Patents by Inventor Leif Sehlström

Leif Sehlström 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: 20250166648
    Abstract: On the basis of a bitstream (P), an n-channel audio signal (X) is reconstructed by deriving an m-channel core signal (Y) and multichannel coding parameters (?) from the bitstream, where 1?m<n. Also derived from the bitstream are pre-processing dynamic range control, DRC, parameters (DRC2) quantifying an encoder-side dynamic range limiting of the core signal. The n-channel audio signal is obtained by parametric synthesis in accordance with the multichannel coding parameters and while cancelling any encoder-side dynamic range limiting based on the pre-processing DRC parameters. In particular embodiments, the reconstruction further includes use of compensated post-processing DRC parameters quantifying a potential decoder-side dynamic range compression. Cancellation of an encoder-side range limitation and range compression are preferably performed by different decoder-side components. Cancellation and compression may be coordinated by a DRC pre-processor.
    Type: Application
    Filed: November 25, 2024
    Publication date: May 22, 2025
    Applicants: DOLBY LABORATORIES LICENSING CORPORATION, DOLBY INTERNATIONAL AB
    Inventors: Jeffrey RIEDMILLER, Karl J. ROEDEN, Kristofer KJOERLING, Heiko PURNHAGEN, Vinay MELKOTE, Leif SEHLSTROM
  • Patent number: 12293768
    Abstract: A method for decoding an encoded audio bitstream in an audio processing system is disclosed. The method includes extracting from the encoded audio bitstream a first waveform-coded signal comprising spectral coefficients corresponding to frequencies up to a first cross-over frequency for a time frame and performing parametric decoding at a second cross-over frequency for the time frame to generate a reconstructed signal. The second cross-over frequency is above the first cross-over frequency and the parametric decoding uses reconstruction parameters derived from the encoded audio bitstream to generate the reconstructed signal. The method also includes extracting from the encoded audio bitstream a second waveform-coded signal comprising spectral coefficients corresponding to a subset of frequencies above the first cross-over frequency for the time frame and interleaving the second waveform-coded signal with the reconstructed signal to produce an interleaved signal for the time frame.
    Type: Grant
    Filed: November 8, 2023
    Date of Patent: May 6, 2025
    Assignee: Dolby International AB
    Inventors: Kristofer Kjörling, Heiko Purnhagen, Harald Mundt, Karl Jonas Roeden, Leif Sehlström
  • Patent number: 12175992
    Abstract: On the basis of a bitstream (P), an n-channel audio signal (X) is reconstructed by deriving an m-channel core signal (Y) and multichannel coding parameters (?) from the bitstream, where 1?m<n. Also derived from the bitstream are pre-processing dynamic range control, DRC, parameters (DRC2) quantifying an encoder-side dynamic range limiting of the core signal. The n-channel audio signal is obtained by parametric synthesis in accordance with the multichannel coding parameters and while cancelling any encoder-side dynamic range limiting based on the pre-processing DRC parameters. In particular embodiments, the reconstruction further includes use of compensated post-processing DRC parameters quantifying a potential decoder-side dynamic range compression. Cancellation of an encoder-side range limitation and range compression are preferably performed by different decoder-side components. Cancellation and compression may be coordinated by a DRC pre-processor.
    Type: Grant
    Filed: July 19, 2023
    Date of Patent: December 24, 2024
    Assignees: DOLBY LABORATORIES LICENSING CORPORATION, DOLBY INTERNATIONAL AB
    Inventors: Jeffrey Riedmiller, Karl J. Roeden, Kristofer Kjoerling, Heiko Purnhagen, Vinay Melkote, Leif Sehlstrom
  • Publication number: 20240153517
    Abstract: A method for decoding an encoded audio bitstream in an audio processing system is disclosed. The method includes extracting from the encoded audio bitstream a first waveform-coded signal comprising spectral coefficients corresponding to frequencies up to a first cross-over frequency for a time frame and performing parametric decoding at a second cross-over frequency for the time frame to generate a reconstructed signal. The second cross-over frequency is above the first cross-over frequency and the parametric decoding uses reconstruction parameters derived from the encoded audio bitstream to generate the reconstructed signal. The method also includes extracting from the encoded audio bitstream a second waveform-coded signal comprising spectral coefficients corresponding to a subset of frequencies above the first cross-over frequency for the time frame and interleaving the second waveform-coded signal with the reconstructed signal to produce an interleaved signal for the time frame.
