You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
44 lines
1.3 KiB
C
44 lines
1.3 KiB
C
3 months ago
|
/**
|
||
|
* aweight.h - Efficient A-weighting algorithm
|
||
|
* Copyright (C) 2024 Clyne Sullivan <clyne@bitgloo.com>
|
||
|
*
|
||
|
* This program is free software: you can redistribute it and/or modify it under
|
||
|
* the terms of the GNU Lesser General Public License as published by the Free
|
||
|
* Software Foundation, either version 3 of the License, or (at your option) any
|
||
|
* later version.
|
||
|
*
|
||
|
* This program is distributed in the hope that it will be useful, but WITHOUT ANY
|
||
|
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
|
||
|
* PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
|
||
|
* details.
|
||
|
*
|
||
|
* You should have received a copy of the GNU Lesser General Public License along
|
||
|
* with this program. If not, see <http://www.gnu.org/licenses/>.
|
||
|
*/
|
||
|
#ifndef AWEIGHT_H
|
||
|
#define AWEIGHT_H
|
||
|
|
||
|
/**
|
||
|
* Applies A-weighting to the given audio sample.
|
||
|
* @param in_div4 The audio sample divided by four
|
||
|
* @return The filtered (A-weighted) sample
|
||
|
*/
|
||
|
inline float process(float in_div4)
|
||
|
{
|
||
|
static float z1 = 0, z2 = 0, z3 = 0, z5 = 0;
|
||
|
|
||
|
float out1 = in_div4 + z1;
|
||
|
z1 = 1.062f * out1 + z2;
|
||
|
z2 = -0.14f * out1 - in_div4;
|
||
|
|
||
|
float out2 = out1 + z3;
|
||
|
z3 = out1;
|
||
|
|
||
|
float out3 = out2 + z5;
|
||
|
z5 = 0.985f * out3 - out2;
|
||
|
|
||
|
return out3;
|
||
|
}
|
||
|
|
||
|
#endif // AWEIGHT_H
|