Programmer Guide/Command Reference/EVAL/lpc - Revision history

Jw at 08:11, 2 May 2018

2018-05-02T08:11:19Z

← Older revision		Revision as of 10:11, 2 May 2018
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	Compute the linear prediction coefficients using the autocorrelation method. This function implements an all-pole filter approximation of the acoustic tube modell of the vocal tract. The implementation is based on the book "Linear Prediction of Speech" (J.D. Markel & A.H. Gray, Springer 1976).		Compute the linear prediction coefficients using the autocorrelation method. This function implements an all-pole filter approximation of the acoustic tube modell of the vocal tract. The implementation is based on the book "Linear Prediction of Speech" (J.D. Markel & A.H. Gray, Springer 1976).
	;Usage:<code>lpc(<var>x</var>, <var>m</var>, <var>p</var> {, <var>type</var> {, <var>lfft</var>}})</code>		;Usage:<code>lpc(<var>x</var>, <var>m</var>, <var>p</var> {, <var>type</var> {, <var>lfft</var>}})</code>
	:;<var>x</var>:the signal vector; this should be a speech signal without windowing function (because the hamming-window is applied to ''x'' by this ~~the~~ function)		:;<var>x</var>:the signal vector; this should be a speech signal without windowing function (because the hamming-window is applied to ''x'' by this function)
	:;<var>m</var>:number of coefficients		:;<var>m</var>:number of coefficients
	::rule of thumb: ''m'' ~ samplingrate / 1000 * 1.25		::rule of thumb: ''m'' ~ samplingrate / 1000 * 1.25

Christian at 18:15, 21 April 2011

2011-04-21T18:15:38Z

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	\|-		\|-
	\|'''1'''		\|'''1'''
	\|<code>''y''[0]=''alpha''</code><BR><code>''y''[1..M+1]=''ai[0..''m'']		\|<code>''y''[0]=''alpha''</code><BR><code>''y''[1..M+1]=''ai[0..''m'']</code>
	\|''m''+2		\|''m''+2
	\|the error energy (''alpha'') and the ''m''+1 inverse filter coefficients ''ai''		\|the error energy (''alpha'') and the ''m''+1 inverse filter coefficients ''ai''
	\|-		\|-
	\|'''2'''		\|'''2'''
	\|<code>''y''[0]=''alpha''</code><BR><code>''y''[1..M]=''rc[0..''m''-1]		\|<code>''y''[0]=''alpha''</code><BR><code>''y''[1..M]=''rc[0..''m''-1]</code>
	\|''m''+1		\|''m''+1
	\|the error energy (''alpha'') and the ''m'' reflection coefficients ''rc''		\|the error energy (''alpha'') and the ''m'' reflection coefficients ''rc''
	\|-		\|-
	\|'''3'''		\|'''3'''
	\|<code>''y''[0]=''alpha''</code><BR><code>''y''[1..M+1]=''ar[0..''m'']		\|<code>''y''[0]=''alpha''</code><BR><code>''y''[1..M+1]=''ar[0..''m'']</code>
	\|''m''+2		\|''m''+2
	\|the error energy (''alpha'') and the ''m'' area coefficients ''ar''<BR>(''ar''[i] ~ area of section i)		\|the error energy (''alpha'') and the ''m'' area coefficients ''ar''<BR>(''ar''[i] ~ area of section i)
	\|-		\|-
	\|'''4'''		\|'''4'''
	\|<code>''y''[0]=''alpha''</code><BR><code>''y''[1..M+1]=''lar[0..''m'']		\|<code>''y''[0]=''alpha''</code><BR><code>''y''[1..M+1]=''lar[0..''m'']</code>
	\|''m''+2		\|''m''+2
	\|the error energy (''alpha'') and the ''m'' log. area coefficients ''lar''<BR>(''lar''[i] ~ diameter of section i)		\|the error energy (''alpha'') and the ''m'' log. area coefficients ''lar''<BR>(''lar''[i] ~ diameter of section i)

Christian at 18:14, 21 April 2011

2011-04-21T18:14:29Z

← Older revision		Revision as of 20:14, 21 April 2011
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	:;<var>m</var>:number of coefficients		:;<var>m</var>:number of coefficients
	::rule of thumb: ''m'' ~ samplingrate / 1000 * 1.25		::rule of thumb: ''m'' ~ samplingrate / 1000 * 1.25
	:;<var>p</var>:differentiation factor; 0 <= ''p'' <= 1 (default=0)		:;<var>p</var>:differentiation factor; 0 ≤ ''p'' ≤ 1 (default=0)
	:;<var>type</var>:output selector; 0 <= ''type'' <= 4 (default=0)		:;<var>type</var>:output selector; 0 ≤ ''type'' ≤ 4 (default=0)
	:;<var>lfft</var>:the length of the fft to be used for the computation of the transfer function (amplitude spectrum) of the inverse filter; ''m+1'' < ''lfft''		:;<var>lfft</var>:the length of the fft to be used for the computation of the transfer function (amplitude spectrum) of the inverse filter; ''m+1'' < ''lfft''
	::note: if necessary, the value of ''lfft'' is automatically corrected to the next possible value		::note: if necessary, the value of ''lfft'' is automatically corrected to the next possible value