    Type: Application
    Filed: November 8, 2023
    Publication date: May 9, 2024
    Applicant: Dolby International AB
    Inventors: Kristofer Kjörling, Heiko Purnhagen, Harald Mundt, Karl Jonas Roeden, Leif Sehlström
  • Patent number: 11894005
    Abstract: An audio communication endpoint receives a bitstream containing spectral components representing spectral content of an audio signal, wherein the spectral components relate to a first range extending up to a first break frequency, above which any spectral components are unassigned. The endpoint adapts the received bitstream in accordance with a second range extending up to a second break frequency by removing spectral components or adding neutral-valued spectral components relating to a range between the first and second break frequencies. The endpoint then attenuates spectral content in a neighbourhood of the least of the first and second break frequencies for thereby achieving a gradual spectral decay. After this, reconstructing the audio signal is reconstructed by an inverse transform operating on spectral components relating to said second range in the adapted and attenuated received bitstream. At small computational expense, the endpoint may to adapt to different sample rates in received bitstreams.
    Type: Grant
    Filed: November 15, 2019
    Date of Patent: February 6, 2024
    Assignees: DOLBY LABORATORIES LICENSING CORPORATION, DOLBY INTERNATIONAL AB
    Inventors: Heiko Purnhagen, Leif Sehlstrom, Lars Villemoes, Glenn N. Dickins, Mark S Vinton
  • Publication number: 20240018844
    Abstract: On the basis of a bitstream (P), an n-channel audio signal (X) is reconstructed by deriving an m-channel core signal (Y) and multichannel coding parameters (a) from the bitstream, where 1?m<n. Also derived from the bitstream are pre-processing dynamic range control, DRC, parameters (DRC2) quantifying an encoder-side dynamic range limiting of the core signal. The n-channel audio signal is obtained by parametric synthesis in accordance with the multichannel coding parameters and while cancelling any encoder-side dynamic range limiting based on the pre-processing DRC parameters. In particular embodiments, the reconstruction further includes use of compensated post-processing DRC parameters quantifying a potential decoder-side dynamic range compression. Cancellation of an encoder-side range limitation and range compression are preferably performed by different decoder-side components. Cancellation and compression may be coordinated by a DRC pre-processor.
    Type: Application
    Filed: July 19, 2023
    Publication date: January 18, 2024
    Applicants: DOLBY LABORATORIES LICENSING CORPORATION, DOLBY INTERNATIONAL AB
    Inventors: Jeffrey RIEDMILLER, Karl J. ROEDEN, Kristofer KJOERLING, Heiko PURNHAGEN, Vinay MELKOTE, Leif SEHLSTROM
  • Patent number: 11830510
    Abstract: A method for decoding an encoded audio bitstream in an audio processing system is disclosed. The method includes extracting from the encoded audio bitstream a first waveform-coded signal comprising spectral coefficients corresponding to frequencies up to a first cross-over frequency for a time frame and performing parametric decoding at a second cross-over frequency for the time frame to generate a reconstructed signal. The second cross-over frequency is above the first cross-over frequency and the parametric decoding uses reconstruction parameters derived from the encoded audio bitstream to generate the reconstructed signal. The method also includes extracting from the encoded audio bitstream a second waveform-coded signal comprising spectral coefficients corresponding to a subset of frequencies above the first cross-over frequency for the time frame and interleaving the second waveform-coded signal with the reconstructed signal to produce an interleaved signal for the time frame.
    Type: Grant
    Filed: August 31, 2021
    Date of Patent: November 28, 2023
    Assignee: Dolby International AB
    Inventors: Kristofer Kjoerling, Heiko Purnhagen, Harald Mundt, Karl Jonas Roeden, Leif Sehlstrom
  • Patent number: 11708741
    Abstract: On the basis of a bitstream (P), an n-channel audio signal (X) is reconstructed by deriving an m-channel core signal (Y) and multichannel coding parameters (?) from the bitstream, where 1?m<n. Also derived from the bitstream are pre-processing dynamic range control, DRC, parameters (DRC2) quantifying an encoder-side dynamic range limiting of the core signal. The n-channel audio signal is obtained by parametric synthesis in accordance with the multichannel coding parameters and while cancelling any encoder-side dynamic range limiting based on the pre-processing DRC parameters. In particular embodiments, the reconstruction further includes use of compensated post-processing DRC parameters quantifying a potential decoder-side dynamic range compression. Cancellation of an encoder-side range limitation and range compression are preferably performed by different decoder-side components. Cancellation and compression may be coordinated by a DRC pre-processor.
