mlib_signallpc2cepstral_s16(3mlib) [opensolaris man page]

mlib_SignalLPC2Cepstral_S16(3MLIB)			    mediaLib Library Functions				mlib_SignalLPC2Cepstral_S16(3MLIB)

NAME

       mlib_SignalLPC2Cepstral_S16 - convert linear prediction coefficients to cepstral coefficients

SYNOPSIS

       cc [ flag... ] file... -lmlib [ library... ]
       #include <mlib.h>

       mlib_status mlib_SignalLPC2Cepstral_S16(mlib_s16 *cepst,
	    mlib_s32 cscale, const mlib_s16 *lpc, mlib_s32 lscale,
	    mlib_s16 gain, mlib_s32 gscale, mlib_s32 length,
	    mlib_s32 order);

DESCRIPTION

       The mlib_SignalLPC2Cepstral_S16() function converts linear prediction coefficients to cepstral coefficients. The user supplied scaling fac-
       tor, cscale, will be used and the output will be saturated if necessary.

       The cepstral coefficients are the coefficients of the Fourier transform representation of the log magnitude spectrum.

       The LPC cepstral coefficients can be derived recursively from the LPC coefficients as following.

	 c(0) = log(G)

		       m-1  k
	 c(m) = a(m) + SUM --- * c(k) * a(m-k), 1 <= m <= M
		       k=1  m

		m-1  k
	 c(m) = SUM --- * c(k) * a(m-k), m > M
		k=1  m

       See Fundamentals of Speech Recognition by Lawrence Rabiner and Biing-Hwang Juang, Prentice Hall, 1993.

PARAMETERS

       The function takes the following arguments:

       cepst	 The cepstral coefficients.

       cscale	 The scaling factor of the cepstral coefficients, where actual_data = output_data * 2**(-scaling_factor).

       lpc	 The linear prediction coefficients.

       lscale	 The scaling factor of the linear prediction coefficients, where actual_data = input_data * 2**(-scaling_factor).

       gain	 The gain of the LPC model.

       gscale	 The scaling factor of the gain of the LPC model, where actual_data = input_data * 2**(-scaling_factor).

       length	 The length of the cepstral coefficients.

       order	 The order of the linear prediction filter.

RETURN VALUES

       The function returns MLIB_SUCCESS if successful. Otherwise it returns MLIB_FAILURE.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Committed 		   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       mlib_SignalLPC2Cepstral_S16(3MLIB), mlib_SignalLPC2Cepstral_S16_Adp(3MLIB), mlib_SignalLPC2Cepstral_F32(3MLIB), attributes(5)

SunOS 5.11							    2 Mar 2007					mlib_SignalLPC2Cepstral_S16(3MLIB)

Check Out this Related Man Page

mlib_SignalLPC2LSP_S16(3MLIB)				    mediaLib Library Functions				     mlib_SignalLPC2LSP_S16(3MLIB)

NAME

       mlib_SignalLPC2LSP_S16 - convert linear prediction coefficients to line spectral pair coefficients

SYNOPSIS

       cc [ flag... ] file... -lmlib [ library... ]
       #include <mlib.h>

       mlib_status mlib_SignalLPC2LSP_S16(mlib_s16 *lsp, const mlib_s16 *lpc, mlib_s32 lscale, mlib_s32 order);

DESCRIPTION

       The mlib_SignalLPC2LSP_S16() function converts linear prediction coefficients to line spectral pair coefficients.

       The line spectral pair (LPS) coefficients are defined as the roots of the following two polynomials:

			   -(M+1)     -1
	    P(z) = A(z) + z	 * A(z	)

			   -(M+1)     -1
	    Q(z) = A(z) - z	 * A(z	)

       where A(z) is the inverse filter

		       M	  -i
	    A(z) = 1- SUM a(i) * z
		      i=1

       Note  that  since P(z) is symmetric and Q(z) is antisymmetric all roots of these polynomials are on the unit circle and they alternate each
       other. P(z) has a root at z = -1 (w = PI) and Q(z) has a root at z = 1 (w = 0).

       The line spectral frequency (LPF) are the angular frequency of the line spectral pair (LPS) coefficients.

	    q = cos(w)

       where q is the LPS and w is the LPF.

       See Fundamentals of Speech Recognition by Lawrence Rabiner and Biing-Hwang Juang, Prentice Hall, 1993.

PARAMETERS

       The function takes the following arguments:

       lsp	       The line spectral pair coefficients in Q15 format.

       lpc	       The linear prediction coefficients.

       lscale	       The scaling factor of the linear prediction coefficients, where actual_data = input_data * 2**(-scaling_factor).

       order	       The order of the linear prediction filter.

RETURN VALUES

       The function returns MLIB_SUCCESS if successful. Otherwise it returns MLIB_FAILURE.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Evolving			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       mlib_SignalLSP2LPC_S16(3MLIB), attributes(5)

SunOS 5.10							    10 Nov 2004 				     mlib_SignalLPC2LSP_S16(3MLIB)

Linux and UNIX Man Pages

mlib_signallpc2cepstral_s16(3mlib) [opensolaris man page]

Check Out this Related Man Page