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

Tu Ilmenau

Sandra Brix

Thomas Sporer

Katrin Reichelt

Gabriel Gatzsche

Frank Melchior

Thomas Roeder

Harald Fuchs

Josef Bernhard

Manfred Lutzky

Harald Popp

Marc Gayer

Stefan Kraegeloh

Michael Beckinger

Daniel Beer

Andreas Franck

Kai-Uwe Sattler

Stefan Krägeloh

Berthold Schlenker

Thomas Heimrich

Haymo Kutschbach

Jan Langhammer

Heinz Gensicke

Martin Kuster

Thomas Röder

Carsten Land

A basic idea of the present application is that in case of determining a position of the object on the surface, it is possible to also use transport mechanisms for the transport of the object on the surface which leads to less reproducible transport movements as the regulation may be executed directly on the basis of the observed movement as compared to the desired movement. Embodiments using compressed air, magnetism and/or bending waves are described.

Transport of an object across a surface

An apparatus for controlling a wave field synthesis renderer with audio objects includes a provider for providing a scene description, wherein the scene description defines a temporal sequence of audio objects in an audio scene and further includes information on the source position of a virtual source as well as on a start or an end of the virtual source. Furthermore, the audio object includes at least a reference to an audio file associated with the virtual source. The audio objects are processed by a processor, in order to generate a single output data stream for each renderer module, wherein both information on the position of the virtual source and the audio file itself are included in mutual association in this output data stream. With this, high portability on the one hand and high quality due to secure data consistency on the other hand are achieved.

Apparatus and method for controlling a wave field synthesis renderer means with audio objects

For generating a low-frequency channel for a low-frequency loudspeaker arranged at a predetermined low-frequency loudspeaker position, a plurality of audio objects are initially provided, each audio object having an object position and an object description associated with it. Hereafter, a calculation of an audio object scaling value is performed for each audio object on the basis of the object description, so that an actual amplitude state at least comes close to a target amplitude state at a reference playback position. Thereafter, each object signal is scaled with an associated audio object scaling value so as to then sum the scaled object signals. From the composite signal obtained there, a low-frequency channel is subsequently derived for the low-frequency loudspeaker, and is provided to the respective low-frequency loudspeaker. Due to the scaling of the individual object signals of the audio objects, this approach is independent of an actual situation of a multichannel playback system with regard to the number and density of the loudspeakers as well as with regard to the size of the presentation area actually present.

Apparatus and method for generating a low-frequency channel

A device for determining a component signal for a WFS system includes a provider for providing WFS parameters, a WFS parameter interpolator, and an audio signal processor. The provider provides WFS parameters for a component signal while using a source position and while using the loudspeaker position at a parameter sampling frequency smaller than the audio sampling frequency. The WFS parameter interpolator interpolates the WFS parameters so as to produce interpolated WFS parameters which are present at a parameter interpolation frequency that is higher than the parameter sampling frequency, the interpolated WFS parameters having interpolated fractions which have a higher level of accuracy than is specified by the audio sampling frequency. The audio signal processor is configured to apply the interpolated fractional values to the audio signal such that the component signal is obtained in a state of having been processed at the higher level of accuracy.

Device and a method for determining a component signal with high accuracy

A loudspeaker diaphragm includes a tapering edge region. Thus, it is possible to prevent or considerably reduce wave reflection and uncontrolled wave propagation caused thereby in a cheap and effective manner.

Loudspeaker diaphragm and method for manufacturing a loudspeaker diaphragm

An apparatus for providing data for wave field synthesis rendering in a wave field synthesis system with plurality of renderer modules, at least one loudspeaker being associated with each renderer module, and the loudspeakers associated with the renderer modules being attachable at different positions in a reproduction room, includes a provider for providing a plurality of audio files, wherein a virtual source at a source position is associated with an audio file, and a data output for providing the audio file to a renderer with which an active loudspeaker is associated, with the data output further formed to not provide the audio file to a renderer if all loudspeakers associated with the renderer are not to be active for the reproduction of the source. Thus, unnecessary data transmissions in the wave field synthesis system are avoided, while making optimum use of the renderer maximum capacity in a multi-renderer system.

Apparatus and method for providing data in a multi-renderer system

Audio files for an audio piece are stored in cross-scene optimized manner, so that when reading out audio files for a scene entailing high utilization of a wave field synthesis system, very short memory access times are achieved, whereas for scenes not entailing such a high utilization of the wave field synthesis system, longer memory access times in turn are accepted.