    Type: Grant
    Filed: March 15, 2021
    Date of Patent: July 25, 2023
    Assignees: DOLBY LABORATORIES LICENSING CORPORATION, DOLBY INTERNATIONAL AB
    Inventors: Jeffrey Riedmiller, Karl J. Roeden, Kristofer Kjoerling, Heiko Purnhagen, Vinay Melkote, Leif Sehlstrom
  • Patent number: 11545166
    Abstract: A technique including receiving and decoding a coded bitstream encoded with audio content including first audio objects corresponding to a first media content type of two consecutive media content types and second audio objects corresponding to a second media content type of the two consecutive media content types, and audio metadata corresponding to the audio content. The audio metadata including first and second audio object gains, for the first and second audio objects, generated in part based on a first fading curve of the first media content type and a second fading curve of the second media content type, respectively. The technique further includes applying the first and second audio object gains to the first and second audio objects, and rendering a sound field represented by the first audio object with the applied first audio object gain and the second audio object with the applied second audio object gain.
    Type: Grant
    Filed: July 1, 2020
    Date of Patent: January 3, 2023
    Assignee: Dolby International AB
    Inventors: Alexander Stahlmann, Reinhold Boehm, Mark C. Leddy, Karsten Linzmeier, Vinay Mathew, Simon Plain, Heiko Purnhagen, Leif Sehlström, Robin Thesing
  • Publication number: 20220059110
    Abstract: A method for decoding an encoded audio bitstream in an audio processing system is disclosed. The method includes extracting from the encoded audio bitstream a first waveform-coded signal comprising spectral coefficients corresponding to frequencies up to a first cross-over frequency for a time frame and performing parametric decoding at a second cross-over frequency for the time frame to generate a reconstructed signal. The second cross-over frequency is above the first cross-over frequency and the parametric decoding uses reconstruction parameters derived from the encoded audio bitstream to generate the reconstructed signal. The method also includes extracting from the encoded audio bitstream a second waveform-coded signal comprising spectral coefficients corresponding to a subset of frequencies above the first cross-over frequency for the time frame and interleaving the second waveform-coded signal with the reconstructed signal to produce an interleaved signal for the time frame.
    Type: Application
    Filed: August 31, 2021
    Publication date: February 24, 2022
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Kristofer KJOERLING, Heiko PURNHAGEN, Harald MUNDT, Karl Jonas ROEDEN, Leif SEHLSTROM
  • Patent number: 11114107
    Abstract: A method for decoding an encoded audio bitstream in an audio processing system is disclosed. The method includes extracting from the encoded audio bitstream a first waveform-coded signal comprising spectral coefficients corresponding to frequencies up to a first cross-over frequency for a time frame and performing parametric decoding at a second cross-over frequency for the time frame to generate a reconstructed signal. The second cross-over frequency is above the first cross-over frequency and the parametric decoding uses reconstruction parameters derived from the encoded audio bitstream to generate the reconstructed signal. The method also includes extracting from the encoded audio bitstream a second waveform-coded signal comprising spectral coefficients corresponding to a subset of frequencies above the first cross-over frequency for the time frame and interleaving the second waveform-coded signal with the reconstructed signal to produce an interleaved signal for the time frame.
    Type: Grant
    Filed: October 4, 2019
    Date of Patent: September 7, 2021
    Assignee: Dolby International AB
    Inventors: Kristofer Kjoerling, Heiko Purnhagen, Harald Mundt, Karl Jonas Roeden, Leif Sehlstrom
  • Publication number: 20210270106
    Abstract: On the basis of a bitstream (P), an n-channel audio signal (X) is reconstructed by deriving an m-channel core signal (Y) and multichannel coding parameters (a) from the bitstream, where 1?m<n. Also derived from the bitstream are pre-processing dynamic range control, DRC, parameters (DRC2) quantifying an encoder-side dynamic range limiting of the core signal. The n-channel audio signal is obtained by parametric synthesis in accordance with the multichannel coding parameters and while cancelling any encoder-side dynamic range limiting based on the pre-processing DRC parameters. In particular embodiments, the reconstruction further includes use of compensated post-processing DRC parameters quantifying a potential decoder-side dynamic range compression. Cancellation of an encoder-side range limitation and range compression are preferably performed by different decoder-side components. Cancellation and compression may be coordinated by a DRC pre-processor.
