While using rtl_sdr i noticed that there was no direct sampling support, despite the rtl-sdr library supporting it, so i wrote a patch:
diff --git a/src/rtl_sdr.c b/src/rtl_sdr.cindex 2c93b57..15a4212 100644
--- a/src/rtl_sdr.c
+++ b/src/rtl_sdr.c
@@ -55,6 +55,7 @@ void usage(void)
"\t[-b output_block_size (default: 16 * 16384)]\n"
"\t[-n number of samples to read (default: 0, infinite)]\n"
"\t[-S force sync output (default: async)]\n"
+ "\t[-D direct sampling (default: 0, 1 for I branch, 2 for Q branch)]\n"
"\tfilename (a '-' dumps samples to stdout)\n\n");
exit(1);
}
@@ -112,6 +113,7 @@ int main(int argc, char **argv)
int n_read;
int r, opt;
int gain = 0;
+ int direct_sampling = 0;
int ppm_error = 0;
int sync_mode = 0;
FILE *file;
@@ -121,8 +123,8 @@ int main(int argc, char **argv)
uint32_t frequency = 100000000;
uint32_t samp_rate = DEFAULT_SAMPLE_RATE;
uint32_t out_block_size = DEFAULT_BUF_LENGTH;
-
- while ((opt = getopt(argc, argv, "d:f:g:s:b:n:p:S")) != -1) {
+
+ while ((opt = getopt(argc, argv, "d:f:g:s:b:n:p:S:D:")) != -1) {
switch (opt) {
case 'd':
dev_index = verbose_device_search(optarg);
@@ -149,6 +151,9 @@ int main(int argc, char **argv)
case 'S':
sync_mode = 1;
break;
+ case 'D':
+ direct_sampling = atoi(optarg);
+ break;
default:
usage();
break;
@@ -200,7 +205,8 @@ int main(int argc, char **argv)
#endif
/* Set the sample rate */
verbose_set_sample_rate(dev, samp_rate);
-
+ /* Set direct sampling*/
+ verbose_direct_sampling(dev, direct_sampling);
/* Set the frequency */
verbose_set_frequency(dev, frequency);
