Patents by Inventor Kei Kikuiri

Kei Kikuiri 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: 10714113
    Abstract: An objective of the present invention is to correct a temporal envelope shape of a decoded signal with a small information volume and to reduce perceptible distortions.
    Type: Grant
    Filed: July 27, 2018
    Date of Patent: July 14, 2020
    Assignee: NTT DOCOMO, INC.
    Inventors: Kei Kikuiri, Atsushi Yamaguchi
  • Publication number: 20200126578
    Abstract: An audio signal transmission device for encoding an audio signal includes an audio encoding unit that encodes an audio signal and a side information encoding unit that calculates and encodes side information from a look-ahead signal. An audio signal receiving device for decoding an audio code and outputting an audio signal includes: an audio code buffer that detects packet loss based on a received state of an audio packet, an audio parameter decoding unit that decodes an audio code when an audio packet is correctly received, a side information decoding unit that decodes a side information code when an audio packet is correctly received, a side information accumulation unit that accumulates side information obtained by decoding a side information code, an audio parameter missing processing unit that outputs an audio parameter upon detection of audio packet loss, and an audio synthesis unit that synthesizes decoded audio from the audio parameter.
    Type: Application
    Filed: December 17, 2019
    Publication date: April 23, 2020
    Applicant: NTT DOCOMO, INC.
    Inventors: Kimitaka Tsutsumi, Kei Kikuiri, Atsushi Yamaguchi
  • Publication number: 20200126576
    Abstract: An audio signal transmission device for encoding an audio signal includes an audio encoding unit that encodes an audio signal and a side information encoding unit that calculates and encodes side information from a look-ahead signal. An audio signal receiving device for decoding an audio code and outputting an audio signal includes: an audio code buffer that detects packet loss based on a received state of an audio packet, an audio parameter decoding unit that decodes an audio code when an audio packet is correctly received, a side information decoding unit that decodes a side information code when an audio packet is correctly received, a side information accumulation unit that accumulates side information obtained by decoding a side information code, an audio parameter missing processing unit that outputs an audio parameter upon detection of audio packet loss, and an audio synthesis unit that synthesizes decoded audio from the audio parameter.
    Type: Application
    Filed: December 17, 2019
    Publication date: April 23, 2020
    Inventors: Kimitaka Tsutsumi, Kei Kikuiri, Atsushi Yamaguchi
  • Publication number: 20200126577
    Abstract: An audio signal transmission device for encoding an audio signal includes an audio encoding unit that encodes an audio signal and a side information encoding unit that calculates and encodes side information from a look-ahead signal. An audio signal receiving device for decoding an audio code and outputting an audio signal includes: an audio code buffer that detects packet loss based on a received state of an audio packet, an audio parameter decoding unit that decodes an audio code when an audio packet is correctly received, a side information decoding unit that decodes a side information code when an audio packet is correctly received, a side information accumulation unit that accumulates side information obtained by decoding a side information code, an audio parameter missing processing unit that outputs an audio parameter upon detection of audio packet loss, and an audio synthesis unit that synthesizes decoded audio from the audio parameter.
    Type: Application
    Filed: December 17, 2019
    Publication date: April 23, 2020
    Inventors: Kimitaka Tsutsumi, Kei Kikuiri, Atsushi Yamaguchi
  • Patent number: 10621999
    Abstract: An audio signal processing device comprises a discontinuity detector configured to determine an occurrence of a discontinuity from a sudden increase of an amplitude of decoded audio obtained by decoding the first audio packet which is received correctly after an occurrence of a packet loss, and a side information encoder configured to encode side information about the discontinuity.
    Type: Grant
    Filed: October 17, 2018
    Date of Patent: April 14, 2020
    Assignee: NTT DOCOMO, INC.
    Inventors: Kimitaka Tsutsumi, Kei Kikuiri, Atsushi Yamaguchi
  • Patent number: 10553231
    Abstract: An audio signal transmission device for encoding an audio signal includes an audio encoding unit that encodes an audio signal and a side information encoding unit that calculates and encodes side information from a look-ahead signal. An audio signal receiving device for decoding an audio code and outputting an audio signal includes: an audio code buffer that detects packet loss based on a received state of an audio packet, an audio parameter decoding unit that decodes an audio code when an audio packet is correctly received, a side information decoding unit that decodes a side information code when an audio packet is correctly received, a side information accumulation unit that accumulates side information obtained by decoding a side information code, an audio parameter missing processing unit that outputs an audio parameter upon detection of audio packet loss, and an audio synthesis unit that synthesizes decoded audio from the audio parameter.