    Type: Application
    Filed: March 15, 2021
    Publication date: September 2, 2021
    Applicants: DOLBY LABORATORIES LICENSING CORPORATION, DOLBY INTERNATIONAL AB
    Inventors: Jeffrey RIEDMILLER, Karl J. ROEDEN, Kristofer KJOERLING, Heiko PURNHAGEN, Vinay MELKOTE, Leif SEHLSTROM
  • Patent number: 10950252
    Abstract: On the basis of a bitstream (P), an n-channel audio signal (X) is reconstructed by deriving an m-channel core signal (Y) and multichannel coding parameters (a) from the bitstream, where 1?m<n. Also derived from the bitstream are pre-processing dynamic range control, DRC, parameters (DRC2) quantifying an encoder-side dynamic range limiting of the core signal. The n-channel audio signal is obtained by parametric synthesis in accordance with the multichannel coding parameters and while cancelling any encoder-side dynamic range limiting based on the pre-processing DRC parameters. In particular embodiments, the reconstruction further includes use of compensated post-processing DRC parameters quantifying a potential decoder-side dynamic range compression. Cancellation of an encoder-side range limitation and range compression are preferably performed by different decoder-side components. Cancellation and compression may be coordinated by a DRC pre-processor.
    Type: Grant
    Filed: December 19, 2019
    Date of Patent: March 16, 2021
    Assignees: Dolby Laboratories Licensing Corporation, Dolby International AB
    Inventors: Jeffrey Riedmiller, Karl J. Roeden, Kristofer Kjoerling, Heiko Purnhagen, Vinay Melkote, Leif Sehlstrom
  • Publication number: 20210005211
    Abstract: A technique including receiving and decoding a coded bitstream encoded with audio content including first audio objects corresponding to a first media content type of two consecutive media content types and second audio objects corresponding to a second media content type of the two consecutive media content types, and audio metadata corresponding to the audio content. The audio metadata including first and second audio object gains, for the first and second audio objects, generated in part based on a first fading curve of the first media content type and a second fading curve of the second media content type, respectively. The technique further includes applying the first and second audio object gains to the first and second audio objects, and rendering a sound field represented by the first audio object with the applied first audio object gain and the second audio object with the applied second audio object gain.
    Type: Application
    Filed: July 1, 2020
    Publication date: January 7, 2021
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Alexander Stahlmann, Reinhold Boehm, Mark C. Leddy, Karsten Linzmeier, Vinay Mathew, Simon Plain, Heiko Purnhagen, Leif Sehlström, Robin Thesing
  • Publication number: 20200202878
    Abstract: On the basis of a bitstream (P), an n-channel audio signal (X) is reconstructed by deriving an m-channel core signal (Y) and multichannel coding parameters (?) from the bitstream, where 1?m<n. Also derived from the bitstream are pre-processing dynamic range control, DRC, parameters (DRC2) quantifying an encoder-side dynamic range limiting of the core signal. The n-channel audio signal is obtained by parametric synthesis in accordance with the multichannel coding parameters and while cancelling any encoder-side dynamic range limiting based on the pre-processing DRC parameters. In particular embodiments, the reconstruction further includes use of compensated post-processing DRC parameters quantifying a potential decoder-side dynamic range compression. Cancellation of an encoder-side range limitation and range compression are preferably performed by different decoder-side components. Cancellation and compression may be coordinated by a DRC pre-processor.
    Type: Application
    Filed: December 19, 2019
    Publication date: June 25, 2020
    Applicants: DOLBY LABORATORIES LICENSING CORPORATION, DOLBY INTERNATIONAL AB
    Inventors: Jeffrey RIEDMILLER, Karl J. ROEDEN, Kristofer KJOERLING, Heiko PURNHAGEN, Vinay MELKOTE, Leif SEHLSTROM
  • Publication number: 20200098381
    Abstract: A method for decoding an encoded audio bitstream in an audio processing system is disclosed. The method includes extracting from the encoded audio bitstream a first waveform-coded signal comprising spectral coefficients corresponding to frequencies up to a first cross-over frequency for a time frame and performing parametric decoding at a second cross-over frequency for the time frame to generate a reconstructed signal. The second cross-over frequency is above the first cross-over frequency and the parametric decoding uses reconstruction parameters derived from the encoded audio bitstream to generate the reconstructed signal. The method also includes extracting from the encoded audio bitstream a second waveform-coded signal comprising spectral coefficients corresponding to a subset of frequencies above the first cross-over frequency for the time frame and interleaving the second waveform-coded signal with the reconstructed signal to produce an interleaved signal for the time frame.
