direct_resampler_conditioner_cc.h

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/*!
 * \file direct_resampler_conditioner_cc.h
 *
 * \brief Nearest neighborhood resampler with
 *        gr_complex input and gr_complex output
 * \author Luis Esteve, 2011. luis(at)epsilon-formacion.com
 *
 * This block takes in a signal stream and performs direct resampling.
 * The theory behind this block can be found in Chapter 7.5 of the following
 * book:
 * R. Lyons, Undestanding Digital Signal Processing, 3rd ed., Pearson Education,
 * 2010.
 *
 * -----------------------------------------------------------------------------
 *
 * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
 * This file is part of GNSS-SDR.
 *
 * Copyright (C) 2010-2020  (see AUTHORS file for a list of contributors)
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 * -----------------------------------------------------------------------------
 */

#ifndef GNSS_SDR_DIRECT_RESAMPLER_CONDITIONER_CC_H
#define GNSS_SDR_DIRECT_RESAMPLER_CONDITIONER_CC_H

#include "gnss_block_interface.h"
#include <gnuradio/block.h>
#include <cstdint>

/** \addtogroup Resampler
 * \{ */
/** \addtogroup Resampler_gnuradio_blocks resampler_gr_blocks
 * \{ */


class direct_resampler_conditioner_cc;

using direct_resampler_conditioner_cc_sptr = gnss_shared_ptr<direct_resampler_conditioner_cc>;

direct_resampler_conditioner_cc_sptr direct_resampler_make_conditioner_cc(
    double sample_freq_in,
    double sample_freq_out);

/*!
 * \brief This class implements a direct resampler conditioner for complex data
 *
 * Direct resampling without interpolation
 */
class direct_resampler_conditioner_cc : public gr::block
{
public:
    ~direct_resampler_conditioner_cc() = default;
    inline unsigned int sample_freq_in() const
    {
        return d_sample_freq_in;
    }

    inline unsigned int sample_freq_out() const
    {
        return d_sample_freq_out;
    }

    void forecast(int noutput_items, gr_vector_int &ninput_items_required);

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

private:
    friend direct_resampler_conditioner_cc_sptr direct_resampler_make_conditioner_cc(
        double sample_freq_in,
        double sample_freq_out);

    direct_resampler_conditioner_cc(
        double sample_freq_in,
        double sample_freq_out);

    double d_sample_freq_in;   // Sampling frequency of the input signal
    double d_sample_freq_out;  // Sampling frequency of the output signal
    uint32_t d_phase;
    uint32_t d_lphase;
    uint32_t d_phase_step;
};


/** \} */
/** \} */
#endif  // GNSS_SDR_DIRECT_RESAMPLER_CONDITIONER_CC_H