mediaLib Library Functions mlib_SignalLPC2LSP_F32(3MLIB)
NAME
mlib_SignalLPC2LSP_F32 - convert linear prediction coeffi-
cients to line spectral pair coefficientsSYNOPSIS
cc [ flag... ] file... -lmlib [ library... ]
#include
mlib_status mlib_SignalLPC2LSP_F32(mlib_f32 *lsp, const mlib_f32 *lpc,
mlib_s32 order);
DESCRIPTION
The mlib_SignalLPC2LSP_F32() function converts linear pred-
iction 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 filterM -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 andthey 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.SunOS 5.11 Last change: 2 Mar 2007 1
mediaLib Library Functions mlib_SignalLPC2LSP_F32(3MLIB)
See Fundamentals of Speech Recognition by Lawrence Rabinerand 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 attri-
butes:____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Interface Stability | Committed ||_____________________________|_____________________________|
| MT-Level | MT-Safe |
|_____________________________|_____________________________|
SEE ALSO
mlib_SignalLSP2LPC_F32(3MLIB), attributes(5)
SunOS 5.11 Last change: 2 Mar 2007 2