Imported Upstream version 3.2.2

[debian/gnuradio] / gnuradio-core / src / lib / general / gr_peak_detector2_fb.cc

diff --git a/gnuradio-core/src/lib/general/gr_peak_detector2_fb.cc b/gnuradio-core/src/lib/general/gr_peak_detector2_fb.cc
new file mode 100644 (file)
index 0000000..4f927bf
--- /dev/null
+++ b/gnuradio-core/src/lib/general/gr_peak_detector2_fb.cc
@@ -0,0 +1,107 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2007 Free Software Foundation, Inc.
+ * 
+ * This file is part of GNU Radio
+ * 
+ * GNU Radio 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 3, or (at your option)
+ * any later version.
+ * 
+ * GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gr_peak_detector2_fb.h>
+#include <gr_io_signature.h>
+#include <string.h>
+
+gr_peak_detector2_fb_sptr
+gr_make_peak_detector2_fb (float threshold_factor_rise,
+                          int look_ahead, float alpha)
+{
+  return gr_peak_detector2_fb_sptr (new gr_peak_detector2_fb (threshold_factor_rise, 
+                                 look_ahead, alpha));
+}
+
+gr_peak_detector2_fb::gr_peak_detector2_fb (float threshold_factor_rise, 
+                                           int look_ahead, float alpha)
+  : gr_sync_block ("peak_detector2_fb",
+                  gr_make_io_signature (1, 1, sizeof(float)),
+                  gr_make_io_signature2 (1, 2, sizeof(char), sizeof(float))),
+    d_threshold_factor_rise(threshold_factor_rise), 
+    d_look_ahead(look_ahead), d_alpha(alpha), d_avg(0.0f), d_found(false)
+{
+}
+
+int
+gr_peak_detector2_fb::work (int noutput_items,
+                           gr_vector_const_void_star &input_items,
+                           gr_vector_void_star &output_items) {
+  float *iptr = (float *) input_items[0];
+  char *optr = (char *) output_items[0];
+  
+  assert(noutput_items >= 2);
+
+  memset(optr, 0, noutput_items*sizeof(char));
+
+  for (int i = 0; i < noutput_items; i++) {
+
+    if (!d_found) {
+      // Have not yet detected presence of peak
+      if (iptr[i] > d_avg * (1.0f + d_threshold_factor_rise)) {
+       d_found = true;
+       d_look_ahead_remaining = d_look_ahead;
+        d_peak_val = -(float)INFINITY;
+      } 
+      else {
+       d_avg = d_alpha*iptr[i] + (1.0f - d_alpha)*d_avg;
+      }
+    } 
+    else {
+      // Detected presence of peak
+      if (iptr[i] > d_peak_val) {
+        d_peak_val = iptr[i];
+        d_peak_ind = i;
+      } 
+      else if (d_look_ahead_remaining <= 0) {
+        optr[d_peak_ind] = 1;
+        d_found = false;
+        d_avg = iptr[i];
+      }
+      
+      // Have not yet located peak, loop and keep searching.
+      d_look_ahead_remaining--;
+    }
+    
+    // Every iteration of the loop, write debugging signal out if
+    // connected:
+    if (output_items.size() == 2) {
+      float *sigout = (float *) output_items[1];
+      sigout[i] = d_avg;
+    }
+  } // loop
+  
+  if (!d_found) 
+    return noutput_items;
+  
+  // else if detected presence, keep searching during the next call to work.
+  int tmp = d_peak_ind;
+  d_peak_ind = 1;
+  
+  return tmp - 1; 
+}
+
+