Patents by Inventor Stefan DOEHLA

Stefan DOEHLA has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20230238005
    Abstract: Apparatus for processing an audio scene representing a sound field, the audio scene having information on a transport signal and a first set of parameters. The apparatus has a parameter processor for processing the first set of parameters to obtain a second set of parameters, wherein the parameter processor is configured to calculate at least one raw parameter for each output time frame using at least one parameter of the first set of parameters for the input time frame, to calculate a smoothing information such as a factor for each raw parameter in accordance with a smoothing rule, and to apply a corresponding smoothing information to the corresponding raw parameter to derive the parameter of the second set of parameters for the output time frame. The apparatus further has an output interface for generating a processed audio scene using the second set of parameters and the information on the transport signal.
    Type: Application
    Filed: April 3, 2023
    Publication date: July 27, 2023
    Inventors: Franz REUTELHUBER, Guillaume FUCHS, Markus MULTRUS, Eleni FOTOPOULOU, Stefan BAYER, Jan BÜTHE, Stefan DÖHLA
  • Publication number: 20230238006
    Abstract: An apparatus for processing an encoded audio scene representing a sound field related to a virtual listener position, the encoded audio scene including information on a transport signal and a first set of parameters related to the virtual listener position includes a parameter converter for converting the first set of parameters into a second set of parameters related to a channel representation including two or more channels for a reproduction at predefined spatial positions for the two or more channels, and an output interface for generating a processed audio scene using the second set of parameters and the information on the transport signal.
    Type: Application
    Filed: April 3, 2023
    Publication date: July 27, 2023
    Inventors: Franz REUTELHUBER, Guillaume FUCHS, Markus MULTRUS, Eleni FOTOPOULOU, Stefan BAYER, Jan BÜTHE, Stefan DÖHLA
  • Publication number: 20230239644
    Abstract: Apparatus for processing an audio scene representing a sound field, the audio scene comprising information on a transport signal and a set of parameters. The apparatus comprising an output interface for generating a processed audio scene using the set of parameters and the information on the transport signal, wherein the output interface is configured to generate a raw representation of two or more channels using the set of parameters and the transport signal and a multichannel enhancer for generating an enhancement representation of the two or more channels using the transport signal, and a signal combiner for combining the raw representation of the two or more channels and the enhancement representation of the two or more channels to obtain the processed audio scene.
    Type: Application
    Filed: March 31, 2023
    Publication date: July 27, 2023
    Inventors: Franz REUTELHUBER, Guillaume FUCHS, Markus MULTRUS, Eleni FOTOPOULOU, Stefan BAYER, Jan BÜTHE, Stefan DÖHLA
  • Publication number: 20230197090
    Abstract: An audio quantizer for quantizing a plurality of audio information items has: a first stage vector quantizer for quantizing the plurality of audio information items to determine a first stage vector quantization result and a plurality of intermediate quantized items corresponding to the first stage vector quantization result; a residual item determiner for calculating a plurality of residual items from the plurality of intermediate quantized items and the plurality of audio information items; and a second stage vector quantizer for quantizing the plurality of residual items to obtain a second stage vector quantization result, wherein the first stage vector quantization result and the second stage vector quantization result are a quantized representation of the plurality of audio information items.
    Type: Application
    Filed: January 5, 2023
    Publication date: June 22, 2023
    Inventors: Emmanuel RAVELLI, Goran MARKOVIC, Jan Frederik KIENE, Franz REUTELHUBER, Stefan DÖHLA, Eleni FOTOPOULOU
  • Patent number: 11670314
    Abstract: An audio decoder decodes a bit stream of encoded audio data, which bit stream represents a sequence of audio sample values and includes a plurality of frames, wherein each frame includes associated encoded audio sample values. The audio decoder includes a determiner configured to determine whether a frame of the encoded audio data is a special frame including encoded audio sample values associated with the special frame and additional information, wherein the additional information include encoded audio sample values of a number of frames preceding the special frame, wherein the encoded audio sample values of the preceding frames are encoded using the same codec configuration as the special frame, wherein the number of preceding frames is sufficient to initialize the decoder to be in a position to decode the audio sample values associated with the special frame if the special frame is the first frame upon start-up of the decoder.
