Added support for modulation (not just two tone addition) in tonezones

git-svn-id: http://svn.digium.com/svn/zaptel/trunk@313 5390a7c7-147a-4af0-8ec9-7488f05a26cb

1 files changed, 13 insertions, 2 deletions

diff --git a/zaptel.h b/zaptel.h
index a45b561..aa42374 100755
--- a/zaptel.h
+++ b/zaptel.h
@@ -641,7 +641,7 @@ struct zt_tone_def {		/* Structure for zone programming */
 	int fac2;		
 	int init_v2_2;		
 	int init_v3_2;
-
+	int modulate;
 
 };
 
@@ -842,6 +842,7 @@ struct zt_tone_state {
 	int v1_2;
 	int v2_2;
 	int v3_2;
+	int modulate;
 };
 
 #ifdef CONFIG_ZAPATA_NET
@@ -1322,12 +1323,16 @@ struct zt_tone {
 	int tonesamples;		/* How long to play this tone before 
 					   going to the next (in samples) */
 	struct zt_tone *next;		/* Next tone in this sequence */
+
+	int modulate;
 };
 
 static inline short zt_tone_nextsample(struct zt_tone_state *ts, struct zt_tone *zt)
 {
 	/* follow the curves, return the sum */
 
+	int p;
+
 	ts->v1_1 = ts->v2_1;
 	ts->v2_1 = ts->v3_1;
 	ts->v3_1 = (zt->fac1 * ts->v2_1 >> 15) - ts->v1_1;
@@ -1337,7 +1342,13 @@ static inline short zt_tone_nextsample(struct zt_tone_state *ts, struct zt_tone
 	ts->v3_2 = (zt->fac2 * ts->v2_2 >> 15) - ts->v1_2;
 
 	/* Return top 16 bits */
-	return ts->v3_1 + ts->v3_2;
+	if (!ts->modulate) return ts->v3_1 + ts->v3_2;
+	/* we are modulating */
+	p = ts->v3_2 - 32768;
+	if (p < 0) p = -p;
+	p = ((p * 9) / 10) + 1;
+	return (ts->v3_1 * p) >> 15;
+
 }
 
 static inline short zt_txtone_nextsample(struct zt_chan *ss)