1mlib_SignalLPCPitchAnalyze_mFe3d2i(a3LMiLbIBL)ibrarymlFiubn_cStiigonnaslLPCPitchAnalyze_F32(3MLIB)
2
3
4

NAME

6       mlib_SignalLPCPitchAnalyze_F32 - perform open-loop pitch analysis
7

SYNOPSIS

9       cc [ flag... ] file... -lmlib [ library... ]
10       #include <mlib.h>
11
12       mlib_status mlib_SignalLPCPitchAnalyze_F32(mlib_s32 *pitch,
13            const mlib_f32 *sigwgt, const mlib_s32 *region,
14            mlib_s32 length);
15
16

DESCRIPTION

18       The  mlib_SignalLPCPitchAnalyze_F32() function performs open-loop pitch
19       analysis.
20
21
22       The open-loop pitch analysis uses perceptual  weighted  signal  and  is
23       done with following steps.
24
25
26       In the first step, three maxima of the correlation
27
28                     N-1
29              R(k) = SUM sw(j) * sw(j-k)
30                     j=0
31
32
33
34       where N = length, is located for each of the three search regions.
35
36
37       In  the  second step, the retained maxima R(Ti), i=0,1,2 are normalized
38       as following.
39
40                                R(Ti)
41              Rn(ti) = ---------------------, i=0,1,2
42                             N-1         2
43                        SQRT(SUM sw(j-Ti) )
44                             j=0
45
46
47
48       where N = length.
49
50
51       In the third step, the best open-loop delay Topt is determined as  fol‐
52       lowing.
53
54              Topt = T0
55              if (Rn(t1) ≥ (0.85 * Rn(Topt))
56                   Topt = t1
57              if (Rn(t2) ≥ (0.85 * Rn(Topt))
58                   Topt = t2
59
60
61
62       See G.729, G.729A, GSM EFR standards.
63

PARAMETERS

65       The function takes the following arguments:
66
67       pitch     The speech pitch estimated.
68
69
70       sigwgt    The weighted signal vector. sigwgt points to the current sam‐
71                 ple of the weighted signal vector,  length  samples  must  be
72                 availabe  after  this  point,  and MAX{region[i],i=0,1,...,5}
73                 samples must be available before this point.
74
75
76       region    The lower/upper boundaries of the three search regions, where
77                 region[2*i]  is  the  lower  boundary  of search region i and
78                 region[2*i+1] is the upper boundary of search region i.
79
80
81       length    The length of the signal vectors over which  the  correlation
82                 is calculated.
83
84

RETURN VALUES

86       The  function  returns MLIB_SUCCESS if successful. Otherwise it returns
87       MLIB_FAILURE.
88

ATTRIBUTES

90       See attributes(5) for descriptions of the following attributes:
91
92
93
94
95       ┌─────────────────────────────┬─────────────────────────────┐
96       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
97       ├─────────────────────────────┼─────────────────────────────┤
98       │Interface Stability          │Committed                    │
99       ├─────────────────────────────┼─────────────────────────────┤
100       │MT-Level                     │MT-Safe                      │
101       └─────────────────────────────┴─────────────────────────────┘
102

SEE ALSO

104       mlib_SignalLPCPitchAnalyze_S16(3MLIB), attributes(5)
105
106
107
108SunOS 5.11                        2 Mar 20m0l7ib_SignalLPCPitchAnalyze_F32(3MLIB)