193.171.195.48 at 10:17, 21 April 2011

2011-04-21T10:17:16Z

← Older revision		Revision as of 12:17, 21 April 2011
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	\|the error energy (''alpha'') and the ''m'' log. area coefficients ''lar''<BR>(''lar''[i] ~ diameter of section i)		\|the error energy (''alpha'') and the ''m'' log. area coefficients ''lar''<BR>(''lar''[i] ~ diameter of section i)
	\|}		\|}
	;See also: [[~~Programmer_Guide/Command_Reference/EVAL~~/fft\|fft]], [[~~Programmer_Guide/Command_Reference/EVAL~~/ifft\|ifft]], [[~~Programmer_Guide/Command_Reference/EVAL~~/dft\|dft]], [[~~Programmer_Guide/Command_Reference/EVAL~~/dct\|dct]], [[~~Programmer_Guide/Command_Reference/EVAL~~/cepstrum\|cepstrum~~]], [[Programmer_Guide/Command_Reference/EVAL/complex arithmetic\|complex arithmetic~~]]		;See also: [[../fft\|fft]], [[../ifft\|ifft]], [[../dft\|dft]], [[../dct\|dct]], [[../cepstrum\|cepstrum]]

	[[~~Programmer_Guide~~/~~Command_Reference/EVAL~~#Functions\|<function list>]]		[[../#Functions\|<function list>]]

Toni at 13:30, 12 April 2011

2011-04-12T13:30:00Z

← Older revision		Revision as of 15:30, 12 April 2011
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	\|}		\|}
	;See also: [[Programmer_Guide/Command_Reference/EVAL/fft\|fft]], [[Programmer_Guide/Command_Reference/EVAL/ifft\|ifft]], [[Programmer_Guide/Command_Reference/EVAL/dft\|dft]], [[Programmer_Guide/Command_Reference/EVAL/dct\|dct]], [[Programmer_Guide/Command_Reference/EVAL/cepstrum\|cepstrum]], [[Programmer_Guide/Command_Reference/EVAL/complex arithmetic\|complex arithmetic]]		;See also: [[Programmer_Guide/Command_Reference/EVAL/fft\|fft]], [[Programmer_Guide/Command_Reference/EVAL/ifft\|ifft]], [[Programmer_Guide/Command_Reference/EVAL/dft\|dft]], [[Programmer_Guide/Command_Reference/EVAL/dct\|dct]], [[Programmer_Guide/Command_Reference/EVAL/cepstrum\|cepstrum]], [[Programmer_Guide/Command_Reference/EVAL/complex arithmetic\|complex arithmetic]]

			[[Programmer_Guide/Command_Reference/EVAL#Functions\|<function list>]]

Toni at 13:21, 12 April 2011

2011-04-12T13:21:07Z

← Older revision		Revision as of 15:21, 12 April 2011
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	::note: if necessary, the value of ''lfft'' is automatically corrected to the next possible value		::note: if necessary, the value of ''lfft'' is automatically corrected to the next possible value
	;Description:		;Description:
	:# apply differentiation to signal ''x''		# apply differentiation to signal ''x''
	:# apply hamming window to signal ''x''		# apply hamming window to signal ''x''
	:# use the autocorelation method to compute the inverse filter coefficients ''ai'', the reflection coefficients ''rc'' and the error (or residual) energy ''alpha''		# use the autocorelation method to compute the inverse filter coefficients ''ai'', the reflection coefficients ''rc'' and the error (or residual) energy ''alpha''
	:# convert coefficients to the selected result		# convert coefficients to the selected result
	;Result:A vector ''y'' containing the result of the function.		;Result:A vector ''y'' containing the result of the function.
	:{\|class="einrahmen"		:{\|class="einrahmen"

Toni at 13:20, 12 April 2011

2011-04-12T13:20:44Z

← Older revision		Revision as of 15:20, 12 April 2011
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	:;<var>type</var>:output selector; 0 <= ''type'' <= 4 (default=0)		:;<var>type</var>:output selector; 0 <= ''type'' <= 4 (default=0)
	:;<var>lfft</var>:the length of the fft to be used for the computation of the transfer function (amplitude spectrum) of the inverse filter; ''m+1'' < ''lfft''		:;<var>lfft</var>:the length of the fft to be used for the computation of the transfer function (amplitude spectrum) of the inverse filter; ''m+1'' < ''lfft''
	:note: if necessary, the value of ''lfft'' is automatically corrected to the next possible value		::note: if necessary, the value of ''lfft'' is automatically corrected to the next possible value
	;Description:		;Description:
	:# apply differentiation to signal ''x''		:# apply differentiation to signal ''x''

