Patents by Inventor Christian Helmrich

Christian Helmrich 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).

  • Patent number: 12380899
    Abstract: An audio decoder for providing at least four audio channel signals on the basis of an encoded representation is configured to provide a first residual signal and a second residual signal on the basis of a jointly encoded representation of the first residual signal and of the second residual signal using a multi-channel decoding. The audio decoder is configured to provide a first audio channel signal and a second audio channel signal on the basis of a first downmix signal and the first residual signal using a residual-signal-assisted multi-channel decoding. The audio decoder is configured to provide a third audio channel signal and a fourth audio channel signal on the basis of a second downmix signal and the second residual signal using a residual-signal-assisted multi-channel decoding. An audio encoder is based on corresponding considerations.
    Type: Grant
    Filed: May 22, 2023
    Date of Patent: August 5, 2025
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Sascha Dick, Christian Ertel, Christian Helmrich, Johannes Hilpert, Andreas Hoelzer, Achim Kuntz
  • Publication number: 20250201253
    Abstract: A schematic block diagram of a decoder for decoding an encoded audio signal is shown. The decoder includes an adaptive spectrum-time converter and an overlap-add-processor. The adaptive spectrum-time converter converts successive blocks of spectral values into successive blocks of time values, e.g. via a frequency-to-time transform. Furthermore, the adaptive spectrum-time converter receives a control information and switches, in response to the control information, between transform kernels of a first group of transform kernels including one or more transform kernels having different symmetries at sides of a kernel, and a second group of transform kernels including one or more transform kernels having the same symmetries at sides of a transform kernel. Moreover, the overlap-add-processor overlaps and adds the successive blocks of time values to obtain decoded audio values, which may be a decoded audio signal.
    Type: Application
    Filed: December 26, 2024
    Publication date: June 19, 2025
    Inventors: Christian HELMRICH, Bernd EDLER
  • Publication number: 20250166646
    Abstract: An apparatus for generating an encoded signal includes: a window sequence controller for generating a window sequence information for windowing an audio or image signal, the window sequence information indicating a first window for generating a first frame of spectral values, a second window function and at least one third window function for generating a second frame of spectral values, wherein the first window function, the second window function and the one or more third window functions overlap within a multi-overlap region; a preprocessor for windowing a second block of samples corresponding to the second window function and the at least one third window functions using an auxiliary window function to acquire a second block of windowed samples, a spectrum converter for applying an aliasing-introducing transform; and a processor for processing the first frame and the second frame to acquire encoded frames of the audio or image signal.
    Type: Application
    Filed: January 17, 2025
    Publication date: May 22, 2025
    Inventors: Christian HELMRICH, Jérémie LECOMTE, Goran MARKOVIC, Markus SCHNELL, Bernd EDLER, Stefan REUSCHL
  • Publication number: 20250150634
    Abstract: Decoder for decoding a picture from a data stream, configured to check whether a plurality of coding parameters, which are contained in the data stream, relate to a predetermined portion of the picture and control a prediction residual transform mode and a quantization accuracy with respect to the predetermined portion, are indicative of a coding parameter setting corresponding to a lossless prediction residual coding. Responsive to the plurality of coding parameters being indicative of the coding parameter setting corresponding to the lossless prediction residual coding, the decoder is configured to set one or more predetermined coding options relating to one or more tools of the decoder for processing a prediction residual corrected predictive reconstruction with respect to the predetermined portion so that the one or more tools are disabled with respect to the predetermined portion.
    Type: Application
    Filed: January 9, 2025
    Publication date: May 8, 2025
    Inventors: Christian HELMRICH, Benjamin BROSS, Tung Hoang NGUYEN, Heiko SCHWARZ, Detlev MARPE, Thomas WIEGAND
  • Publication number: 20250118316
    Abstract: An apparatus for processing an audio signal having associated therewith a pitch lag information and a gain information, includes a domain converter for converting a first domain representation of the audio signal into a second domain representation of the audio signal; and a harmonic post-filter for filtering the second domain representation of the audio signal, wherein the post-filter is based on a transfer function including a numerator and a denominator, wherein the numerator includes a gain value indicated by the gain information, and wherein the denominator includes an integer part of a pitch lag indicated by the pitch lag information and a multi-tap filter depending on a fractional part of the pitch lag.
    Type: Application
    Filed: December 17, 2024
    Publication date: April 10, 2025
    Inventors: Emmanuel RAVELLI, Christian HELMRICH, Goran MARKOVIC, Matthias NEUSINGER, Sascha DISCH, Manuel JANDER, Martin DIETZ
  • Patent number: 12272365
    Abstract: An apparatus processing an encoded signal to acquire first and second frames comprising spectral values and an aliasing portion; applying a transform to the first frame using a first window function to acquire a first block of samples, applying another transform to a first portion of the second frame using a second window function, and applying another one or more transforms to a second portion of the second frame using one or more third window functions to acquire a second block of samples; and post-processing the second block of samples using a folding-out operation to acquire a post-processed second block of samples comprising a portion of the second block of samples overlapping with the first block of samples in a multi-overlap region, windowing the post-processed second block of samples using an auxiliary window function, and overlap-adding a windowed post-processed second block of samples and the first block of samples.
