diff options
Diffstat (limited to 'src/libdisplay/display_spectrum.c')
-rw-r--r-- | src/libdisplay/display_spectrum.c | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/src/libdisplay/display_spectrum.c b/src/libdisplay/display_spectrum.c new file mode 100644 index 0000000..3c885b7 --- /dev/null +++ b/src/libdisplay/display_spectrum.c @@ -0,0 +1,292 @@ +/* display spectrum of IQ data + * + * (C) 2016 by Andreas Eversberg <jolly@eversberg.eu> + * All Rights Reserved + * + * 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 3 of the License, 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. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <stdio.h> +#include <stdint.h> +#include <stdlib.h> +#include <string.h> +#include <math.h> +#include "../libsample/sample.h" +#include "../libmobile/sender.h" +#include "../libfft/fft.h" + +#define HEIGHT 20 + +static double buffer_max[MAX_DISPLAY_SPECTRUM]; +static char screen[HEIGHT][MAX_DISPLAY_WIDTH]; +static uint8_t screen_color[HEIGHT][MAX_DISPLAY_WIDTH]; +static int spectrum_on = 0; +static double db = 120; +static double center_frequency, frequency_range; + +static dispspectrum_t disp; + +void display_spectrum_init(int samplerate, double _center_frequency) +{ + memset(&disp, 0, sizeof(disp)); + disp.interval_max = (double)samplerate * DISPLAY_INTERVAL + 0.5; + /* should not happen due to low interval */ + if (disp.interval_max < MAX_DISPLAY_SPECTRUM - 1) + disp.interval_max = MAX_DISPLAY_SPECTRUM - 1; + memset(buffer_max, 0, sizeof(buffer_max)); + + center_frequency = _center_frequency; + frequency_range = (double)samplerate; +} + +void display_spectrum_on(int on) +{ + int j; + int w, h; + + get_win_size(&w, &h); + + if (spectrum_on) { + memset(&screen, ' ', sizeof(screen)); + printf("\0337\033[H"); + for (j = 0; j < HEIGHT; j++) { + screen[j][w] = '\0'; + puts(screen[j]); + } + printf("\0338"); fflush(stdout); + } + + if (on < 0) { + if (++spectrum_on == 2) + spectrum_on = 0; + } else + spectrum_on = on; +} + +void display_spectrum_limit_scroll(int on) +{ + int w, h; + + if (!spectrum_on) + return; + + get_win_size(&w, &h); + + printf("\0337"); + printf("\033[%d;%dr", (on) ? HEIGHT + 1 : 1, h); + printf("\0338"); +} + +/* + * plot spectrum data: + * + */ +void display_spectrum(float *samples, int length) +{ + sender_t *sender; + char print_channel[32], print_frequency[32]; + int width, h; + int pos, max; + double *buffer_I, *buffer_Q; + int color = 9; /* default color */ + int i, j, k, o; + double I, Q, v; + int s, e, l, n; + + if (!spectrum_on) + return; + + get_win_size(&width, &h); + if (width > MAX_DISPLAY_WIDTH) + width = MAX_DISPLAY_WIDTH; + + /* calculate size of FFT */ + int m, fft_size = 0, fft_taps = 0; + for (m = 0; m < 16; m++) { + if ((1 << m) > MAX_DISPLAY_SPECTRUM) + break; + if ((1 << m) <= width) { + fft_taps = m; + fft_size = 1 << m; + } + } + if (m == 16) { + fprintf(stderr, "Size of spectrum is not a power of 2, please fix!\n"); + abort(); + } + + int heigh[fft_size], low[fft_size]; + + pos = disp.interval_pos; + max = disp.interval_max; + buffer_I = disp.buffer_I; + buffer_Q = disp.buffer_Q; + + for (i = 0; i < length; i++) { + if (pos >= fft_size) { + if (++pos == max) + pos = 0; + continue; + } + buffer_I[pos] = samples[i * 2]; + buffer_Q[pos] = samples[i * 2 + 1]; + pos++; + if (pos == fft_size) { + fft_process(1, fft_taps, buffer_I, buffer_Q); + k = 0; + for (j = 0; j < fft_size; j++) { + /* scale result vertically */ + I = buffer_I[(j + fft_size / 2) % fft_size]; + Q = buffer_Q[(j + fft_size / 2) % fft_size]; + v = sqrt(I*I + Q*Q); + v = log10(v) * 20 + db; + if (v < 0) + v = 0; + v /= db; + buffer_max[j] -= DISPLAY_INTERVAL / 10.0; + if (v > buffer_max[j]) + buffer_max[j] = v; + + /* heigh is the maximum value */ + heigh[j] = (double)(HEIGHT * 2 - 1) * (1.0 - buffer_max[j]); + if (heigh[j] < 0) + heigh[j] = 0; + if (heigh[j] >= (HEIGHT * 2)) + heigh[j] = (HEIGHT * 2) - 1; + /* low is the current value */ + low[j] = (double)(HEIGHT * 2 - 1) * (1.0 - v); + if (low[j] < 0) + low[j] = 0; + if (low[j] >= (HEIGHT * 2)) + low[j] = (HEIGHT * 2) - 1; + } + /* plot scaled buffer */ + memset(&screen, ' ', sizeof(screen)); + memset(&screen_color, 7, sizeof(screen_color)); /* all white */ + sprintf(screen[0], "(spectrum log %.0f dB", db); + *strchr(screen[0], '\0') = ')'; + o = (width - fft_size) / 2; /* offset from left border */ + for (j = 0; j < fft_size; j++) { + s = l = n = low[j]; + /* get last and next value */ + if (j > 0) + l = (low[j - 1] + s) / 2; + if (j < fft_size - 1) + n = (low[j + 1] + s) / 2; + if (s > l && s > n) { + /* current value is a minimum */ + e = s; + s = (l < n) ? (l + 1) : (n + 1); + } else if (s < l && s < n) { + /* current value is a maximum */ + e = (l > n) ? l : n; + } else if (l < n) { + /* last value is higher, next value is lower */ + s = l + 1; + e = n; + } else if (l > n) { + /* last value is lower, next value is higher */ + s = n + 1; + e = l; + } else { + /* current, last and next values are equal */ + e = s; + } + if (s == e) { + if ((s & 1) == 0) + screen[s >> 1][j + o] = '\''; + else + screen[s >> 1][j + o] = '.'; + screen_color[s >> 1][j + o] = 13; + } else { + if ((s & 1) == 0) + screen[s >> 1][j + o] = '|'; + else + screen[s >> 1][j + o] = '.'; + screen_color[s >> 1][j + o] = 13; + if ((e & 1) == 0) + screen[e >> 1][j + o] = '\''; + else + screen[e >> 1][j + o] = '|'; + screen_color[e >> 1][j + o] = 13; + for (k = (s >> 1) + 1; k < (e >> 1); k++) { + screen[k][j + o] = '|'; + screen_color[k][j + o] = 13; + } + } + e = s; + s = heigh[j]; + if ((s >> 1) < (e >> 1)) { + if ((s & 1) == 0) + screen[s >> 1][j + o] = '|'; + else + screen[s >> 1][j + o] = '.'; + screen_color[s >> 1][j + o] = 4; + for (k = (s >> 1) + 1; k < (e >> 1); k++) { + screen[k][j + o] = '|'; + screen_color[k][j + o] = 4; + } + } + } + for (sender = sender_head; sender; sender = sender->next) { + j = (int)((sender->empfangsfrequenz - center_frequency) / frequency_range * (double) fft_size + width / 2 + 0.5); + if (j < 0 || j >= width) /* check out-of-range, should not happen */ + continue; + for (k = 0; k < HEIGHT; k++) { + /* skip yellow graph */ + if (screen_color[k][j] == 13) + continue; + screen[k][j] = ':'; + screen_color[k][j] = 12; + } + sprintf(print_channel, "Ch%d", sender->kanal); + for (o = 0; o < (int)strlen(print_channel); o++) { + s = j - strlen(print_channel) + o; + if (s >= 0 && s < width) { + screen[HEIGHT - 1][s] = print_channel[o]; + screen_color[HEIGHT - 1][s] = 7; + } + } + if (fmod(sender->empfangsfrequenz, 1000.0)) + sprintf(print_frequency, "%.4f", sender->empfangsfrequenz / 1e6); + else + sprintf(print_frequency, "%.3f", sender->empfangsfrequenz / 1e6); + for (o = 0; o < (int)strlen(print_frequency); o++) { + s = j + o + 1; + if (s >= 0 && s < width) { + screen[HEIGHT - 1][s] = print_frequency[o]; + screen_color[HEIGHT - 1][s] = 7; + } + } + } + printf("\0337\033[H"); + for (j = 0; j < HEIGHT; j++) { + for (k = 0; k < width; k++) { + if (screen_color[j][k] != color) { + color = screen_color[j][k]; + printf("\033[%d;3%dm", color / 10, color % 10); + } + putchar(screen[j][k]); + } + printf("\n"); + } + /* reset color and position */ + printf("\033[0;39m\0338"); fflush(stdout); + } + } + + disp.interval_pos = pos; +} + + |