noaa_apt_sink_impl.h

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/* -*- c++ -*- */
/*
 * gr-satnogs: SatNOGS GNU Radio Out-Of-Tree Module
 *
 *  Copyright (C) 2017,2018 Libre Space Foundation <http://librespacefoundation.org/>
 *
 *  This program 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 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
#ifndef INCLUDED_SATNOGS_NOAA_APT_SINK_IMPL_H
#define INCLUDED_SATNOGS_NOAA_APT_SINK_IMPL_H
 
#include <gnuradio/satnogs/noaa_apt_sink.h>
#define PNG_DEBUG 3
#include <png++/png.hpp>
#include <chrono>
 
 
namespace gr {
namespace satnogs {
enum class noaa_apt_sync_marker { SYNC_A, SYNC_B, NONE };
 
class noaa_apt_sink_impl : public noaa_apt_sink
{
private:
    // Factor exponential smoothing average,
    // which is used for sync pattern detection
    const float f_average_alpha;
    static const bool synca_seq[];
    static const bool syncb_seq[];
 
    std::string d_filename_png;
    size_t d_width;
    size_t d_height;
    bool d_synchronize_opt;
    bool d_flip;
    size_t d_history_length;
    bool d_has_sync;
    bool d_image_received;
 
    png::image<png::gray_pixel> d_full_image;
    png::image<png::gray_pixel> d_left_image;
    png::image<png::gray_pixel> d_right_image;
    std::string d_full_filename;
    std::string d_left_filename;
    std::string d_right_filename;
 
    size_t d_current_x;
    size_t d_current_y;
    size_t d_num_images;
 
    float f_max_level;
    float f_min_level;
    float f_average;
 
public:
    noaa_apt_sink_impl(
        const char* filename_png, size_t width, size_t height, bool sync, bool flip);
    ~noaa_apt_sink_impl();
 
    // Where all the action really happens
    int work(int noutput_items,
             gr_vector_const_void_star& input_items,
             gr_vector_void_star& output_items);
 
    bool stop();
 
private:
    /*
     * Checks if the history portion of the input contains a sync marker.
     * Matches the 40 samples before pos against the patterns.
     */
    noaa_apt_sync_marker is_marker(size_t pos, const float* samples);
 
    // Sets the pixel indicated by coordinates in the images (both full and split)
    void set_pixel(size_t x, size_t y, float sample);
 
    /*
     * Updates d_current_x to new_x,
     * while using historical samples to fill any resulting gaps in the images.
     */
    void skip_to(size_t new_x, size_t pos, const float* samples);
 
    // Writes a single image to disk, also takes care of flipping
    void write_image(png::image<png::gray_pixel> image, std::string filename);
};
 
} // namespace satnogs
} // namespace gr
 
#endif /* INCLUDED_SATNOGS_NOAA_APT_SINK_IMPL_H */