1 files changed, 106 insertions, 0 deletions
diff --git a/gr-analog/lib/simple_squelch_cc_impl.cc b/gr-analog/lib/simple_squelch_cc_impl.cc
new file mode 100644
index 000000000..02ccc535d
--- /dev/null
+++ b/gr-analog/lib/simple_squelch_cc_impl.cc
@@ -0,0 +1,106 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2005,2010,2012 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 "simple_squelch_cc_impl.h"
+#include <gr_io_signature.h>
+#include <cmath>
+
+namespace gr {
+  namespace analog {
+    
+    simple_squelch_cc::sptr
+    simple_squelch_cc::make(double threshold_db, double alpha)
+    {
+      return gnuradio::get_initial_sptr
+	(new simple_squelch_cc_impl(threshold_db, alpha));
+    }
+
+    simple_squelch_cc_impl::simple_squelch_cc_impl(double threshold_db, double alpha)
+      : gr_sync_block("simple_squelch_cc",
+		      gr_make_io_signature(1, 1, sizeof(gr_complex)),
+		      gr_make_io_signature(1, 1, sizeof(gr_complex))),
+	d_unmuted(false), d_iir(alpha)
+    {
+      set_threshold(threshold_db);
+    }
+
+    simple_squelch_cc_impl::~simple_squelch_cc_impl()
+    {
+    }
+
+    void
+    simple_squelch_cc_impl::set_threshold(double decibels)
+    {
+      // convert to absolute threshold (mag squared)
+      d_threshold = std::pow(10.0, decibels/10);
+    }
+
+    double
+    simple_squelch_cc_impl::threshold() const
+    {
+      return 10 * log10(d_threshold);
+    }
+
+    void
+    simple_squelch_cc_impl::set_alpha(double alpha)
+    {
+      d_iir.set_taps(alpha);
+    }
+
+    std::vector<float>
+    simple_squelch_cc_impl::squelch_range() const
+    {
+      std::vector<float> r(3);
+      r[0] = -50.0;			// min	FIXME
+      r[1] = +50.0;			// max	FIXME
+      r[2] = (r[1] - r[0]) / 100;	// step size
+
+      return r;
+    }
+
+    int
+    simple_squelch_cc_impl::work(int noutput_items,
+				 gr_vector_const_void_star &input_items,
+				 gr_vector_void_star &output_items)
+    {
+      const gr_complex *in = (const gr_complex*)input_items[0];
+      gr_complex *out = (gr_complex*)output_items[0];
+
+      for(int i = 0; i < noutput_items; i++) {
+	double mag_sqrd = in[i].real()*in[i].real() + in[i].imag()*in[i].imag();
+	double f = d_iir.filter(mag_sqrd);
+	if(f >= d_threshold)
+	  out[i] = in[i];
+	else
+	  out[i] = 0;
+      }
+
+      d_unmuted = d_iir.prev_output() >= d_threshold;
+      return noutput_items;
+    }
+
+  } /* namespace analog */
+} /* namespace gr */