Allow specifying frequencies in kHz, MHz or GHz

README.md

@@ -403,6 +403,14 @@ bit to the side of the desired channel frequency, like this:
 ./dumpvdl2 --rtlsdr 0 --gain 40 --correction 42 --centerfreq 137100000 <channel freqs here...>
 ```
 
+Frequencies might be specified in Hertz (as integer numbers) or in kHz, MHz, GHz
+(as integer or floating-point numbers followed by any of the following suffixes:
+k, K, m, M, g, G).
+
+```
+./dumpvdl2 --rtlsdr 0 --gain 40 --centerfreq 136M 136.725M 136975k 0.136875G
+```
+
 ### Mirics
 
 Mirics is similar, however `libmirisdr-4` library currently lacks support for
@@ -465,15 +473,15 @@ as an "expert mode" knob, which is hardly ever needed.
 Example 1: use SDRplay device ID=0, with auto gain and three VDL2 channels:
 
 ```
-./dumpvdl2 --sdrplay 0 136975000 136875000 136775000
+./dumpvdl2 --sdrplay 0 136.975M 136.875M 136.775M
 ```
 
 Example 2: use SDRplay device with serial number 35830222, set gain reduction to
 40 dB, use antenna A port, disable Bias-T, enable AM/FM notch filter, set
 frequency correction to -1ppm:
 
 ```
-./dumpvdl2 --sdrplay 35830222 --gr 40 --correction -1 --antenna A --biast 0 --notch-filter 1 136975000
+./dumpvdl2 --sdrplay 35830222 --gr 40 --correction -1 --antenna A --biast 0 --notch-filter 1 136.975M
 ```
 
 ### SDRplay RSP native driver, version 3
@@ -1062,7 +1070,7 @@ dumpvdl2 --iq-file <file_name> --centerfreq 136955000 136975000
 Putting it all together:
 
