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).
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Patent number: 11417350Abstract: Embodiments relate to an audio processing unit that includes a bitstream payload deformatter and a decoding subsystem. The decoding subsystem is coupled to the bitstream payload deformatter and configured to decode at least a portion of a block of an encoded audio bitstream. The block includes a fill element with an identifier indicating a start of the fill element and fill data after the identifier. The fill data includes at least one flag identifying whether a base form of spectral band replication or an enhanced form of spectral band replication is to be performed on audio content of the block. The identifier is a three bit unsigned integer transmitted most significant bit first and having a value of 0x6.Type: GrantFiled: January 21, 2021Date of Patent: August 16, 2022Assignee: DOLBY INTERNATIONAL ABInventors: Lars Villemoes, Heiko Purnhagen, Per Ekstrand
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Patent number: 11367455Abstract: 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: GrantFiled: July 17, 2020Date of Patent: June 21, 2022Assignee: Dolby International ABInventors: Lars Villemoes, Heiko Purnhagen, Per Ekstrand
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Publication number: 20220180849Abstract: 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: ApplicationFiled: December 13, 2021Publication date: June 9, 2022Applicant: Dolby International ABInventors: Per EKSTRAND, Lars VILLEMOES, Per HEDELIN
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Publication number: 20220180880Abstract: 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: ApplicationFiled: February 22, 2022Publication date: June 9, 2022Applicant: DOLBY INTERNATIONAL ABInventors: Kristofer KJOERLING, Lars VILLEMOES, Heiko PURNHAGEN, Per EKSTRAND
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Patent number: 11297533Abstract: 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: GrantFiled: June 19, 2020Date of Patent: April 5, 2022Assignee: Dolby International ABInventors: Heiko Purnhagen, Per Ekstrand
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Patent number: 11289106Abstract: 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: GrantFiled: January 28, 2019Date of Patent: March 29, 2022Assignee: Dolby International ABInventors: Kristofer Kjoerling, Lars Villemoes, Heiko Purnhagen, Per Ekstrand
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Publication number: 20220059111Abstract: 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: ApplicationFiled: August 30, 2021Publication date: February 24, 2022Applicant: Dolby International ABInventor: Per EKSTRAND
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Patent number: 11238876Abstract: The present invention proposes a new method and a new apparatus for enhancement of audio source coding systems utilising high frequency reconstruction (HFR). It utilises a detection mechanism on the encoder side to assess what parts of the spectrum will not be correctly reproduced by the HFR method in the decoder. Information on this is efficiently coded and sent to the decoder, where it is combined with the output of the HFR input.Type: GrantFiled: August 29, 2019Date of Patent: February 1, 2022Assignee: Dolby International ABInventors: Kristofer Kjoerling, Per Ekstrand, Holger Hoerich
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Patent number: 11200874Abstract: 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: GrantFiled: May 18, 2020Date of Patent: December 14, 2021Assignee: Dolby International ABInventors: Per Ekstrand, Lars Villemoes, Per Hedelin
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Publication number: 20210383817Abstract: 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: ApplicationFiled: August 23, 2021Publication date: December 9, 2021Applicant: Dolby International ABInventors: Per EKSTRAND, Lars VILLEMOES
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Publication number: 20210269880Abstract: 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: ApplicationFiled: March 15, 2021Publication date: September 2, 2021Applicant: Dolby International ABInventors: Lars VILLEMOES, Per EKSTRAND
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Patent number: 11107487Abstract: 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: GrantFiled: October 28, 2019Date of Patent: August 31, 2021Assignee: Dolby International ABInventor: Per Ekstrand
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Patent number: 11100937Abstract: 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: GrantFiled: March 23, 2020Date of Patent: August 24, 2021Assignee: Dolby International ABInventors: Per Ekstrand, Lars Villemoes
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Publication number: 20210151062Abstract: 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: ApplicationFiled: April 25, 2019Publication date: May 20, 2021Applicant: Dolby International ABInventors: Kristofer KJOERLING, Lars VILLEMOES, Heiko PURNHAGEN, Per EKSTRAND
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Publication number: 20210142813Abstract: Embodiments relate to an audio processing unit that includes a bitstream payload deformatter and a decoding subsystem. The decoding subsystem is coupled to the bitstream payload deformatter and configured to decode at least a portion of a block of an encoded audio bitstream. The block includes a fill element with an identifier indicating a start of the fill element and fill data after the identifier. The fill data includes at least one flag identifying whether a base form of spectral band replication or an enhanced form of spectral band replication is to be performed on audio content of the block. The identifier is a three bit unsigned integer transmitted most significant bit first and having a value of 0x6.Type: ApplicationFiled: January 21, 2021Publication date: May 13, 2021Applicant: DOLBY INTERNATIONAL ABInventors: Lars Villemoes, Heiko Purnhagen, Per Ekstrand
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Publication number: 20210104252Abstract: 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: ApplicationFiled: October 23, 2020Publication date: April 8, 2021Applicant: DOLBY INTERNATIONAL ABInventors: Lars Villemoes, Heiko Purnhagen, Per Ekstrand
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Publication number: 20210082451Abstract: 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: ApplicationFiled: April 25, 2019Publication date: March 18, 2021Applicant: Dolby International ABInventors: Kristofer KJOERLING, Lars VILLEMOES, Heiko PURNHAGEN, Per EKSTRAND
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Patent number: 10947594Abstract: 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: GrantFiled: March 5, 2020Date of Patent: March 16, 2021Assignee: Dolby International ABInventors: Lars Villemoes, Per Ekstrand
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Patent number: 10943595Abstract: Embodiments relate to an audio processing unit that includes a bitstream payload deformatter and a decoding subsystem. The decoding subsystem is coupled to the bitstream payload deformatter and configured to decode at least a portion of a block of an encoded audio bitstream. The block includes a fill element with an identifier indicating a start of the fill element and fill data after the identifier. The fill data includes at least one flag identifying whether a base form of spectral band replication or an enhanced form of spectral band replication is to be performed on audio content of the block. The identifier is a three bit unsigned integer transmitted most significant bit first and having a value of 0x6.Type: GrantFiled: December 10, 2019Date of Patent: March 9, 2021Assignee: Dolby International ABInventors: Lars Villemoes, Heiko Purnhagen, Per Ekstrand
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Publication number: 20200411024Abstract: 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: ApplicationFiled: July 17, 2020Publication date: December 31, 2020Applicant: DOLBY INTERNATIONAL ABInventors: Lars Villemoes, Heiko Purnhagen, Per Ekstrand