公开(公告)号：US12165659B2

公开(公告)日：2024-12-10

申请号：US17908965

申请日：2021-02-08

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Ryosuke Sugiura ,  Takehiro Moriya ,  Yutaka Kamamoto

IPC: G10L19/008 ,  G10L19/24 ,  H04S1/00 ,  H04S7/00

Abstract: A sound signal downmix method includes an inter-channel relationship information obtaining step of obtaining an inter-channel correlation value and preceding channel information of every pair of two channels included in N channels, the inter-channel correlation value being a value indicating a degree of a correlation between input sound signals of the two channels, the preceding channel information being information indicating which of the input sound signals of the two channels is preceding, and a downmix step of obtaining a downmix signal by weighting and adding the input sound signals of the N channels, the input sound signal of each channel being weighted based on the inter-channel correlation value and the preceding channel information such that the larger a correlation with an input sound signal of a preceding channel that precedes the channel, the smaller a weight, whereas the larger a correlation with an input sound signal of a succeeding channel that succeeds the channel, the larger the weight.

公开(公告)号：US12051430B2

公开(公告)日：2024-07-30

申请号：US18195015

申请日：2023-05-09

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takehiro Moriya ,  Yutaka Kamamoto ,  Noboru Harada

IPC: G10L19/00 ,  G10L19/038 ,  G10L19/07 ,  G10L21/00 ,  G10L19/005

CPC classification number: G10L19/07 ,  G10L19/038 ,  G10L2019/0016 ,  G10L19/005

Abstract: A coding method and a decoding method are provided which can use in combination a predictive coding and decoding method which is a coding and decoding method that can accurately express coefficients which are convertible into linear prediction coefficients with a small code amount and a coding and decoding method that can obtain correctly, by decoding, coefficients which are convertible into linear prediction coefficients of the present frame if a linear prediction coefficient code of the present frame is correctly input to a decoding device. A coding device includes: a predictive coding unit that obtains a first code by coding a differential vector formed of differentials between a vector of coefficients which are convertible into linear prediction coefficients of more than one order of the present frame and a prediction vector containing at least a predicted vector from a past frame, and obtains a quantization differential vector corresponding to the first code; and a non-predictive coding unit that generates a second code by coding a correction vector which is formed of differentials between the vector of the coefficients which are convertible into the linear prediction coefficients of more than one order of the present frame and the quantization differential vector or formed of some of elements of the differentials.

公开(公告)号：US12021549B2

公开(公告)日：2024-06-25

申请号：US17414870

申请日：2019-12-09

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Ryosuke Sugiura ,  Takehiro Moriya ,  Yutaka Kamamoto

IPC: H03M5/00 ,  H03M7/30 ,  H03M7/40

CPC classification number: H03M7/3062 ,  H03M7/4075 ,  H03M7/6005 ,  H03M7/6011 ,  H03M7/30 ,  H03M7/4006

Abstract: Provided is a technique for converting an integer value sequence for encoding/decoding which allows an integer value sequence having a distribution including small values other than a zero value and greatly biased to small values to be encoded with a small average bit number. Provided are: a unary coding unit which subjects an input sequence of non-negative integer values to unary coding to obtain a unary code sequence; a bit reversing unit which replaces a bit value ‘0’ with a bit value ‘1’ and a bit value ‘1’ with a bit value ‘0’ in the bits in the unary code sequence to obtain a replaced code sequence; and a unary decoding unit which subjects the replaced code sequence to unary decoding to obtain a sequence of non-negative integer values.

公开(公告)号：US11848021B2

公开(公告)日：2023-12-19

申请号：US17955980

申请日：2022-09-29

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takehiro Moriya ,  Yutaka Kamamoto ,  Noboru Harada

IPC: G10L19/02 ,  G10L19/06 ,  G10L19/12

CPC classification number: G10L19/06 ,  G10L19/12 ,  G10L19/02 ,  G10L19/0212

Abstract: An envelope sequence is provided that can improve approximation accuracy near peaks caused by the pitch period of an audio signal. A periodic-combined-envelope-sequence generation device according to the present invention takes, as an input audio signal, a time-domain audio digital signal in each frame, which is a predetermined time segment, and generates a periodic combined envelope sequence as an envelope sequence. The periodic-combined-envelope-sequence generation device according to the present invention comprises at least a spectral-envelope-sequence calculating part and a periodic-combined-envelope generating part. The spectral-envelope-sequence calculating part calculates a spectral envelope sequence of the input audio signal on the basis of time-domain linear prediction of the input audio signal. The periodic-combined-envelope generating part transforms an amplitude spectral envelope sequence to a periodic combined envelope sequence on the basis of a periodic component of the input audio signal in the frequency domain.

公开(公告)号：US11837241B2

公开(公告)日：2023-12-05

申请号：US17422692

申请日：2020-01-07

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takehiro Moriya ,  Yutaka Kamamoto ,  Ryosuke Sugiura

IPC: G10L19/008 ,  G10L19/005 ,  H04L65/80 ,  H04L65/70

CPC classification number: G10L19/008 ,  G10L19/005 ,  H04L65/70 ,  H04L65/80

Abstract: A technique is provided that can reduce degradation of the sound quality due to a tandem connection of paired coding and decoding, and can reduce the operation processing amount and the required memory amount of a multipoint control unit. At a terminal of a communication network having a larger communication capacity in multipoint connection between terminals in a plurality of communication networks (e.g., a fixed phone line and a mobile phone line) having different communication capacities, a multichannel coding including a monaural coding scheme of the communication network having the smaller communication capacity is performed on the coding side, whereas decoding of a multichannel-coded code of one point, decoding of a monaural-coded code of one point, or decoding of a monaural-coded code of a plurality of points is performed on the decoding side in accordance with the input code.

