公开(公告)号：US11164589B2

公开(公告)日：2021-11-02

申请号：US16788539

申请日：2020-02-12

申请人： Nippon Telegraph and Telephone Corporation

发明人： Takehiro Moriya ,  Yutaka Kamamoto ,  Noboru Harada

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

摘要： 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.

公开(公告)号：US11074919B2

公开(公告)日：2021-07-27

申请号：US16687176

申请日：2019-11-18

申请人： Nippon Telegraph and Telephone Corporation

发明人： Takehiro Moriya ,  Noboru Harada ,  Yutaka Kamamoto ,  Yusuke Hiwasaki ,  Masahiro Fukui

IPC分类号： G10L19/02 ,  G10L19/008 ,  G10L19/24 ,  G10L19/16 ,  G10L21/038 ,  G10L19/005 ,  G10L19/032 ,  G10L19/00 ,  G10L19/035 ,  G10L19/038

摘要： In encoding, a frequency-domain sample sequence derived from an acoustic signal is divided by a weighted envelope and is then divided by a gain, the result obtained is quantized, and each sample is variable-length encoded. The error between the sample before quantization and the sample after quantization is quantized with information saved in this variable-length encoding. This quantization is performed under a rule that specifies, according to the number of saved bits, samples whose errors are to be quantized. In decoding, variable-length codes in an input sequence of codes are decoded to obtain a frequency-domain sample sequence; an error signal is further decoded under a rule that depends on the number of bits of the variable-length codes; and from the obtained sample sequence, the original sample sequence is obtained according to supplementary information.

公开(公告)号：US11024319B2

公开(公告)日：2021-06-01

申请号：US16687144

申请日：2019-11-18

申请人： Nippon Telegraph and Telephone Corporation

发明人： Takehiro Moriya ,  Noboru Harada ,  Yutaka Kamamoto ,  Yusuke Hiwasaki ,  Masahiro Fukui

IPC分类号： G10L19/008 ,  G10L19/24 ,  G10L19/16 ,  G10L21/038 ,  G10L19/02 ,  G10L19/005 ,  G10L19/032 ,  G10L19/00 ,  G10L19/035 ,  G10L19/038

摘要： In encoding, a frequency-domain sample sequence derived from an acoustic signal is divided by a weighted envelope and is then divided by a gain, the result obtained is quantized, and each sample is variable-length encoded. The error between the sample before quantization and the sample after quantization is quantized with information saved in this variable-length encoding. This quantization is performed under a rule that specifies, according to the number of saved bits, samples whose errors are to be quantized. In decoding, variable-length codes in an input sequence of codes are decoded to obtain a frequency-domain sample sequence; an error signal is further decoded under a rule that depends on the number of bits of the variable-length codes; and from the obtained sample sequence, the original sample sequence is obtained according to supplementary information.

公开(公告)号：US20210098009A1

公开(公告)日：2021-04-01

申请号：US17120462

申请日：2020-12-14

申请人： NIPPON TELEGRAPH AND TELEPHONE CORPORATION

发明人： Yutaka Kamamoto ,  Takehiro Moriya ,  Noboru Harada

IPC分类号： G10L19/06 ,  G10L25/12 ,  G10L19/02 ,  G10L19/032 ,  G10L21/04 ,  G10L25/06 ,  G10L25/18 ,  G10L25/27

摘要： An autocorrelation calculation unit 21 calculates an autocorrelation Ro(i) from an input signal. A prediction coefficient calculation unit 23 performs linear prediction analysis by using a modified autocorrelation R′o(i) obtained by multiplying a coefficient wo(i) by the autocorrelation Ro(i). It is assumed here, for each order i of some orders i at least, that the coefficient wo(i) corresponding to the order i is in a monotonically increasing relationship with an increase in a value that is negatively correlated with a fundamental frequency of the input signal of the current frame or a past frame.

