1mlib_SignalLSP2LPC_S16(3MLImBe)diaLib Library Functiomnlsib_SignalLSP2LPC_S16(3MLIB)
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NAME

6       mlib_SignalLSP2LPC_S16, mlib_SignalLSP2LPC_S16_Adp - convert line spec‐
7       tral pair coefficients to linear prediction coefficients
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SYNOPSIS

10       cc [ flag... ] file... -lmlib [ library... ]
11       #include <mlib.h>
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13       mlib_status mlib_SignalLSP2LPC_S16(mlib_s16 *lpc,
14            mlib_s32 lscale, const mlib_s16 *lsp, mlib_s32 order);
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17       mlib_status mlib_SignalLSP2LPC_S16_Adp(mlib_s16 *lpc,
18            mlib_s32 *lscale, const mlib_s16 *lsp, mlib_s32 order);
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20

DESCRIPTION

22       Each of the functions in this group converts line spectral pair coeffi‐
23       cients to linear prediction coefficients.
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26       The  line  spectral pair (LPS) coefficients are defined as the roots of
27       the following two polynomials:
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29                             -(M+1)     -1
30              P(z) = A(z) + z      * A(z  )
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32                             -(M+1)     -1
33              Q(z) = A(z) - z      * A(z  )
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35
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37       where A(z) is the inverse filter
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39                         M          -i
40              A(z) = 1- SUM a(i) * z
41                        i=1
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45       Note that since P(z) is symmetric and Q(z) is antisymmetric  all  roots
46       of  these  polynomials  are  on the unit circle and they alternate each
47       other. P(z) has a root at z = -1 (w = PI) and Q(z) has a root at z =  1
48       (w = 0).
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51       The line spectral frequency (LPF) are the angular frequency of the line
52       spectral pair (LPS) coefficients.
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54              q = cos(w)
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58       where q is the LPS and w is the LPF.
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61       See Fundamentals of Speech Recognition by Lawrence Rabiner  and  Biing-
62       Hwang Juang, Prentice Hall, 1993.
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65       Note for functions with adaptive scaling (with _Adp postfix), the scal‐
66       ing factor of the output data will be calculated based  on  the  actual
67       data;  for  functions with non-adaptive scaling (without _Adp postfix),
68       the user supplied scaling factor will be used and the  output  will  be
69       saturated if necessary.
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PARAMETERS

72       Each function takes the following arguments:
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74       lpc       The linear prediction coefficients.
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77       lscale    The  scaling  factor  of the line spectral pair coefficients,
78                 where actual_data = output_data * 2**(-scaling_factor).
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81       lsp       The line spectral pair coefficients in Q15 format.
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84       order     The order of the linear prediction filter.
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RETURN VALUES

88       Each function returns MLIB_SUCCESS if successful. Otherwise it  returns
89       MLIB_FAILURE.
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ATTRIBUTES

92       See attributes(5) for descriptions of the following attributes:
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96
97       ┌─────────────────────────────┬─────────────────────────────┐
98       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
99       ├─────────────────────────────┼─────────────────────────────┤
100       │Interface Stability          │Committed                    │
101       ├─────────────────────────────┼─────────────────────────────┤
102       │MT-Level                     │MT-Safe                      │
103       └─────────────────────────────┴─────────────────────────────┘
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SEE ALSO

106       mlib_SignalLPC2LSP_S16(3MLIB), attributes(5)
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110SunOS 5.11                        2 Mar 2007     mlib_SignalLSP2LPC_S16(3MLIB)
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