- added alpha to s quelch

git-svn-id: http://moon:8086/svn/software/trunk/projects/GnuRadio@519 b431acfa-c32f-4a4a-93f1-934dc6c82436

gr-jay/lib/squelch_impl.cc

@@ -30,22 +30,23 @@ namespace gr {
   namespace jay {
 
     squelch::sptr
-    squelch::make(float initValue)
+    squelch::make(float initValue, float alpha)
     {
       return gnuradio::get_initial_sptr
-        (new squelch_impl(initValue));
+        (new squelch_impl(initValue, alpha));
     }
 
     /*
      * The private constructor
      */
 	
-    squelch_impl::squelch_impl(float initValue)
+    squelch_impl::squelch_impl(float initValue, float alpha)
       : gr::sync_block("squelch",
               gr::io_signature::make(1, 1, sizeof(float)),
               gr::io_signature::make(1, 1, sizeof(float)))
 	  , m_gain_target(initValue)
 	  , m_gain(0.0f)
+	  , m_alpha(alpha)
     {
 		m_msg_port_in = pmt::mp("control");
 		message_port_register_in(m_msg_port_in);
@@ -120,7 +121,7 @@ namespace gr {
       const float *in = (const float *) input_items[0];
       float *out = (float *) output_items[0];
 
-	  m_gain = 0.99f*m_gain + 0.01f*m_gain_target;
+	  m_gain = (1.f-m_alpha)*m_gain + m_alpha*m_gain_target;
 	  
       // Do <+signal processing+>
 	  for (int i=0; i < noutput_items; i++)

gr-jay/lib/squelch_impl.h

@@ -33,9 +33,10 @@ namespace gr {
 		pmt::pmt_t m_msg_port_in;
 		float m_gain_target;
 		float m_gain;
-		
+		float m_alpha;
+
      public:
-      squelch_impl(float initValue);
+      squelch_impl(float initValue, float alpha);
       ~squelch_impl();
 	  void print_pair(pmt::pmt_t pair);
 	  void on_message(pmt::pmt_t msg);