    Type: Grant
    Filed: March 22, 2022
    Date of Patent: June 6, 2023
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Daniel Fischer, Bernd Czelhan, Max Neuendorf, Nikolaus Rettelbach, Ingo Hofmann, Harald Fuchs, Stefan Doehla, Nikolaus Faerber
  • Publication number: 20230169985
    Abstract: An apparatus for estimating an inter-channel time difference between a first channel signal and a second channel signal, includes a signal analyzer for estimating a signal characteristic of the first channel signal or the second channel signal or both signals or a signal derived from the first channel signal or the second channel signal; a calculator for calculating a cross-correlation spectrum for a time block from the first channel signal in the time block and the second channel signal in the time block; a weighter for weighting a smoothed or non-smoothed cross-correlation spectrum to obtain a weighted cross correlation spectrum using a first weighting procedure or using a second weighting procedure depending on a signal characteristic estimated by the signal analyzer, wherein the first weighting procedure is different from the second weighting procedure; and a processor for processing the weighted cross-correlation spectrum to obtain the inter-channel time difference.
    Type: Application
    Filed: January 26, 2023
    Publication date: June 1, 2023
    Inventors: Eleni FOTOPOULOU, Jan BÜTHE, Emmanuel RAVELLI, Pallavi MABEN, Martin DIETZ, Franz REUTELHUBER, Stefan DÖHLA, Srikanth KORSE
  • Publication number: 20230133513
    Abstract: Audio decoder for decoding an encoded audio signal having multi-channel audio data having data for two or more audio channels, and information on jointly encoded scale parameters, having: a scale parameter decoder for decoding the information on the jointly encoded scale parameters to obtain a first and a second set of scale parameters for a first channel and a second channel, respectively, of a decoded audio signal; and a signal processor for applying the first and second sets of scale parameters to a first and second channel representation, respectively, derived from the multi-channel audio data to obtain the first and second channels of the decoded audio signal, wherein the jointly encoded scale parameters have information on a first group and on a second group of jointly encoded scale parameters, and wherein the scale parameter decoder is configured to combine a jointly encoded scale parameter of the first group and one of the second group using a first and a second combination rule, respectively, to obta
    Type: Application
    Filed: December 21, 2022
    Publication date: May 4, 2023
    Inventors: Emmanuel RAVELLI, Goran MARKOVIC, Jan Frederik KIENE, Franz REUTELHUBER, Stefan DÖHLA, Eleni FOTOPOULOU
  • Publication number: 20230087652
    Abstract: The invention provides an audio encoder including a combination of a linear predictive coding filter having a plurality of linear predictive coding coefficients and a time-frequency converter, wherein the combination is configured to filter and to convert a frame of the audio signal into a frequency domain in order to output a spectrum based on the frame and on the linear predictive coding coefficients; a low frequency emphasizer configured to calculate a processed spectrum based on the spectrum, wherein spectral lines of the processed spectrum representing a lower frequency than a reference spectral line are emphasized; and a control device configured to control the calculation of the processed spectrum by the low frequency emphasizer depending on the linear predictive coding coefficients of the linear predictive coding filter.
    Type: Application
    Filed: November 22, 2022
    Publication date: March 23, 2023
    Inventors: Stefan DOEHLA, Bernhard GRILL, Christian HELMRICH, Nikolaus RETTELBACH
  • Publication number: 20230079574
    Abstract: An apparatus for selecting one of a first encoding algorithm having a first characteristic and a second encoding algorithm having a second characteristic for encoding a portion of an audio signal to obtain an encoded version of the portion of the audio signal has a first estimator for estimating a first quality measure for the portion of the audio signal, which is associated with the first encoding algorithm, without actually encoding and decoding the portion of the audio signal using the first encoding algorithm. A second estimator is provided for estimating a second quality measure for the portion of the audio signal, which is associated with the second encoding algorithm, without actually encoding and decoding the portion of the audio signal using the second encoding algorithm. The apparatus has a controller for selecting the first or second encoding algorithms based on a comparison between the first and second quality measures.
    Type: Application
    Filed: November 23, 2022
    Publication date: March 16, 2023
    Inventors: Emmanuel RAVELLI, Stefan DOEHLA, Guillaume FUCHS, Eleni FOTOPOULOU, Christian HELMRICH
  • Patent number: 11594231
    Abstract: An apparatus for estimating an inter-channel time difference between a first channel signal and a second channel signal, includes a signal analyzer for estimating a signal characteristic of the first channel signal or the second channel signal or both signals or a signal derived from the first channel signal or the second channel signal; a calculator for calculating a cross-correlation spectrum for a time block from the first channel signal in the time block and the second channel signal in the time block; a weighter for weighting a smoothed or non-smoothed cross-correlation spectrum to obtain a weighted cross correlation spectrum using a first weighting procedure or using a second weighting procedure depending on a signal characteristic estimated by the signal analyzer, wherein the first weighting procedure is different from the second weighting procedure; and a processor for processing the weighted cross-correlation spectrum to obtain the inter-channel time difference.
    Type: Grant
    Filed: September 29, 2020
    Date of Patent: February 28, 2023
    Assignee: FRAUNHOFER-GESELLSCHAFT ZUR FÖRDERUNG DER ANGEWANDTEN FORSCHUNG E.V.
