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).

  • Patent number: 11823696
    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: March 3, 2023
    Date of Patent: November 21, 2023
    Assignee: Dolby International AB
    Inventors: Kristofer Kjoerling, Lars Villemoes, Heiko Purnhagen, Per Ekstrand
  • Publication number: 20230368805
    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: May 16, 2023
    Publication date: November 16, 2023
    Applicant: Dolby International AB
    Inventors: Lars Villemoes, Heiko Purnhagen, Per Ekstrand
  • Patent number: 11810592
    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: February 23, 2023
    Date of Patent: November 7, 2023
    Assignee: Dolby International AB
    Inventors: Kristofer Kjoerling, Lars Villemoes, Heiko Purnhagen, Per Ekstrand
  • Patent number: 11810591
    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: February 23, 2023
    Date of Patent: November 7, 2023
    Assignee: Dolby International AB
    Inventors: Kristofer Kjoerling, Lars Villemoes, Heiko Purnhagen, Per Ekstrand
  • Patent number: 11810590
    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: February 23, 2023
    Date of Patent: November 7, 2023
    Assignee: Dolby International AB
    Inventors: Kristofer Kjoerling, Lars Villemoes, Heiko Purnhagen, Per Ekstrand
  • Patent number: 11810589
    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 15, 2022
    Date of Patent: November 7, 2023
    Assignee: Dolby International AB
    Inventors: Kristofer Kjoerling, Lars Villemoes, Heiko Purnhagen, Per Ekstrand
  • Patent number: 11763830
    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: October 11, 2022
    Date of Patent: September 19, 2023
    Assignee: DOLBY INTERNATIONAL AB
    Inventors: Lars Villemoes, Heiko Purnhagen, Per Ekstrand
  • Patent number: 11756559
    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: February 22, 2022
    Date of Patent: September 12, 2023
    Assignee: DOLBY INTERNATIONAL AB
    Inventors: Kristofer Kjoerling, Lars Villemoes, Heiko Purnhagen, Per Ekstrand
  • Patent number: 11735198
    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 30, 2021
    Date of Patent: August 22, 2023
    Assignee: Dolby International AB
    Inventor: Per Ekstrand
  • Publication number: 20230245637
    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: March 31, 2023
    Publication date: August 3, 2023
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Per EKSTRAND, Lars VILLEMOES, Per HEDELIN
  • Publication number: 20230217166
    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: Application
    Filed: March 19, 2021
    Publication date: July 6, 2023
    Applicants: Dolby International AB, Dolby Laboratories Licensing Corporation
    Inventors: Per EKSTRAND, Yuxing HAO, Xuemei YU
  • Publication number: 20230206932
    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: Application
    Filed: March 3, 2023
    Publication date: June 29, 2023
    Applicant: Dolby International AB
    Inventors: Kristofer KJOERLING, Lars VILLEMOES, Heiko PURNHAGEN, Per EKSTRAND
  • Publication number: 20230206935
    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: Application
    Filed: March 3, 2023
    Publication date: June 29, 2023
    Applicant: Dolby International AB
    Inventors: Kristofer KJOERLING, Lars VILLEMOES, Heiko PURNHAGEN, Per EKSTRAND
  • Publication number: 20230206934
    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: Application
    Filed: March 3, 2023
    Publication date: June 29, 2023
    Applicant: Dolby International AB
    Inventors: Kristofer KJOERLING, Lars VILLEMOES, Heiko PURNHAGEN, Per EKSTRAND
  • Publication number: 20230206933
    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: Application
    Filed: March 3, 2023
    Publication date: June 29, 2023
    Applicant: Dolby International AB
    Inventors: Kristofer KJOERLING, Lars VILLEMOES, Heiko PURNHAGEN, Per EKSTRAND
  • Publication number: 20230197089
    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: February 3, 2023
    Publication date: June 22, 2023
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Per EKSTRAND, Lars VILLEMOES
  • Publication number: 20230197104
    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: Application
    Filed: February 23, 2023
    Publication date: June 22, 2023
    Applicant: Dolby International AB
    Inventors: Kristofer KJOERLING, Lars VILLEMOES, Heiko PURNHAGEN, Per EKSTRAND
  • Publication number: 20230197102
    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: Application
    Filed: February 23, 2023
    Publication date: June 22, 2023
    Applicant: Dolby International AB
    Inventors: Kristofer KJOERLING, Lars VILLEMOES, Heiko PURNHAGEN, Per EKSTRAND
  • Publication number: 20230197101
    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: Application
    Filed: February 23, 2023
    Publication date: June 22, 2023
    Applicant: Dolby International AB
    Inventors: Kristofer KJOERLING, Lars VILLEMOES, Heiko PURNHAGEN, Per EKSTRAND
  • Publication number: 20230197103
    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: Application
    Filed: February 23, 2023
    Publication date: June 22, 2023
    Applicant: Dolby International AB
    Inventors: Kristofer KJOERLING, Lars VILLEMOES, Heiko PURNHAGEN, Per EKSTRAND