    Type: Grant
    Filed: February 17, 2023
    Date of Patent: April 8, 2025
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Christian Helmrich, Jérémie Lecomte, Goran Markovic, Markus Schnell, Bernd Edler, Stefan Reuschl
  • Patent number: 12249340
    Abstract: In multichannel audio coding, an improved coding efficiency is achieved by the following measure: the noise filling of zero-quantized scale factor bands is performed using noise filling sources other than artificially generated noise or spectral replica. In particular, the coding efficiency in multichannel audio coding may be rendered more efficient by performing the noise filling based on noise generated using spectral lines from a previous frame of, or a different channel of the current frame of, the multichannel audio signal.
    Type: Grant
    Filed: December 21, 2023
    Date of Patent: March 11, 2025
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Maria Luis Valero, Christian Helmrich, Johannes Hilpert
  • Patent number: 12230286
    Abstract: A schematic block diagram of a decoder for decoding an encoded audio signal is shown. The decoder includes an adaptive spectrum-time converter and an overlap-add-processor. The adaptive spectrum-time converter converts successive blocks of spectral values into successive blocks of time values, e.g. via a frequency-to-time transform. Furthermore, the adaptive spectrum-time converter receives a control information and switches, in response to the control information, between transform kernels of a first group of transform kernels including one or more transform kernels having different symmetries at sides of a kernel, and a second group of transform kernels including one or more transform kernels having the same symmetries at sides of a transform kernel. Moreover, the overlap-add-processor overlaps and adds the successive blocks of time values to obtain decoded audio values, which may be a decoded audio signal.
    Type: Grant
    Filed: November 16, 2023
    Date of Patent: February 18, 2025
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Christian Helmrich, Bernd Edler
  • Patent number: 12225238
    Abstract: Decoder for decoding a picture from a data stream, configured to check whether a plurality of coding parameters, which are contained in the data stream, relate to a predetermined portion of the picture and control a prediction residual transform mode and a quantization accuracy with respect to the predetermined portion, are indicative of a coding parameter setting corresponding to a lossless prediction residual coding. Responsive to the plurality of coding parameters being indicative of the coding parameter setting corresponding to the lossless prediction residual coding, the decoder is configured to set one or more predetermined coding options relating to one or more tools of the decoder for processing a prediction residual corrected predictive reconstruction with respect to the predetermined portion so that the one or more tools are disabled with respect to the predetermined portion.
    Type: Grant
    Filed: February 14, 2024
    Date of Patent: February 11, 2025
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Christian Helmrich, Benjamin Bross, Tung Hoang Nguyen, Heiko Schwarz, Detlev Marpe, Thomas Wiegand
  • Publication number: 20250014586
    Abstract: An encoder for encoding an audio signal is configured to encode the audio signal in a transform domain or filter-bank domain, is configured to determine spectral coefficients of the audio signal for a current frame and at least one previous frame, and is configured to selectively apply predictive encoding to a plurality of individual spectral coefficients or groups of spectral coefficients which are separated by at least one spectral coefficient.
    Type: Application
    Filed: September 17, 2024
    Publication date: January 9, 2025
    Inventors: Bernd EDLER, Christian HELMRICH, Max NEUENDORF, Benjamin SCHUBERT
  • Patent number: 12190897
    Abstract: An apparatus for processing an audio signal having associated therewith a pitch lag information and a gain information, includes a domain converter for converting a first domain representation of the audio signal into a second domain representation of the audio signal; and a harmonic post-filter for filtering the second domain representation of the audio signal, wherein the post-filter is based on a transfer function including a numerator and a denominator, wherein the numerator includes a gain value indicated by the gain information, and wherein the denominator includes an integer part of a pitch lag indicated by the pitch lag information and a multi-tap filter depending on a fractional part of the pitch lag.
    Type: Grant
    Filed: May 16, 2023
    Date of Patent: January 7, 2025
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Emmanuel Ravelli, Christian Helmrich, Goran Markovic, Matthias Neusinger, Sascha Disch, Manuel Jander, Martin Dietz
  • Publication number: 20240428812
    Abstract: Embodiments according to the invention are related to methods and apparatuses for spectrotemporally improved spectral gap filling in audio coding using a filtering. Embodiments according to the invention are related to methods and apparatuses for spectrotemporally improved spectral gap filling in audio coding using different noise filling methods. Embodiments according to the invention are related to methods and apparatuses for spectrotemporally improved spectral gap filling in audio coding using a tilt.
    Type: Application
    Filed: June 23, 2024
    Publication date: December 26, 2024
    Applicant: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
    Inventors: Christian HELMRICH, Eleni FOTOPOULOU, Richard FÜG, Goran MARKOVIC, Markus MULTRUS, Franz REUTELHUBER
  • Publication number: 20240420711
    Abstract: Embodiments according to the invention are related to methods and apparatuses for spectrotemporally improved spectral gap filling in audio coding using a filtering. Embodiments according to the invention are related to methods and apparatuses for spectrotemporally improved spectral gap filling in audio coding using different noise filling methods. Embodiments according to the invention are related to methods and apparatuses for spectrotemporally improved spectral gap filling in audio coding using a tilt.
