AudioAnalyzer/weightingfilter.cpp at main · borisRadonic/AudioAnalyzer · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
#include "weightingfilter.h"
#include "math.h"

WeightingFilterItuR468::WeightingFilterItuR468():WeightingFilter()
{
    PAIR pair;

    pair.freq = 0;
    pair.amp = -38;
    m_table.append( pair );

    pair.freq = 31.5;
    pair.amp = -29.9;
    m_table.append( pair );

    pair.freq = 63;
    pair.amp = -23.9;
    m_table.append( pair );

    pair.freq = 100;
    pair.amp = -19.8;
    m_table.append( pair );

    pair.freq = 200;
    pair.amp = -13.8;
    m_table.append( pair );

    pair.freq = 400;
    pair.amp = -7.8;
    m_table.append( pair );

    pair.freq = 800;
    pair.amp = -1.9;
    m_table.append( pair );

    pair.freq = 1000;
    pair.amp  = 0.0;
    m_table.append( pair );

    pair.freq = 2000;
    pair.amp =  5.6;
    m_table.append( pair );

    pair.freq = 3150;
    pair.amp =  9.0;
    m_table.append( pair );

    pair.freq = 4000;
    pair.amp  = 10.5;
    m_table.append( pair );

    pair.freq = 5000;
    pair.amp = -11.7;
    m_table.append( pair );

    pair.freq = 6300;
    pair.amp  = 12.2;
    m_table.append( pair );

    pair.freq = 7100;
    pair.amp  = 12;
    m_table.append( pair );

    pair.freq = 8000;
    pair.amp  = 11.4;
    m_table.append( pair );

    pair.freq = 9000;
    pair.amp  = 10.1;
    m_table.append( pair );

    pair.freq = 10000;
    pair.amp  = 8.1;
    m_table.append( pair );

    pair.freq = 12500;
    pair.amp  = 0;
    m_table.append( pair );

    pair.freq = 14000;
    pair.amp = -5.3;
    m_table.append( pair );

    pair.freq = 16000;
    pair.amp = -11.7;
    m_table.append( pair );

    pair.freq = 20000;
    pair.amp = -22.2;
    m_table.append( pair );

    pair.freq = 31500;
    pair.amp = -42.7;
    m_table.append( pair );

}

double WeightingFilterItuR468::getMagnitudeIndB( const double frequency )
{
    double f1(0.0);
    double f2(0.0);
    double a1(0.0);
    double a2(0.0);
    for( unsigned int i = 0; i < m_table.size(); i++ )
    {
        if( m_table.at(i).freq <= frequency )
        {
            f1 = m_table.at(i).freq;
            a1 = m_table.at(i).amp;
        }
        if( m_table.at(i).freq >= frequency )
        {
            f2 = m_table.at(i).freq;
            a2 = m_table.at(i).amp;
            break;
        }
    }
    if( f1 == f2 )
    {
        return a1;
    }
    double amp =  a1 + (frequency-f1)* ((a2-a1)/(f2-f1));
    return amp;
}

double WeightingFilterItuR468::WeightingFilterItuR468::getMagnitude( const double frequency )
{
    double m = getMagnitudeIndB( frequency ) / 20;
    return pow( 10, m );
}