1mlib_SignalLPC2LSP_S16(3MLImBe)diaLib Library Functiomnlsib_SignalLPC2LSP_S16(3MLIB)
2
3
4

NAME

6       mlib_SignalLPC2LSP_S16 - convert linear prediction coefficients to line
7       spectral pair coefficients
8

SYNOPSIS

10       cc [ flag... ] file... -lmlib [ library... ]
11       #include <mlib.h>
12
13       mlib_status mlib_SignalLPC2LSP_S16(mlib_s16 *lsp, const mlib_s16 *lpc,
14            mlib_s32 lscale, mlib_s32 order);
15
16

DESCRIPTION

18       The mlib_SignalLPC2LSP_S16() function converts linear prediction  coef‐
19       ficients to line spectral pair coefficients.
20
21
22       The  line  spectral pair (LPS) coefficients are defined as the roots of
23       the following two polynomials:
24
25                             -(M+1)     -1
26              P(z) = A(z) + z      * A(z  )
27
28                             -(M+1)     -1
29              Q(z) = A(z) - z      * A(z  )
30
31
32
33       where A(z) is the inverse filter
34
35                         M          -i
36              A(z) = 1- SUM a(i) * z
37                        i=1
38
39
40
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).
45
46
47       The line spectral frequency (LPF) are the angular frequency of the line
48       spectral pair (LPS) coefficients.
49
50              q = cos(w)
51
52
53
54       where q is the LPS and w is the LPF.
55
56
57       See Fundamentals of Speech Recognition by Lawrence Rabiner  and  Biing-
58       Hwang Juang, Prentice Hall, 1993.
59

PARAMETERS

61       The function takes the following arguments:
62
63       lsp       The line spectral pair coefficients in Q15 format.
64
65
66       lpc       The linear prediction coefficients.
67
68
69       lscale    The  scaling  factor  of  the linear prediction coefficients,
70                 where actual_data = input_data * 2**(-scaling_factor).
71
72
73       order     The order of the linear prediction filter.
74
75

RETURN VALUES

77       The function returns MLIB_SUCCESS if successful. Otherwise  it  returns
78       MLIB_FAILURE.
79

ATTRIBUTES

81       See attributes(5) for descriptions of the following attributes:
82
83
84
85
86       ┌─────────────────────────────┬─────────────────────────────┐
87       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
88       ├─────────────────────────────┼─────────────────────────────┤
89       │Interface Stability          │Committed                    │
90       ├─────────────────────────────┼─────────────────────────────┤
91       │MT-Level                     │MT-Safe                      │
92       └─────────────────────────────┴─────────────────────────────┘
93

SEE ALSO

95       mlib_SignalLSP2LPC_S16(3MLIB), attributes(5)
96
97
98
99SunOS 5.11                        2 Mar 2007     mlib_SignalLPC2LSP_S16(3MLIB)
Impressum