    Type: Application
    Filed: June 23, 2024
    Publication date: December 19, 2024
    Applicant: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
    Inventors: Christian HELMRICH, Eleni FOTOPOULOU, Richard FÜG, Goran MARKOVIC, Markus MULTRUS, Franz REUTELHUBER
  • Publication number: 20240420710
    Abstract: Embodiments according to the invention are related to methods and apparatuses for spectrotemporally improved spectral gap filling in audio coding using a filtering. Embodiments according to the invention are related to methods and apparatuses for spectrotemporally improved spectral gap filling in audio coding using different noise filling methods. Embodiments according to the invention are related to methods and apparatuses for spectrotemporally improved spectral gap filling in audio coding using a tilt.
    Type: Application
    Filed: June 23, 2024
    Publication date: December 19, 2024
    Applicant: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
    Inventors: Christian HELMRICH, Eleni FOTOPOULOU, Richard FÜG, Goran MARKOVIC, Markus MULTRUS, Franz REUTELHUBER
  • Patent number: RE50341
    Abstract: A device and method for manipulating an audio signal includes a windower for generating a plurality of consecutive blocks of audio samples, the plurality of consecutive blocks including at least one padded block of audio samples, the padded block having padded values and audio signal values, a first converter for converting the padded block into a spectral representation having spectral values, a phase modifier for modifying phases of the spectral values to obtain a modified spectral representation and a second converter for converting the modified spectral representation into a modified time domain audio signal.
    Type: Grant
    Filed: June 28, 2022
    Date of Patent: March 18, 2025
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Sascha Disch, Frederik Nagel, Max Neuendorf, Christian Helmrich, Dominik Zorn
  • Patent number: RE50418
    Abstract: A device and method for manipulating an audio signal includes a windower for generating a plurality of consecutive blocks of audio samples, the plurality of consecutive blocks including at least one padded block of audio samples, the padded block having padded values and audio signal values, a first converter for converting the padded block into a spectral representation having spectral values, a phase modifier for modifying phases of the spectral values to obtain a modified spectral representation and a second converter for converting the modified spectral representation into a modified time domain audio signal.
    Type: Grant
    Filed: June 28, 2022
    Date of Patent: May 6, 2025
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Sascha Disch, Frederik Nagel, Max Neuendorf, Christian Helmrich, Dominik Zorn
  • Patent number: RE50419
    Abstract: A device and method for manipulating an audio signal includes a windower for generating a plurality of consecutive blocks of audio samples, the plurality of consecutive blocks including at least one padded block of audio samples, the padded block having padded values and audio signal values, a first converter for converting the padded block into a spectral representation having spectral values, a phase modifier for modifying phases of the spectral values to obtain a modified spectral representation and a second converter for converting the modified spectral representation into a modified time domain audio signal.
    Type: Grant
    Filed: June 29, 2022
    Date of Patent: May 6, 2025
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Sascha Disch, Frederik Nagel, Max Neuendorf, Christian Helmrich, Dominik Zorn
  • Patent number: RE50430
    Abstract: A device and method for manipulating an audio signal includes a windower for generating a plurality of consecutive blocks of audio samples, the plurality of consecutive blocks including at least one padded block of audio samples, the padded block having padded values and audio signal values, a first converter for converting the padded block into a spectral representation having spectral values, a phase modifier for modifying phases of the spectral values to obtain a modified spectral representation and a second converter for converting the modified spectral representation into a modified time domain audio signal.
    Type: Grant
    Filed: June 28, 2022
    Date of Patent: May 13, 2025
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Sascha Disch, Frederik Nagel, Max Neuendorf, Christian Helmrich, Dominik Zorn
  • Patent number: RE50492
    Abstract: A device and method for manipulating an audio signal includes a windower for generating a plurality of consecutive blocks of audio samples, the plurality of consecutive blocks including at least one padded block of audio samples, the padded block having padded values and audio signal values, a first converter for converting the padded block into a spectral representation having spectral values, a phase modifier for modifying phases of the spectral values to obtain a modified spectral representation and a second converter for converting the modified spectral representation into a modified time domain audio signal.
    Type: Grant
    Filed: June 28, 2022
    Date of Patent: July 15, 2025
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Sascha Disch, Frederik Nagel, Max Neuendorf, Christian Helmrich, Dominik Zorn
  • Patent number: RE50493
    Abstract: A device and method for manipulating an audio signal includes a windower for generating a plurality of consecutive blocks of audio samples, the plurality of consecutive blocks including at least one padded block of audio samples, the padded block having padded values and audio signal values, a first converter for converting the padded block into a spectral representation having spectral values, a phase modifier for modifying phases of the spectral values to obtain a modified spectral representation and a second converter for converting the modified spectral representation into a modified time domain audio signal.
    Type: Grant
    Filed: June 29, 2022
    Date of Patent: July 15, 2025
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Sascha Disch, Frederik Nagel, Max Neuendorf, Christian Helmrich, Dominik Zorn