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US5749065A Expired / Lapsed US ⏱️ 0.0 years remaining

Speech encoding method, speech decoding method and speech encoding/decoding method

Assignee: Sony Corp
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Filing: 1995-08-23
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Granted: 1998-05-05
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Expires: 2015-08-23
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Abstract

Abstract A speech encoding/decoding method calculates a short-term prediction error of an input speech signal that is divided on a time axis into blocks, represents the short-term prediction residue by a synthesized sine wave and a noise and encodes a frequency spectrum of each of the synthesized sine wave and the noise to encode the speech signal. The speech encoding/decoding method decodes the speech signal on a block basis and finds a short-term prediction residue waveform by sine wave synthesis and noise synthesis of the encoded speech signal. The speech encoding/decoding method then synthesizes the time-axis waveform signal based on the short-term prediction residue waveform of the encoded speech signal.

Inventors

  • 👤 Masayuki Nishiguchi
  • 👤 Jun Matsumoto

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 11:50
CPC Classifications
G; G10; G10L; G10L19/00; G10L19/04; G10L19/16; G10L19/18; G10L25/00; G10L25/93

Claims Analysis

Total Claims: 44
Claim 1
Independent Claim 95 words
A speech encoding method which divides an input speech signal into blocks on a time axis and encodes the input speech signal on a block basis, the speech encoding method comprising the steps of: finding a short-term prediction residue of the input speech signal; representing the short-term prediction residue by at least a sum of sine waves; and encoding information of a frequency spectrum of the sum of the sine waves, wherein the frequency spectrum is processed by matrix quantization or vector quantization with weighting that takes into account factors relating to human hearing sense.
Claim 2
Dependent Claim 95 words
A speech encoding method which divides an input speech signal into blocks on a time axis and encodes the input speech signal on a block basis, the speech encoding method comprising the steps of: finding a short-term prediction residue of the input speech signal; representing the short-term prediction residue by at least a sum of sine waves; and encoding information of a frequency spectrum of the sum of the sine waves, wherein the frequency spectrum is processed by matrix quantization or vector quantization with weighting that takes into account factors relating to human hearing sense.
Claim 3
Dependent Claim 80 words
The speech encoding method as claimed in claim 1, further comprising the step of discriminating whether the input speech signal is a voiced sound signal or an unvoiced sound signal, wherein a set of parameters for sine wave synthesis is extracted in a portion of the input speech signal found to be voiced and a frequency component of noise is modified in a portion of the input speech signal found to be unvoiced in order to synthesize an unvoiced sound.
Claim 4
Dependent Claim 30 words
The speech encoding method as claimed in claim 2, wherein the step of discriminating between the voiced sound signal and the unvoiced sound signal is done on a block basis.
Claim 5
Dependent Claim 39 words
The speech encoding method as claimed in claim 3, wherein each block contains spectral information divided into bands and the step of discriminating between the voiced sound signal and the unvoiced sound signal is done on a band basis.
Claim 6
Dependent Claim 77 words
The speech encoding method as claimed in claim 1, wherein a linear predictive coding (LPC) residue by linear prediction analysis is used as the short-term prediction residue, and further comprising the step of outputting respective parameters representing LPC coefficients, pitch information representing a basic period of the LPC residue, index information from vector quantization or matrix quantization of a spectral envelope of the LPC residue, and information indicating whether the input speech signal is voiced or unvoiced.
Claim 7
Dependent Claim 36 words
The speech encoding method as claimed in claim 5, wherein for an unvoiced portion of the sound signal, information indicating a characteristic quantity of a LPC residual waveform is output in place of the pitch information.
Claim 8
Dependent Claim 35 words
The speech encoding method as claimed in claim 6, wherein the information indicating the characteristic quantity is an index of a vector indicating a short-term energy sequence of the LPC residual waveform in one block.
Claim 9
Dependent Claim 54 words
The speech encoding method as claimed in claim 2, wherein, depending upon a result of the discrimination step, a codebook for processing by matrix quantization or vector quantization with weighting that takes into account factors relating to human hearing sense is switched between a codebook for voiced sound and a codebook for unvoiced sound.
Claim 10
Dependent Claim 38 words
The speech encoding method as claimed in claim 8, wherein for the weighting that takes into account factors relating to human hearing sense, a weighting coefficient of a past block is used in calculating a current weighting coefficient.
Claim 11
Dependent Claim 71 words
The speech encoding method as claimed in claim 1, wherein a codebook for matrix quantization or vector quantization of the frequency spectrum is one of a codebook for male speech and a codebook for female speech and a switching selection is made between the codebook for male speech and the codebook for female speech depending upon whether the input speech signal is a male speech signal or a female speech signal.
