satdump/src-core/modules/module_bpsk_demod.cpp

#include "module_bpsk_demod.h"
#include <dsp/fir_gen.h>
#include "logger.h"
#include "imgui/imgui.h"

// Return filesize
size_t getFilesize(std::string filepath);

BPSKDemodModule::BPSKDemodModule(std::string input_file, std::string output_file_hint, std::map<std::string, std::string> parameters) : ProcessingModule(input_file, output_file_hint, parameters),
                                                                                                                                        d_agc_rate(std::stof(parameters["agc_rate"])),
                                                                                                                                        d_samplerate(std::stoi(parameters["samplerate"])),
                                                                                                                                        d_symbolrate(std::stoi(parameters["symbolrate"])),
                                                                                                                                        d_rrc_alpha(std::stof(parameters["rrc_alpha"])),
                                                                                                                                        d_rrc_taps(std::stoi(parameters["rrc_taps"])),
                                                                                                                                        d_loop_bw(std::stof(parameters["costas_bw"])),
                                                                                                                                        d_buffer_size(std::stoi(parameters["buffer_size"])),
                                                                                                                                        d_dc_block(parameters.count("dc_block") > 0 ? std::stoi(parameters["dc_block"]) : 0)
{
    if (parameters["baseband_format"] == "i16")
    {
        i16 = true;
    }
    else if (parameters["baseband_format"] == "i8")
    {
        i8 = true;
    }
    else if (parameters["baseband_format"] == "f32")
    {
        f32 = true;
    }
    else if (parameters["baseband_format"] == "w8")
    {
        w8 = true;
    }

    // Init DSP blocks
    agc = std::make_shared<libdsp::AgcCC>(d_agc_rate, 1.0f, 1.0f, 65536);
    rrc = std::make_shared<libdsp::FIRFilterCCF>(1, libdsp::firgen::root_raised_cosine(1, d_samplerate, d_symbolrate, d_rrc_alpha, d_rrc_taps));
    pll = std::make_shared<libdsp::CostasLoop>(d_loop_bw, 2);
    rec = std::make_shared<libdsp::ClockRecoveryMMCC>((float)d_samplerate / (float)d_symbolrate, pow(8.7e-3, 2) / 4.0, 0.5f, 8.7e-3, 0.005f);

    // Buffers
    in_buffer = new std::complex<float>[d_buffer_size];
    in_buffer2 = new std::complex<float>[d_buffer_size];
    agc_buffer = new std::complex<float>[d_buffer_size];
    agc_buffer2 = new std::complex<float>[d_buffer_size];
    rrc_buffer = new std::complex<float>[d_buffer_size];
    rrc_buffer2 = new std::complex<float>[d_buffer_size];
    pll_buffer = new std::complex<float>[d_buffer_size];
    pll_buffer2 = new std::complex<float>[d_buffer_size];
    rec_buffer = new std::complex<float>[d_buffer_size];
    rec_buffer2 = new std::complex<float>[d_buffer_size];
    sym_buffer = new int8_t[d_buffer_size * 2];

    buffer_i16 = new int16_t[d_buffer_size * 2];
    buffer_i8 = new int8_t[d_buffer_size * 2];
    buffer_u8 = new uint8_t[d_buffer_size * 2];

    // Init FIFOs
    in_pipe = new libdsp::Pipe<std::complex<float>>(d_buffer_size * 10);
    rrc_pipe = new libdsp::Pipe<std::complex<float>>(d_buffer_size * 10);
    agc_pipe = new libdsp::Pipe<std::complex<float>>(d_buffer_size * 10);
    pll_pipe = new libdsp::Pipe<std::complex<float>>(d_buffer_size * 10);
    rec_pipe = new libdsp::Pipe<std::complex<float>>(d_buffer_size * 10);
}

