Patents by Inventor Kristofer Kjorling

Kristofer Kjorling 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: 7469206
    Abstract: The present invention proposes a new method and a new apparatus for enhancement of audio source coding systems utilizing high frequency reconstruction (HFR). It utilizes a detection mechanism (703a) 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 (703b) and sent to the decoder, where it is combined with the output of the HFR unit.
    Type: Grant
    Filed: November 28, 2002
    Date of Patent: December 23, 2008
    Assignee: Coding Technologies AB
    Inventors: Kristofer Kjörling, Per Ekstrand, Holger Hörich
  • Publication number: 20080255856
    Abstract: An audio encoder (109) has a hierarchical encoding structure and generates a data stream comprising one or more audio channels as well as parametric audio encoding data. The encoder (109) comprises an encoding structure processor (305) which inserts decoder tree structure data into the data stream. The decoder tree structure data comprises at least one data value indicative of a channel split characteristic for an audio channel at a hierarchical layer of the hierarchical decoder structure and may specifically specify the decoder tree structures to be applied by a decoder A decoder (115) comprises a receiver (401) which receives the data stream and a decoder structure processor (405) for generating the hierarchical decoder structure in response to the decoder tree structure data. A decode processor (403) then generates output audio channels from the data stream using the hierarchical decoder structure.
    Type: Application
    Filed: July 7, 2006
    Publication date: October 16, 2008
    Applicant: KONINKLIJKE PHILIPS ELECTRONCIS N.V.
    Inventors: Erik Gosuinus Petrus Schuijers, Gerard Herman Hotho, Heiko Purnhagen, Wolfgang Schildbach, Holger Horich, Hans Magnus Kristofer Kjorling, Karl Jonas Roden
  • Patent number: 7433817
    Abstract: 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 adaptive filtering to reduce artifacts due to different tonal characteristics in different frequency ranges of an audio signal upon which HFR is performed. The present invention is applicable to both speech coding and natural audio coding systems.
    Type: Grant
    Filed: October 12, 2005
    Date of Patent: October 7, 2008
    Assignee: Coding Technologies AB
    Inventors: Kristofer Kjörling, Per Ekstrand, Fredrik Henn, Lars Villemoes
  • Patent number: 7382886
    Abstract: The present invention provides improvements to prior art audio codecs that generate a stereo-illusion through post-processing of a received mono signal. These improvements are accomplished by extraction of stereo-image describing parameters at the encoder side, which are transmitted and subsequently used for control of a stereo generator at the decoder side. Furthermore, the invention bridges the gap between simple pseudo-stereo methods, and current methods of true stereo-coding, by using a new form of parametric stereo coding. A stereo-balance parameter is introduced, which enables more advanced stereo modes, and in addition forms the basis of a new method of stereo-coding of spectral envelopes, of particular use in systems where guided HFR (High Frequency Reconstruction) is employed. As a special case, the application of this stereo-coding scheme in scalable HFR-based codecs is described.
    Type: Grant
    Filed: July 10, 2002
    Date of Patent: June 3, 2008
    Assignee: Coding Technologies AB
    Inventors: Fredrik Henn, Kristofer Kjorling, Lars Liljeryd, Jonas Roden, Jonas Engdegard
  • Patent number: 7328162
    Abstract: The present invention proposes a new method and apparatus for the enhancement of source coding systems. The invention employs bandwidth reduction (101) prior to or in the encoder (103), followed by spectral-band replication (105) at the decoder (107). This is accomplished by the use of new transposition methods, in combination with spectral envelope adjustments. Reduced bitrate at a given perceptual quality or an improved perceptual quality at a given bitrate is offered. The invention is preferably integrated in a hardware or software codec, but can also be implemented as a separate processor in combination with a codec. The invention offers substantial improvements practically independent of codec type and technological progress.
    Type: Grant
    Filed: October 9, 2003
    Date of Patent: February 5, 2008
    Assignee: Coding Technologies AB
    Inventors: Lars Gustaf Liljeryd, Per Rune Albin Ekstrand, Lars Fredrik Henn, Hans Magnus Kristofer Kjörling
  • Publication number: 20080015868
    Abstract: 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: Application
    Filed: September 26, 2007
    Publication date: January 17, 2008
    Inventors: Kristofer KJORLING, Lars Villemoes
  • Publication number: 20080010061
    Abstract: 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: Application
    Filed: September 21, 2007
    Publication date: January 10, 2008
    Inventors: Kristofer Kjorling, Lars Villemoes
  • Publication number: 20080002842
    Abstract: On an encoder-side, a multi-channel input signal is analyzed for obtaining smoothing control information, which is to be used by a decoder-side multi-channel synthesis for smoothing quantized transmitted parameters or values derived from the quantized transmitted parameters for providing an improved subjective audio quality in particular for slowly moving point sources and rapidly moving point sources having tonal material such as fast moving sinusoids.
