atsc_equalizer_impl.h

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/* -*- c++ -*- */
/*
 * Copyright 2014 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.
 */

#ifndef INCLUDED_DTV_ATSC_EQUALIZER_IMPL_H
#define INCLUDED_DTV_ATSC_EQUALIZER_IMPL_H

#include <gnuradio/dtv/atsc_equalizer.h>
#include <gnuradio/dtv/atsc_consts.h>
#include "atsc_syminfo_impl.h"

namespace gr {
  namespace dtv {

    class atsc_equalizer_impl : public atsc_equalizer
    {
    private:
      static const int NTAPS = 64;
      static const int NPRETAPS = (int) (NTAPS * 0.8); // probably should be either .2 or .8

      // the length of the field sync pattern that we know unequivocally
      static const int KNOWN_FIELD_SYNC_LENGTH = 4 + 511 + 3 * 63;

      float training_sequence1[KNOWN_FIELD_SYNC_LENGTH];
      float training_sequence2[KNOWN_FIELD_SYNC_LENGTH];

      void filterN(const float *input_samples, float *output_samples, int nsamples);
      void adaptN(const float *input_samples, const float *training_pattern,
                  float *output_samples, int nsamples);

      float d_taps[NTAPS];

      float data_mem[ATSC_DATA_SEGMENT_LENGTH + NTAPS]; // Buffer for previous data packet
      float data_mem2[ATSC_DATA_SEGMENT_LENGTH];
      unsigned short d_flags;
      short d_segno;

      int d_buff_not_filled;

    public:
      atsc_equalizer_impl();
      ~atsc_equalizer_impl();

      virtual int general_work(int noutput_items,
                               gr_vector_int &ninput_items,
                               gr_vector_const_void_star &input_items,
                               gr_vector_void_star &output_items);
    };

  } /* namespace dtv */
} /* namespace gr */

#endif /* INCLUDED_DTV_ATSC_EQUALIZER_IMPL_H */