1mlib_SignalLPC2LSP_F32(3MLImBe)diaLib Library Functiomnlsib_SignalLPC2LSP_F32(3MLIB)
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NAME

6       mlib_SignalLPC2LSP_F32 - convert linear prediction coefficients to line
7       spectral pair coefficients
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SYNOPSIS

10       cc [ flag... ] file... -lmlib [ library... ]
11       #include <mlib.h>
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13       mlib_status mlib_SignalLPC2LSP_F32(mlib_f32 *lsp, const mlib_f32 *lpc,
14            mlib_s32 order);
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DESCRIPTION

18       The mlib_SignalLPC2LSP_F32() function converts linear prediction  coef‐
19       ficients to line spectral pair coefficients.
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22       The  line  spectral pair (LPS) coefficients are defined as the roots of
23       the following two polynomials:
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25                             -(M+1)     -1
26              P(z) = A(z) + z      * A(z  )
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28                             -(M+1)     -1
29              Q(z) = A(z) - z      * A(z  )
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33       where A(z) is the inverse filter
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35                         M          -i
36              A(z) = 1- SUM a(i) * z
37                        i=1
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41       Note that since P(z) is symmetric and Q(z) is antisymmetric  all  roots
42       of  these  polynomials  are  on the unit circle and they alternate each
43       other. P(z) has a root at z = -1 (w = PI) and Q(z) has a root at z =  1
44       (w = 0).
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47       The line spectral frequency (LPF) are the angular frequency of the line
48       spectral pair (LPS) coefficients.
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50              q = cos(w)
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54       where q is the LPS and w is the LPF.
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57       See Fundamentals of Speech Recognition by Lawrence Rabiner  and  Biing-
58       Hwang Juang, Prentice Hall, 1993.
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PARAMETERS

61       The function takes the following arguments:
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63       lsp      The line spectral pair coefficients.
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66       lpc      The linear prediction coefficients.
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69       order    The order of the linear prediction filter.
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RETURN VALUES

73       The  function  returns MLIB_SUCCESS if successful. Otherwise it returns
74       MLIB_FAILURE.
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ATTRIBUTES

77       See attributes(5) for descriptions of the following attributes:
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82       ┌─────────────────────────────┬─────────────────────────────┐
83       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
84       ├─────────────────────────────┼─────────────────────────────┤
85       │Interface Stability          │Committed                    │
86       ├─────────────────────────────┼─────────────────────────────┤
87       │MT-Level                     │MT-Safe                      │
88       └─────────────────────────────┴─────────────────────────────┘
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SEE ALSO

91       mlib_SignalLSP2LPC_F32(3MLIB), attributes(5)
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95SunOS 5.11                        2 Mar 2007     mlib_SignalLPC2LSP_F32(3MLIB)
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