Patents by Inventor Per Ekstrand

Per Ekstrand 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: 20250037688
    Abstract: The present document relates to audio coding systems which make use of a harmonic transposition method for high frequency reconstruction (HFR), and to digital effect processors, e.g. so-called exciters, where generation of harmonic distortion adds brightness to the processed signal. In particular, a system configured to generate a high frequency component of a signal from a low frequency component of the signal is described. The system may comprise an analysis filter bank (501) configured to provide a set of analysis subband signals from the low frequency component of the signal; wherein the set of analysis subband signals comprises at least two analysis subband signals; wherein the analysis filter bank (501) has a frequency resolution of ?f.
    Type: Application
    Filed: October 10, 2024
    Publication date: January 30, 2025
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Per EKSTRAND, Lars VILLEMOES, Per HEDELIN
  • Patent number: 12213004
    Abstract: The present disclosure provides methods, devices and computer program products for non-uniform quantization of parameters. The disclosure further relates to a method and apparatus for reconstructing an audio object in an audio decoding system taking the non-uniformly quantized parameters into account. According to the disclosure, such an approach renders it possible to reduce bit consumption without substantially reducing the quality of the reconstructed audio object.
    Type: Grant
    Filed: November 6, 2023
    Date of Patent: January 28, 2025
    Assignee: DOLBY INTERNATIONAL AB
    Inventors: Heiko Purnhagen, Per Ekstrand
  • Patent number: 12211513
    Abstract: A method for decoding an encoded audio bitstream is disclosed. The method includes receiving the encoded audio bitstream and decoding the audio data to generate a decoded lowband audio signal. The method further includes extracting high frequency reconstruction metadata and filtering the decoded lowband audio signal with an analysis filterbank to generate a filtered lowband audio signal. The method also includes extracting a flag indicating whether either spectral translation or harmonic transposition is to be performed on the audio data and regenerating a highband portion of the audio signal using the filtered lowband audio signal and the high frequency reconstruction metadata in accordance with the flag. The high frequency regeneration is performed as a post-processing operation with a delay of 3010 samples per audio channel.
    Type: Grant
    Filed: November 14, 2023
    Date of Patent: January 28, 2025
    Assignee: DOLBY INTERNATIONAL AB
    Inventors: Kristofer Kjoerling, Lars Villemoes, Heiko Purnhagen, Per Ekstrand
  • Publication number: 20250029621
    Abstract: The present invention relates to transposing signals in time and/or frequency and in particular to coding of audio signals. More particular, the present invention relates to high frequency reconstruction (HFR) methods including a frequency domain harmonic transposer. A method and system for generating a transposed output signal from an input signal using a transposition factor T is described. The system comprises an analysis window of length La, extracting a frame of the input signal, and an analysis transformation unit of order M transforming the samples into M complex coefficients. M is a function of the transposition factor T. The system further comprises a nonlinear processing unit altering the phase of the complex coefficients by using the transposition factor T, a synthesis transformation unit of order M transforming the altered coefficients into M altered samples, and a synthesis window of length Ls, generating a frame of the output signal.
    Type: Application
    Filed: October 3, 2024
    Publication date: January 23, 2025
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Per EKSTRAND, Lars VILLEMOES
  • Patent number: 12205602
    Abstract: A method for decoding an encoded audio bitstream is disclosed. The method includes receiving the encoded audio bitstream and decoding the audio data to generate a decoded lowband audio signal. The method further includes extracting high frequency reconstruction metadata and filtering the decoded lowband audio signal with an analysis filterbank to generate a filtered lowband audio signal. The method also includes extracting a flag indicating whether either spectral translation or harmonic transposition is to be performed on the audio data and regenerating a highband portion of the audio signal using the filtered lowband audio signal and the high frequency reconstruction metadata in accordance with the flag.
    Type: Grant
    Filed: March 11, 2024
    Date of Patent: January 21, 2025
    Assignee: Dolby International AB
    Inventors: Kristofer Kjoerling, Lars Villemoes, Heiko Purnhagen, Per Ekstrand
  • Publication number: 20250015785
    Abstract: The present document describes a method (200) for determining N coefficients of an asymmetric prototype filter p0 for use in a low delay M-channel analysis and/or synthesis filter bank (101, 102) comprising M analysis filters hk (103) and/or M synthesis filters fk(106), k=0, . . . , M?1, wherein M is greater than 1, and wherein subband signals which are processed by the analysis and/or synthesis filter bank (101, 102) are decimated by a decimation factor S, with S<M. The method (200) comprises determining (201) a target transfer function of the analysis and/or synthesis filler bank (101, 102) comprising a target delay D; wherein D is smaller or equal to N. Furthermore.
