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: 10796703Abstract: 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: September 3, 2019Date of Patent: October 6, 2020Assignee: Dolby International ABInventors: Heiko Purnhagen, Pontus Carlsson, Kristofer Kjoerling
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Publication number: 20200304913Abstract: 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: April 13, 2020Publication date: September 24, 2020Applicant: DOLBY INTERNATIONAL ABInventors: Heiko PURNHAGEN, Lars VILLEMOES, Jonas ENGDEGARD, Jonas ROEDEN, Kristofer KJOERLING
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Publication number: 20200293272Abstract: 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 23, 2020Publication date: September 17, 2020Applicants: DOLBY LABORATORIES LICENSING CORPORATION, DOLBY INTERNATIONAL ABInventors: Jeroen Koppens, Jeffrey Riedmiller, Kristofer Kjoerling, Alexander Stahlmann, Holger Hoerich, Alan J. Seefeldt
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Publication number: 20200286497Abstract: The present disclosure provides methods, devices and computer program products for encoding and decoding a stereo audio signal based on an input signal. According to the disclosure, a hybrid approach of using both parametric stereo coding and a discrete representation of the stereo audio signal is used which may improve the quality of the encoded and decoded audio for certain bitrates.Type: ApplicationFiled: March 23, 2020Publication date: September 10, 2020Applicant: DOLBY INTERNATIONAL ABInventors: Heiko PURNHAGEN, Kristofer KJOERLING
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Publication number: 20200275171Abstract: A method for providing media content within a media distribution network. The method comprises transforming source media content into an interim format, thereby providing transformed content. Furthermore, the method comprises storing the transformed content on at least one core storage unit. In addition, the method comprises receiving a request for the source media content from a client. The method further comprises encoding the transformed content or intermediate coded content derived therefrom into encoded content suitable for transmission over a core network and/or an edge network, as well as sending the encoded content via the core network and/or the edge network to the client.Type: ApplicationFiled: July 26, 2018Publication date: August 27, 2020Applicants: DOLBY LABORATORIES LICENSING CORPORATION, DOLBY INTERNATIONAL ABInventors: Jason Michael CLOUD, Jeffrey RIEDMILLER, Kristofer KJOERLING, Janusz KLEJSA
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Publication number: 20200265844Abstract: There are provided decoding and encoding methods for encoding and decoding of multichannel audio content for playback on a speaker configuration with N channels. The decoding method comprises decoding, in a first decoding module, M input audio signals into M mid signals which are suitable for playback on a speaker configuration with M channels; and for each of the N channels in excess of M channels, receiving an additional input audio signal corresponding to one of the M mid signals and decoding the input audio signal and its corresponding mid signal so as to generate a stereo signal including a first and a second audio signal which are suitable for playback on two of the N channels of the speaker configuration.Type: ApplicationFiled: February 25, 2020Publication date: August 20, 2020Applicant: DOLBY INTERNATIONAL ABInventors: Heiko Purnhagen, Harald Mundt, Kristofer Kjoerling
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Patent number: 10699724Abstract: The present invention relates to a new method and apparatus for improvement of High Frequency Reconstruction (HFR) techniques using frequency translation or folding or a combination thereof. The proposed invention is applicable to audio source coding systems, and offers significantly reduced computational complexity. This is accomplished by means of frequency translation or folding in the subband domain, preferably integrated with spectral envelope adjustment in the same domain. The concept of dissonance guard-band filtering is further presented. The proposed invention offers a low-complexity, intermediate quality HFR method useful in speech and natural audio coding applications.Type: GrantFiled: February 12, 2019Date of Patent: June 30, 2020Assignee: Dolby International ABInventors: Lars G. Liljeryd, Per Ekstrand, Fredrik Henn, Kristofer Kjoerling
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Publication number: 20200202878Abstract: 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: ApplicationFiled: December 19, 2019Publication date: June 25, 2020Applicants: DOLBY LABORATORIES LICENSING CORPORATION, DOLBY INTERNATIONAL ABInventors: Jeffrey RIEDMILLER, Karl J. ROEDEN, Kristofer KJOERLING, Heiko PURNHAGEN, Vinay MELKOTE, Leif SEHLSTROM
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Patent number: 10685661Abstract: The present invention proposes a new method for improving the performance of a real-valued filterbank based spectral envelope adjuster. By adaptively locking the gain values for adjacent channels dependent on the sign of the channels, as defined in the application, reduced aliasing is achieved. Furthermore, the grouping of the channels during gain-calculation, gives an improved energy estimate of the real valued subband signals in the filterbank.Type: GrantFiled: August 7, 2019Date of Patent: June 16, 2020Assignee: Dolby International ABInventors: Kristofer Kjoerling, Lars Villemoes
