rtl_power: adjustable sample rate

src/rtl_power.c

@@ -72,8 +72,9 @@
 #define AUTO_GAIN			-100
 #define BUFFER_DUMP			(1<<12)
 
-#define MAXIMUM_RATE			2400000
+#define MAXIMUM_RATE			3200000
 #define MINIMUM_RATE			1000000
+int target_rate =			2400000;
 
 static volatile int do_exit = 0;
 static rtlsdr_dev_t *dev = NULL;
@@ -158,6 +159,8 @@ void usage(void)
 		"\t  enables low-leakage downsample filter,\n"
 		"\t  fir_size can be 0 or 9.  0 has bad roll off,\n"
 		"\t  try -F 0 with '-c 50%%' to hide the roll off\n"
+		"\t[-r max_sample_rate (default: 2.4M)]\n"
+		"\t  possible values are 2M to 3.2M\n"
 		"\t[-P enables peak hold (default: off)]\n"
 		"\t[-D direct_sampling_mode, 0 (default/off), 1 (I), 2 (Q), 3 (no-mod)]\n"
 		"\t[-O enable offset tuning (default: off)]\n"
@@ -496,7 +499,7 @@ int solve_downsample(struct channel_solve *c, int boxcar)
 		} else {
 			ds_next = c->downsample * 2;
 		}
-		if ((bw * ds_next) > MAXIMUM_RATE) {
+		if ((bw * ds_next) > target_rate) {
 			break;}
 
 		c->downsample = ds_next;
@@ -523,7 +526,7 @@ int solve_hopping(struct channel_solve *c)
 		bins_2 = 1 << c->bin_e;
 		c->bw_needed = bins_2 * c->bin_spec;
 		c->crop_tmp = (double)(bins_2 - bins_crop) / (double)bins_2;
-		if (c->bw_needed > MAXIMUM_RATE) {
+		if (c->bw_needed > target_rate) {
 			continue;}
 		if (c->crop_tmp < c->crop) {
 			continue;}
@@ -880,7 +883,7 @@ int main(int argc, char **argv)
 	double (*window_fn)(int, int) = rectangle;
 	freq_optarg = "";
 
-	while ((opt = getopt(argc, argv, "f:i:s:t:d:g:p:e:w:c:F:1PD:Oh")) != -1) {
+	while ((opt = getopt(argc, argv, "f:i:s:r:t:d:g:p:e:w:c:F:1PD:Oh")) != -1) {
 		switch (opt) {
 		case 'f': // lower:upper:bin_size
 			freq_optarg = strdup(optarg);
@@ -933,6 +936,9 @@ int main(int argc, char **argv)
 			ppm_error = atoi(optarg);
 			custom_ppm = 1;
 			break;
+		case 'r':
+			target_rate = (int)atofs(optarg);
+			break;
 		case '1':
 			single = 1;
 			break;
@@ -966,6 +972,13 @@ int main(int argc, char **argv)
 		exit(1);
 	}
 
+	if (target_rate < 2 * MINIMUM_RATE) {
+		target_rate = 2 * MINIMUM_RATE;
+	}
+	if (target_rate > MAXIMUM_RATE) {
+		target_rate = MAXIMUM_RATE;
+	}
+
 	frequency_range(freq_optarg, crop, boxcar);
 
 	if (tune_count == 0) {