Toni at 13:20, 12 April 2011

2011-04-12T13:20:35Z

← Older revision		Revision as of 15:20, 12 April 2011
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	:;<var>type</var>:output selector; 0 <= ''type'' <= 4 (default=0)		:;<var>type</var>:output selector; 0 <= ''type'' <= 4 (default=0)
	:;<var>lfft</var>:the length of the fft to be used for the computation of the transfer function (amplitude spectrum) of the inverse filter; ''m+1'' < ''lfft''		:;<var>lfft</var>:the length of the fft to be used for the computation of the transfer function (amplitude spectrum) of the inverse filter; ''m+1'' < ''lfft''
			:note: if necessary, the value of ''lfft'' is automatically corrected to the next possible value
	;Description:		;Description:
	:# apply differentiation to signal ''x''		:# apply differentiation to signal ''x''

Toni at 13:19, 12 April 2011

2011-04-12T13:19:44Z

← Older revision		Revision as of 15:19, 12 April 2011
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	Compute the linear prediction coefficients using the autocorrelation method. This function implements an all-pole filter approximation of the acoustic tube modell of the vocal tract. The implementation is based on the book "Linear Prediction of Speech" (J.D. Markel & A.H. Gray, Springer 1976).		Compute the linear prediction coefficients using the autocorrelation method. This function implements an all-pole filter approximation of the acoustic tube modell of the vocal tract. The implementation is based on the book "Linear Prediction of Speech" (J.D. Markel & A.H. Gray, Springer 1976).
	;Usage:<code>lpc(<var>x</var>, <var>m</var>, <var>p</var> {, <var>type</var> {, <var>lfft</var>}})</code>		;Usage:<code>lpc(<var>x</var>, <var>m</var>, <var>p</var> {, <var>type</var> {, <var>lfft</var>}})</code>
	:;<var>x</var>the signal vector; this should be a speech signal without windowing function (because the hamming-window is applied to ''x'' by this the function)		:;<var>x</var>:the signal vector; this should be a speech signal without windowing function (because the hamming-window is applied to ''x'' by this the function)
	:;<var>m</var>:number of coefficients		:;<var>m</var>:number of coefficients
	::rule of thumb: ''m'' ~ samplingrate / 1000 * 1.25		::rule of thumb: ''m'' ~ samplingrate / 1000 * 1.25
	:;<var>p</var>differentiation factor; 0 <= ''p'' <= 1 (default=0)		:;<var>p</var>:differentiation factor; 0 <= ''p'' <= 1 (default=0)
	:;<var>type</var>:output selector; 0 <= ''type'' <= 4 (default=0)		:;<var>type</var>:output selector; 0 <= ''type'' <= 4 (default=0)
	:;<var>lfft</var>:the length of the fft to be used for the computation of the transfer function (amplitude spectrum) of the inverse filter; ''m+1'' < ''lfft''		:;<var>lfft</var>:the length of the fft to be used for the computation of the transfer function (amplitude spectrum) of the inverse filter; ''m+1'' < ''lfft''

Toni at 13:19, 12 April 2011

2011-04-12T13:19:08Z

← Older revision		Revision as of 15:19, 12 April 2011
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	{{DISPLAYTITLE:{{SUBPAGENAME}}}}		{{DISPLAYTITLE:{{SUBPAGENAME}}}}
	Compute the linear prediction coefficients using the autocorrelation method ("Linear Prediction of Speech", Markel & Gray).		Compute the linear prediction coefficients using the autocorrelation method. This function implements an all-pole filter approximation of the acoustic tube modell of the vocal tract. The implementation is based on the book "Linear Prediction of Speech" (J.D. Markel & A.H. Gray, Springer 1976).
	;Usage:<code>lpc(<var>x</var>, <var>m</var>, <var>p</var> {, <var>type</var> {, <var>lfft</var>}})</code>		;Usage:<code>lpc(<var>x</var>, <var>m</var>, <var>p</var> {, <var>type</var> {, <var>lfft</var>}})</code>
	:;<var>x</var>the signal vector; this should be a speech signal without windowing function (because the hamming-window is applied to ''x'' by this the function)		:;<var>x</var>the signal vector; this should be a speech signal without windowing function (because the hamming-window is applied to ''x'' by this the function)
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	:# use the autocorelation method to compute the inverse filter coefficients ''ai'', the reflection coefficients ''rc'' and the error (or residual) energy ''alpha''		:# use the autocorelation method to compute the inverse filter coefficients ''ai'', the reflection coefficients ''rc'' and the error (or residual) energy ''alpha''
	:# convert coefficients to the selected result		:# convert coefficients to the selected result
	:This function implements an all-pole filter approximation of the acoustic tube modell of the vocal tract. The implementation is based on the book "Linear Prediction of Speech" (J.D. Markel & A.H. Gray, Springer 1976).
	;Result:A vector ''y'' containing the result of the function.		;Result:A vector ''y'' containing the result of the function.
	:{\|class="einrahmen"		:{\|class="einrahmen"