization block alone provides a lossy psychoacoustically coded/decoded audio signal after the decoding, whereas the quantization block, together with the combination block, provides a lossless or almost lossless coded and again decoded audio signal in the decoding. By generating the differential signal in the frequency domain, a simpler coder/decoder structure results.

Apparatus and method for coding a time-discrete audio signal to obtain coded audio data and for decoding coded audio data

In a method for generating a second data stream from a first data stream, which comprises a first header and a first payload data block with payload data, the first header is initially extracted from the first data stream. Subsequently the second header for the second data stream is generated. Then, at least a part of the first header is entered into the second header, the part of the first header including information, which allows conclusions as to the origin of the payload data. Finally, the second payload data block is generated, which comprises the same payload data, so as to obtain the complete second data stream. The method according to the invention enables device-specific encrypting of payload data, a flexible, device-specific 'copy' for other devices of a user and, in particular, complete documentation of the origin of the present copy, such that effective copyright protection may be realized.

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Munich, Germany

Juergen Koller