    Type: Application
    Filed: August 25, 2005
    Publication date: January 3, 2008
    Inventors: Matthias Neusinger, Jurgen Herre, Sascha Disch, Heiko Purnhagen, Kristofer Kjorling, Jonas Engdegard, Jeroen Breebaart, Erik Schuijers, Werner Oomen
  • Patent number: 7283955
    Abstract: The present invention proposes a new method and apparatus for the enhancement of source coding systems. The invention employs bandwidth reduction (101) prior to or in the encoder (103), followed by spectral-band replication (105) at the decoder (107). This is accomplished by the use of new transposition methods, in combination with spectral envelope adjustments. Reduced bitrate at a given perceptual quality or an improved perceptual quality at a given bitrate is offered. The invention is preferably integrated in a hardware or software codec, but can also be implemented as a separate processor in combination with a codec. The invention offers substantial improvements practically independent f codec type and technological progress.
    Type: Grant
    Filed: October 10, 2003
    Date of Patent: October 16, 2007
    Assignee: Coding Technologies AB
    Inventors: Lars Gustaf Liljeryd, Per Rune Albin Ekstrand, Lars Fredrik Henn, Hans Magnus Kristofer Kjorling
  • Patent number: 7260520
    Abstract: The present invention relates to a new method for enhancement of source coding systems using high-frequency reconstruction. The invention teaches that tonal signals can be classified as either pulse-train-like or non-pulse-train-like. Relying on this classification, significant improvements on the perceived audio quality can be obtained by adaptive switching of transposers. The invention shows that the so-switched transposers must have fundamental differences in their characteristics.
    Type: Grant
    Filed: December 20, 2001
    Date of Patent: August 21, 2007
    Assignee: Coding Technologies AB
    Inventors: Fredrik Henn, Kristofer Kjörling, Per Ekstrand, Lars Villemoes
  • Patent number: 7191121
    Abstract: The present invention provides a new method and an apparatus for spectral envelope encoding. The invention teaches how to perform and signal compactly a time/frequency mapping of the envelope representation, and further, encode the spectral envelope data efficiently using adaptive time/frequency directional coding. The method is applicable to both natural audio coding and speech coding systems and is especially suited for coders using SBR [WO 98/57436] or other high frequency reconstruction methods.
    Type: Grant
    Filed: October 11, 2005
    Date of Patent: March 13, 2007
    Assignee: Coding Technologies Sweden AB
    Inventors: Lars Gustaf Liljeryd, Kristofer Kjörling, Per Ekstrand, Fredrik Henn
  • Patent number: 7181389
    Abstract: The present invention provides a new method and an apparatus for spectral envelope encoding. The invention teaches how to perform and signal compactly a time/frequency mapping of the envelope representation, and further, encode the spectral envelope data efficiently using adaptive time/frequency directional coding. The method is applicable to both natural audio coding and speech coding systems and is especially suited for coders using SBR [WO 98/57436] or other high frequency reconstruction methods.
    Type: Grant
    Filed: October 11, 2005
    Date of Patent: February 20, 2007
    Assignee: Coding Technologies AB
    Inventors: Lars Gustaf Liljeryd, Kristofer Kjörling, Per Ekstrand, Fredrik Henn
  • Publication number: 20060239473
    Abstract: The envelope of a decorrelated signal derived from an original signal can be shaped without introducing additional distortion, when a spectral flattener is used to spectrally flatten the spectrum of the decorrelated signal and the original signal prior to using the flattened spectra for deriving a gain factor describing the energy distribution between the flattened spectra, and when the so derived gain factor is used by an envelope shaper to timely shape the envelope of the decorrelated signal.
    Type: Application
    Filed: April 12, 2006
    Publication date: October 26, 2006
    Inventors: Kristofer Kjorling, Jurgen Herre, Sascha Disch, Lars Villemoes
  • Publication number: 20060233380
    Abstract: A parametric representation of a multi-channel audio signal describes the spatial properties of the audio signal well with compact side information when a coherence information, describing the coherence between a first and a second channel, is derived within a hierarchical encoding process only for channel pairs including a first channel having only information of a left side with respect to a listening position and including a second channel having only information from a right side with respect to a listening position. As within the hierarchical process the multiple audio channels of the audio signal are downmixed iteratively into monophonic channels, one can pick the relevant parameters from an encoding step involving only channel pairs carrying the information needed to describe the spatial properties of the multi-channel audio signal.
