rtl-sdr/rtl-sdr-0021-rtl_fm-add-option-for-2nd-direct-sampling-mode.patch

From a4eab76c8cafc6f3ebed8b6757b0643df9453bec Mon Sep 17 00:00:00 2001
From: Doug Hammond <doug@lon.dev>
Date: Thu, 29 Jul 2021 18:27:17 +0100
Subject: [PATCH] rtl_fm: add a new option to select 2nd direct sampling mode

---
 src/rtl_fm.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/rtl_fm.c b/src/rtl_fm.c
index 283542d..7c84332 100644
--- a/src/rtl_fm.c
+++ b/src/rtl_fm.c
@@ -201,11 +201,12 @@ void usage(void)
 		"\t[-p ppm_error (default: 0)]\n"
 		"\t[-E enable_option (default: none)]\n"
 		"\t    use multiple -E to enable multiple options\n"
-		"\t    edge:   enable lower edge tuning\n"
-		"\t    dc:     enable dc blocking filter\n"
-		"\t    deemp:  enable de-emphasis filter\n"
-		"\t    direct: enable direct sampling\n"
-		"\t    offset: enable offset tuning\n"
+		"\t    edge:    enable lower edge tuning\n"
+		"\t    dc:      enable dc blocking filter\n"
+		"\t    deemp:   enable de-emphasis filter\n"
+		"\t    direct:  enable direct sampling 1 (usually I)\n"
+		"\t    direct2: enable direct sampling 2 (usually Q)\n"
+		"\t    offset:  enable offset tuning\n"
 		"\tfilename ('-' means stdout)\n"
 		"\t    omitting the filename also uses stdout\n\n"
 		"Experimental options:\n"
@@ -892,7 +893,7 @@ static void *controller_thread_fn(void *arg)
 	/* set up primary channel */
 	optimal_settings(s->freqs[0], demod.rate_in);
 	if (dongle.direct_sampling) {
-		verbose_direct_sampling(dongle.dev, 1);}
+		verbose_direct_sampling(dongle.dev, dongle.direct_sampling);}
 	if (dongle.offset_tuning) {
 		verbose_offset_tuning(dongle.dev);}
 
@@ -1119,6 +1120,8 @@ int main(int argc, char **argv)
 				demod.deemph = 1;}
 			if (strcmp("direct",  optarg) == 0) {
 				dongle.direct_sampling = 1;}
+			if (strcmp("direct2", optarg) == 0) {
+				dongle.direct_sampling = 2;}
 			if (strcmp("offset",  optarg) == 0) {
 				dongle.offset_tuning = 1;}
 			break;