mlib_signallpccovariancefree_f32(3mlib) [opensolaris man page]

mlib_SignalLPCCovarianceFree_S16(3MLIB) 		    mediaLib Library Functions			   mlib_SignalLPCCovarianceFree_S16(3MLIB)

NAME

       mlib_SignalLPCCovarianceFree_S16, mlib_SignalLPCCovarianceFree_F32 - clean up for covariance method

SYNOPSIS

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

       void mlib_SignalLPCCovarianceFree_S16(void *state);

       void mlib_SignalLPCCovarianceFree_F32(void *state);

DESCRIPTION

       Each of these functions frees the internal state structure for covariance method of linear predictive coding (LPC).

       This function cleans up the internal state structure and releases all memory buffers.

PARAMETERS

       Each of the functions takes the following arguments:

       state	Pointer to the internal state structure.

RETURN VALUES

       None.

ATTRIBUTES

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

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

SEE ALSO

       mlib_SignalLPCCovarianceInit_S16(3MLIB),  mlib_SignalLPCCovarianceInit_F32(3MLIB),  mlib_SignalLPCCovariance_S16(3MLIB),  mlib_SignalLPCCo-
       variance_S16_Adp(3MLIB), mlib_SignalLPCCovariance_F32(3MLIB), attributes(5)

SunOS 5.11							    2 Mar 2007				   mlib_SignalLPCCovarianceFree_S16(3MLIB)

mlib_SignalLPCCovariance_F32(3MLIB)			    mediaLib Library Functions			       mlib_SignalLPCCovariance_F32(3MLIB)

NAME

       mlib_SignalLPCCovariance_F32 - perform linear predictive coding with covariance method

SYNOPSIS

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

       mlib_status mlib_SignalLPCCovariance_F32(mlib_f32 *coeff,
	    const mlib_f32 *signal, void *state);

DESCRIPTION

       The mlib_SignalLPCCovariance_F32() function performs linear predictive coding with covariance method.

       In linear predictive coding (LPC) model, each speech sample is represented as a linear combination of the past M samples.

		      M
	      s(n) = SUM a(i) * s(n-i) + G * u(n)
		     i=1

       where  s(*)  is the speech signal, u(*) is the excitation signal, and G is the gain constants, M is the order of the linear prediction fil-
       ter. Given s(*), the goal is to find a set of coefficient a(*) that minimizes the prediction error e(*).

			     M
	      e(n) = s(n) - SUM a(i) * s(n-i)
			    i=1

       In covariance method, the coefficients can be obtained by solving following set of linear equations.

	       M
	      SUM a(i) * c(i,k) = c(0,k), k=1,...,M
	      i=1

       where

		       N-k-1
	      c(i,k) =	SUM s(j) * s(j+k-i)
			j=0

       are the covariance coefficients of s(*), N is the length of the input speech vector.

       Note that the covariance matrix R is a symmetric matrix, and the equations can be solved efficiently with Cholesky decomposition method.

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

PARAMETERS

       The function takes the following arguments:

       coeff	 The linear prediction coefficients.

       signal	 The input signal vector.

       state	 Pointer to the internal state structure.

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_SignalLPCCovarianceInit_F32(3MLIB), mlib_SignalLPCCovarianceFree_F32(3MLIB), attributes(5)

SunOS 5.11							    2 Mar 2007				       mlib_SignalLPCCovariance_F32(3MLIB)