Patent US2286413A successfully refreshed from Google Patents.
Patent EP0577488A1 successfully refreshed from Google Patents.
EP0577488A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Speech coding method and apparatus for the same
Assignee: NTT Inc
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Filing: 1993-06-28
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Granted: —
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Expires: 2013-06-28
Abstract
Abstract In a speech coding method of the present invention, initially, a plurality of samples of speech data are analyzed by a linear prediction analysis and thereby prediction coefficients are calculated. Then, the prediction coefficients are quantized, and the quantized prediction coefficients are set in a synthesis filter. Moreover, a pitch period vector is selected from an adaptive codebook in which a plurality of pitch period vector are stored, and the selected pitch period vector is multiplied by a first gain which is obtained, at the same time, with a second gain. In addition, a noise waveform vector is selected from a random codebook in which a plurality of the noise waveform vectors are stored, and is multiplied by a predicted gain and the second gain. Then, the speech vector is synthesized by exciting the synthesis filter with the pitch period vector multiplied by the first gain, and with the noise waveform vector multiplied by the predicted gain and the second gain. Consequently, speech data comprising a plurality of samples are coded as a unit of a frame operation. Furthermore, the predicted gain multiplied by the noise waveform vector which is selected in a subsequent frame operation, is predicted based on the current noise waveform vector which is multiplied by the predicted gain and the second gain at the current frame operation, and also the previous waveform vector which is multiplied by the predicted gain and the second gain in the previous frame operation.
Inventors
- 👤 Moriya Takehiro
- 👤 Kataoka Akitoshi
- 👤 Mano Kazunori
- 👤 Miki Satoshi
- 👤 Omuro Hitoshi
- 👤 Hayashi Shinji
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 04:15
CPC Classifications
G; G10; G10L; G10L19/00; G10L19/04; G10L19/08; G10L19/005; G10L19/06; G10L19/07; G10L19/083; G10L19/12; G10L19/135; G10L2019/0001; G10L2019/0002; G10L2019/0003; G10L2019/0004; G10L2019/0005
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
224 words
A speech coding method for coding speech data comprising a plurality of samples as a unit of a frame operation wherein: the plurality of samples of speech data are analyzed by a linear prediction analysis and thereby prediction coefficients are calculated, and quantized; the quantized prediction coefficients are set in a synthesis filter; the synthetic speech vector is synthesized by exciting the synthesis filter with a pitch period vector which is selected from an adaptive codebook in which a plurality of pitch period vectors are stored, and which is multiplied by a first gain, and with a noise waveform vector which is selected from a random codebook in which a plurality of the noise waveform vectors are stored, and which is multiplied by a second gain; and wherein said method comprises: choosing said first and second gain at the same time; providing a means of multiplying the selected noise waveform vector by a predicted gain; and predicting said predicted gain which is to be multiplied by the noise waveform vector selected in a subsequent frame operation, and is based on the current noise waveform vector which is multiplied by said predicted gain and said second gain in the current frame operation, and on the previous noise waveform vector which is multiplied by said predicted gain and said second gain in the previous frame operation.
Claim 2
Dependent Claim
112 words
A speech coding method in accordance with claim 1 further comprising the steps of: when said prediction coefficients are quantized, representing the resultant quantized parameter vector by the weighted mean of a prospective parameter vector selected from a parameter codebook in which a plurality of the prospective parameter vectors are stored in the current frame operation, and a part of the prospective parameter vector selected from said parameter codebook in the previous frame operation; selecting said prospective parameter vector from said parameter codebook so that the quantization distortion between said quantized parameter vector and an input parameter vector is minimized; and transmitting a vector code corresponding to the selected prospective parameter vector.
Claim 3
Dependent Claim
147 words
A speech coding method in accordance with claim 2 further comprising the steps of: representing said prospective parameter vector by the sum of subparameter vectors which are respectively selected from stages of subparameter codebooks; respectively selecting subparameter vectors from stages of said subparameter codebooks; adding the selected subparameter vectors to obtain the prospective parameter vector in the current frame operation; judging whether or not said prospective parameter vector in the current frame operation is stable; converting said prospective parameter vector into a new prospective parameter vector so that said prospective parameter vector in the current frame operation becomes stable using the fixed rule in the case where said prospective parameter vector in the current frame operation is not stable; selecting the prospective parameter vector from said parameter codebook so that said quantization distortion is minimized; and transmitting a vector code corresponding to the selected prospective parameter vector.