BPSKDemodModule::~BPSKDemodModule()
{
    delete[] in_buffer;
    delete[] in_buffer2;
    delete[] agc_buffer;
    delete[] agc_buffer2;
    delete[] rrc_buffer;
    delete[] rrc_buffer2;
    delete[] pll_buffer;
    delete[] pll_buffer2;
    delete[] rec_buffer;
    delete[] rec_buffer2;
    delete[] sym_buffer;
    delete[] buffer_i16;
    delete[] buffer_i8;
    delete[] buffer_u8;
    //delete[] in_pipe;
    //delete[] rrc_pipe;
    //delete[] agc_pipe;
    //delete[] pll_pipe;
    //delete[] rec_pipe;
}

void BPSKDemodModule::process()
{
    filesize = getFilesize(d_input_file);
    data_in = std::ifstream(d_input_file, std::ios::binary);
    data_out = std::ofstream(d_output_file_hint + ".soft", std::ios::binary);
    d_output_files.push_back(d_output_file_hint + ".soft");

    logger->info("Using input baseband " + d_input_file);
    logger->info("Demodulating to " + d_output_file_hint + ".soft");
    logger->info("Buffer size : " + std::to_string(d_buffer_size));

    time_t lastTime = 0;

    agcRun = rrcRun = pllRun = recRun = true;

    fileThread = std::thread(&BPSKDemodModule::fileThreadFunction, this);
    agcThread = std::thread(&BPSKDemodModule::agcThreadFunction, this);
    rrcThread = std::thread(&BPSKDemodModule::rrcThreadFunction, this);
    pllThread = std::thread(&BPSKDemodModule::pllThreadFunction, this);
    recThread = std::thread(&BPSKDemodModule::clockrecoveryThreadFunction, this);

    int dat_size = 0;
    while (!data_in.eof())
    {
        dat_size = rec_pipe->pop(rec_buffer2, d_buffer_size);

        if (dat_size <= 0)
            continue;

        for (int i = 0; i < dat_size; i++)
        {
            sym_buffer[i] = clamp(rec_buffer2[i].real() * 50);
        }

        data_out.write((char *)sym_buffer, dat_size);

        if (time(NULL) % 10 == 0 && lastTime != time(NULL))
        {
            lastTime = time(NULL);
            logger->info("Progress " + std::to_string(round(((float)progress / (float)filesize) * 1000.0f) / 10.0f) + "%");
        }
    }

    logger->info("Demodulation finished");

    data_out.close();
    data_in.close();

    // Exit all threads... Without causing a race condition!
    agcRun = rrcRun = pllRun = recRun = false;

    in_pipe->~Pipe();

    if (fileThread.joinable())
        fileThread.join();

    logger->debug("FILE OK");

    agc_pipe->~Pipe();

    if (agcThread.joinable())
        agcThread.join();

    logger->debug("AGC OK");

    rrc_pipe->~Pipe();

    if (rrcThread.joinable())
        rrcThread.join();

    logger->debug("RRC OK");

    pll_pipe->~Pipe();

    if (pllThread.joinable())
        pllThread.join();

    logger->debug("PLL OK");

    rec_pipe->~Pipe();

    if (recThread.joinable())
        recThread.join();

    logger->debug("REC OK");
}

#include <dsp/dc_blocker.h>

void BPSKDemodModule::fileThreadFunction()
{
    libdsp::DCBlocker dcB(320, true);
    while (!data_in.eof())
    {
        // Get baseband, possibly convert to F32
        if (f32)
        {
            data_in.read((char *)in_buffer, d_buffer_size * sizeof(std::complex<float>));
        }
        else if (i16)
        {
            data_in.read((char *)buffer_i16, d_buffer_size * sizeof(int16_t) * 2);
            for (int i = 0; i < d_buffer_size; i++)
            {
                using namespace std::complex_literals;
                in_buffer[i] = (float)buffer_i16[i * 2] + (float)buffer_i16[i * 2 + 1] * 1if;
            }
        }
        else if (i8)
        {
            data_in.read((char *)buffer_i8, d_buffer_size * sizeof(int8_t) * 2);
            for (int i = 0; i < d_buffer_size; i++)
            {
                using namespace std::complex_literals;
                in_buffer[i] = (float)buffer_i8[i * 2] + (float)buffer_i8[i * 2 + 1] * 1if;
            }
        }
        else if (w8)
        {
            data_in.read((char *)buffer_u8, d_buffer_size * sizeof(uint8_t) * 2);
            for (int i = 0; i < d_buffer_size; i++)
            {
                float imag = (buffer_u8[i * 2] - 127) * 0.004f;
                float real = (buffer_u8[i * 2 + 1] - 127) * 0.004f;
                using namespace std::complex_literals;
                in_buffer[i] = real + imag * 1if;
            }
        }

