portapack-mayhem/firmware/baseband/proc_nfm_audio.hpp

/*
 * Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
 * Copyright (C) 2016 Furrtek
 *
 * This file is part of PortaPack.
 *
 * 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 2, 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; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#ifndef __PROC_NFM_AUDIO_H__
#define __PROC_NFM_AUDIO_H__

#include "baseband_processor.hpp"
#include "baseband_thread.hpp"
#include "rssi_thread.hpp"

#include "dsp_decimate.hpp"
#include "dsp_demodulate.hpp"
#include "dsp_iir.hpp"

#include "audio_output.hpp"
#include "spectrum_collector.hpp"

#include <cstdint>

#define Z_MIN_FILTER_COUNT 224
#define Z_MIN_ZERO_CROSSINGS 20

class NarrowbandFMAudio : public BasebandProcessor {
   public:
    void execute(const buffer_c8_t& buffer) override;

    void on_message(const Message* const message) override;

   private:
    static constexpr size_t baseband_fs = 3072000;

    BasebandThread baseband_thread{baseband_fs, this, NORMALPRIO + 20, baseband::Direction::Receive};
    RSSIThread rssi_thread{NORMALPRIO + 10};

    std::array<complex16_t, 512> dst{};
    const buffer_c16_t dst_buffer{
        dst.data(),
        dst.size()};
    const buffer_s16_t work_audio_buffer{
        (int16_t*)dst.data(),
        sizeof(dst) / sizeof(int16_t)};

    std::array<int16_t, 16> audio{};
    const buffer_s16_t audio_buffer{
        (int16_t*)audio.data(),
        sizeof(audio) / sizeof(int16_t)};

    std::array<int16_t, 16> tone{};
    const buffer_s16_t tone_buffer{
        (int16_t*)tone.data(),
        sizeof(tone) / sizeof(int16_t)};

    dsp::decimate::FIRC8xR16x24FS4Decim8 decim_0{};
    dsp::decimate::FIRC16xR16x32Decim8 decim_1{};
    dsp::decimate::FIRAndDecimateComplex channel_filter{};
    int32_t channel_filter_low_f = 0;
    int32_t channel_filter_high_f = 0;
    int32_t channel_filter_transition = 0;

    // For CTCSS decoding
    dsp::decimate::FIR64AndDecimateBy2Real ctcss_filter{};
    IIRBiquadFilter hpf{};

    dsp::demodulate::FM demod{};

    AudioOutput audio_output{};

    SpectrumCollector channel_spectrum{};

    uint32_t tone_phase{0};
    uint32_t tone_delta{0};
    bool pitch_rssi_enabled{false};

    float cur_sample{}, prev_sample{};
    uint32_t z_acc{0}, z_timer{0}, z_count{0}, z_filter_count{0};
    bool ctcss_detect_enabled{true};
    static constexpr float k = 32768.0f;
    static constexpr float ki = 1.0f / k;

    bool configured{false};
    void pitch_rssi_config(const PitchRSSIConfigureMessage& message);
    void configure(const NBFMConfigureMessage& message);
    void capture_config(const CaptureConfigMessage& message);

    // RequestSignalMessage sig_message { RequestSignalMessage::Signal::Squelched };
    CodedSquelchMessage ctcss_message{0};
};

#endif /*__PROC_NFM_AUDIO_H__*/