    Inventors: Eleni Fotopoulou, Jan Büthe, Emmanuel Ravelli, Pallavi Maben, Martin Dietz, Franz Reutelhuber, Stefan Döhla, Srikanth Korse
  • Patent number: 11581003
    Abstract: The coding efficiency of an audio codec using a controllable—switchable or even adjustable—harmonic filter tool is improved by performing the harmonicity-dependent controlling of this tool using a temporal structure measure in addition to a measure of harmonicity in order to control the harmonic filter tool. In particular, the temporal structure of the audio signal is evaluated in a manner which depends on the pitch. This enables to achieve a situation-adapted control of the harmonic filter tool so that in situations where a control made solely based on the measure of harmonicity would decide against or reduce the usage of this tool, although using the harmonic filter tool would, in that situation, increase the coding efficiency, the harmonic filter tool is applied, while in other situations where the harmonic filter tool may be inefficient or even destructive, the control reduces the appliance of the harmonic filter tool appropriately.
    Type: Grant
    Filed: May 27, 2020
    Date of Patent: February 14, 2023
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Goran Markovic, Christian Helmrich, Emmanuel Ravelli, Manuel Jander, Stefan Doehla
  • Patent number: 11580997
    Abstract: A jitter buffer control for controlling a provision of a decoded audio content on the basis of an input audio content is configured to select a frame-based time scaling or a sample-based time scaling in a signal-adaptive manner. An audio decoder uses such a jitter buffer control.
    Type: Grant
    Filed: June 11, 2020
    Date of Patent: February 14, 2023
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Stefan Reuschl, Stefan Doehla, Jérémie Lecomte, Manuel Jander
  • Patent number: 11568883
    Abstract: The invention provides an audio encoder including a combination of a linear predictive coding filter having a plurality of linear predictive coding coefficients and a time-frequency converter, wherein the combination is configured to filter and to convert a frame of the audio signal into a frequency domain in order to output a spectrum based on the frame and on the linear predictive coding coefficients; a low frequency emphasizer configured to calculate a processed spectrum based on the spectrum, wherein spectral lines of the processed spectrum representing a lower frequency than a reference spectral line are emphasized; and a control device configured to control the calculation of the processed spectrum by the low frequency emphasizer depending on the linear predictive coding coefficients of the linear predictive coding filter.
    Type: Grant
    Filed: June 11, 2020
    Date of Patent: January 31, 2023
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Stefan Doehla, Bernhard Grill, Christian Helmrich, Nikolaus Rettelbach
  • Publication number: 20230022258
    Abstract: Audio decoder device for decoding a bitstream, the audio decoder device including: a predictive decoder for producing a decoded audio frame from the bitstream, wherein the predictive decoder includes a parameter decoder for producing one or more audio parameters for the decoded audio frame from the bitstream and wherein the predictive decoder includes a synthesis filter device for producing the decoded audio frame by synthesizing the one or more audio parameters for the decoded audio frame; a memory device including one or more memories, wherein each of the memories is configured to store a memory state for the decoded audio frame, wherein the memory state for the decoded audio frame of the one or more memories is used by the synthesis filter device for synthesizing the one or more audio parameters for the decoded audio frame; and a memory state resampling device configured to determine the memory state for synthesizing the one or more audio parameters for the decoded audio frame, which has a sampling rate, f
    Type: Application
    Filed: August 5, 2022
    Publication date: January 26, 2023
    Inventors: Stefan DOEHLA, Guillaume FUCHS, Bernhard GRILL, Markus MULTRUS, Grzegorz PIETRZYK, Emmanuel RAVELLI, Markus SCHNELL
  • Patent number: 11521631
    Abstract: An apparatus for selecting one of a first encoding algorithm having a first characteristic and a second encoding algorithm having a second characteristic for encoding a portion of an audio signal to obtain an encoded version of the portion of the audio signal has a first estimator for estimating a first quality measure for the portion of the audio signal, which is associated with the first encoding algorithm, without actually encoding and decoding the portion of the audio signal using the first encoding algorithm. A second estimator is provided for estimating a second quality measure for the portion of the audio signal, which is associated with the second encoding algorithm, without actually encoding and decoding the portion of the audio signal using the second encoding algorithm. The apparatus has a controller for selecting the first or second encoding algorithms based on a comparison between the first and second quality measures.