Claim 12
Dependent Claim 73 words
The speech encoding method as claimed in claim 5, wherein a codebook for matrix quantization or vector quantization of the parameter representing the LPC coefficients is one of a codebook for male speech or a codebook for female speech, and a switch is made between the codebook for male speech and the codebook for female speech depending upon whether the input speech signal is a male speech signal or a female speech signal.
Claim 13
Dependent Claim 64 words
The speech encoding method as claimed in claim 10, wherein a pitch of the input speech signal is detected and is discriminated to determine whether the input speech signal is the male speech signal or the female speech signal and, based upon the discrimination of the detected pitch, a switch is made between the codebook for male speech and the codebook for female speech.
Claim 14
Independent Claim 152 words
A method for decoding an encoded speech signal formed using a short-term prediction residue of an input speech signal which is divided on a time axis on a block basis, the short-term prediction residue being represented by a sum of sine waves on the block basis, wherein information of a frequency spectrum of the sum of the sine waves is encoded to form the encoded speech signal to be decoded, the method for decoding comprising the steps of: finding a short-term prediction residual waveform by sine wave synthesis of the encoded speech signal by converting a fixed number of data of the frequency spectrum into a variable number thereof, wherein the encoded speech signal is encoded by matrix quantization or vector quantization with weighting that takes into account factors relating to human hearing sense; and synthesizing a time-axis waveform signal based on the short-term prediction residual waveform of the encoded speech signal.
Claim 15
Independent Claim 152 words
A method for decoding an encoded speech signal formed using a short-term prediction residue of an input speech signal which is divided on a time axis on a block basis, the short-term prediction residue being represented by a sum of sine waves on the block basis, wherein information of a frequency spectrum of the sum of the sine waves is encoded to form the encoded speech signal to be decoded, the method for decoding comprising the steps of: finding a short-term prediction residual waveform by sine wave synthesis of the encoded speech signal by converting a fixed number of data of the frequency spectrum into a variable number thereof, wherein the encoded speech signal is encoded by matrix quantization or vector quantization with weighting that takes into account factors relating to human hearing sense; and synthesizing a time-axis waveform signal based on the short-term prediction residual waveform of the encoded speech signal.
Claim 16
Dependent Claim 78 words
The speech decoding method as claimed in claim 13, wherein a linear predictive coding (LPC) residue by linear prediction analysis is used as the short-term prediction residue, and respective parameters representing LPC coefficients, pitch information representing a basic period of the LPC residue, index information from vector quantization or matrix quantization of a spectral envelope of the LPC residue, and information indicating whether the input speech signal is voiced or unvoiced are included in the encoded speech signal.
Claim 17
Dependent Claim 141 words
A speech encoding/decoding method comprising the steps of: dividing an input speech signal on a time axis into blocks; encoding the input speech signal on a block basis; and decoding the encoded speech signal, wherein the step of encoding comprises sub-steps of finding a short-term prediction residue of the input speech signal, representing the short-term prediction residue by a sum of sine waves, and encoding information of a frequency spectrum of the sum of the sine waves, wherein the frequency spectrum is processed by matrix quantization or vector quantization with weighting that takes into account factors relating to human hearing sense, and the step of decoding comprises sub-steps of finding a short-term prediction residual waveform of the encoded speech signal by sine wave synthesis, synthesizing a time-axis waveform signal based on the short-term prediction residual waveform of the encoded speech signal.
Claim 18
Dependent Claim 141 words
A speech encoding/decoding method comprising the steps of: dividing an input speech signal on a time axis into blocks; encoding the input speech signal on a block basis; and decoding the encoded speech signal, wherein the step of encoding comprises sub-steps of finding a short-term prediction residue of the input speech signal, representing the short-term prediction residue by a sum of sine waves, and encoding information of a frequency spectrum of the sum of the sine waves, wherein the frequency spectrum is processed by matrix quantization or vector quantization with weighting that takes into account factors relating to human hearing sense, and the step of decoding comprises sub-steps of finding a short-term prediction residual waveform of the encoded speech signal by sine wave synthesis, synthesizing a time-axis waveform signal based on the short-term prediction residual waveform of the encoded speech signal.
Claim 19
Dependent Claim 79 words
The speech encoding/decoding method as claimed in claim 15, further comprising the step of discriminating whether the input speech signal is a voiced sound signal or an unvoiced sound signal, wherein a the sum of the sine waves is synthesized in a portion of the input speech signal found to be voiced and a frequency component of noise is modified in a portion of the input speech signal found to be unvoiced in order to synthesize an unvoiced sound.
Claim 20
Dependent Claim 30 words
