linear declick

diff --git a/libs/ardour/amp.cc b/libs/ardour/amp.cc
index cca465a0b466908415253b03b0250a26f6f05fa4..523b538359e097d0417821f7be6ede8a962ccccc 100644 (file)
--- a/libs/ardour/amp.cc
+++ b/libs/ardour/amp.cc
@@ -210,51 +210,39 @@ Amp::apply_gain (BufferSet& bufs, framecnt_t sample_rate, framecnt_t nframes, ga
 void
 Amp::declick (BufferSet& bufs, framecnt_t nframes, int dir)
 {
-       /* Similar to ::apply_gain() but skips MIDI buffers
-        * and use cos() Sigmoid decay with fixed initial+target values.
-        */
-
        if (nframes == 0 || bufs.count().n_total() == 0) {
                return;
        }
 
-       const framecnt_t declick = std::min ((framecnt_t) 128, nframes);
-       gain_t         delta, initial, target;
-       double         fractional_shift = -1.0/(declick-1);
-       double         fractional_pos;
+       const framecnt_t declick = std::min ((framecnt_t) 512, nframes);
+       const double     fractional_shift = 1.0 / declick ;
+       gain_t           delta, initial;
 
        if (dir < 0) {
                /* fade out: remove more and more of delta from initial */
                delta = -1.0;
                 initial = 1.0;
-                target = 0.0;
        } else {
                /* fade in: add more and more of delta from initial */
                delta = 1.0;
                 initial = 0.0;
-                target = 1.0;
        }
 
        /* Audio Gain */
-
        for (BufferSet::audio_iterator i = bufs.audio_begin(); i != bufs.audio_end(); ++i) {
                Sample* const buffer = i->data();
 
-               fractional_pos = 1.0;
+               double fractional_pos = 0.0;
 
                for (pframes_t nx = 0; nx < declick; ++nx) {
-                       buffer[nx] *= (initial + (delta * (0.5 + 0.5 * cos (M_PI * fractional_pos))));
+                       buffer[nx] *= initial + (delta * fractional_pos);
                        fractional_pos += fractional_shift;
                }
 
                /* now ensure the rest of the buffer has the target value applied, if necessary. */
-
                if (declick != nframes) {
-
-                       if (target == 0.0) {
+                       if (dir < 0) {
                                 memset (&buffer[declick], 0, sizeof (Sample) * (nframes - declick));
-                       } else if (target != 1.0) {
-                               apply_gain_to_buffer (&buffer[declick], nframes - declick, target);
                        }
                }
        }