    Type: Application
    Filed: November 29, 2022
    Publication date: January 9, 2025
    Applicant: DOLBY INTERNATIONAL AB
    Inventor: Per EKSTRAND
  • Patent number: 12175993
    Abstract: A method for decoding an encoded audio bitstream is disclosed. The method includes receiving the encoded audio bitstream and decoding the audio data to generate a decoded lowband audio signal. The method further includes extracting high frequency reconstruction metadata and filtering the decoded lowband audio signal with an analysis filterbank to generate a filtered lowband audio signal. The method also includes extracting a flag indicating whether either spectral translation or harmonic transposition is to be performed on the audio data and regenerating a highband portion of the audio signal using the filtered lowband audio signal and the high frequency reconstruction metadata in accordance with the flag.
    Type: Grant
    Filed: May 29, 2024
    Date of Patent: December 24, 2024
    Assignee: DOLBY INTERNATIONAL AB
    Inventors: Lars Villemoes, Heiko Purnhagen, Per Ekstrand
  • Patent number: 12159642
    Abstract: An apparatus and method are disclosed for processing an audio signal. The apparatus includes an input interface, a digital filterbank having an analysis part and a synthesis part, a first phase shifter, a spectral envelope adjuster, a second phase shifter, and an output interface. The first phase shifter and the second phase shifter reduce a complexity of the digital filterbank, which includes both analysis and synthesis filters that are complex-exponential modulated versions of a prototype filter.
    Type: Grant
    Filed: August 21, 2023
    Date of Patent: December 3, 2024
    Assignee: DOLBY INTERNATIONAL AB
    Inventor: Per Ekstrand
  • Patent number: 12142251
    Abstract: The present document relates to audio coding systems which make use of a harmonic transposition method for high frequency reconstruction (HFR), and to digital effect processors, e.g. so-called exciters, where generation of harmonic distortion adds brightness to the processed signal. In particular, a system configured to generate a high frequency component of a signal from a low frequency component of the signal is described. The system may comprise an analysis filter bank (501) configured to provide a set of analysis subband signals from the low frequency component of the signal; wherein the set of analysis subband signals comprises at least two analysis subband signals; wherein the analysis filter bank (501) has a frequency resolution of ?f.
    Type: Grant
    Filed: February 12, 2024
    Date of Patent: November 12, 2024
    Assignee: DOLBY INTERNATIONAL AB
    Inventors: Per Ekstrand, Lars Villemoes, Per Hedelin
  • Patent number: 12136429
    Abstract: The present invention relates to transposing signals in time and/or frequency and in particular to coding of audio signals. More particular, the present invention relates to high frequency reconstruction (HFR) methods including a frequency domain harmonic transposer. A method and system for generating a transposed output signal from an input signal using a transposition factor T is described. The system comprises an analysis window of length La, extracting a frame of the input signal, and an analysis transformation unit of order M transforming the samples into M complex coefficients. M is a function of the transposition factor T. The system further comprises a nonlinear processing unit altering the phase of the complex coefficients by using the transposition factor T, a synthesis transformation unit of order M transforming the altered coefficients into M altered samples, and a synthesis window of length Ls, generating a frame of the output signal.
    Type: Grant
    Filed: November 29, 2023
    Date of Patent: November 5, 2024
    Assignee: DOLBY INTERNATIONAL AB
    Inventors: Per Ekstrand, Lars Villemoes
  • Publication number: 20240355345
    Abstract: Embodiments relate to an audio processing unit that includes a buffer, bitstream payload deformatter, and a decoding subsystem. The buffer stores at least one block of an encoded audio bitstream. The block includes a fill element that begins with an identifier followed by fill data. The fill data includes at least one flag identifying whether enhanced spectral band replication (eSBR) processing is to be performed on audio content of the block. A corresponding method for decoding an encoded audio bitstream is also provided.
    Type: Application
    Filed: April 11, 2024
    Publication date: October 24, 2024
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Lars Villemoes, Heiko Purnhagen, Per Ekstrand
  • Patent number: 12101613
    Abstract: A method of audio processing includes generating harmonics in a hybrid complex quadrature mirror filter domain. Generating the harmonics may include multiplication, using a feedback delay loop, and dynamic compression. The harmonics may be generated based on one or more hybrid sub-bands of the complex transform domain signal.
    Type: Grant
    Filed: March 19, 2021
    Date of Patent: September 24, 2024
    Assignees: Dolby International AB, Dolby Laboratories Licensing Corporation
    Inventors: Per Ekstrand, Yuxing Hao, Xuemei Yu
  • Publication number: 20240312471
    Abstract: A method for decoding an encoded audio bitstream is disclosed. The method includes receiving the encoded audio bitstream and decoding the audio data to generate a decoded lowband audio signal. The method further includes extracting high frequency reconstruction metadata and filtering the decoded lowband audio signal with an analysis filterbank to generate a filtered lowband audio signal. The method also includes extracting a flag indicating whether either spectral translation or harmonic transposition is to be performed on the audio data and regenerating a highband portion of the audio signal using the filtered lowband audio signal and the high frequency reconstruction metadata in accordance with the flag.
