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-rw-r--r--src/libsdr/display_spectrum.c292
1 files changed, 292 insertions, 0 deletions
diff --git a/src/libsdr/display_spectrum.c b/src/libsdr/display_spectrum.c
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--- /dev/null
+++ b/src/libsdr/display_spectrum.c
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+/* 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 "../common/sample.h"
+#include "../common/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;
+}
+
+