    Type: Grant
    Filed: December 26, 2017
    Date of Patent: February 4, 2020
    Assignee: NTT DOCOMO, INC.
    Inventors: Kimitaka Tsutsumi, Kei Kikuiri, Atsushi Yamaguchi
  • Publication number: 20190355371
    Abstract: The purpose of the present invention is to reduce distortion a frequency band component encoded with a small number of bits in a time domain and improve quality. An audio decoding device (10) decodes an encoded audio signal and outputs the audio signal. A decoding unit (10a) decodes an encoded sequence containing an encoded audio signal and obtains a decoded signal. A selective temporal envelope shaping unit (10b) shapes a temporal envelope of a decoded signal in the frequency band on the basis of decoding related information concerning decoding of the encoded sequence.
    Type: Application
    Filed: July 31, 2019
    Publication date: November 21, 2019
    Applicant: NTT DOCOMO, INC.
    Inventors: Kei Kikuiri, Atsushi Yamaguchi
  • Patent number: 10410647
    Abstract: The purpose of the present invention is to reduce distortion a frequency band component encoded with a small number of bits in a time domain and improve quality. An audio decoding device decodes an encoded audio signal and outputs the audio signal. A decoding unit decodes an encoded sequence containing an encoded audio signal and obtains a decoded signal. A selective temporal envelope shaping unit shapes a temporal envelope of a decoded signal in the frequency band on the basis of decoding related information concerning decoding of the encoded sequence.
    Type: Grant
    Filed: March 20, 2015
    Date of Patent: September 10, 2019
    Assignee: NTT DOCOMO, INC.
    Inventors: Kei Kikuiri, Atsushi Yamaguchi
  • Patent number: 10366696
    Abstract: A linear prediction coefficient of a signal represented in a frequency domain is obtained by performing linear prediction analysis in a frequency direction by using a covariance method or an autocorrelation method. After the filter strength of the obtained linear prediction coefficient is adjusted, filtering may be performed in the frequency direction on the signal by using the adjusted coefficient, whereby the temporal envelope of the signal is shaped. This reduces the occurrence of pre-echo and post-echo and improves the subjective quality of the decoded signal, without significantly increasing the bit rate in a bandwidth extension technique in the frequency domain represented by SBR.
    Type: Grant
    Filed: August 18, 2016
    Date of Patent: July 30, 2019
    Assignee: NTT DOCOMO, INC.
    Inventors: Kosuke Tsujino, Kei Kikuiri, Nobuhiko Naka
  • Publication number: 20190051313
    Abstract: An audio signal processing device comprises a discontinuity detector configured to determine an occurrence of a discontinuity from a sudden increase of an amplitude of decoded audio obtained by decoding the first audio packet which is received correctly after an occurrence of a packet loss, and a discontinuity corrector for correcting the discontinuity of the decoded audio.
    Type: Application
    Filed: October 17, 2018
    Publication date: February 14, 2019
    Inventors: Kimitaka Tsutsumi, Kei Kikuiri, Atsushi Yamaguchi
  • Publication number: 20190019519
    Abstract: An audio packet error concealment system includes an encoding unit for encoding an audio signal consisting of a plurality of frames, and an auxiliary information encoding unit for estimating and encoding auxiliary information about a temporal change of power of the audio signal. The auxiliary information is used in packet loss concealment in decoding of the audio signal. The auxiliary information about the temporal change of power may contain a parameter that functionally approximates a plurality of powers of subframes shorter than one frame, or may contain information about a vector obtained by vector quantization of a plurality of powers of subframes shorter than one frame.
    Type: Application
    Filed: September 20, 2018
    Publication date: January 17, 2019
    Applicant: NTT DOCOMO, INC.
    Inventors: Kimitaka Tsutsumi, Kei Kikuiri
  • Patent number: 10152982
    Abstract: An audio signal processing device comprises a discontinuity detector configured to determine an occurrence of a discontinuity from a sudden increase of an amplitude of decoded audio obtained by decoding the first audio packet which is received correctly after an occurrence of a packet loss, and a discontinuity corrector for correcting the discontinuity of the decoded audio.
    Type: Grant
    Filed: September 15, 2017
    Date of Patent: December 11, 2018
    Assignee: NTT DOCOMO, INC.
    Inventors: Kimitaka Tsutsumi, Kei Kikuiri, Atsushi Yamaguchi
  • Publication number: 20180336909
    Abstract: An objective of the present invention is to correct a temporal envelope shape of a decoded signal with a small information volume and to reduce perceptible distortions.
    Type: Application
    Filed: August 7, 2018
    Publication date: November 22, 2018
    Applicant: NTT DOCOMO, INC.