公开(公告)号：US20200090673A1

公开(公告)日：2020-03-19

申请号：US16691764

申请日：2019-11-22

申请人： Nippon Telegraph and Telephone Corporation

发明人： Takehiro Moriya ,  Yutaka Kamamoto ,  Noboru Harada

IPC分类号： G10L19/07 ,  G10L19/06 ,  G10L19/032

摘要： A technology of accurately coding and decoding coefficients which are convertible into linear prediction coefficients even for a frame in which the spectrum variation is great while suppressing an increase in the code amount as a whole is provided. A coding device includes: a first coding unit that obtains a first code by coding coefficients which are convertible into linear prediction coefficients of more than one order; and a second coding unit that obtains a second code by coding at least quantization errors of the first coding unit if (A−1) an index Q commensurate with how high the peak-to-valley height of a spectral envelope is, the spectral envelope corresponding to the coefficients which are convertible into the linear prediction coefficients of more than one order, is larger than or equal to a predetermined threshold value Th1 and/or (B−1) an index Q′ commensurate with how short the peak-to-valley height of the spectral envelope is, is smaller than or equal to a predetermined threshold value Th1′.

公开(公告)号：US20200043506A1

公开(公告)日：2020-02-06

申请号：US16601740

申请日：2019-10-15

申请人： Nippon Telegraph and Telephone Corporation ,  The University of Tokyo

发明人： Takehiro Moriya ,  Yutaka Kamamoto ,  Noboru Harada ,  Hirokazu Kameoka ,  Ryosuke Sugiura

IPC分类号： G10L19/07 ,  G10L19/02 ,  G10L25/12 ,  G10L19/12 ,  G10L25/06

摘要： The present invention reduces encoding distortion in frequency domain encoding compared to conventional techniques, and obtains LSP parameters that correspond to quantized LSP parameters for the preceding frame and are to be used in time domain encoding from coefficients equivalent to linear prediction coefficients resulting from frequency domain encoding. When p is an integer equal to or greater than 1, a linear prediction coefficient sequence which is obtained by linear prediction analysis of audio signals in a predetermined time segment is represented as a[1], a[2], . . . , a[p], and ω[1], ω[2], . . . , ω[p] are a frequency domain parameter sequence derived from the linear prediction coefficient sequence a[1], a[2], . . . , a[p], an LSP linear transformation unit (300) determines the value of each converted frequency domain parameter ˜ω[i] (i=1, 2, . . . , p) in a converted frequency domain parameter sequence ˜ω[1], ˜ω[2], . . . , ˜ω[p] using the frequency domain parameter sequence ω[1], c[2], . . . , ω[p] as input, through linear transformation which is based on the relationship of values between ω[i] and one or more frequency domain parameters adjacent to ω[i].

公开(公告)号：US20190355369A1

公开(公告)日：2019-11-21

申请号：US16527160

申请日：2019-07-31

申请人： Nippon Telegraph and Telephone Corporation

发明人： Takehiro MORIYA ,  Yutaka Kamamoto ,  Noboru Harada

IPC分类号： G10L19/07 ,  G10L19/038

摘要： 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：US20190096414A1

公开(公告)日：2019-03-28

申请号：US16199387

申请日：2018-11-26

申请人： Nippon Telegraph and Telephone Corporation

发明人： Takehiro MORIYA ,  Yutaka KAMAMOTO ,  Noboru Harada

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

摘要： 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.

公开(公告)号：US10199046B2

公开(公告)日：2019-02-05

申请号：US15304733

申请日：2015-02-20

申请人： NIPPON TELEGRAPH AND TELEPHONE CORPORATION

发明人： Takehiro Moriya ,  Yutaka Kamamoto ,  Noboru Harada

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

摘要： An encoder includes 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 includes 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.

公开(公告)号：US10134420B2

公开(公告)日：2018-11-20

申请号：US15889775

申请日：2018-02-06

申请人： NIPPON TELEGRAPH AND TELEPHONE CORPORATION

发明人： Yutaka Kamamoto ,  Takehiro Moriya ,  Noboru Harada

IPC分类号： G10L25/12 ,  G10L25/06 ,  G10L19/06 ,  G10L25/90 ,  G10L25/21

摘要： An autocorrelation calculating part calculates autocorrelation Ro(i) from an input signal. A predictive coefficient calculating part performs linear predictive analysis using modified autocorrelation R′o(i) obtained by multiplying the autocorrelation Ro(i) by a coefficient wo(i). Here, it is assumed that a case where, for at least part of each order i, the coefficient wo(i) corresponding to each order i monotonically increases as a value having negative correlation with a fundamental frequency of an input signal in a current frame or a past frame increases and a case where the coefficient wo(i) monotonically decreases as a value having positive correlation with a pitch gain in a current frame or a past frame increases, are included.