Dolby International Ab

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

Michael Beer

Juergen Herre

Daniel Fischer

Christof Fersch

Robin Thesing

Bodo Teichmann

Oliver Kunz

Klaus Peichl

Markus Werner

Eytan Rubin

Jan Mueller

Described herein are methods, apparatus and computer products for decoding an encoded MPEG-D USAC bitstream. Described herein are such methods, apparatus and computer products that reduce a computational complexity.

Methods and apparatus for unified speech and audio decoding improvements

The invention relates to an apparatus () for improving a stereo audio signal of an FM stereo radio receiver (). It is suggested to employ components of a standard HE-ACC v2 decoder () in such apparatus () to efficiently recover the stereo audio signal (L\R') while also exhibiting good signal quality. To that end, parametric stereo parameters () shall be quantized and submitted to such decoder () together with a mono-downmix signal (). The decoder () can then easily recover the parametric stereo parameters () by de-quantizing them via a simple lookup table, and finally creating the stereo output signal (L&#x2032;R&#x2032;) from the de-quantized parametric stereo parameters and the mono-downmix signal (). The apparatus () further includes a parameter estimation stage () which may again be embodied on the basis of components of a standard HE-ACC v2 encoder (). After estimating the parametric stereo parameters () and generating the mono-downmix signal (), the encoder () will not use further encoding other than the already performed PS-coding. An apparatus () according to the invention therefore advantageously includes decoder () and/or encoder () components of a standard HE-ACC v2 codec&#x2014;utilizing its parametric stereo parameter processing capabilities.

FM stereo radio receiver by using parametric stereo

In a device for processing a stereo audio signal having a first channel and a second channel the stereo signal is at first analyzed to obtain a measure for a quantity of bits required by a coder to code the stereo audio signal using a coding algorithm. The first channel and the second channel are then modified when the measure for the quantity of bits is larger than a predetermined value, the modification being performed in such a way that the energy of a sum signal of the first and the second modified channel is in a predetermined relation to the energy of a sum signal of the first and the second channel and that a difference signal of the first and the second modified channel is attenuated in contrast to the difference signal of the first and the second channel. Especially for audio coders requiring a constant output bit rate the side channel is attenuated in the case of stereo audio signals, the coding of which cannot meet the output bit rate of the coder, by which a stereo channel separation is abandoned for the benefit of an increased audio bandwidth or a reduction of quantizing disturbances, respectively.

Method and device for processing a stereo audio signal

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Erlangen, Germany

Michael Beer