    Type: Grant
    Filed: March 31, 2020
    Date of Patent: December 6, 2022
    Assignee: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
    Inventors: Emmanuel Ravelli, Stefan Doehla, Guillaume Fuchs, Eleni Fotopoulou, Christian Helmrich
  • Publication number: 20220310103
    Abstract: An apparatus for estimating an inter-channel time difference between a first channel signal and a second channel signal, includes: a calculator for calculating a cross-correlation spectrum for a time block from the first channel signal in the time block and the second channel signal in the time block; a spectral characteristic estimator for estimating a characteristic of a spectrum of the first channel signal or the second channel signal for the time block; a smoothing filter for smoothing the cross-correlation spectrum over time using the spectral characteristic to obtain a smoothed cross-correlation spectrum; and a processor for processing the smoothed cross-correlation spectrum to obtain the inter-channel time difference.
    Type: Application
    Filed: May 23, 2022
    Publication date: September 29, 2022
    Inventors: Stefan BAYER, Eleni FOTOPOULOU, Markus MULTRUS, Guillaume FUCHS, Emmanuel RAVELLI, Markus SCHNELL, Stefan DOEHLA, Wolfgang JAEGERS, Martin DIETZ, Goran MARKOVIC
  • Patent number: 11443754
    Abstract: Audio decoder device for decoding a bitstream, the audio decoder device including: a predictive decoder for producing a decoded audio frame from the bitstream, wherein the predictive decoder includes a parameter decoder for producing one or more audio parameters for the decoded audio frame from the bitstream and wherein the predictive decoder includes a synthesis filter device for producing the decoded audio frame by synthesizing the one or more audio parameters for the decoded audio frame; a memory device including one or more memories, wherein each of the memories is configured to store a memory state for the decoded audio frame, wherein the memory state for the decoded audio frame of the one or more memories is used by the synthesis filter device for synthesizing the one or more audio parameters for the decoded audio frame; and a memory state resampling device configured to determine the memory state for synthesizing the one or more audio parameters for the decoded audio frame, which has a sampling rate, f
    Type: Grant
    Filed: August 18, 2020
    Date of Patent: September 13, 2022
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Stefan Doehla, Guillaume Fuchs, Bernhard Grill, Markus Multrus, Grzegorz Pietrzyk, Emmanuel Ravelli, Markus Schnell
  • Publication number: 20220286756
    Abstract: Audio data processor, having: a receiver interface for receiving encoded audio data and metadata related to the encoded audio data; a metadata parser for parsing the metadata to determine an audio data manipulation possibility; an interaction interface for receiving an interaction input and for generating, from the interaction input, interaction control data related to the audio data manipulation possibility; and a data stream generator for obtaining the interaction control data and the encoded audio data and the metadata and for generating an output data stream, the output data stream having the encoded audio data, at least a portion of the metadata, and the interaction control data.
    Type: Application
    Filed: May 20, 2022
    Publication date: September 8, 2022
    Inventors: Stephan SCHREINER, Simone NEUKAM, Harald FUCHS, Jan PLOGSTIES, Stefan DOEHLA
  • Patent number: 11423919
    Abstract: An audio decoder decodes a bit stream of encoded audio data, which bit stream represents a sequence of audio sample values and includes a plurality of frames, wherein each frame includes associated encoded audio sample values. The audio decoder includes a determiner configured to determine whether a frame of the encoded audio data is a special frame including encoded audio sample values associated with the special frame and additional information, wherein the additional information include encoded audio sample values of a number of frames preceding the special frame, wherein the encoded audio sample values of the preceding frames are encoded using the same codec configuration as the special frame, wherein the number of preceding frames is sufficient to initialize the decoder to be in a position to decode the audio sample values associated with the special frame if the special frame is the first frame upon start-up of the decoder.
    Type: Grant
    Filed: April 6, 2020
    Date of Patent: August 23, 2022
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Daniel Fischer, Bernd Czelhan, Max Neuendorf, Nikolaus Rettelbach, Ingo Hofmann, Harald Fuchs, Stefan Doehla, Nikolaus Faerber
  • Patent number: 11410664
    Abstract: An apparatus for estimating an inter-channel time difference between a first channel signal and a second channel signal, includes: a calculator for calculating a cross-correlation spectrum for a time block from the first channel signal in the time block and the second channel signal in the time block; a spectral characteristic estimator for estimating a characteristic of a spectrum of the first channel signal or the second channel signal for the time block; a smoothing filter for smoothing the cross-correlation spectrum over time using the spectral characteristic to obtain a smoothed cross-correlation spectrum; and a processor for processing the smoothed cross-correlation spectrum to obtain the inter-channel time difference.
    Type: Grant
    Filed: February 19, 2020
    Date of Patent: August 9, 2022
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Stefan Bayer, Eleni Fotopoulou, Markus Multrus, Guillaume Fuchs, Emmanuel Ravelli, Markus Schnell, Stefan Doehla, Wolfgang Jaegers, Martin Dietz, Goran Markovic