Merge commit 'v3.3.0' into upstream

[debian/gnuradio] / gr-pager / lib / pager_slicer_fb.cc

diff --git a/gr-pager/lib/pager_slicer_fb.cc b/gr-pager/lib/pager_slicer_fb.cc
new file mode 100644 (file)
index 0000000..d419db7
--- /dev/null
+++ b/gr-pager/lib/pager_slicer_fb.cc
@@ -0,0 +1,84 @@
+/*
+ * Copyright 2004,2006,2007 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 <pager_slicer_fb.h>
+#include <gr_io_signature.h>
+
+pager_slicer_fb_sptr pager_make_slicer_fb(float alpha)
+{
+    return pager_slicer_fb_sptr(new pager_slicer_fb(alpha));
+}
+
+pager_slicer_fb::pager_slicer_fb(float alpha) :
+    gr_sync_block ("slicer_fb",
+                   gr_make_io_signature (1, 1, sizeof(float)),
+                   gr_make_io_signature (1, 1, sizeof(unsigned char)))
+{
+    d_alpha = alpha;
+    d_beta = 1.0-alpha;
+    d_avg = 0.0;
+}
+
+// Tracks average, minimum, and peak, then converts input into one of:
+//
+// [0, 1, 2, 3]
+unsigned char pager_slicer_fb::slice(float sample)
+{
+    unsigned char decision;
+
+    // Update DC level and remove
+    d_avg = d_avg*d_beta+sample*d_alpha;
+    sample -= d_avg;
+
+    if (sample > 0) {
+        if (sample > 2.0)          
+            decision = 3;
+        else
+            decision = 2;
+    }
+    else {
+        if (sample < -2.0)
+            decision = 0;
+        else
+            decision = 1;
+    }
+
+    return decision;
+}
+
+int pager_slicer_fb::work(int noutput_items,
+                          gr_vector_const_void_star &input_items,
+                                 gr_vector_void_star &output_items)
+{
+    float *iptr = (float *) input_items[0];
+    unsigned char *optr = (unsigned char *) output_items[0];
+
+    int size = noutput_items;
+
+    for (int i = 0; i < size; i++)
+        *optr++ = slice(*iptr++);
+
+    return noutput_items;
+}