The speech encoding/decoding method as claimed in claim 16, wherein the step of discriminating between the voiced sound signal and the unvoiced sound signal is done on a block basis.
Claim 21
Dependent Claim 77 words
The speech encoding/decoding method as claimed in claim 15, wherein a linear predictive coding (LPC) residue by linear prediction analysis is used as the short-term prediction residue, and further comprising the step of outputting respective parameters representing LPC coefficients, pitch information representing a basic period of the LPC residue, index information from vector quantization or matrix quantization of a spectral envelope of the LPC residue, and information indicating whether the input speech signal is voiced or unvoiced.
Claim 22
Dependent Claim 33 words
The speech encoding/decoding method as claimed in claim 18, wherein for an unvoiced sound signal information indicating a characteristic quantity of a LPC residual waveform is output in place of the pitch information.
Claim 23
Dependent Claim 35 words
The speech encoding/decoding method as claimed in claim 19, wherein the information indicating the characteristic quantity is an index of a vector indicating a short-term energy sequence of the LPC residual waveform in one block.
Claim 24
Dependent Claim 52 words
The speech encoding/decoding method as claimed in claim 16, wherein, depending upon a result of the discrimination step, a codebook for matrix quantization or vector quantization with weighting that takes into account factors relating to human hearing sense is switched between a codebook for voiced sound and a codebook for unvoiced sound.
Claim 25
Dependent Claim 38 words
The speech encoding/decoding method as claimed in claim 21, wherein for the weighting that takes into account factors relating to human hearing sense a weighting coefficient of a past block is used in calculating a current weighting coefficient.
Claim 26
Dependent Claim 70 words
The speech encoding/decoding method as claimed in claim 15, wherein a codebook for matrix quantization or vector quantization of the frequency spectrum is one of a codebook for male speech and a codebook for female speech, and a switch is made between the codebook for male speech and the codebook for female speech depending upon whether the input speech signal is a male speech signal or a female speech signal.
Claim 27
Dependent Claim 73 words
The speech encoding/decoding method as claimed in claim 18, wherein a codebook for matrix quantization or vector quantization of the parameter specifying the LPC coefficients is one of a codebook for male speech or a codebook for female speech, and a switch is made between the codebook for male speech and the codebook for female speech depending upon whether the input speech signal is a male speech signal or a female speech signal.
Claim 28
Dependent Claim 64 words
The speech encoding/decoding method as claimed in claim 23, wherein a pitch of the input speech signal is detected and is discriminated to determine whether the input speech signal is the male speech signal or the female speech signal and, based upon the discrimination of the detected pitch, a switch is made between the codebook for male speech and the codebook for female speech.
Claim 29
Dependent Claim 96 words
A speech encoding apparatus for dividing an input speech signal into blocks on a time axis and encoding the signal on a block basis, the encoding apparatus comprising: computation means for finding a short-term prediction residue of the input speech signal; analysis means for representing the short-term prediction residue by a sum of sine waves; means for encoding information of a frequency spectrum of the sum of the sine waves: and weighting means for quantizing the frequency spectrum by matrix quantization or vector quantization with weighting that takes into account factors relating to human hearing sense.
Claim 30
Dependent Claim 96 words
A speech encoding apparatus for dividing an input speech signal into blocks on a time axis and encoding the signal on a block basis, the encoding apparatus comprising: computation means for finding a short-term prediction residue of the input speech signal; analysis means for representing the short-term prediction residue by a sum of sine waves; means for encoding information of a frequency spectrum of the sum of the sine waves: and weighting means for quantizing the frequency spectrum by matrix quantization or vector quantization with weighting that takes into account factors relating to human hearing sense.
Claim 31
Dependent Claim 84 words
The speech encoding apparatus as claimed in claim 26, wherein the analysis means includes means for discriminating whether the input speech signal is a voiced sound signal or an unvoiced sound signal, and wherein a set of parameters for sine wave synthesis is extracted by the analysis means in a portion of the speech signal found to be voiced and modifies a frequency component of noise in a portion of the speech signal found to be unvoiced in order to synthesize an unvoiced sound.
Claim 32
Dependent Claim 28 words
The speech encoding apparatus as claimed in claim 27, wherein the discriminating means discriminates between the voiced sound signal and the unvoiced sound signal on a block basis.
Claim 33
Dependent Claim 36 words
The speech encoding apparatus as claimed in claim 28, wherein each block contains spectral information divided into bands and discrimination between the voiced sound signal and the unvoiced sound signal is done on a band basis.
Claim 34
Dependent Claim 79 words
The speech encoding apparatus as claimed in claim 26, wherein the computation means outputs a linear predictive code (LPC) residue by linear prediction analysis as the short-term prediction residue, and wherein the analysis means outputs respective parameters representing LPC coefficients, pitch information representing a basic period of the LPC residue, index information from weighted vector quantization or matrix quantization of a spectral envelope of the LPC residue, and information indicating whether the input speech signal is voiced or unvoiced.