公开(公告)号：US11810581B2

公开(公告)日：2023-11-07

申请号：US17422711

申请日：2020-01-07

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takehiro Moriya ,  Yutaka Kamamoto ,  Ryosuke Sugiura

IPC: G10L19/008 ,  G10L19/16 ,  H04M3/56 ,  H04M7/00

CPC classification number: G10L19/008 ,  G10L19/173 ,  H04M3/561 ,  H04M3/568 ,  H04M7/006

Abstract: A technique is provided that can reduce degradation of the sound quality due to a tandem connection of paired coding and decoding, and can reduce the operation processing amount and the required memory amount of a multipoint control unit. In multipoint connection between terminals of a plurality of communication networks (for example, a fixed phone line and a mobile phone line) having different communication capacities, when a multichannel coding including a monaural coding scheme of a communication network having a smaller communication capacity is used in a communication network having a larger communication capacity to transmit sounds of a plurality points to the communication network terminal having the larger communication capacity, control is exercised such that monaural codes of the plurality points are output.

公开(公告)号：US11501782B2

公开(公告)日：2022-11-15

申请号：US17044968

申请日：2019-03-04

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Ryosuke Sugiura ,  Yutaka Kamamoto ,  Takehiro Moriya

IPC: G10L19/00

Abstract: The present invention aims to encode and decode a sequence of integer values by substantially assigning the number of bits of a decimal fraction value per sample. An integer converter 11 selects M selected integer values from L input integer values for a set of the L input integer values and obtains J-value selection information that specifies which of the L input integer values the M selected integer values are. Furthermore, the integer converter 11 obtains one converted integer value by reversibly converting the M selected integer value and an integer value corresponding to the J-value selection information. An integer encoder 12 encodes the converted integer value to obtain a code.

公开(公告)号：US20220343936A1

公开(公告)日：2022-10-27

申请号：US17856221

申请日：2022-07-01

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Ryosuke SUGIURA ,  Yutaka Kamamoto ,  Takehiro Moriya

IPC: G10L21/0388 ,  G10L19/032

Abstract: A decoding apparatus includes: a bandwidth extending part 25 obtaining a decoded extended frequency spectrum sequence by arranging samples based on K samples included in a frequency-domain sample sequence obtained by decoding, on a higher side than the frequency-domain sample sequence; and a fricative sound adjustment releasing part 23 obtaining, if inputted information indicating whether a hissing sound or not indicates being a hissing sound, what is obtained by exchanging all or a part of a low-side frequency sample sequence existing on a lower side than a predetermined frequency in the decoded extended frequency spectrum sequence for all or a part of a high-side frequency sample sequence existing on a higher side than the predetermined frequency in the decoded extended frequency spectrum sequence as an adjusted frequency spectrum sequence, the number of all or the part of the high-side frequency spectrum sequence being the same as the number of all or the part of the low-side frequency spectrum sequence.

公开(公告)号：US11302340B2

公开(公告)日：2022-04-12

申请号：US17053711

申请日：2019-04-23

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yutaka Kamamoto ,  Ryosuke Sugiura ,  Takehiro Moriya

IPC: G10L21/013 ,  G10L21/034 ,  G10L21/0364

Abstract: Provided is pitch enhancement processing having little unnaturalness even in time segments for consonants, and having little unnaturalness to listeners caused by discontinuities even when time segments for consonants and other time segments switch frequently. A pitch emphasis apparatus obtains an output signal by executing pitch enhancement processing on each of time segments of a signal originating from an input audio signal. The pitch emphasis apparatus includes a pitch enhancing unit that carries out the following as the pitch enhancement processing: obtaining an output signal for each of times n in each of the time segments, the output signal being a signal including a signal obtained by adding (1) a signal obtained by multiplying the signal of a time further in the past than the time n by a number of samples T0 corresponding to a pitch period of the time segment for the time n, η-th power of a pitch gain σ0 of the time segment, and a predetermined constant B0, to (2) the signal of the time n, η being a value greater than 1.

公开(公告)号：US11164589B2

公开(公告)日：2021-11-02

申请号：US16788539

申请日：2020-02-12

Applicant: Nippon Telegraph and Telephone Corporation

Inventor： Takehiro Moriya ,  Yutaka Kamamoto ,  Noboru Harada

IPC: G10L19/04 ,  G10L25/90 ,  G10L19/02 ,  G10L19/06 ,  H03M7/40 ,  G10L19/12

Abstract: An encoder and a decoder are provided that are capable of reproducing a frequency-domain envelope sequence that provides high approximation accuracy around peaks caused by the pitch period of an audio signal by using a small amount of code. An encoder of the present invention comprises a periodic-combined-envelope generating part and a variable-length coding part. The periodic-combined-envelope generating part generates a periodic combined envelope sequence which is a frequency-domain sequence based on a spectral envelope sequence which is a frequency-domain sequence corresponding to a linear predictive coefficient code obtained from an input audio signal and on a frequency-domain period. The variable-length coding part encodes a frequency-domain sequence derived from the input audio signal. A decoder of the present invention comprises a periodic-combined-envelope generating part and a variable-length decoding part. The periodic-combined-envelope generating part generates a periodic combined envelope sequence which is a frequency-domain sequence based on a spectral envelope sequence which is a frequency-domain sequence corresponding to a linear predictive coefficient code and on a frequency-domain period. The variable-length decoding part decodes a variable-length code to obtain a frequency-domain sequence.