Apparatus and method for storing audio files

For simulating a wave field synthesis system, an audio scene description defining a temporal sequence of audio objects is provided, an audio object having an audio file for a virtual source or a reference to the audio file and information on a source position of the virtual source. Furthermore, an output condition the wave field synthesis system is to satisfy is given. Furthermore, a simulator for simulating the behavior of the wave field synthesis system for the audio scene description, using the audio data and the source positions as well as information on the wave field synthesis system, is provided. Finally a checker performs a check to determine if the simulated behavior of the wave field synthesis system satisfies the output condition. This achieves more flexible audio scene description creation as well as flexible portability of an audio scene description developed for one system to another wave field synthesis system.

Apparatus and method for simulating a wave field synthesis system

For reducing Doppler artifacts in the wave-field synthesis due to delay changes from one time to a second time, first, the delay for the first time and the delay for the second time are determined. Then, a value of an audio signal delayed by the first delay for the current time and the value for the audio signal delayed by the second delay for the current time are determined. Then, the first value is weighted by a first weighting factor and a second value is averaged with a second weighting factor, whereupon the two weighted values are added up to obtain a discrete value for the current time of the component in a loudspeaker signal for a loudspeaker based on a virtual source. Thus, by knowing a delay present at a later time, panning is obtained from a delay to a subsequent delay, which reduces undesired Doppler artifacts.

Calculating a doppler compensation value for a loudspeaker signal in a wavefield synthesis system

An audio reproduction system is divided into a central wave-field synthesis module and a plurality of loudspeaker modules disposed in a distributed way, wherein synthesis signals for the individual loudspeakers as well as corresponding channel information associated to the synthesis signals are calculated in the central wave-field synthesis module. The synthesis signals for a loudspeaker as well as associated channel information will then be transmitted to respective loudspeaker modules via a transmission path, wherein every loudspeaker module obtains the synthesis signals and associated channel information intended for the loudspeaker associated to the loudspeaker module. A distributed audio rendering and digital/analog converting takes place in the loudspeaker module to generate the actually analog loudspeaker signals in a distributed way in spatial proximity to every loudspeaker. The division into a central wave-field synthesis module and the plurality of distributed loudspeaker modules allows that audio reproduction systems that are scalable with regard to the price can be generated in order to offer systems of different size scalable in price particularly for cinema reproduction rooms varying strongly in size.

Audio reproduction system and method for reproducing an audio signal

In a wave field synthesis apparatus for driving an array of loudspeakers with drive signals, the loudspeakers being arranged at different defined positions, a drive signal for a loudspeaker being based on an audio signal associated with a virtual source having a virtual position with reference to the loudspeaker array and on the defined position of the loudspeaker, at first relevant loudspeakers of the loudspeaker array are determined on the basis of the position of the virtual source, a predefined listener position, and the defined positions of the loudspeakers, so that artifacts due to loudspeaker signals moving opposite to a direction from the virtual source to the predefined listener position are reduced. Downstream to means for calculating the drive signal components for the relevant loudspeakers and for a virtual source, there is means for providing the drive signal components for the relevant loudspeakers for the virtual source to the relevant loudspeakers, wherein no drive signals for the virtual source are provided to loudspeakers of the loudspeaker array not belonging to the relevant loudspeakers. With this, artifacts in an area of the audience room due to a generation wave field are suppressed, so that in this area only the useful wave field is heard in artifact-free manner.

Wave field synthesis apparatus and method of driving an array of loudspeakers

An apparatus for generating, storing or editing an audio representation of an audio scene includes audio processing means for generating a plurality of speaker signals from a plurality of input channels as well as means for providing an object-oriented description of the audio scene, wherein the object-oriented description of the audio scene includes a plurality of audio objects, wherein an audio object is associated with an audio signal, a starting time instant and an end time instant. The apparatus for generating further distinguishes itself by mapping means for mapping the object-oriented description of the audio scene to the plurality of input channels, wherein an assignment of temporally overlapping audio objects to parallel input channels is performed by the mapping means, whereas temporally sequential audio objects are associated with the same channel. With this, an object-oriented representation is transferred into a channel-oriented representation, whereby on the object-oriented side the optimal representation of a scene may be used, whereas on channel-oriented side the channel-oriented concept users are used to may be maintained.

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Ilmenau, Germany

Sandra Brix