Claim 4
Dependent Claim
94 words
A speech coding method in accordance with claim 1 further comprising the steps of: respectively calculating the correlation value between an input speech vector comprising a plurality of samples of speech data and said synthesis speech vector when said pitch period vector and said noise waveform vector are respectively selected from said adaptive codebook and said noise waveform codebook; and calculating only about the pitch period vector and the noise waveform vector when each of the correlation values is large for a final selection of said pitch period vector and said noise waveform vector.
Claim 5
Dependent Claim
46 words
A speech coding method in accordance with claim 1 further comprising the steps of: comprising said random codebook of a plurality of subrandom codebooks; and representing said noise waveform vector by the sum of a plurality of excitation vectors selected from each of said subrandom codebooks.
Claim 6
Dependent Claim
53 words
A speech coding method in accordance with claim 1 further comprising the steps of: comprising two gain codebooks wherein said first and second gain are respectively stored by a plurality of subgain codebooks; and respectively representing said first and second gain by the sum of the output from each of said subgain codebooks.
Claim 7
Dependent Claim
191 words
A parameter coding method of speech for quantizing a parameter such as spectral envelope information and power information at a unit of a frame operation comprising a plurality of samples of speech data, wherein said method comprises the steps of: in a coding portion, (a) wherein said parameter is quantized, representing the resultant quantized parameter vector by the weighted mean of a prospective parameter vector selected from a parameter codebook in which a plurality of the prospective parameter vectors are stored in the current frame operation and a part of the prospective parameter vector selected from said parameter codebook in the previous frame operation, (b) selecting said prospective parameter vector from said parameter codebook so that a quantization distortion between said quantized parameter vector and an input parameter vector, is minimized, and (c) transmitting a vector code corresponding to the selected prospective parameter vector; and in a decoding portion, (a) calculating the weighted mean of the prospective parameter vector selected from said parameter codebook in the current frame operation corresponding to the transmitted vector code, and the prospective parameter vector in the previous frame operation, and (b) outputting the resultant vector.
Claim 8
Dependent Claim
68 words
A parameter coding method of speech in accordance with claim 7 further comprising the steps of: modifying the prospective parameter vector selected from said parameter codebook at the frame operation preceding the current frame operation, and using the resultant prospective parameter vector as the prospective parameter vector in the previous frame operation in the case where the transmitting error of the code is estimated in a transmission line.
Claim 9
Dependent Claim
54 words
A parameter coding method of speech in accordance with claim 7 further comprising the step of: previously setting the appropriate values as the ratio of said weighted mean for every group of said prospective parameter vectors stored in said parameter codebook, or every prospective parameter vector, or every element of said prospective parameter vector.
Claim 10
Dependent Claim
125 words
A parameter coding method of speech in accordance with claim 7 further comprising the steps of: previously setting a ratio of said weighted mean; in said coding portion, (a) selecting the combination of said ratio and said prospective parameter vector so that said quantization distortion becomes minimized, and (b) transmitting a ratio code corresponding to the selected ratio and a vector code corresponding to the selected prospective parameter vector; and in said decoding portion, (a) calculating the weighted mean of the prospective parameter vector selected from said parameter codebook in the current frame operation corresponding to the transmitted vector code, and the prospective parameter vector in the previous frame operation at the ratio corresponding to the transmitted ratio code, and (b) outputting the resultant vector.