    Inventors: Kei Kikuiri, Atsushi Yamaguchi
  • Patent number: 10115402
    Abstract: An audio packet error concealment system includes an encoding unit for encoding an audio signal consisting of a plurality of frames, and an auxiliary information encoding unit for estimating and encoding auxiliary information about a temporal change of power of the audio signal. The auxiliary information is used in packet loss concealment in decoding of the audio signal. The auxiliary information about the temporal change of power may contain a parameter that functionally approximates a plurality of powers of subframes shorter than one frame, or may contain information about a vector obtained by vector quantization of a plurality of powers of subframes shorter than one frame.
    Type: Grant
    Filed: October 20, 2016
    Date of Patent: October 30, 2018
    Assignee: NTT DOCOMO, INC.
    Inventors: Kimitaka Tsutsumi, Kei Kikuiri
  • Patent number: 10068584
    Abstract: An objective of the present invention is to correct a temporal envelope shape of a decoded signal with a small information volume and to reduce perceptible distortions.
    Type: Grant
    Filed: June 27, 2017
    Date of Patent: September 4, 2018
    Assignee: NTT DOCOMO, INC.
    Inventors: Kei Kikuiri, Atsushi Yamaguchi
  • Publication number: 20180122394
    Abstract: An audio signal transmission device for encoding an audio signal includes an audio encoding unit that encodes an audio signal and a side information encoding unit that calculates and encodes side information from a look-ahead signal. An audio signal receiving device for decoding an audio code and outputting an audio signal includes: an audio code buffer that detects packet loss based on a received state of an audio packet, an audio parameter decoding unit that decodes an audio code when an audio packet is correctly received, a side information decoding unit that decodes a side information code when an audio packet is correctly received, a side information accumulation unit that accumulates side information obtained by decoding a side information code, an audio parameter missing processing unit that outputs an audio parameter upon detection of audio packet loss, and an audio synthesis unit that synthesizes decoded audio from the audio parameter.
    Type: Application
    Filed: December 26, 2017
    Publication date: May 3, 2018
    Applicant: NTT DOCOMO, INC.
    Inventors: Kimitaka Tsutsumi, Kei Kikuiri, Atsushi Yamaguchi
  • Publication number: 20180068669
    Abstract: An audio signal processing device comprises a discontinuity detector configured to determine an occurrence of a discontinuity from a sudden increase of an amplitude of decoded audio obtained by decoding the first audio packet which is received correctly after an occurrence of a packet loss, and a discontinuity corrector for correcting the discontinuity of the decoded audio.
    Type: Application
    Filed: September 15, 2017
    Publication date: March 8, 2018
    Applicant: NTT DOCOMO, INC.
    Inventors: Kimitaka Tsutsumi, Kei Kikuiri, Atsushi Yamaguchi
  • Patent number: 9881627
    Abstract: An audio signal transmission device for encoding an audio signal includes an audio encoding unit that encodes an audio signal and a side information encoding unit that calculates and encodes side information from a look-ahead signal. An audio signal receiving device for decoding an audio code and outputting an audio signal includes: an audio code buffer that detects packet loss based on a received state of an audio packet, an audio parameter decoding unit that decodes an audio code when an audio packet is correctly received, a side information decoding unit that decodes a side information code when an audio packet is correctly received, a side information accumulation unit that accumulates side information obtained by decoding a side information code, an audio parameter missing processing unit that outputs an audio parameter upon detection of audio packet loss, and an audio synthesis unit that synthesizes decoded audio from the audio parameter.
    Type: Grant
    Filed: December 20, 2016
    Date of Patent: January 30, 2018
    Assignee: NTT DoCoMo, Inc.
    Inventors: Kimitaka Tsutsumi, Kei Kikuiri, Atsushi Yamaguchi
  • Patent number: 9799344
    Abstract: An audio signal processing device comprises a discontinuity detector configured to determine an occurrence of a discontinuity from a sudden increase of an amplitude of decoded audio obtained by decoding the first audio packet which is received correctly after an occurrence of a packet loss, and a discontinuity corrector for correcting the discontinuity of the decoded audio.
    Type: Grant
    Filed: April 28, 2016
    Date of Patent: October 24, 2017
    Assignee: NTT DoCoMo, Inc.
    Inventors: Kimitaka Tsutsumi, Kei Kikuiri, Atsushi Yamaguchi
  • Publication number: 20170301363
    Abstract: An objective of the present invention is to correct a temporal envelope shape of a decoded signal with a small information volume and to reduce perceptible distortions.
    Type: Application
    Filed: June 27, 2017
    Publication date: October 19, 2017
    Inventors: Kei Kikuiri, Atsushi Yamaguchi