BaseBandRX.hxx

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#pragma once
/*
Copyright (c) 2012,2013,2014, 2026 Matthew H. Reilly (kb1vc)
All rights reserved.
 
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
 
    Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
    Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in
    the documentation and/or other materials provided with the
    distribution.
 
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "SoDaBase.hxx"
#include "SoDaThread.hxx"
#include "Params.hxx"
 
#include "Command.hxx"
#include "HilbertTransformer.hxx"
#include "AudioIfc.hxx"
#include "MedianFilter.hxx"
 
#include <SoDa/ReSampler.hxx>
#include <SoDa/OSFilter.hxx>
#include <SoDa/MailBox.hxx>
 
#include <queue>
#include <mutex>
#include <fstream>
#include <string>
#include <memory>
 
namespace SoDa {
 
  class BaseBandRX;
  typedef std::shared_ptr<BaseBandRX> BaseBandRXPtr;
  typedef std::weak_ptr<BaseBandRX> BaseBandRXWeakPtr;
  
  class BaseBandRX : public SoDa::Thread {
  private:
    
    BaseBandRX(ParamsPtr params,
           AudioIfcPtr audio_ifc);
 
  public:
    static BaseBandRXPtr make(ParamsPtr params, AudioIfcPtr audio_ifc) {
      auto ret = std::shared_ptr<BaseBandRX>(new BaseBandRX(params, audio_ifc));
      ret->self = ret; 
      ret->registerThread(ret);
      return ret; 
    }
 
    
    void subscribeToMailBoxes(const std::vector<MailBoxBasePtr> & mailboxes);
    
    void run();
 
     
     
  private:
    void reportModes();

    void reportAFFilters();
    
    void execGetCommand(CommandPtr cmd); 
    void execSetCommand(CommandPtr cmd); 
    void execRepCommand(CommandPtr cmd); 

    void demodulateSSB(SoDa::CBufPtr drxbuf,
               SoDa::Command::ModulationType mod); 

    void demodulateAM(SoDa::CBufPtr drxbuf);

    void demodulateNBFM(SoDa::CBufPtr drxbuf,
            SoDa::Command::ModulationType mod,
            float af_gain); 

    void demodulateWBFM(SoDa::CBufPtr rxbuf,
            SoDa::Command::ModulationType mod,
            float af_gain);
 
    
    void demodulate(SoDa::CBufPtr rxbuf);

    void repAFFilterShape();
 
    // parameters
    unsigned int audio_buffer_size; 
    unsigned int rf_buffer_size; 
    double audio_sample_rate; 
    double rf_sample_rate; 
    bool audio_rx_stream_enabled; 
    bool audio_rx_stream_needs_start; 
    bool sidetone_stream_enabled;  
 
    SoDa::Command::ModulationType rx_modulation; 
    
    CDatMBoxPtr rx_stream; 
    CmdMBoxPtr cmd_stream; 
    CDatMBox::Subscription rx_subs; 
    CmdMBox::Subscription cmd_subs; 
 
    AudioIfcPtr audio_ifc; 
    
    // buffer pool management

    void pendAudioBuffer(SoDa::FBufPtr b); 
     
    void pendNullBuffer(int count = 1);
    
    float * getNextAudioBuffer();
    void flushAudioBuffers();
    
    // flow timing management
    bool in_catchup;  
    bool in_fallback;  
    unsigned int catchup_rand_mask; 
 
    SoDa::FBufPtr sidetone_silence;  
 
    // resampler -- downsample from 625K samples / sec to 48K samples/sec
    SoDa::ReSamplerPtr rf_resampler; 
    // a second resampler for wideband fm    
    SoDa::ReSamplerPtr wbfm_resampler; 

    void buildFilterMap();
    
    SoDa::Command::AudioFilterBW af_filter_selection; 
    SoDa::OSFilterPtr cur_audio_filter; 
    SoDa::OSFilterPtr fm_audio_filter; 
    SoDa::OSFilterPtr am_pre_filter; 
    SoDa::OSFilterPtr nbfm_pre_filter; 
    SoDa::OSFilterPtr am_audio_filter; 
    
    std::map<SoDa::Command::AudioFilterBW, SoDa::OSFilterPtr> filter_map; 
 
    // hilbert transformer
    SoDa::HilbertTransformerPtr hilbert; 
    
    // audio gain
    float af_gain;   
    float af_sidetone_gain; 
    float *cur_af_gain; 
 
    // support for NBFM/WBFM demodulator
    float last_phase_samp; 
 
    // median filter for FM demods
    MedianFilter3<float> fmMedianFilter; 
    
    // debug helper
    unsigned int dbg_ctr; 
    std::ofstream dbg_out;
 
    // audio output file
    bool audio_save_enable; 
    std::ofstream audio_file;
    std::ofstream audio_file2;     
 
    // recent audio level
    float audio_level; 
    float log_audio_buffer_size; 
 
    float nbfm_squelch_level;  
    int nbfm_squelch_hang_count; 
    int nbfm_squelch_hang_time; 
  };
}