Claim 11
Dependent Claim
275 words
A parameter coding method of speech in accordance with claim 7 further comprising the steps of: in said coding portion, (a) representing said prospective parameter vector by the sum of subparameter vectors respectively selected from stages of subparameter codebooks, (b) respectively selecting subparameter vectors from stages of said subparameter codebooks, (c) adding subparameter vectors selected to obtain the prospective parameter vector in the current frame operation, (d) judging whether or not said prospective parameter vector in the current frame operation is stable, (e) converting said prospective parameter vector into a new prospective parameter vector so that said prospective parameter vector in the current frame operation becomes stable using the fixed rule in the case where said prospective parameter vector in the current frame operation is not stable, (f) selecting the prospective parameter vector from said parameter codebook so that said quantization distortion is minimized, and (g) transmitting a vector code corresponding to the selected prospective parameter vector; and in said decoding portion, (a) respectively selecting subparameter vectors corresponding to the transmitted vector code from stages of said subparameter codebooks, (b) adding selected subparameter vectors to obtain the prospective parameter vector in the current frame operation, (c) judging whether or not said prospective parameter vector in the current frame operation is stable, (d) converting said prospective parameter vector into a new prospective parameter vector so that said prospective parameter vector in the current frame operation becomes stable using the fixed rule in the case where said prospective parameter vector in the current frame operation is not stable, and (e) using the converted prospective parameter vector as a final prospective parameter vector in the current frame operation.
Claim 12
Dependent Claim
165 words
A parameter coding method of speech in accordance with claim 7 further comprising the steps of: in said decoding portion, (a) in the case where the transmission error of the transmitted code in the previous frame operation is detected, lowering the ratio concerning said prospective parameter vector in the previous frame operation, and calculating the weighted mean of the prospective parameter vector selected from said parameter codebook corresponding to the transmitted vector code in the current frame operation, and the prospective parameter vector in the previous frame operation at the lowered ratio, and (b) in the case where the transmission error of the transmitted code in the current frame operation is detected, lowering the ratio concerning said prospective parameter vector in the current frame operation, and calculating the weighted mean of the prospective parameter vector selected from said parameter codebook corresponding to the transmitted vector code in the current frame operation, and the prospective parameter vector in the previous frame operation at the lowered ratio.
Claim 13
Dependent Claim
275 words
A parameter coding method of speech in accordance with claim 7 further comprising the steps of: in said coding portion, (a) representing said prospective parameter vector by the sum of subparameter vectors respectively selected from stages of subparameter codebooks, (b) respectively selecting subparameter vectors from stages of said subparameter codebooks, (c) adding subparameter vectors selected to obtain the prospective parameter vector in the current frame operation, (d) judging whether or not said prospective parameter vector in the current frame operation is stable, (e) converting said prospective parameter vector into a new prospective parameter vector so that said prospective parameter vector in the current frame operation becomes stable using the fixed rule in the case where said prospective parameter vector in the current frame operation is not stable, (f) selecting the prospective parameter vector from said parameter codebook so that said quantization distortion is minimized, and (g) transmitting a vector code corresponding to the selected prospective parameter vector; and in said decoding portion, (a) respectively selecting subparameter vectors corresponding to the transmitted vector code from stages of said subparameter codebooks, (b) adding subparameter vectors selected to obtain the prospective parameter vector in the current frame operation, (c) judging whether or not said prospective parameter vector in the current frame operation is stable, (d) converting said prospective parameter vector into a new prospective parameter vector so that said prospective parameter vector in the current frame operation becomes stable using the fixed rule in the case where said prospective parameter vector in the current frame operation is not stable, and (e) using the converted prospective parameter vector as a final prospective parameter vector in the current frame operation.
