13
0
livetrax/libs/ardour/vumeterdsp.cc

92 lines
1.9 KiB
C++

/*
* Copyright (C) 2012 Fons Adriaensen <fons@linuxaudio.org>
* Copyright (C) 2013 Robin Gareus <robin@gareus.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <math.h>
#include "ardour/vumeterdsp.h"
float Vumeterdsp::_w;
float Vumeterdsp::_g;
Vumeterdsp::Vumeterdsp (void) :
_z1 (0),
_z2 (0),
_m (0),
_res (true)
{
}
Vumeterdsp::~Vumeterdsp (void)
{
}
void Vumeterdsp::process (float const *p, int n)
{
float z1, z2, m, t1, t2;
z1 = _z1 > 20 ? 20 : (_z1 < -20 ? -20 : _z1);
z2 = _z2 > 20 ? 20 : (_z2 < -20 ? -20 : _z2);
m = _res ? 0: _m;
_res = false;
n /= 4;
while (n--)
{
t2 = z2 / 2;
t1 = fabsf (*p++) - t2;
z1 += _w * (t1 - z1);
t1 = fabsf (*p++) - t2;
z1 += _w * (t1 - z1);
t1 = fabsf (*p++) - t2;
z1 += _w * (t1 - z1);
t1 = fabsf (*p++) - t2;
z1 += _w * (t1 - z1);
z2 += 4 * _w * (z1 - z2);
if (z2 > m) m = z2;
}
if (isnan(z1)) z1 = 0;
if (isnan(z2)) z2 = 0;
_z1 = z1;
_z2 = z2 + 1e-10f;
_m = m;
}
float Vumeterdsp::read (void)
{
_res = true;
return _g * _m;
}
void Vumeterdsp::reset ()
{
_z1 = _z2 = _m = .0f;
_res = true;
}
void Vumeterdsp::init (float fsamp)
{
_w = 11.1f / fsamp;
_g = 1.5f * 1.571f;
}