Patents by Inventor Kristofer Kjoerling
Kristofer Kjoerling 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: 11380336Abstract: Encoding and decoding devices for encoding the channels of an audio system having at least four channels are disclosed. The decoding device has a first stereo decoding component which subjects a first pair of input channels to a first stereo decoding, and a second stereo decoding component which subjects a second pair of input channels to a second stereo decoding. The results of the first and second stereo decoding components are crosswise coupled to a third and a fourth stereo decoding component which each performs stereo decoding on one channel resulting from the first stereo decoding component, and one channel resulting from the second stereo decoding component.Type: GrantFiled: November 4, 2019Date of Patent: July 5, 2022Assignee: Dolby International ABInventors: Kristofer Kjoerling, Harald Mundt, Heiko Purnhagen
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Publication number: 20220189493Abstract: There is provided encoding and decoding methods for encoding and decoding of object based audio. An exemplary encoding method includes inter alia calculating M downmix signals by forming combinations of N audio objects, wherein M?N, and calculating parameters which allow reconstruction of a set of audio objects formed on basis of the N audio objects from the M downmix signals. The calculation of the M downmix signals is made according to a criterion which is independent of any loudspeaker configuration.Type: ApplicationFiled: March 7, 2022Publication date: June 16, 2022Applicant: DOLBY INTERNATIONAL ABInventors: Heiko PURNHAGEN, Kristofer KJOERLING, Toni HIRVONEN, Lars VILLEMOES, Dirk Jeroen BREEBAART
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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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Publication number: 20220157327Abstract: In some embodiments, a pitch filter for filtering a preliminary audio signal generated from an audio bitstream is disclosed. The pitch filter has an operating mode selected from one of either: (i) an active mode where the preliminary audio signal is filtered using filtering information to obtain a filtered audio signal, and (ii) an inactive mode where the pitch filter is disabled. The preliminary audio signal is generated in an audio encoder or audio decoder having a coding mode selected from at least two distinct coding modes, and the pitch filter is capable of being selectively operated in either the active mode or the inactive mode while operating in the coding mode based on control information.Type: ApplicationFiled: November 22, 2021Publication date: May 19, 2022Applicant: DOLBY INTERNATIONAL ABInventors: Barbara RESCH, Kristofer KJÖRLING, Lars VILLEMOES
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Publication number: 20220159379Abstract: A method and apparatus for reconstructing N audio channels from M audio channels is disclosed. The method includes receiving a bitstream containing an encoded audio signal representing the M audio channels and decoding the encoded audio signal to obtain a frequency domain representation of the M audio channels. The method further includes extracting a parameter from the bitstream and reconstructing at least one of the N audio channels using the parameter. The parameter represents an angle between two signals, at least one of which is included in the M audio channels.Type: ApplicationFiled: November 22, 2021Publication date: May 19, 2022Applicant: DOLBY INTERNATIONAL ABInventors: Heiko PURNHAGEN, Lars VILLEMOES, Jonas ENGDEGARD, Jonas ROEDEN, Kristofer KJOERLING
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Patent number: 11322161Abstract: Methods and systems encoding a stereo audio signal having an original left channel and an original right channel are disclosed. The method includes generating a downmix signal and a residual signal based on the stereo audio signal and determining one or more stereo parameters based on the stereo audio signal. The residual signal covers only a part of an audio frequency range of the stereo signal, and the one or more stereo parameters describing a stereo image of the stereo audio signal. The method further includes analyzing the stereo audio signal and selecting, based on the analyzing, left/right perceptual encoding or mid/side perceptual encoding in a time variant manner.Type: GrantFiled: June 28, 2019Date of Patent: May 3, 2022Assignee: Dolby International ABInventors: Heiko Purnhagen, Pontus Carlsson, Kristofer Kjoerling