Claim 14
Dependent Claim
312 words
A multistage vector quantizing method for selecting the prospective parameter vector from a parameter codebook so that the quantization distortion between the prospective parameter vector and an input parameter vector becomes minimized, a vector code corresponding to the selected prospective parameter vector is transmitted, and wherein said method comprises the steps of: in a coding portion, (a) representing said prospective parameter vector by the sum of subparameter vectors respectively selected from stages of the subparameter codebooks, (b) respectively selecting subparameter vectors from stages of said subparameter codebooks, (c) adding subparameter vectors selected to obtain the prospective parameter vector in the current frame operation, (d) judging whether or not said prospective parameter vector in the current frame operation is stable, (e) converting said prospective parameter vector into a new prospective parameter vector so that said prospective parameter vector in the current frame operation becomes stable using the fixed rule in the case where said prospective parameter vector in the current frame operation is not stable, (f) selecting the prospective parameter vector from said parameter codebook so that said quantization distortion is minimized, and (g) transmitting a vector code corresponding to the selected prospective parameter vector; and in said decoding portion, (a) respectively selecting subparameter vectors corresponding to the transmitted vector code from stages of said subparameter codebooks, (b) adding the selected subparameter vectors to obtain the prospective parameter vector in the current frame operation, (c) judging whether or not said prospective parameter vector in the current frame operation is stable, (d) converting said prospective parameter vector into a new prospective parameter vector so that said prospective parameter vector in the current frame operation becomes stable using the fixed rule in the case where said prospective parameter vector in the current frame operation is not stable, and (e) using the converted prospective parameter vector as final prospective parameter vector in the current frame operation.
Claim 15
Dependent Claim
299 words
A speech coding apparatus for coding speech data comprising a plurality of samples as a unit of a frame operation wherein: the plurality of samples of speech data are analyzed by a linear prediction analysis and thereby prediction coefficients are calculated and quantized; the quantized prediction coefficients are set in a synthesis filter; the synthetic speech vector is synthesized by exciting the synthesis filter with a pitch period vector which is selected from an adaptive codebook in which a plurality of pitch period vectors are stored, and which is multiplied by a first gain, and with a noise waveform vector which is selected from a random codebook in which a plurality of the noise waveform vectors are stored, and which is multiplied by a second gain; and wherein said apparatus comprises: a gain predicting means for multiplying said selected noise waveform vector by a predicted gain; a gain means for multiplying said selected pitch period vector and an output vector derived from said gain predicting means using said first and second gain, respectively, a distortion calculating means for respectively selecting said pitch period vector and said noise waveform vector and setting, at the same time, said first and second gain so that a quantization distortion between an input speech vector comprising a plurality of samples of speech data and said synthesis speech vector is minimized; and a gain adapting means for predicting said predicted gain which is to be multiplied by the noise waveform vector selected in the subsequent frame operation, and is based on the current noise waveform vector which is multiplied by said predicted gain and said second gain at the current frame operation, and on the previous noise waveform vector which is multiplied by said predicted gain and said second gain in the previous frame operation.
Claim 16
Dependent Claim
119 words
A speech coding apparatus in accordance with claim 15 further comprising: a parameter codebook for storing a plurality of prediction parameter vectors, and a vector quantization portion for calculating the weighted mean of the prospective parameter vector selected from said parameter codebook in the current frame operation, and the part of the prospective parameter vector selected from said parameter codebook in the previous frame operation, using the resultant vector as the resultant quantized parameter vector of the quantization of prediction coefficients, selecting said prospective parameter vector from said parameter codebook so that a quantization distortion between said quantized parameter vector and an input parameter vector is minimized, and transmitting a vector code corresponding to the selected prospective parameter vector.
Claim 17
Dependent Claim
143 words
A speech coding apparatus in accordance with claim 16 wherein; said parameter codebook comprising stages of subparameter codebooks in which subparameter vectors are respectively stored; said vector quantization portion respectively selects subparameter vectors from stages of said subparameter codebooks, and adds the selected subparameter vectors to obtain the prospective parameter vector in the current frame operation; judges whether or not said prospective parameter vector in the current frame operation is stable; converts said prospective parameter vector into a new prospective parameter vector so that said prospective parameter vector in the current frame operation becomes stable using the fixed rule in the case where said prospective parameter vector in the current frame operation is not stable; selects the prospective parameter vector from said parameter codebook so that said quantization distortion is minimized; and transmits a vector code corresponding to the selected prospective parameter vector.
Claim 18
Dependent Claim
95 words
A speech coding apparatus in accordance with claim 15 further comprising a preselecting means for respectively calculating the correlation value between an input speech vector comprising a plurality of samples of speech data and said synthesis speech vector, and calculating only about the pitch period vector and the noise waveform vector wherein each of the correlation values is large for a final selection of said pitch period vector and said noise waveform vector when said pitch period vector and said noise waveform vector are respectively selected from said adaptive codebook and said noise waveform codebook.
