portapack-mayhem/firmware/baseband/tv_collector.cpp

/*
 * Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
 * Copyright (C) 2020 Shao
 *
 * 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.
 */

#include "tv_collector.hpp"

#include "dsp_fft.hpp"

#include "utility.hpp"
#include "event_m4.hpp"
#include "portapack_shared_memory.hpp"

#include "event_m4.hpp"

#include <algorithm>

void TvCollector::on_message(const Message* const message) {
    switch (message->id) {
        case Message::ID::UpdateSpectrum:
            update();
            break;

        case Message::ID::SpectrumStreamingConfig:
            set_state(*reinterpret_cast<const SpectrumStreamingConfigMessage*>(message));
            break;

        default:
            break;
    }
}

void TvCollector::set_state(const SpectrumStreamingConfigMessage& message) {
    if (message.mode == SpectrumStreamingConfigMessage::Mode::Running) {
        start();
    } else {
        stop();
    }
}

void TvCollector::start() {
    streaming = true;
    ChannelSpectrumConfigMessage message{&fifo};
    shared_memory.application_queue.push(message);
}

void TvCollector::stop() {
    streaming = false;
    fifo.reset_in();
}

void TvCollector::set_decimation_factor(
    const size_t decimation_factor) {
    channel_spectrum_decimator.set_factor(decimation_factor);
}

/* TODO: Refactor to register task with idle thread?
 * It's sad that the idle thread has to call all the way back here just to
 * perform the deferred task on the buffer of data we prepared.
 */

void TvCollector::feed(
    const buffer_c16_t& channel) {
    // Called from baseband processing thread.
    channel_spectrum_decimator.feed(channel, [this](const buffer_c16_t& data) { this->post_message(data); });
}

void TvCollector::post_message(const buffer_c16_t& data) {
    // Called from baseband processing thread.
    float re, im;
    float mag;
    if (streaming && !channel_spectrum_request_update) {
        for (size_t i = 0; i < 256; i++) {
            re = (float)(data.p[i].real());
            im = (float)(data.p[i].imag());
            mag = __builtin_sqrtf((re * re) + (im * im));
            channel_spectrum[i] = {mag, mag};
        }
        channel_spectrum_sampling_rate = data.sampling_rate;
        channel_spectrum_request_update = true;
        EventDispatcher::events_flag(EVT_MASK_SPECTRUM);
    }
}

void TvCollector::update() {
    // Called from idle thread (after EVT_MASK_SPECTRUM is flagged)
    if (streaming && channel_spectrum_request_update) {
        ChannelSpectrum spectrum;
        spectrum.sampling_rate = channel_spectrum_sampling_rate;
        for (size_t i = 0; i < spectrum.db.size(); i++) {
            const auto corrected_sample = channel_spectrum[i].real();
            const unsigned int v = corrected_sample + 127.0f;
            spectrum.db[i] = std::max(0U, std::min(255U, v));
        }
        fifo.in(spectrum);
    }

    channel_spectrum_request_update = false;
}