 ```
-dumpvdl2 --iq-file iq.dat --sample-format S16_LE --oversample 13 --centerfreq 136955000 136975000 136725000
+dumpvdl2 --iq-file iq.dat --sample-format S16_LE --oversample 13 --centerfreq 136.955M 136.975M 136.725M
 ```
 
 processes `iq.dat` file recorded at 1365000 samples/sec using 16-bit signed

src/dumpvdl2.c

@@ -399,15 +399,15 @@ void usage() {
 	describe_option("--debug <filter_spec>", "Debug message classes to display (default: none) (\"--debug help\" for details)", 1);
 #endif
 	fprintf(stderr, "common options:\n");
-	describe_option("<freq_1> [<freq_2> [...]]", "VDL2 channel frequencies, in Hz", 1);
+	describe_option("<freq_1> [<freq_2> [...]]", "VDL2 channel frequencies", 1);
 	fprintf(stderr, "If channel frequencies are omitted, VDL2 Common Signalling Channel (%u Hz) will be used as default.\n\n", CSC_FREQ);
 
 #ifdef WITH_RTLSDR
 	fprintf(stderr, "rtlsdr_options:\n");
 	describe_option("--rtlsdr <device_id>", "Use RTL device with specified ID or serial number (default: ID=0)", 1);
 	describe_option("--gain <gain>", "Set gain (decibels)", 1);
 	describe_option("--correction <correction>", "Set freq correction (ppm)", 1);
-	describe_option("--centerfreq <center_frequency>", "Set center frequency in Hz (default: auto)", 1);
+	describe_option("--centerfreq <center_frequency>", "Set center frequency (default: auto)", 1);
 	describe_option("--bias <bias>", "Enable(1) or Disable(0) bias tee (default: 0)", 1);
 #endif
 #ifdef WITH_MIRISDR
@@ -416,7 +416,7 @@ void usage() {
 	describe_option("--hw-type <device_type>", "0 - default, 1 - SDRPlay", 1);
 	describe_option("--gain <gain>", "Set gain (in decibels, from 0 to 102 dB)", 1);
 	describe_option("--correction <correction>", "Set freq correction (in Hertz)", 1);
-	describe_option("--centerfreq <center_frequency>", "Set center frequency in Hz (default: auto)", 1);
+	describe_option("--centerfreq <center_frequency>", "Set center frequency (default: auto)", 1);
 	describe_option("--usb-mode <usb_transfer_mode>", "0 - isochronous (default), 1 - bulk", 1);
 #endif
 #ifdef WITH_SDRPLAY
@@ -425,7 +425,7 @@ void usage() {
 	describe_option("--gr <gr>", "Set system gain reduction, in dB, positive (if omitted, auto gain is enabled)", 1);
 	describe_option("--agc <AGC_set_point>", "Auto gain set point in dBFS, negative (default: -30)", 1);
 	describe_option("--correction <correction>", "Set freq correction (ppm)", 1);
-	describe_option("--centerfreq <center_frequency>", "Set center frequency in Hz (default: auto)", 1);
+	describe_option("--centerfreq <center_frequency>", "Set center frequency (default: auto)", 1);
 	describe_option("--antenna <A/B>", "RSP2 antenna port selection (default: A)", 1);
 	describe_option("--biast <0/1>", "RSP2/1a/duo Bias-T control: 0 - off (default), 1 - on", 1);
 	describe_option("--notch-filter <0/1>", "RSP2/1a/duo AM/FM/bcast notch filter control: 0 - off (default), 1 - on", 1);
@@ -439,7 +439,7 @@ void usage() {
 	describe_option("", "(if omitted, auto gain is enabled)", 1);
 	describe_option("--agc <AGC_set_point>", "Auto gain set point in dBFS, negative (default: -30)", 1);
 	describe_option("--correction <correction>", "Set freq correction (ppm)", 1);
-	describe_option("--centerfreq <center_frequency>", "Set center frequency in Hz (default: auto)", 1);
+	describe_option("--centerfreq <center_frequency>", "Set center frequency (default: auto)", 1);
 	describe_option("--antenna <A/B/C>", "RSP2/dx antenna port selection (default: A)", 1);
 	describe_option("--biast <0/1>", "RSP2/1a/duo/dx Bias-T control: 0 - off (default), 1 - on", 1);
 	describe_option("--notch-filter <0/1>", "RSP2/1a/duo/dx AM/FM/bcast notch filter control: 0 - off (default), 1 - on", 1);
@@ -457,7 +457,7 @@ void usage() {
 #endif
 	fprintf(stderr, "\nfile_options:\n");
 	describe_option("--iq-file <input_file>", "Read I/Q samples from a file (use \"-\" to read from standard input)", 1);
-	describe_option("--centerfreq <center_frequency>", "Center frequency of the input data, in Hz (default: 0)", 1);
+	describe_option("--centerfreq <center_frequency>", "Center frequency of the input data, (default: 0)", 1);
 	describe_option("--oversample <oversample_rate>", "Oversampling rate for recorded data", 1);
 	fprintf(stderr, "%*s(sampling rate will be set to %u * oversample_rate)\n", USAGE_OPT_NAME_COLWIDTH, "", SYMBOL_RATE * SPS);
 	fprintf(stderr, "%*sDefault: %u\n", USAGE_OPT_NAME_COLWIDTH, "", FILE_OVERSAMPLE);
@@ -493,6 +493,11 @@ void usage() {
 	describe_option("--extended-header", "Print additional fields in message header", 1);
 	describe_option("--prettify-xml", "Pretty-print XML payloads in ACARS and MIAM CORE PDUs", 1);
 	describe_option("--prettify-json", "Pretty-print JSON payloads in OHMA messages", 1);
+
+	fprintf(stderr, "\nFrequencies might be specified in Hz (as integer numbers) or in kHz, MHz, GHz (as integer\n");
+	fprintf(stderr, "or floating-point numbers followed by any of the following suffixes: k, K, m, M, g, G).\n");
+	fprintf(stderr, "Examples: 136975000, 136975k, 136.975M, 0.136975G\n");
+
 	_exit(0);
 }
 
@@ -620,10 +625,60 @@ static uint32_t parse_msg_filterspec(msg_filterspec_t const *filters, void (*hel
 	return fmask;
 }
 
+static bool parse_frequency(char const *str, uint32_t *result) {
+	ASSERT(str != NULL);
+	ASSERT(result != NULL);
+
+	char *endptr = NULL;
+	double val = strtod(str, &endptr);
+	if(endptr == str) {
+		fprintf(stderr, "Cannot parse '%s' as frequency: not a valid floating-point number\n", str);
+		return false;
+	} else if(errno == ERANGE) {
+		fprintf(stderr, "Cannot parse '%s' as frequency: value too large\n", str);
+		return false;
+	}
+
+	switch(endptr[0]) {
+		case 'k':
+		case 'K':
+			val *= 1e3;
+			endptr++;
+			break;
+		case 'm':
+		case 'M':
+			val *= 1e6;
+			endptr++;
+			break;
+		case 'g':
+		case 'G':
+			val *= 1e9;
+			endptr++;
+			break;
+		case '\0':
+			break;
+		default:
+			fprintf(stderr, "Cannot parse '%s' as frequency: '%c' is not a valid suffix\n", str, endptr[0]);
+			return false;
+	}
+	if(endptr[0] != '\0') {
+		fprintf(stderr, "Cannot parse '%s' as frequency: invalid trailing characters after value\n", str);
+		return false;
+	}
+	if(val < 0 || val > UINT32_MAX) {
+		fprintf(stderr, "Cannot parse '%s' as frequency: value is negative or too large\n", str);
+		return false;
+	}
+	*result = (uint32_t)val;
+	debug_print(D_MISC, "str: %s val: %u\n", str, *result);
+	return true;
+}
+
+
 int main(int argc, char **argv) {
 	vdl2_state_t ctx;
 	uint32_t centerfreq = 0, sample_rate = 0, oversample = 0;
-	uint32_t *freqs;
+	uint32_t *freqs = NULL;
 	int num_channels = 0;
 	enum input_types input = INPUT_UNDEF;
 	enum sample_formats sample_fmt = SFMT_UNDEF;
@@ -832,7 +887,9 @@ int main(int argc, char **argv) {
 				Config.station_id = strndup(optarg, STATION_ID_LEN_MAX);
 				break;
 			case __OPT_CENTERFREQ:
-				centerfreq = strtoul(optarg, NULL, 10);
+				if(parse_frequency(optarg, &centerfreq) == false) {
+					_exit(1);
+				}
 				break;
 #ifdef WITH_MIRISDR
 			case __OPT_MIRISDR:
@@ -979,7 +1036,9 @@ int main(int argc, char **argv) {
 			num_channels = argc - optind;
 			freqs = XCALLOC(num_channels, sizeof(uint32_t));
 			for(int i = 0; i < num_channels; i++)
-				freqs[i] = strtoul(argv[optind+i], NULL, 10);
+				if(parse_frequency(argv[optind + i], &freqs[i]) == false) {
+					return 1;
+				}
 		} else {
 			fprintf(stderr, "Warning: frequency not set - using VDL2 Common Signalling Channel as a default (%u Hz)\n", CSC_FREQ);
 			num_channels = 1;