From 4b50f692bc27bd6275483c80720829b126fa2951 Mon Sep 17 00:00:00 2001
From: Harvie <tomas@mudrunka.cz>
Date: Wed, 1 Aug 2012 01:24:22 +0200
Subject: [PATCH] More goertzel improvements

---
 c/goertzel/dtmf.sh    | 7 +++++--
 c/goertzel/goertzel.c | 8 ++++++--
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/c/goertzel/dtmf.sh b/c/goertzel/dtmf.sh
index 6c7798e..2c6547d 100755
--- a/c/goertzel/dtmf.sh
+++ b/c/goertzel/dtmf.sh
@@ -1,11 +1,14 @@
 #!/bin/bash
 #This is sample implementation of DTMF decoder using my C implementation of Goertzel Algorithm
 #This is not very efficient or precise, it's just proof of concept
+#Note that it's also quite tricky (but not imposible) to detect DTMF using microphone
+#You will probably need to tune treshold and mixer settings a bit...
+#I've had best results using dtmfdial (Linux software) and two soundcards connected directly using cable
 #Usage example: arecord 2>/dev/null | ./dtmf.sh
 
-tresh=3
+tresh=10
 last='';
-./goertzel -i -q -r 8000 -s 400 -t $tresh -f 697 -f 770 -f 852 -f 941 -f 1209 -f 1336 -f 1477 -f 1633 | while read line; do
+./goertzel -i -q -a -r 8000 -s 400 -t $tresh -f 697 -f 770 -f 852 -f 941 -f 1209 -f 1336 -f 1477 -f 1633 $@ | while read line; do
 	#echo "$line";
 
 	#Get time
diff --git a/c/goertzel/goertzel.c b/c/goertzel/goertzel.c
index f5250a0..a269750 100644
--- a/c/goertzel/goertzel.c
+++ b/c/goertzel/goertzel.c
@@ -76,12 +76,13 @@ int main(int argc, char ** argv) {
 	int samplecount = 4000;
 	int treshold = -1;
 	char noreturn = 0;
+	char repeat = 1;
 	char integers=0;
 	char verbose=1;
 	int freqs[argc+1]; freqs[0]=-1;
 
 	int opt;
-	while ((opt = getopt(argc, argv, "?r:s:f:t:iqn")) != -1) {
+	while ((opt = getopt(argc, argv, "?r:s:f:t:iqna")) != -1) {
 		switch (opt) {
 			case 'r':
 				samplerate = atoi(optarg);
@@ -98,6 +99,9 @@ int main(int argc, char ** argv) {
 			case 'i':
 				integers = 1;
 				break;
+			case 'a':
+				repeat = 0;
+				break;
 			case 'n':
 				noreturn = 1;
 				break;
@@ -152,7 +156,7 @@ int main(int argc, char ** argv) {
 
 			//Set print true if over treshold or if changed to false (print for the last time after going under treshold)
 			printnow = power[i] > treshold;
-			print = print || printnow || (printlast && !noreturn);
+			print = !(!repeat && printlast && !(!printnow)) && (print || printnow || (printlast && !noreturn));
 		}
 		printlast = printnow;
 		fflush(stdout);
-- 
2.30.2