Claim 35
Dependent Claim 37 words
The speech encoding apparatus as claimed in claim 30, wherein for an unvoiced portion of the input speech signal, information indicating a characteristic quantity of an LPC residual waveform is output in place of the pitch information.
Claim 36
Dependent Claim 35 words
The speech encoding apparatus as claimed in claim 31, wherein the information indicating the characteristic quantity is an index of a vector indicating a short-term energy sequence of the LPC residual waveform in one block.
Claim 37
Dependent Claim 64 words
The speech encoding apparatus as claimed in claim 26, wherein a codebook for the matrix quantization or vector quantization with weighting that takes into account factors relating to hearing sense is switched by the weighting means between a codebook for voiced sound and a codebook for unvoiced sound depending upon whether the analysis/synthesis means discriminates the input speech signal to be voiced or unvoiced.
Claim 38
Dependent Claim 27 words
The speech encoding apparatus as claimed in claim 26, wherein the weighting means uses a weighting coefficient of a past block in calculating a current weighting coefficient.
Claim 39
Dependent Claim 70 words
The speech encoding apparatus as claimed in claim 26, wherein a codebook for matrix quantization or vector quantization of the frequency spectrum is one of a codebook for male speech and a codebook for female speech, and a switch is made between the codebook for male speech and the codebook for female speech depending upon whether the input speech signal is a male speech signal or a female speech signal.
Claim 40
Dependent Claim 78 words
The speech encoding apparatus as claimed in claim 26, wherein the weighting means employs a codebook for matrix quantization or vector quantization of the parameter specifying the LPC coefficients, one of a codebook for male speech and a codebook for female speech is used, and a switch is made between the codebook for male speech and the codebook for female speech depending upon whether the input speech signal is a male speech signal or a female speech signal.
Claim 41
Dependent Claim 75 words
The speech encoding apparatus as claimed in claim 36, further comprising detection means for N detecting a pitch of the input speech signal and for determining whether the input speech signal is the male speech signal or the female speech signal, and wherein the weighting means effects a switch between the codebook for male speech and the codebook for female speech based on the pitch of the input speech signal detected by the detection means.
Claim 42
Dependent Claim 147 words
A speech decoding apparatus for decoding an encoded speech signal formed using a short-term prediction residue of an input speech signal divided on a time axis on a block basis, the short-term prediction residue represented by a sum of sine waves on the block basis, wherein information of a frequency spectrum of the sum of the sine waves is encoded to form the encoded speech signal to be decoded, the decoding apparatus comprising: computation means for finding a short-term prediction residual waveform by sine wave synthesis of the encoded speech signal by converting a fixed number of data of the frequency spectrum into a variable number thereof, wherein the encoded speech signal is encoded by matrix quantization or vector quantization with weighting that takes into account factors relating to human hearing sense; and synthesizing means for synthesizing a time-axis waveform signal based on the short-term residual waveform.
Claim 43
Dependent Claim 147 words
A speech decoding apparatus for decoding an encoded speech signal formed using a short-term prediction residue of an input speech signal divided on a time axis on a block basis, the short-term prediction residue represented by a sum of sine waves on the block basis, wherein information of a frequency spectrum of the sum of the sine waves is encoded to form the encoded speech signal to be decoded, the decoding apparatus comprising: computation means for finding a short-term prediction residual waveform by sine wave synthesis of the encoded speech signal by converting a fixed number of data of the frequency spectrum into a variable number thereof, wherein the encoded speech signal is encoded by matrix quantization or vector quantization with weighting that takes into account factors relating to human hearing sense; and synthesizing means for synthesizing a time-axis waveform signal based on the short-term residual waveform.
Claim 44
Dependent Claim 79 words
The speech decoding apparatus as claimed in claim 38, wherein the computation means outputs a linear predictive coding (LPC) residue as the short-term prediction residue, and wherein the synthesizing means employs as the encoded speech signal parameters respectively representing LPC coefficients, pitch information representing a basic period of the LPC residue, index information from vector quantization or matrix quantization of a spectral envelope of the LPC residue and information indicating whether the input speech signal is voice or unvoiced.

References Cited (Backward Citations)

US5293448A Cited
US5293449A Cited
US5226084A Cited
US5488704A Cited
US5473727A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2001-05-04 2001-11-03 2002-05-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-05-04 2005-11-03 2006-05-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-05-04 2009-11-03 2010-05-05 $7700.00 Window Closed / Lapsed

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