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/* -*- c++ -*- */
/*
* Copyright 2006,2010,2012 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 "agc3_cc_impl.h"
#include <gr_io_signature.h>
namespace gr {
namespace analog {
agc3_cc::sptr
agc3_cc::make(float attack_rate, float decay_rate, float reference)
{
return gnuradio::get_initial_sptr (new agc3_cc_impl(attack_rate, decay_rate, reference));
}
agc3_cc_impl::agc3_cc_impl(float attack_rate, float decay_rate, float reference)
: gr_sync_block("agc3_cc",
gr_make_io_signature(1, 1, sizeof(gr_complex)),
gr_make_io_signature(1, 1, sizeof(gr_complex))),
d_attack(attack_rate), d_decay(decay_rate),
d_reference(reference), d_gain(1.0),
d_reset(true)
{
}
agc3_cc_impl::~agc3_cc_impl()
{
}
int
agc3_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];
// Compute a linear average on reset (no expected)
if(__builtin_expect (d_reset, false)){
float mag;
for(int i=0; i<noutput_items; i++){
mag += abs(in[i]);
}
d_gain = d_reference * (noutput_items/mag);
for(int i=0; i<noutput_items; i++){
out[i] = in[i] * d_gain;
}
d_reset = false;
printf("computed initial mean on %d values = %f\n", noutput_items, d_gain);
} else {
// Otherwise perform a normal iir update
for(int i=0; i<noutput_items; i++){
float newlevel = abs(in[i]);
float rate = (newlevel > d_reference/d_gain)?d_attack:d_decay;
d_gain = (d_gain*(1-rate)) + (d_reference/newlevel)*rate;
out[i] = in[i] * d_gain;
}
}
return noutput_items;
}
} /* namespace analog */
} /* namespace gr */
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