13
0
livetrax/libs/ardour/mtdm.cc
Paul Davis 0e0c15833e new MTDM implementation from Fons' latest jack_delay implementation
git-svn-id: svn://localhost/ardour2/branches/3.0@13394 d708f5d6-7413-0410-9779-e7cbd77b26cf
2012-11-07 17:13:37 +00:00

126 lines
2.7 KiB
C++

/*
Copyright (C) 2003-2012 Fons Adriaensen <fons@kokkinizita.net>
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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <math.h>
#include "ardour/mtdm.h"
MTDM::MTDM (int fsamp)
: _cnt (0)
, _inv (0)
{
int i;
Freq *F;
_freq [0].f = 4096;
_freq [1].f = 2048;
_freq [2].f = 3072;
_freq [3].f = 2560;
_freq [4].f = 2304;
_freq [5].f = 2176;
_freq [6].f = 1088;
_freq [7].f = 1312;
_freq [8].f = 1552;
_freq [9].f = 1800;
_freq [10].f = 3332;
_freq [11].f = 3586;
_freq [12].f = 3841;
_wlp = 200.0f / fsamp;
for (i = 0, F = _freq; i < 13; i++, F++)
{
F->p = 128;
F->xa = F->ya = 0.0f;
F->x1 = F->y1 = 0.0f;
F->x2 = F->y2 = 0.0f;
}
}
int MTDM::process (size_t len, float *ip, float *op)
{
int i;
float vip, vop, a, c, s;
Freq *F;
while (len--)
{
vop = 0.0f;
vip = *ip++;
for (i = 0, F = _freq; i < 13; i++, F++)
{
a = 2 * (float) M_PI * (F->p & 65535) / 65536.0;
F->p += F->f;
c = cosf (a);
s = -sinf (a);
vop += (i ? 0.01f : 0.20f) * s;
F->xa += s * vip;
F->ya += c * vip;
}
*op++ = vop;
if (++_cnt == 16)
{
for (i = 0, F = _freq; i < 13; i++, F++)
{
F->x1 += _wlp * (F->xa - F->x1 + 1e-20);
F->y1 += _wlp * (F->ya - F->y1 + 1e-20);
F->x2 += _wlp * (F->x1 - F->x2 + 1e-20);
F->y2 += _wlp * (F->y1 - F->y2 + 1e-20);
F->xa = F->ya = 0.0f;
}
_cnt = 0;
}
}
return 0;
}
int MTDM::resolve (void)
{
int i, k, m;
double d, e, f0, p;
Freq *F = _freq;
if (hypot (F->x2, F->y2) < 0.001) return -1;
d = atan2 (F->y2, F->x2) / (2 * M_PI);
if (_inv) d += 0.5;
if (d > 0.5) d -= 1.0;
f0 = _freq [0].f;
m = 1;
_err = 0.0;
for (i = 0; i < 12; i++)
{
F++;
p = atan2 (F->y2, F->x2) / (2 * M_PI) - d * F->f / f0;
if (_inv) p += 0.5;
p -= floor (p);
p *= 2;
k = (int)(floor (p + 0.5));
e = fabs (p - k);
if (e > _err) _err = e;
if (e > 0.4) return 1;
d += m * (k & 1);
m *= 2;
}
_del = 16 * d;
return 0;
}