Claim 19
Dependent Claim
42 words
A speech coding apparatus in accordance with claim 15 wherein said random codebook comprising a plurality of subrandom codebooks, and said noise waveform vector are represented by the sum of a plurality of excitation vectors selected from each of said subrandom codebooks.
Claim 20
Dependent Claim
53 words
A speech coding apparatus in accordance with claim 15 where said first gain and second gain are respectively stored in two gain codebooks, are comprised of a plurality of subgain codebooks, and said first gain and second gain are respectively represented by the sum of the output from each of said subgain codebooks.
Claim 21
Dependent Claim
196 words
A parameter coding apparatus of speech for quantizing a parameter such as spectral envelope information and power information as a unit of a frame operation comprising a plurality of samples of speech data, wherein said apparatus comprises: a coding portion comprising, (a) a parameter codebook for storing a plurality of prediction parameter vectors, and (b) a vector quantization portion for calculating the weighted mean of the prospective parameter vector selected from said parameter codebook in the current frame operation, and the part of the prospective parameter vector selected from said parameter codebook in the previous frame operation, using the resultant vector as the resultant quantized parameter vector of the quantization of prediction coefficients, selecting said prospective parameter vector from said parameter codebook so that a quantization distortion between said quantized parameter vector and an input parameter vector is minimized, and transmitting a vector code corresponding to the selected prospective parameter vector; and a decoding portion for calculating the weighted mean of the prospective parameter vector selected from said parameter codebook in the current frame operation corresponding to the transmitted vector code, and the prospective parameter vector in the previous frame operation, and outputting the resultant vector.
Claim 22
Dependent Claim
70 words
A parameter coding apparatus of speech in accordance with claim 21 wherein said vector quantization portion for modifying the prospective parameter vector selected from said parameter codebook in the frame operation preceding the current frame operation, and for using the resultant prospective parameter vector as the prospective parameter vector in the previous frame operation in the case where the transmitting error of the code is estimated in a transmission line.
Claim 23
Dependent Claim
50 words
A parameter coding apparatus of speech in accordance with claim 21 wherein proper values are previously set as the ratio of said weighted mean of every group of said prospective parameter vectors stored in said parameter codebook, or every prospective parameter vector, or every element of said prospective parameter vector.
Claim 24
Dependent Claim
119 words
A parameter coding apparatus of speech in accordance with claim 21 wherein the ratio of said weighted mean is previously set, and further comprising: setting said coding portion for selecting the combination of said ratio and said prospective parameter vector so that said quantization distortion becomes minimized; transmitting a ratio code corresponding to the selected ratio, a vector code corresponding to the selected prospective parameter vector, said decoding portion for calculating the weighted mean of the prospective parameter vector selected from said parameter codebook in the current frame operation corresponding to the transmitted vector code, and the prospective parameter vector of the previous frame operation at the ratio corresponding to the transmitted ratio code; and outputting the resultant vector.
Claim 25
Dependent Claim
266 words
A parameter coding apparatus of speech in accordance with claim 24 and further comprising: said coding portion for representing said prospective parameter vector by the sum of the subparameter vectors respectively selected from stages of subparameter codebooks, and respectively selecting subparameter vectors from stages of said subparameter codebooks, adding the selected subparameter vectors to obtain the prospective parameter vector in the current frame operation, judging whether or not said prospective parameter vector in the current frame operation is stable, converting said prospective parameter vector into a new prospective parameter vector so that said prospective parameter vector in the current frame operation becomes stable using the fixed rule in the case where said prospective parameter vector in the current frame operation is not stable, selecting the prospective parameter vector from said parameter codebook so that said quantization distortion is minimized, and transmitting a vector code corresponding to the selected prospective parameter vector; and said decoding portion, for respectively selecting subparameter vectors corresponding to the transmitted vector code from stages of said subparameter codebooks, by adding the selected subparameter vectors to obtain the prospective parameter vector in the current frame operation, judging whether or not said prospective parameter vector in the current frame operation is stable, converting said prospective parameter vector into a new prospective parameter vector so that said prospective parameter vector in the current frame operation becomes stable using the fixed rule in the case where said prospective parameter vector in the current frame operation is not stable, and using the converted prospective parameter vector as a final prospective parameter vector in the current frame operation.
