CuteLogger
Fast and simple logging solution for Qt based applications
iecscale.h
1/*
2 * Copyright (c) 2015 Meltytech, LLC
3 *
4 * This program is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 3 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
16 */
17
18#ifndef IECSCALE_H
19#define IECSCALE_H
20
21//----------------------------------------------------------------------------
22// IEC standard dB scaling -- as borrowed from meterbridge (c) Steve Harris
23
24static inline double IEC_Scale(double dB)
25{
26 double fScale = 1.0f;
27
28 if (dB < -70.0f)
29 fScale = 0.0f;
30 else if (dB < -60.0f)
31 fScale = (dB + 70.0f) * 0.0025f;
32 else if (dB < -50.0f)
33 fScale = (dB + 60.0f) * 0.005f + 0.025f;
34 else if (dB < -40.0)
35 fScale = (dB + 50.0f) * 0.0075f + 0.075f;
36 else if (dB < -30.0f)
37 fScale = (dB + 40.0f) * 0.015f + 0.15f;
38 else if (dB < -20.0f)
39 fScale = (dB + 30.0f) * 0.02f + 0.3f;
40 else if (dB < -0.001f || dB > 0.001f) /* if (dB < 0.0f) */
41 fScale = (dB + 20.0f) * 0.025f + 0.5f;
42
43 return fScale;
44}
45
46static inline double IEC_ScaleMax(double dB, double max)
47{
48 return IEC_Scale(dB) / IEC_Scale(max);
49}
50
51#endif // IECSCALE_H