    Type: Application
    Filed: December 21, 2005
    Publication date: October 19, 2006
    Inventors: Andreas Holzer, Jurgen Herre, Heiko Purnhagen, Kristofer Kjorling, Jonas Roden, Lars Villemoes, Jonas Engdegard, Jeroen Breebaart, Erik Schuijers, Werner Oomen
  • Patent number: 7003451
    Abstract: The present invention proposes a new method and a new apparatus for enhancement of audio source coding systems utilizing high frequency reconstruction (HFR). It utilizes adaptive filtering to reduce artifacts due to different tonal characteristics in different frequency ranges of an audio signal upon which HFR is performed. Tie present invention is applicable to both speech coding and natural audio coding systems.
    Type: Grant
    Filed: November 14, 2001
    Date of Patent: February 21, 2006
    Assignee: Coding Technologies AB
    Inventors: Kristofer Kjörling, Per Ekstrand, Fredrik Henn, Lars Villemoes
  • Publication number: 20060036432
    Abstract: 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 adaptive filtering to reduce artifacts due to different tonal characteristics in different frequency ranges of an audio signal upon which HFR is performed. The present invention is applicable to both speech coding and natural audio coding systems.
    Type: Application
    Filed: October 12, 2005
    Publication date: February 16, 2006
    Inventors: Kristofer Kjorling, Per Ekstrand, Fredrik Henn, Lars Villemoes
  • Publication number: 20060031065
    Abstract: The present invention provides a new method and an apparatus for spectral envelope encoding. The invention teaches how to perform and signal compactly a time/frequency mapping of the envelope representation, and further, encode the spectral envelope data efficiently using adaptive time/frequency directional coding. The method is applicable to both natural audio coding and speech coding systems and is especially suited for coders using SBR [WO 98/57436] or other high frequency reconstruction methods.
    Type: Application
    Filed: October 11, 2005
    Publication date: February 9, 2006
    Inventors: Lars Liljeryd, Kristofer Kjorling, Per Ekstrand, Fredrik Henn
  • Publication number: 20060031064
    Abstract: The present invention provides a new method and an apparatus for spectral envelope encoding. The invention teaches how to perform and signal compactly a time/frequency mapping of the envelope representation, and further, encode the spectral envelope data efficiently using adaptive time/frequency directional coding. The method is applicable to both natural audio coding and speech coding systems and is especially suited for coders using SBR [WO 98/57436] or other high frequency reconstruction methods.
    Type: Application
    Filed: October 11, 2005
    Publication date: February 9, 2006
    Inventors: Lars Liljeryd, Kristofer Kjorling, Per Ekstrand, Fredrik Henn
  • Publication number: 20060029231
    Abstract: The present invention provides improvements to prior art audio codecs that generate a stereo-illusion through post-processing of a received mono signal. These improvements are accomplished by extraction of stereo-image describing parameters at the encoder side, which are transmitted and subsequently used for control of a stereo generator at the decoder side. Furthermore, the invention bridges the gap between simple pseudo-stereo methods, and current methods of true stereo-coding, by using a new form of parametric stereo coding. A stereo-balance parameter is introduced, which enables more advanced stereo modes, and in addition forms the basis of a new method of stereo-coding of spectral envelopes, of particular use in systems where guided HFR (High Frequency Reconstruction) is employed. As a special case, the application of this stereo-coding scheme in scalable HFR-based codecs is described.
    Type: Application
    Filed: September 27, 2005
    Publication date: February 9, 2006
    Inventors: Fredrik Henn, Kristofer Kjorling, Lars Liljeryd, Jonas Roden, Jonas Engdegard
  • Publication number: 20060023895
    Abstract: The present invention provides improvements to prior art audio codecs that generate a stereo-illusion through post-processing of a received mono signal. These improvements are accomplished by extraction of stereo-image describing parameters at the encoder side, which are transmitted and subsequently used for control of a stereo generator at the decoder side. Furthermore, the invention bridges the gap between simple pseudo-stereo methods, and current methods of true stereo-coding, by using a new form of parametric stereo coding. A stereo-balance parameter is introduced, which enables more advanced stereo modes, and in addition forms the basis of a new method of stereo-coding of spectral envelopes, of particular use in systems where guided HFR (High Frequency Reconstruction) is employed. As a special case, the application of this stereo-coding scheme in scalable HFR-based codecs is described.
    Type: Application
    Filed: September 27, 2005
    Publication date: February 2, 2006
    Inventors: Fredrik Henn, Kristofer Kjorling, Lars Liljeryd, Jonas Roden, Jonas Engdegard