/* -*- 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 "probe_avg_mag_sqrd_f_impl.h"
#include <gr_io_signature.h>
#include <cmath>

namespace gr {
  namespace analog {

    probe_avg_mag_sqrd_f::sptr
    probe_avg_mag_sqrd_f::make(double threshold_db, double alpha)
    {
      return gnuradio::get_initial_sptr
	(new probe_avg_mag_sqrd_f_impl(threshold_db, alpha));
    }

    probe_avg_mag_sqrd_f_impl::probe_avg_mag_sqrd_f_impl(double threshold_db, double alpha)
      : gr_sync_block("probe_avg_mag_sqrd_f",
		      gr_make_io_signature(1, 1, sizeof(float)),
		      gr_make_io_signature(0, 0, 0)),
	d_unmuted(false), d_level(0), d_iir(alpha)
    {
      set_threshold(threshold_db);
    }

    probe_avg_mag_sqrd_f_impl::~probe_avg_mag_sqrd_f_impl()
    {
    }

    int
    probe_avg_mag_sqrd_f_impl::work(int noutput_items,
				    gr_vector_const_void_star &input_items,
				    gr_vector_void_star &output_items)
    {
      const float *in = (const float*)input_items[0];

      for(int i = 0; i < noutput_items; i++) {
	double mag_sqrd = in[i]*in[i];
	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
    probe_avg_mag_sqrd_f_impl::threshold() const
    {
      return 10 * std::log10(d_threshold);
    }

    void
    probe_avg_mag_sqrd_f_impl::set_threshold(double decibels)
    {
      // convert to absolute threshold (mag sqrd)
      d_threshold = std::pow(10.0, decibels/10);
    }

    void
    probe_avg_mag_sqrd_f_impl::set_alpha(double alpha)
    {
      d_iir.set_taps(alpha);
    }

  } /* namespace analog */
} /* namespace gr */