# mlib_signallpc2lsp_f32(3mlib) [sunos man page]

```mlib_SignalLPC2LSP_F32(3MLIB)				    mediaLib Library Functions				     mlib_SignalLPC2LSP_F32(3MLIB)

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

SEE ALSO
mlib_SignalLSP2LPC_F32(3MLIB), attributes(5)

SunOS 5.10							    10 Nov 2004 				     mlib_SignalLPC2LSP_F32(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)```
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