    Type: Application
    Filed: May 29, 2024
    Publication date: September 19, 2024
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Lars Villemoes, Heiko Purnhagen, Per Ekstrand
  • Patent number: 12094477
    Abstract: Embodiments relate to an audio processing unit that includes a buffer, bitstream payload deformatter, and a decoding subsystem. The buffer stores at least one block of an encoded audio bitstream. The block includes a fill element that begins with an identifier followed by fill data. The fill data includes at least one flag identifying whether enhanced spectral band replication (eSBR) processing is to be performed on audio content of the block. A corresponding method for decoding an encoded audio bitstream is also provided.
    Type: Grant
    Filed: May 16, 2023
    Date of Patent: September 17, 2024
    Assignee: Dolby International AB
    Inventors: Lars Villemoes, Heiko Purnhagen, Per Ekstrand
  • Patent number: 12094480
    Abstract: A method for decoding an encoded audio bitstream is disclosed. The method includes receiving the encoded audio bitstream and decoding the audio data to generate a decoded lowband audio signal. The method further includes extracting high frequency reconstruction metadata and filtering the decoded lowband audio signal with an analysis filterbank to generate a filtered lowband audio signal. The method also includes extracting a flag indicating whether either spectral translation or harmonic transposition is to be performed on the audio data and regenerating a highband portion of the audio signal using the filtered lowband audio signal and the high frequency reconstruction metadata in accordance with the flag.
    Type: Grant
    Filed: July 31, 2023
    Date of Patent: September 17, 2024
    Assignee: DOLBY INTERNATIONAL AB
    Inventors: Lars Villemoes, Heiko Purnhagen, Per Ekstrand
  • Publication number: 20240294987
    Abstract: The present invention relates to coding of audio signals, and in particular to high frequency reconstruction methods including a frequency domain harmonic transposer. A system and method for generating a high frequency component of a signal from a low frequency component of the signal is described.
    Type: Application
    Filed: April 17, 2024
    Publication date: September 5, 2024
    Applicant: Dolby International AB
    Inventors: Lars VILLEMOES, Per EKSTRAND
  • Publication number: 20240271217
    Abstract: The present invention relates to coding of audio signals, and in particular to high frequency reconstruction methods including a frequency domain harmonic transposer. A system and method for generating a high frequency component of a signal from a low frequency component of the signal is described.
    Type: Application
    Filed: April 17, 2024
    Publication date: August 15, 2024
    Applicant: Dolby International AB
    Inventors: Lars VILLEMOES, Per EKSTRAND
  • Publication number: 20240257790
    Abstract: The present document relates to audio coding systems which make use of a harmonic transposition method for high frequency reconstruction (HFR), and to digital effect processors, e.g. so-called exciters, where generation of harmonic distortion adds brightness to the processed signal. In particular, a system configured to generate a high frequency component of a signal from a low frequency component of the signal is described. The system may comprise an analysis filter bank (501) configured to provide a set of analysis subband signals from the low frequency component of the signal; wherein the set of analysis subband signals comprises at least two analysis subband signals; wherein the analysis filter bank (501) has a frequency resolution of ?f.
    Type: Application
    Filed: February 12, 2024
    Publication date: August 1, 2024
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Per EKSTRAND, Lars VILLEMOES, Per HEDELIN
  • Publication number: 20240212695
    Abstract: A method for decoding an encoded audio bitstream is disclosed. The method includes receiving the encoded audio bitstream and decoding the audio data to generate a decoded lowband audio signal. The method further includes extracting high frequency reconstruction metadata and filtering the decoded lowband audio signal with an analysis filterbank to generate a filtered lowband audio signal. The method also includes extracting a flag indicating whether either spectral translation or harmonic transposition is to be performed on the audio data and regenerating a highband portion of the audio signal using the filtered lowband audio signal and the high frequency reconstruction metadata in accordance with the flag.
    Type: Application
    Filed: March 11, 2024
    Publication date: June 27, 2024
    Applicant: Dolby International AB
    Inventors: Kristofer Kjoerling, Lars Villemoes, Heiko Purnhagen, Per Ekstrand
  • Patent number: 11993817
    Abstract: The present invention relates to coding of audio signals, and in particular to high frequency reconstruction methods including a frequency domain harmonic transposer. A system and method for generating a high frequency component of a signal from a low frequency component of the signal is described.
    Type: Grant
    Filed: January 19, 2023
    Date of Patent: May 28, 2024
    Assignee: Dolby International AB
    Inventors: Lars Villemoes, Per Ekstrand