opensolaris man page for mlib_signallsp2lpc_s16

mlib_SignalLSP2LPC_S16(3MLIB)				    mediaLib Library Functions				     mlib_SignalLSP2LPC_S16(3MLIB)

NAME
       mlib_SignalLSP2LPC_S16, mlib_SignalLSP2LPC_S16_Adp - convert line spectral pair coefficients to linear prediction coefficients

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

       mlib_status mlib_SignalLSP2LPC_S16(mlib_s16 *lpc,
	    mlib_s32 lscale, const mlib_s16 *lsp, mlib_s32 order);

       mlib_status mlib_SignalLSP2LPC_S16_Adp(mlib_s16 *lpc,
	    mlib_s32 *lscale, const mlib_s16 *lsp, mlib_s32 order);

DESCRIPTION
       Each of the functions in this group converts line spectral pair coefficients to linear prediction 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.

       Note for functions with adaptive scaling (with _Adp postfix), the scaling factor of the output data will be calculated based on the  actual
       data;  for functions with non-adaptive scaling (without _Adp postfix), the user supplied scaling factor will be used and the output will be
       saturated if necessary.

PARAMETERS
       Each function takes the following arguments:

       lpc	 The linear prediction coefficients.

       lscale	 The scaling factor of the line spectral pair coefficients, where actual_data = output_data * 2**(-scaling_factor).

       lsp	 The line spectral pair coefficients in Q15 format.

       order	 The order of the linear prediction filter.

RETURN VALUES
       Each 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_SignalLPC2LSP_S16(3MLIB), attributes(5)

SunOS 5.11							    2 Mar 2007					     mlib_SignalLSP2LPC_S16(3MLIB)