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Patent number: 10623860Abstract: 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: September 26, 2019Date of Patent: April 14, 2020Assignee: Dolby International ABInventors: Heiko Purnhagen, Lars Villemoes, Jonas Engdegard, Jonas Roeden, Kristofer Kjoerling
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Patent number: 10606550Abstract: 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: GrantFiled: April 17, 2019Date of Patent: March 31, 2020Assignees: Dolby Laboratories Licensing Corporation, Dolby International ABInventors: Jeroen Koppens, Jeffrey Riedmiller, Kristofer Kjoerling, Alexander Stahlmann, Holger Hoerich, Alan J. Seefeldt
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Publication number: 20200098381Abstract: 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: October 4, 2019Publication date: March 26, 2020Applicant: DOLBY INTERNATIONAL ABInventors: Kristofer KJOERLING, Heiko PURNHAGEN, Harald MUNDT, Karl Jonas ROEDEN, Leif SEHLSTROM
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Patent number: 10600429Abstract: The present disclosure provides methods, devices and computer program products for encoding and decoding a stereo audio signal based on an input signal. According to the disclosure, a hybrid approach of using both parametric stereo coding and a discrete representation of the stereo audio signal is used which may improve the quality of the encoded and decoded audio for certain bitrates.Type: GrantFiled: November 19, 2018Date of Patent: March 24, 2020Assignee: Dolby International ABInventors: Heiko Purnhagen, Kristofer Kjoerling
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Patent number: 10593340Abstract: There are provided decoding and encoding methods for encoding and decoding of multichannel audio content for playback on a speaker configuration with N channels. The decoding method comprises decoding, in a first decoding module, M input audio signals into M mid signals which are suitable for playback on a speaker configuration with M channels; and for each of the N channels in excess of M channels, receiving an additional input audio signal corresponding to one of the M mid signals and decoding the input audio signal and its corresponding mid signal so as to generate a stereo signal including a first and a second audio signal which are suitable for playback on two of the N channels of the speaker configuration.Type: GrantFiled: May 9, 2019Date of Patent: March 17, 2020Assignee: Dolby International ABInventors: Heiko Purnhagen, Harald Mundt, Kristofer Kjoerling
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Publication number: 20200066282Abstract: 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: ApplicationFiled: November 4, 2019Publication date: February 27, 2020Applicant: Dolby International ABInventors: Kristofer KJOERLING, Harald MUNDT, Heiko PURNHAGEN
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Publication number: 20200021915Abstract: 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: September 26, 2019Publication date: January 16, 2020Applicant: DOLBY INTERNATIONAL ABInventors: Heiko PURNHAGEN, Lars VILLEMOES, Jonas ENGDEGARD, Jonas ROEDEN, Kristofer KJOERLING
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Patent number: 10522163Abstract: 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: GrantFiled: July 17, 2019Date of Patent: December 31, 2019Assignees: Dolby Laboratories Licensing Corporation, Dolby International ABInventors: Jeffrey Riedmiller, Karl J. Roeden, Kristofer Kjoerling, Heiko Purnhagen, Vinay Melkote, Leif Sehlstrom
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Publication number: 20190392844Abstract: 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: ApplicationFiled: September 3, 2019Publication date: December 26, 2019Applicant: Dolby International ABInventors: Heiko Purnhagen, Pontus Carlsson, Kristofer Kjoerling
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Publication number: 20190385624Abstract: 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: ApplicationFiled: August 29, 2019Publication date: December 19, 2019Applicant: Dolby International ABInventors: Kristofer Kjoerling, Per Ekstrand, Holger Hoerich
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Patent number: 10510355Abstract: The present document relates to time-alignment of encoded data of an audio encoder with associated metadata, such as spectral band replication (SBR) metadata. An audio decoder (100, 300) configured to determine a reconstructed frame of an audio signal (237) from an access unit (110) of a received data stream is described. The access unit (110) comprises waveform data (111) and metadata (112), wherein the waveform data (111) and the metadata (112) are associated with the same reconstructed frame of the audio signal (127). The audio decoder (100, 300) comprises a waveform processing path (101, 102, 103, 104, 105) configured to generate a plurality of waveform subband signals (123) from the waveform data (111), and a metadata processing path (108, 109) configured to generate decoded metadata (128) from the metadata (111).Type: GrantFiled: September 8, 2014Date of Patent: December 17, 2019Assignee: Dolby International ABInventors: Kristofer Kjoerling, Heiko Purnhagen, Jens Popp