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Patent number: 11322164Abstract: The present document describes a method (400) for encoding a soundfield representation (SR) input signal (101, 301) describing a soundfield at a reference position, wherein the SR input signal (101, 301) comprises a plurality of channels for a plurality of different directivity patterns of the soundfield at the reference position. The method (400) comprises extracting (401) one or more audio objects (103, 303) from the SR input signal (101, 301). Furthermore, the method (400) comprises determining (402) a residual signal (102, 302) based on the SR input signal (101, 301) and based on the one or more audio objects (103, 303). The method (400) also comprises performing joint coding of the one or more audio objects (103, 303) and/or the residual signal (102, 302). In addition, the method (400) comprises generating (403) a bitstream (701) based on data generated in the context of joint coding of the one or more audio objects (103, 303) and/or the residual signal (102, 302).Type: GrantFiled: January 17, 2019Date of Patent: May 3, 2022Assignees: Dolby Laboratories Licensing Corporation, Dolby International ABInventors: Kristofer Kjoerling, David S. McGrath, Heiko Purnhagen, Mark R. P. Thomas
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Patent number: 11315576Abstract: Methods and systems for advanced stereo processing of an audio signal are disclosed. The methods and systems include selecting a coding mode of either transform coding or linear predictive coding and performing advanced stereo processing when in the selected coding mode. Both encoding and decoding operations are provided.Type: GrantFiled: June 6, 2019Date of Patent: April 26, 2022Assignee: Dolby International ABInventors: Heiko Purnhagen, Pontus Carlsson, Kristofer Kjoerling
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Publication number: 20220101865Abstract: There is provided methods and apparatuses for decoding and encoding of audio signals. In particular, a method for decoding includes receiving a waveform-coded signal having a spectral content corresponding to a subset of the frequency range above a cross-over frequency. The waveform-coded signal is interleaved with a parametric high frequency reconstruction of the audio signal above the cross-over frequency. In this way an improved reconstruction of the high frequency bands of the audio signal is achieved.Type: ApplicationFiled: October 6, 2021Publication date: March 31, 2022Applicant: Dolby International ABInventors: Kristofer KJOERLING, Robin THESING, Harald MUNDT, Heiko PURNHAGEN, Karl Jonas ROEDEN
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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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Patent number: 11270709Abstract: There is provided encoding and decoding methods for encoding and decoding of object based audio. An exemplary encoding method includes inter alia calculating M downmix signals by forming combinations of N audio objects, wherein M?N, and calculating parameters which allow reconstruction of a set of audio objects formed on basis of the N audio objects from the M downmix signals. The calculation of the M downmix signals is made according to a criterion which is independent of any loudspeaker configuration.Type: GrantFiled: November 22, 2017Date of Patent: March 8, 2022Assignee: Dolby International ABInventors: Heiko Purnhagen, Kristofer Kjoerling, Toni Hirvonen, Lars Villemoes, Dirk Jeroen Breebaart
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Publication number: 20220059110Abstract: 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: ApplicationFiled: August 31, 2021Publication date: February 24, 2022Applicant: DOLBY INTERNATIONAL ABInventors: Kristofer KJOERLING, Heiko PURNHAGEN, Harald MUNDT, Karl Jonas ROEDEN, Leif SEHLSTROM
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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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Publication number: 20210375304Abstract: An audio processing system (100) accepts an audio bitstream having one of a plurality of predefined audio frame rates. The system comprises a front-end component (110), which receives a variable number of quantized spectral components, corresponding to one audio frame in any of the predefined audio frame rates, and performs an inverse quantization according to predetermined, frequency-dependent quantization levels. The front-end component may be agnostic of the audio frame rate. The audio processing system further comprises a frequency-domain processing stage (120) and a sample rate converter (130), which provide a reconstructed audio signal sampled at a target sampling frequency independent of the audio frame rate. By its frame-rate adaptability, the system can be configured to operate frame-synchronously in parallel with a video processing system that accepts plural video frame rates.Type: ApplicationFiled: June 10, 2021Publication date: December 2, 2021Applicant: DOLBY INTERNATIONAL ABInventors: Heiko Purnhagen, Kristofer Kjoerling, Alexander Stahlmann, Jens Popp, Karl Jonas Roeden
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Publication number: 20210366494Abstract: The application relates to HFR (High Frequency Reconstruction/Regeneration) of audio signals. In particular, the application relates to a method and system for performing HFR of audio signals having large variations in energy level across the low frequency range which is used to reconstruct the high frequencies of the audio signal. A system configured to generate a plurality of high frequency subband signals covering a high frequency interval from a plurality of low frequency subband signals is described.Type: ApplicationFiled: June 4, 2021Publication date: November 25, 2021Applicant: Dolby International ABInventor: Kristofer Kjoerling
