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

Opticom Dipl.-ing. Michael Keyhl Gmbh

Opticom Dipl.-ing M. Keyhl Gmbh

Opticom Gmbh

Roland Bitto

Christian Schmidmer

Michael Keyhl

Karlheinz Brandenburg

Martin Dietz

Ralph Sperschneider

Thomas Sporer

Heinz Gerhaeuser

Andreas Ehret

Pierre Lauber

Ali Nowbakht-Irani

Matthias Obermann

Determining a quality of a media data stream including a sequence of data stream sections which transmit different media sections of a media content at quality-to-bitrate levels that vary across the media content, such as within the context of adaptive streaming, is configured to be more effective by deriving, from each data stream section, an identifier for the respective section, and by looking up, for each data stream section, a parameter set from a look-up table by means of the identifier derived for the respective data stream section, so that it is possible to aggregate the parameter sets and to determine the quality on the basis thereof.

Concept for determining the quality of a media data stream with varying quality-to-bitrate

In embodiments, a device is illustrated for determining a sample rate difference between a first information signal and a second information signal including an offset determiner for determining for each of a plurality of segments of the first information signal, associated offset values which temporally align the plurality of segments with respect to the second information signal and a calculator for calculating the sample rate difference on the basis of the offset values.

Device and method for determining a sample rate difference

An apparatus for determining information in order to temporally align first and second information signals, each including one or several information values for successive sampling times, the apparatus including a characteristic extractor for extracting a characteristic per sampling time or per subsequence of sampling times from the first information signal within a first search pattern to obtain a first characteristic curve, and for extracting the characteristic per sampling time or per subsequence of sampling times from the second information signal within a second search pattern to obtain a second characteristic curve and a determiner for determining the information for temporal alignment based on similarities between the first and second characteristic curves of the characteristic by means of a first search for a search pattern from one of the first and second characteristic curves of the characteristic within the other of the first and second characteristic curves of the characteristic.

Apparatus for determining information in order to temporally align two information signals

For extracting signal test sections conforming to an auditory test from an audio signal, in particular for non-intrusive tests for a quality assessment of a transmission system, first of all a temporal structure of the audio signal is parsed in order to differentiate an information-carrying section of the audio signal from a preceding non-information-carrying section of the audio signal or a subsequent non-information-carrying section of the audio signal. Hereupon, a test signal section is generated based on the information-carrying section of the audio signal. Thus, test signal sections conforming to an auditory test are obtained, on the one hand determining the comparability with other auditory tests and, on the other hand, reducing a too inaccurate assessment of the transmission system based on system-immanent artefacts.

Apparatus and method for extracting a test signal section from an audio signal

A system for evaluating the quality of an audio test signal derived from an audio reference signal by coding and decoding, said audio test signal and said audio reference signal each comprising a plurality of channels, comprises a unit for converting the audio reference signal into a first audio reference sum signal at a first reference point and into a second audio reference sum signal at a second reference point and for converting the audio test signal into a first audio test sum signal at the first reference point and into a second audio test sum signal at the second reference point, the audio reference sum signals and the audio test sum signals at the first and second reference points being a superposition of the respective channels, which can be emitted by a plurality of loudspeakers, weighted with a respective transfer function between the respective loudspeaker and the reference point in question, and a unit for evaluating the quality of the audio test sum signals while taking into consideration the audio reference sum signals so as to provide an indication of the quality of the audio test signal. The system according to the present invention permits real rooms and an arbitrary number of channels of the audio test signal to be taken into account so as to execute a listening-adapted evaluation of the quality of a specific coding/decoding method.

System and method for evaluating the quality of multi-channel audio signals

In a method for coding an audio signal to obtain a coded bit stream, discrete-time samples of the audio signal are transformed into the frequency domain to obtain spectral values. The spectral values are coded with a code table having a limited number of code words of different lengths to obtain spectral values coded by code words, the length of a code word assigned to a spectral value being that much shorter the higher the probability of occurrence of the spectral value is. A raster is then specified for the coded bit stream, the raster having equidistant raster points and the distance between the raster points depending on the code table(s) used. In order to obtain error-tolerant Huffman coding, priority code words, which represent particular spectral values which are psychoacoustically more important than other spectral values, are so arranged in the raster that the start of each priority code word coincides with a raster point.

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Nuremberg, Germany

Roland Bitto