Noaa apt decoder (#2648)

firmware/baseband/proc_noaaapt_rx.hpp

@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2025 Brumi, HTotoo
+ *
+ * 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_NOAAAPTRX_H__
+#define __PROC_NOAAAPTRX_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_compressor.hpp"
+
+#include "audio_output.hpp"
+#include "spectrum_collector.hpp"
+
+#include <cstdint>
+
+class NoaaAptRx : public BasebandProcessor {
+   public:
+    void execute(const buffer_c8_t& buffer) override;
+    void on_message(const Message* const message) override;
+
+   private:
+    void update_params();
+    // todo rethink
+
+    uint32_t samples_per_pixel = 0;
+
+    // to exactly match the pixel / samples.
+    double pxRem = 0;   // if has remainder, it'll store it
+    double pxRoll = 0;  // summs remainders, so won't misalign
+
+    uint32_t cnt = 0;  // signal counter
+    uint16_t sync_cnt = 0;
+    uint16_t syncnot_cnt = 0;
+
+    static constexpr size_t baseband_fs = 3072000;
+    static constexpr auto spectrum_rate_hz = 50.0f;
+
+    std::array<complex16_t, 512> dst{};
+    const buffer_c16_t dst_buffer{
+        dst.data(),
+        dst.size()};
+    // work_audio_buffer and dst_buffer use the same data pointer
+    const buffer_s16_t work_audio_buffer{
+        (int16_t*)dst.data(),
+        sizeof(dst) / sizeof(int16_t)};
+
+    std::array<complex16_t, 64> complex_audio{};
+    const buffer_c16_t complex_audio_buffer{
+        complex_audio.data(),
+        complex_audio.size()};
+
+    dsp::decimate::FIRC8xR16x24FS4Decim4 decim_0{};
+    // dsp::decimate::FIRC16xR16x16Decim2 decim_1{};   //original condition , before adding wfmam
+
+    // decim_1 will handle different types of FIR filters depending on selection.
+    dsp::decimate::FIRC16xR16x32Decim8 decim_1{};
+
+    // dsp::decimate::FIRC16xR16x32Decim8 decim_1{}; // For FMAM
+
+    int32_t channel_filter_low_f = 0;
+    int32_t channel_filter_high_f = 0;
+    int32_t channel_filter_transition = 0;
+
+    dsp::demodulate::FM demod{};
+    dsp::decimate::DecimateBy2CIC4Real audio_dec_1{};
+    dsp::decimate::DecimateBy2CIC4Real audio_dec_2{};
+    dsp::decimate::FIR64AndDecimateBy2Real audio_filter{};
+
+    AudioOutput audio_output{};
+
+    // For fs=96kHz FFT streaming
+    BlockDecimator<complex16_t, 256> audio_spectrum_decimator{1};
+    std::array<std::complex<float>, 256> audio_spectrum{};
+    uint32_t audio_spectrum_timer{0};
+    enum AudioSpectrumState {
+        IDLE = 0,
+        FEED,
+        FFT
+    };
+    AudioSpectrumState audio_spectrum_state{IDLE};
+    AudioSpectrum spectrum{};
+    uint32_t fft_step{0};
+
+    // SpectrumCollector channel_spectrum{};
+    // size_t spectrum_interval_samples = 0;
+    // size_t spectrum_samples = 0;
+
+    bool configured{false};
+
+    void configure(const NoaaAptRxConfigureMessage& message);
+    void capture_config(const CaptureConfigMessage& message);
+
+    NoaaAptRxStatusDataMessage status_message{0};
+    NoaaAptRxImageDataMessage image_message{};
+
+    /* NB: Threads should be the last members in the class definition. */
+    BasebandThread baseband_thread{baseband_fs, this, baseband::Direction::Receive};
+    RSSIThread rssi_thread{};
+};
+
+#endif /*__PROC_NOAAAPTRX_H__*/