Content-type: text/html Man page of mlib_SignalLPC2LSP_F32

mlib_SignalLPC2LSP_F32

Section: mediaLib Library Functions (3MLIB)
Updated: 2 Mar 2007
Index Return to Main Contents
 

NAME

mlib_SignalLPC2LSP_F32 - convert linear prediction coefficients to line spectral pair coefficients  

SYNOPSIS

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

mlib_status mlib_SignalLPC2LSP_F32(mlib_f32 *lsp, const mlib_f32 *lpc,
    mlib_s32 order);

 

DESCRIPTION

The mlib_SignalLPC2LSP_F32() 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.

lpc

The linear prediction 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 TYPEATTRIBUTE VALUE

Interface StabilityCommitted

MT-Level

 

SEE ALSO

mlib_SignalLSP2LPC_F32(3MLIB), attributes(5)


 

Index

NAME
SYNOPSIS
DESCRIPTION
PARAMETERS
RETURN VALUES
ATTRIBUTES
SEE ALSO

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Time: 02:38:11 GMT, October 02, 2010