Claim 26
Dependent Claim
160 words
A parameter coding apparatus of speech in accordance with claim 21 and further comprising : said decoding portion for lowering the ratio concerning said prospective parameter vector in the previous frame operation; calculating the weighted mean of the prospective parameter vector selected from said parameter codebook corresponding to the transmitted vector code in the current frame operation, and the prospective parameter vector of the previous frame operation at the lowered ratio, in the case where the transmission error of the transmitted code in the previous frame operation is detected; lowering the ratio concerning said prospective parameter vector in the current frame operation; and calculating the weighted mean of the prospective parameter vector selected from said parameter codebook corresponding to the transmitted vector code in the current frame operation, and the prospective parameter vector in the previous frame operation at the lowered ratio in the case where the transmission error of the transmitted code in the current frame operation is detected.
Claim 27
Dependent Claim
265 words
A parameter coding apparatus of speech in accordance with claim 21 and further comprising : said coding portion for representing said prospective parameter vector by the sum of the subparameter vectors respectively selected from stages of subparameter codebooks, respectively selecting subparameter vectors from stages of said subparameter codebooks, adding the selected subparameter vectors to obtain the prospective parameter vector in the current frame operation, judging whether or not said prospective parameter vector in the current frame operation is stable, converting said prospective parameter vector into a new prospective parameter vector so that said prospective parameter vector in the current frame operation becomes stable using the fixed rule in the case where said prospective parameter vector in the current frame operation is not stable, selecting the prospective parameter vector from said parameter codebook so that said quantization distortion is minimized; and transmitting a vector code corresponding to the selected prospective parameter vector; and said decoding portion for respectively selecting subparameter vectors corresponding to the transmitted vector code from stages of said subparameter codebooks, adding the selected subparameter vectors to obtain the prospective parameter vector in the current frame operation, judging whether or not said prospective parameter vector in the current frame operation is stable, converting said prospective parameter vector into a new prospective parameter vector so that said prospective parameter vector in the current frame operation becomes stable using the fixed rule in the case where said prospective parameter vector in the current frame operation is not stable, and using the converted prospective parameter vector as a final prospective parameter vector in the current frame operation.
Claim 28
Dependent Claim
300 words
A multistage vector quantizing apparatus for selecting the prospective parameter vector from a parameter codebook so that the quantization distortion between the prospective parameter vector and an input parameter vector becomes minimized, and transmitting a vector code corresponding to the selected prospective parameter vector, wherein said apparatus comprises: said parameter codebook comprising stages of subparameter codebooks in which subparameter vectors are respectively stored, a coding portion comprising a vector quantization portion for respectively selecting subparameter vectors from stages of said subparameter codebooks, and adding the selected subparameter vectors to obtain the prospective parameter vector in the current frame operation, judging whether or not said prospective parameter vector in the current frame operation is stable, converting said prospective parameter vector into a new prospective parameter vector so that said prospective parameter vector in the current frame operation becomes stable using the fixed rule in the case where said prospective parameter vector in the current frame operation is not stable, selecting the prospective parameter vector from said parameter codebook so that said quantization distortion is minimized, and transmitting a vector code corresponding to the selected prospective parameter vector: and a decoding portion for respectively selecting subparameter vectors corresponding to the transmitted vector code from stages of said subparameter codebooks, adding the selected subparameter vectors to obtain the prospective parameter vector in the current frame operation, judging whether or not said prospective parameter vector in the current frame operation is stable, converting said prospective parameter vector into a new prospective parameter vector so that said prospective parameter vector in the current frame operation becomes stable using the fixed rule in the case where said prospective parameter vector in the current frame operation is not stable, and using the converted prospective parameter vector as a final prospective parameter vector in the current frame operation.
References Cited (Backward Citations)
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