/*
Copyright (C) 2008-2011 Fons Adriaensen <fons@linuxaudio.org>
- Adopted for Ardour 2013 by Robin Gareus <robin@gareus.org>
+ Adopted for Ardour 2013 by 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
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
-
#include <math.h>
-#include "kmeterdsp.h"
+#include "ardour/kmeterdsp.h"
+
float Kmeterdsp::_omega;
+
Kmeterdsp::Kmeterdsp (void) :
_z1 (0),
_z2 (0),
{
}
+void Kmeterdsp::init (int fsamp)
+{
+ _omega = 9.72f / fsamp; // ballistic filter coefficient
+}
-void Kmeterdsp::process (float *p, int n)
+void Kmeterdsp::process (float const *p, int n)
{
// Called by JACK's process callback.
//
// p : pointer to sample buffer
// n : number of samples to process
- float s, t, z1, z2;
-
- if (_flag) // Display thread has read the rms value.
- {
- _rms = 0;
- _flag = false;
- }
+ float s, z1, z2;
// Get filter state.
- z1 = _z1;
- z2 = _z2;
-
- // Process n samples. Find digital peak value for this
- // period and perform filtering. The second filter is
- // evaluated only every 4th sample - this is just an
- // optimisation.
- t = 0;
+ z1 = _z1 > 50 ? 50 : (_z1 < 0 ? 0 : _z1);
+ z2 = _z2 > 50 ? 50 : (_z2 < 0 ? 0 : _z2);
+
+ // Perform filtering. The second filter is evaluated
+ // only every 4th sample - this is just an optimisation.
n /= 4; // Loop is unrolled by 4.
while (n--)
{
s = *p++;
s *= s;
- if (t < s) t = s; // Update digital peak.
z1 += _omega * (s - z1); // Update first filter.
s = *p++;
s *= s;
- if (t < s) t = s; // Update digital peak.
z1 += _omega * (s - z1); // Update first filter.
s = *p++;
s *= s;
- if (t < s) t = s; // Update digital peak.
z1 += _omega * (s - z1); // Update first filter.
s = *p++;
s *= s;
- if (t < s) t = s; // Update digital peak.
z1 += _omega * (s - z1); // Update first filter.
z2 += 4 * _omega * (z1 - z2); // Update second filter.
}
- t = sqrtf (t);
+ if (isnan(z1)) z1 = 0;
+ if (isnan(z2)) z2 = 0;
// Save filter state. The added constants avoid denormals.
_z1 = z1 + 1e-20f;
_z2 = z2 + 1e-20f;
- // Adjust RMS value and update maximum since last read().
- s = sqrtf (2 * z2);
- if (s > _rms) _rms = s;
-}
+ s = sqrtf (2.0f * z2);
+ if (_flag) // Display thread has read the rms value.
+ {
+ _rms = s;
+ _flag = false;
+ }
+ else
+ {
+ // Adjust RMS value and update maximum since last read().
+ if (s > _rms) _rms = s;
+ }
+}
/* Returns highest _rms value since last call */
float Kmeterdsp::read ()
return rv;
}
-void Kmeterdsp::init (int fsamp)
-{
- _omega = 9.72f / fsamp; // ballistic filter coefficient
-}
-
void Kmeterdsp::reset ()
{
- _z1 = _z2 = _rms = 0.0;
- _flag=false;
+ _z1 = _z2 = _rms = .0f;
+ _flag = false;
}
-/* vi:set ts=8 sts=8 sw=8: */
+/* vi:set ts=8 sts=8 sw=4: */