fix crash when copy'ing latent plugins

[ardour.git] / libs / ardour / kmeterdsp.cc

diff --git a/libs/ardour/kmeterdsp.cc b/libs/ardour/kmeterdsp.cc
index afd0f71719c0397046e5cf793e5ef86243cb6b2a..add026797d263cb3e5f96ef40109cc70ec96c083 100644 (file)
--- a/libs/ardour/kmeterdsp.cc
+++ b/libs/ardour/kmeterdsp.cc
@@ -1,6 +1,6 @@
 /*
     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
@@ -17,12 +17,13 @@
     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),
@@ -36,53 +37,51 @@ Kmeterdsp::~Kmeterdsp (void)
 {
 }
 
+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;
+    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;
 
-    s = sqrtf (2 * z2);
+    s = sqrtf (2.0f * z2);
 
     if (_flag) // Display thread has read the rms value.
     {
@@ -96,7 +95,6 @@ void Kmeterdsp::process (float *p, int n)
     }
 }
 
-
 /* Returns highest _rms value since last call */
 float Kmeterdsp::read ()
 {
@@ -105,15 +103,10 @@ 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: */