/* -*- c++ -*- */

/*

 * Copyright 2005,2010 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_probe_avg_mag_sqrd_c.h>

#include <gr_io_signature.h>

#include <cmath>

gr_probe_avg_mag_sqrd_c_sptr

gr_make_probe_avg_mag_sqrd_c(double threshold_db, double alpha)

{

  return gnuradio::get_initial_sptr(new gr_probe_avg_mag_sqrd_c(threshold_db, alpha));

}

gr_probe_avg_mag_sqrd_c::gr_probe_avg_mag_sqrd_c (double threshold_db, double alpha)

  : gr_sync_block ("probe_avg_mag_sqrd_c",

                   gr_make_io_signature(1, 1, sizeof(gr_complex)),

                   gr_make_io_signature(0, 0, 0)),

    d_iir(alpha), d_unmuted(false), d_level(0)

{

  set_threshold (threshold_db);

}

gr_probe_avg_mag_sqrd_c::~gr_probe_avg_mag_sqrd_c()

{

}

int

gr_probe_avg_mag_sqrd_c::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];

  for (int i = 0; i < noutput_items; i++){

    double mag_sqrd = in[i].real()*in[i].real() + in[i].imag()*in[i].imag();

    d_iir.filter(mag_sqrd);        // computed for side effect: prev_output()

  }

  d_unmuted = d_iir.prev_output() >= d_threshold;

  d_level = d_iir.prev_output();

  return noutput_items;

}

double

gr_probe_avg_mag_sqrd_c::threshold() const

{

  return 10 * std::log10(d_threshold);

}

void

gr_probe_avg_mag_sqrd_c::set_threshold(double decibels)

{

  // convert to absolute threshold (mag squared)

  d_threshold = std::pow(10.0, decibels/10);

}

void

gr_probe_avg_mag_sqrd_c::set_alpha(double alpha)

{

  d_iir.set_taps(alpha);

}