kopia lustrzana https://github.com/F5OEO/ft8_lib
101 wiersze
2.8 KiB
C++
101 wiersze
2.8 KiB
C++
#include <cstdlib>
|
|
#include <cstring>
|
|
#include <cstdio>
|
|
#include <cmath>
|
|
|
|
#include "common/wave.h"
|
|
//#include "ft8/v1/pack.h"
|
|
//#include "ft8/v1/encode.h"
|
|
#include "ft8/pack.h"
|
|
#include "ft8/encode.h"
|
|
#include "ft8/constants.h"
|
|
|
|
// Convert a sequence of symbols (tones) into a sinewave of continuous phase (FSK).
|
|
// Symbol 0 gets encoded as a sine of frequency f0, the others are spaced in increasing
|
|
// fashion.
|
|
void synth_fsk(const uint8_t *symbols, int num_symbols, float f0, float spacing,
|
|
float symbol_rate, float signal_rate, float *signal) {
|
|
float phase = 0;
|
|
float dt = 1/signal_rate;
|
|
float dt_sym = 1/symbol_rate;
|
|
float t = 0;
|
|
int j = 0;
|
|
int i = 0;
|
|
while (j < num_symbols) {
|
|
float f = f0 + symbols[j] * spacing;
|
|
phase += 2 * M_PI * f / signal_rate;
|
|
signal[i] = sin(phase);
|
|
t += dt;
|
|
if (t >= dt_sym) {
|
|
// Move to the next symbol
|
|
t -= dt_sym;
|
|
++j;
|
|
}
|
|
++i;
|
|
}
|
|
}
|
|
|
|
|
|
void usage() {
|
|
printf("Generate a 15-second WAV file encoding a given message.\n");
|
|
printf("Usage:\n");
|
|
printf("\n");
|
|
printf("gen_ft8 MESSAGE WAV_FILE\n");
|
|
printf("\n");
|
|
printf("(Note that you might have to enclose your message in quote marks if it contains spaces)\n");
|
|
}
|
|
|
|
|
|
int main(int argc, char **argv) {
|
|
// Expect two command-line arguments
|
|
if (argc < 3) {
|
|
usage();
|
|
return -1;
|
|
}
|
|
|
|
const char *message = argv[1];
|
|
const char *wav_path = argv[2];
|
|
|
|
// First, pack the text data into binary message
|
|
uint8_t packed[ft8::K_BYTES];
|
|
//int rc = packmsg(message, packed);
|
|
int rc = ft8::pack77(message, packed);
|
|
if (rc < 0) {
|
|
printf("Cannot parse message!\n");
|
|
printf("RC = %d\n", rc);
|
|
return -2;
|
|
}
|
|
|
|
printf("Packed data: ");
|
|
for (int j = 0; j < 10; ++j) {
|
|
printf("%02x ", packed[j]);
|
|
}
|
|
printf("\n");
|
|
|
|
// Second, encode the binary message as a sequence of FSK tones
|
|
uint8_t tones[ft8::NN]; // FT8_NN = 79, lack of better name at the moment
|
|
//genft8(packed, 0, tones);
|
|
ft8::genft8(packed, tones);
|
|
|
|
printf("FSK tones: ");
|
|
for (int j = 0; j < ft8::NN; ++j) {
|
|
printf("%d", tones[j]);
|
|
}
|
|
printf("\n");
|
|
|
|
// Third, convert the FSK tones into an audio signal
|
|
const int sample_rate = 12000;
|
|
const float symbol_rate = 6.25f;
|
|
const int num_samples = (int)(0.5f + ft8::NN / symbol_rate * sample_rate);
|
|
const int num_silence = (15 * sample_rate - num_samples) / 2;
|
|
float signal[num_silence + num_samples + num_silence];
|
|
for (int i = 0; i < num_silence + num_samples + num_silence; i++) {
|
|
signal[i] = 0;
|
|
}
|
|
|
|
synth_fsk(tones, ft8::NN, 1000, symbol_rate, symbol_rate, sample_rate, signal + num_silence);
|
|
save_wav(signal, num_silence + num_samples + num_silence, sample_rate, wav_path);
|
|
|
|
return 0;
|
|
}
|