        progress = data_in.tellg();

        if (d_dc_block)
            dcB.work(in_buffer, d_buffer_size, in_buffer);

        in_pipe->push(in_buffer, d_buffer_size);
    }
}

void BPSKDemodModule::agcThreadFunction()
{
    int gotten;
    while (agcRun)
    {
        gotten = in_pipe->pop(in_buffer2, d_buffer_size);

        if (gotten <= 0)
            continue;

        /// AGC
        agc->work(in_buffer2, gotten, agc_buffer);

        agc_pipe->push(agc_buffer, gotten);
    }
}

void BPSKDemodModule::rrcThreadFunction()
{
    int gotten;
    while (rrcRun)
    {
        gotten = agc_pipe->pop(agc_buffer2, d_buffer_size);

        if (gotten <= 0)
            continue;

        // Root-raised-cosine filtering
        int out = rrc->work(agc_buffer2, gotten, rrc_buffer);

        rrc_pipe->push(rrc_buffer, out);
    }
}

void BPSKDemodModule::pllThreadFunction()
{
    int gotten;
    while (pllRun)
    {
        gotten = rrc_pipe->pop(rrc_buffer2, d_buffer_size);

        if (gotten <= 0)
            continue;

        // Costas loop, frequency offset recovery
        pll->work(rrc_buffer2, gotten, pll_buffer);

        pll_pipe->push(pll_buffer, gotten);
    }
}

void BPSKDemodModule::clockrecoveryThreadFunction()
{
    int gotten;
    while (recRun)
    {
        gotten = pll_pipe->pop(pll_buffer2, d_buffer_size);

        if (gotten <= 0)
            continue;

        int recovered_size = 0;

        try
        {
            // Clock recovery
            recovered_size = rec->work(pll_buffer2, gotten, rec_buffer);
        }
        catch (std::runtime_error &e)
        {
            logger->error(e.what());
        }

        rec_pipe->push(rec_buffer, recovered_size);
    }
}

void BPSKDemodModule::drawUI()
{
    ImGui::Begin("BPSK Demodulator", NULL);

    // Constellation
    {
        ImDrawList *draw_list = ImGui::GetWindowDrawList();
        draw_list->AddRectFilled(ImGui::GetCursorScreenPos(),
                                 ImVec2(ImGui::GetCursorScreenPos().x + 200, ImGui::GetCursorScreenPos().y + 200),
                                 ImColor::HSV(0, 0, 0));

        for (int i = 0; i < 2048; i++)
        {
            draw_list->AddCircleFilled(ImVec2(ImGui::GetCursorScreenPos().x + (int)(100 + rec_buffer2[i].real() * 50) % 200,
                                              ImGui::GetCursorScreenPos().y + (int)(100 + rec_buffer2[i].imag() * 50) % 200),
                                       2,
                                       ImColor::HSV(113.0 / 360.0, 1, 1, 1.0));
        }

        ImGui::Dummy(ImVec2(200 + 3, 200 + 3));
    }

    ImGui::ProgressBar((float)progress / (float)filesize, ImVec2(ImGui::GetWindowWidth() - 10, 20));

    ImGui::End();
}

std::string BPSKDemodModule::getID()
{
    return "bpsk_demod";
}

std::vector<std::string> BPSKDemodModule::getParameters()
{
    return {"samplerate", "symbolrate", "agc_rate", "rrc_alpha", "rrc_taps", "costas_bw", "iq_invert", "buffer_size", "dc_block", "baseband_format"};
}

std::shared_ptr<ProcessingModule> BPSKDemodModule::getInstance(std::string input_file, std::string output_file_hint, std::map<std::string, std::string> parameters)
{
    return std::make_shared<BPSKDemodModule>(input_file, output_file_hint, parameters);
}