    Type: Application
    Filed: October 4, 2019
    Publication date: March 26, 2020
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Kristofer KJOERLING, Heiko PURNHAGEN, Harald MUNDT, Karl Jonas ROEDEN, Leif SEHLSTROM
  • Publication number: 20200082836
    Abstract: An audio communication endpoint receives a bitstream containing spectral components representing spectral content of an audio signal, wherein the spectral components relate to a first range extending up to a first break frequency, above which any spectral components are unassigned. The endpoint adapts the received bitstream in accordance with a second range extending up to a second break frequency by removing spectral components or adding neutral-valued spectral components relating to a range between the first and second break frequencies. The endpoint then attenuates spectral content in a neighbourhood of the least of the first and second break frequencies for thereby achieving a gradual spectral decay. After this, reconstructing the audio signal is reconstructed by an inverse transform operating on spectral components relating to said second range in the adapted and attenuated received bitstream. At small computational expense, the endpoint may to adapt to different sample rates in received bitstreams.
    Type: Application
    Filed: November 15, 2019
    Publication date: March 12, 2020
    Applicant: DOLBY LABORATORIES LICENSING CORPORATION
    Inventors: Heiko PURNHAGEN, Leif SEHLSTROM, Lars VILLEMOES, Glenn N. DICKINS, Mark S. VINTON
  • Patent number: 10522163
    Abstract: On the basis of a bitstream (P), an n-channel audio signal (X) is reconstructed by deriving an m-channel core signal (Y) and multichannel coding parameters (a) from the bitstream, where 1?m<n. Also derived from the bitstream are pre-processing dynamic range control, DRC, parameters (DRC2) quantifying an encoder-side dynamic range limiting of the core signal. The n-channel audio signal is obtained by parametric synthesis in accordance with the multichannel coding parameters and while cancelling any encoder-side dynamic range limiting based on the pre-processing DRC parameters. In particular embodiments, the reconstruction further includes use of compensated post-processing DRC parameters quantifying a potential decoder-side dynamic range compression. Cancellation of an encoder-side range limitation and range compression are preferably performed by different decoder-side components. Cancellation and compression may be coordinated by a DRC pre-processor.
    Type: Grant
    Filed: July 17, 2019
    Date of Patent: December 31, 2019
    Assignees: Dolby Laboratories Licensing Corporation, Dolby International AB
    Inventors: Jeffrey Riedmiller, Karl J. Roeden, Kristofer Kjoerling, Heiko Purnhagen, Vinay Melkote, Leif Sehlstrom
  • Patent number: 10482891
    Abstract: An audio communication endpoint receives a bitstream containing spectral components representing spectral content of an audio signal, wherein the spectral components relate to a first range extending up to a first break frequency, above which any spectral components are unassigned. The endpoint adapts the received bitstream in accordance with a second range extending up to a second break frequency by removing moving spectral components or adding neutral-valued spectral components relating to a range between the first and second break frequencies. The endpoint then attenuates spectral content in a neighbourhood of the least of the first and second break frequencies for thereby achieving a gradual spectral decay. After this, reconstructing the audio signal is reconstructed by an inverse transform operating on spectral components relating to said second range in the adapted and attenuated received bitstream.
    Type: Grant
    Filed: January 10, 2018
    Date of Patent: November 19, 2019
    Assignees: Dolby Laboratories Licensing Corporation, Dolby International AB
    Inventors: Heiko Purnhagen, Leif Sehlstrom, Lars Villemoes, Glenn N. Dickins, Mark S. Vinton
  • Publication number: 20190341066
    Abstract: On the basis of a bitstream (P), an n-channel audio signal (X) is reconstructed by deriving an m-channel core signal (Y) and multichannel coding parameters (?) from the bitstream, where 1?m<n. Also derived from the bitstream are pre-processing dynamic range control, DRC, parameters (DRC2) quantifying an encoder-side dynamic range limiting of the core signal. The n-channel audio signal is obtained by parametric synthesis in accordance with the multichannel coding parameters and while cancelling any encoder-side dynamic range limiting based on the pre-processing DRC parameters. In particular embodiments, the reconstruction further includes use of compensated post-processing DRC parameters quantifying a potential decoder-side dynamic range compression. Cancellation of an encoder-side range limitation and range compression are preferably performed by different decoder-side components. Cancellation and compression may be coordinated by a DRC pre-processor.
    Type: Application
    Filed: July 17, 2019
    Publication date: November 7, 2019
    Applicants: DOLBY LABORATORIES LICENSING CORPORATION, DOLBY INTERNATIONAL AB
    Inventors: Jeffrey RIEDMILLER, Karl J. ROEDEN, Kristofer KJOERLING, Heiko PURNHAGEN, Vinay MELKOTE, Leif SEHLSTROM