HackRF-Treasure-Chest/Software/portapack-mayhem/firmware/baseband/proc_sstvtx.cpp

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2022-09-22 18:26:57 +02:00
/*
* Copyright (C) 2015 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.
*/
#include "proc_sstvtx.hpp"
#include "sine_table_int8.hpp"
#include "event_m4.hpp"
#include <cstdint>
// This is called at 3072000/2048 = 1500Hz
void SSTVTXProcessor::execute(const buffer_c8_t& buffer) {
if (!configured) return;
for (size_t i = 0; i < buffer.count; i++) {
if (!sample_count) {
// This FSM is a mess. It seems to do a lot where it shouldn't (I/Q loop),
// but it actually doesn't do much. Used for sequencing the different parts
// of the scanline. Todo: simplify !
if (state == STATE_CALIBRATION) {
// Once per picture
tone_delta = calibration_sequence[substep].first;
sample_count = calibration_sequence[substep].second;
if (substep == 2) {
substep = 0;
state = STATE_VIS;
} else
substep++;
} else if (state == STATE_VIS) {
// Once per picture
if (substep == 10) {
current_scanline = &scanline_buffer[buffer_flip];
buffer_flip ^= 1;
// Ask application for a new scanline
shared_memory.application_queue.push(sig_message);
// Do we have to transmit a start tone ?
if (current_scanline->start_tone.duration) {
state = STATE_SYNC;
tone_delta = current_scanline->start_tone.frequency;
sample_count = current_scanline->start_tone.duration;
} else {
state = STATE_PIXELS;
tone_delta = current_scanline->gap_tone.frequency;
sample_count = current_scanline->gap_tone.duration;
}
} else {
tone_delta = vis_code_sequence[substep];
sample_count = SSTV_MS2S(30); // A VIS code bit is 30ms
substep++;
}
} else if (state == STATE_SYNC) {
// Once per scanline, optional
state = STATE_PIXELS;
tone_delta = current_scanline->gap_tone.frequency;
sample_count = current_scanline->gap_tone.duration;
} else if (state == STATE_PIXELS) {
// Many times per scanline
tone_delta = SSTV_F2D(1500 + ((current_scanline->luma[pixel_index] * 800) / 256));
sample_count = pixel_duration;
pixel_index++;
if (pixel_index >= 320) {
// Scanline done, (dirty) state jump
pixel_index = 0;
state = STATE_VIS;
substep = 10;
}
}
} else {
sample_count--;
}
// Tone synth
tone_sample = (sine_table_i8[(tone_phase & 0xFF000000U) >> 24]);
tone_phase += tone_delta;
// FM
delta = tone_sample * fm_delta;
phase += delta;
sphase = phase + (64 << 24);
re = (sine_table_i8[(sphase & 0xFF000000U) >> 24]);
im = (sine_table_i8[(phase & 0xFF000000U) >> 24]);
buffer.p[i] = {re, im};
}
}
void SSTVTXProcessor::on_message(const Message* const msg) {
const auto message = *reinterpret_cast<const SSTVConfigureMessage*>(msg);
uint8_t vis_code;
switch(msg->id) {
case Message::ID::SSTVConfigure:
pixel_duration = message.pixel_duration;
if (!pixel_duration) {
configured = false; // Shutdown
return;
}
vis_code = message.vis_code;
// VIS code:
// 1200, (0=1300, 1=1100), 1200
vis_code_sequence[0] = SSTV_VIS_SS;
for (uint32_t c = 0; c < 8; c++)
vis_code_sequence[c + 1] = ((vis_code >> c) & 1) ? SSTV_VIS_ONE : SSTV_VIS_ZERO;
vis_code_sequence[9] = SSTV_VIS_SS;
fm_delta = 9000 * (0xFFFFFFULL / 3072000); // Fixed bw for now
pixel_index = 0;
sample_count = 0;
tone_phase = 0;
state = STATE_CALIBRATION;
substep = 0;
configured = true;
break;
case Message::ID::FIFOData:
memcpy(&scanline_buffer[buffer_flip], static_cast<const FIFODataMessage*>(msg)->data, sizeof(sstv_scanline));
break;
default:
break;
}
}
int main() {
EventDispatcher event_dispatcher { std::make_unique<SSTVTXProcessor>() };
event_dispatcher.run();
return 0;
}