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Patent number: 11184709Abstract: A method and apparatus for reconstructing N audio channels from M audio channels is disclosed. The method includes receiving a bitstream containing an encoded audio signal representing the M audio channels and decoding the encoded audio signal to obtain a frequency domain representation of the M audio channels. The method further includes extracting a parameter from the bitstream and reconstructing at least one of the N audio channels using the parameter. The parameter represents an angle between two signals, at least one of which is included in the M audio channels.Type: GrantFiled: April 13, 2020Date of Patent: November 23, 2021Assignee: Dolby International ABInventors: Heiko Purnhagen, Lars Villemoes, Jonas Engdegard, Jonas Roeden, Kristofer Kjoerling
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Patent number: 11183200Abstract: In some embodiments, a pitch filter for filtering a preliminary audio signal generated from an audio bitstream is disclosed. The pitch filter has an operating mode selected from one of either: (i) an active mode where the preliminary audio signal is filtered using filtering information to obtain a filtered audio signal, and (ii) an inactive mode where the pitch filter is disabled. The preliminary audio signal is generated in an audio encoder or audio decoder having a coding mode selected from at least two distinct coding modes, and the pitch filter is capable of being selectively operated in either the active mode or the inactive mode while operating in the coding mode based on control information.Type: GrantFiled: October 16, 2020Date of Patent: November 23, 2021Assignee: Dolby International ABInventors: Barbara Resch, Kristofer Kjörling, Lars Villemoes
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Publication number: 20210318848Abstract: In an audio encoder, for audio content received in a source audio format, default gains are generated based on a default dynamic range compression (DRC) curve, and non-default gains are generated for a non-default gain profile. Based on the default gains and non-default gains, differential gains are generated. An audio signal comprising the audio content, the default DRC curve, and differential gains is generated. In an audio decoder, the default DRC curve and the differential gains are identified from the audio signal. Default gains are re-generated based on the default DRC curve. Based on the combination of the re-generated default gains and the differential gains, operations are performed on the audio content extracted from the audio signal.Type: ApplicationFiled: March 22, 2021Publication date: October 14, 2021Applicants: DOLBY LABORATORIES LICENSING CORPORATION, DOLBY INTERNATIONAL ABInventors: Jeroen Koppens, Jeffrey Riedmiller, Kristofer Kjoerling, Alexander Stahlmann, Holger Hoerich, Alan J. Seefeldt
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Patent number: 11145318Abstract: There is provided methods and apparatuses for decoding and encoding of audio signals. In particular, a method for decoding includes receiving a waveform-coded signal having a spectral content corresponding to a subset of the frequency range above a cross-over frequency. The waveform-coded signal is interleaved with a parametric high frequency reconstruction of the audio signal above the cross-over frequency. In this way an improved reconstruction of the high frequency bands of the audio signal is achieved.Type: GrantFiled: October 24, 2018Date of Patent: October 12, 2021Assignee: Dolby International ABInventors: Kristofer Kjoerling, Robin Thesing, Harald Mundt, Heiko Purnhagen, Karl Jonas Roeden
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Patent number: 11133013Abstract: Methods and systems encoding a stereo audio signal having a left channel and a right channel are disclosed. The system includes a downmixer for generating a downmix signal and a residual signal from the stereo audio signal in selected frequency bands representing only part of a used audio frequency range of the stereo audio signal, and a decision module for selecting, in a time variant manner, either left/right perceptual encoding or mid/side perceptual encoding. The system also includes a parameter estimator for estimating stereo parameters for reconstructing a stereo image of a portion of the stereo audio signal, and a perceptual encoder for performing either left/right perceptual encoding or mid/side perceptual encoding based on the selecting to generate an encoded output signal. Finally, the system includes a bitstream generator for creating a bitstream signal comprising the encoded output signal.Type: GrantFiled: August 20, 2019Date of Patent: September 28, 2021Assignee: Dolby International ABInventors: Heiko Purnhagen, Pontus Carlsson, Kristofer Kjoerling