147 lines
3.3 KiB
C
147 lines
3.3 KiB
C
/*
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* rtl-sdr, a poor man's SDR using a Realtek RTL2832 based DVB-stick
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* Copyright (C) 2012 by Steve Markgraf <steve@steve-m.de>
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 2 of the License, or
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*(at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <errno.h>
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#include <signal.h>
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#include <string.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <math.h>
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#include <unistd.h>
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#include "rtl-sdr.h"
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#define READLEN (16 * 16384)
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static int do_exit = 0;
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void usage(void)
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{
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printf("rtl-sdr, an I/Q recorder for RTL2832 based DVB-T receivers\n\n"
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"Usage:\t -f frequency to tune to [Hz]\n"
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"\t[-s samplerate (default: 2048000 Hz)]\n"
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"\toutput filename\n");
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exit(1);
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}
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static void sighandler(int signum)
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{
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do_exit = 1;
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}
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int main(int argc, char **argv)
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{
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struct sigaction sigact;
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int r, opt;
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char *filename = NULL;
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uint32_t frequency = 0, samp_rate = 2048000;
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uint8_t buffer[READLEN];
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uint32_t n_read;
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FILE *file;
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rtlsdr_dev_t *dev = NULL;
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while ((opt = getopt(argc, argv, "f:s:")) != -1) {
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switch (opt) {
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case 'f':
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frequency = atoi(optarg);
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break;
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case 's':
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samp_rate = atoi(optarg);
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break;
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default:
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usage();
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break;
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}
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}
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if (argc <= optind) {
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usage();
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} else {
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filename = argv[optind];
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}
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rtlsdr_init();
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int device_count = rtlsdr_get_device_count();
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if (!device_count) {
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fprintf(stderr, "No supported devices found.\n");
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exit(1);
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}
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printf("Found %d device(s).\n", device_count);
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dev = rtlsdr_open(0); /* open the first device */
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if (NULL == dev) {
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fprintf(stderr, "Failed to open rtlsdr device.\n");
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exit(1);
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}
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sigact.sa_handler = sighandler;
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sigemptyset(&sigact.sa_mask);
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sigact.sa_flags = 0;
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sigaction(SIGINT, &sigact, NULL);
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sigaction(SIGTERM, &sigact, NULL);
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sigaction(SIGQUIT, &sigact, NULL);
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/* Set the sample rate */
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r = rtlsdr_set_sample_rate(dev, samp_rate);
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if (r < 0) {
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fprintf(stderr, "WARNING: Failed to set sample rate.\n");
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}
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/* Set the frequency */
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r = rtlsdr_set_center_freq(dev, frequency);
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if (r < 0) {
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fprintf(stderr, "WARNING: Failed to set center freq.\n");
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}
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file = fopen(filename, "wb");
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if (!file) {
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printf("Failed to open %s\n", filename);
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goto out;
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}
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/* Reset endpoint before we start reading from it */
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r = rtlsdr_reset_buffer(dev);
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if (r < 0) {
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fprintf(stderr, "WARNING: Failed to reset buffers.\n");
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}
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printf("Reading samples...\n");
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while (!do_exit) {
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r = rtlsdr_read_sync(dev, buffer, READLEN, &n_read);
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if (r < 0) {
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fprintf(stderr, "WARNING: sync read failed.\n");
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}
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fwrite(buffer, n_read, 1, file);
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if (n_read < READLEN) {
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printf("Short read, samples lost, exiting!\n");
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break;
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}
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}
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fclose(file);
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rtlsdr_exit();
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out:
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return r >= 0 ? r : -r;
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}
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