X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=libs%2Fardour%2Fkmeterdsp.cc;h=add026797d263cb3e5f96ef40109cc70ec96c083;hb=c7ff67004a51ae3f0453531c3d64bd9876f1df3b;hp=d4460f94cb8fe843fb886d7c8c1e07e3def3c272;hpb=bd2ddc09ab3091c7a57d814751c88eea0838c553;p=ardour.git

diff --git a/libs/ardour/kmeterdsp.cc b/libs/ardour/kmeterdsp.cc
index d4460f94cb..add026797d 100644
--- a/libs/ardour/kmeterdsp.cc
+++ b/libs/ardour/kmeterdsp.cc
@@ -42,52 +42,46 @@ 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.
     {