Index: dsp.c
===================================================================
RCS file: /usr/cvsroot/asterisk/dsp.c,v
retrieving revision 1.46
diff -u -r1.46 dsp.c
--- dsp.c	25 Jul 2005 21:57:14 -0000	1.46
+++ dsp.c	27 Jul 2005 17:26:47 -0000
@@ -93,7 +93,7 @@
 
 #define DEFAULT_THRESHOLD	512
 
-#define BUSY_PERCENT		10	/* The percentage diffrence between the two last silence periods */
+#define BUSY_PERCENT		15	/* The percentage diffrence between the two last silence periods */
 #define BUSY_THRESHOLD		100	/* Max number of ms difference between max and min times in busy */
 #define BUSY_MIN		75	/* Busy must be at least 80 ms in half-cadence */
 #define BUSY_MAX		1100	/* Busy can't be longer than 1100 ms in half-cadence */
@@ -304,6 +304,8 @@
 	int features;
 	int busymaybe;
 	int busycount;
+	int busy_tonelength;
+	int busy_quietlength;
 	int historicnoise[DSP_HISTORY];
 	int historicsilence[DSP_HISTORY];
 	goertzel_state_t freqs[7];
@@ -1154,6 +1156,7 @@
 		accum += abs(s[x]);
 	accum /= len;
 	if (accum < dsp->threshold) {
+		/* Silent */
 		dsp->totalsilence += len/8;
 		if (dsp->totalnoise) {
 			/* Move and save history */
@@ -1167,6 +1170,7 @@
 		dsp->totalnoise = 0;
 		res = 1;
 	} else {
+		/* Not silent */
 		dsp->totalnoise += len/8;
 		if (dsp->totalsilence) {
 			int silence1 = dsp->historicsilence[DSP_HISTORY - 1];
@@ -1176,12 +1180,12 @@
 			dsp->historicsilence[DSP_HISTORY - 1] = dsp->totalsilence;
 			/* check if the previous sample differs only by BUSY_PERCENT from the one before it */
 			if (silence1 < silence2) {
-				if (silence1 + silence1/BUSY_PERCENT >= silence2)
+				if (silence1 + silence1*BUSY_PERCENT/100 >= silence2)
 					dsp->busymaybe = 1;
 				else 
 					dsp->busymaybe = 0;
 			} else {
-				if (silence1 - silence1/BUSY_PERCENT <= silence2)
+				if (silence1 - silence1*BUSY_PERCENT/100 <= silence2)
 					dsp->busymaybe = 1;
 				else 
 					dsp->busymaybe = 0;
@@ -1193,6 +1197,7 @@
 		*totalsilence = dsp->totalsilence;
 	return res;
 }
+
 #ifdef BUSYDETECT_MARTIN
 int ast_dsp_busydetect(struct ast_dsp *dsp)
 {
@@ -1216,18 +1221,18 @@
 	for (x=DSP_HISTORY - dsp->busycount;x<DSP_HISTORY;x++) {
 #ifndef BUSYDETECT_TONEONLY
 		if (avgsilence > dsp->historicsilence[x]) {
-			if (avgsilence - (avgsilence / BUSY_PERCENT) <= dsp->historicsilence[x])
+			if (avgsilence - (avgsilence*BUSY_PERCENT/100) <= dsp->historicsilence[x])
 				hitsilence++;
 		} else {
-			if (avgsilence + (avgsilence / BUSY_PERCENT) >= dsp->historicsilence[x])
+			if (avgsilence + (avgsilence*BUSY_PERCENT/100) >= dsp->historicsilence[x])
 				hitsilence++;
 		}
 #endif
 		if (avgtone > dsp->historicnoise[x]) {
-			if (avgtone - (avgtone / BUSY_PERCENT) <= dsp->historicnoise[x])
+			if (avgtone - (avgtone*BUSY_PERCENT/100) <= dsp->historicnoise[x])
 				hittone++;
 		} else {
-			if (avgtone + (avgtone / BUSY_PERCENT) >= dsp->historicnoise[x])
+			if (avgtone + (avgtone*BUSY_PERCENT/100) >= dsp->historicnoise[x])
 				hittone++;
 		}
 	}
@@ -1243,19 +1248,39 @@
 #error You cant use BUSYDETECT_TONEONLY together with BUSYDETECT_COMPARE_TONE_AND_SILENCE
 #endif
 		if (avgtone > avgsilence) {
-			if (avgtone - avgtone/(BUSY_PERCENT*2) <= avgsilence)
+			if (avgtone - avgtone*BUSY_PERCENT/100 <= avgsilence)
 				res = 1;
 		} else {
-			if (avgtone + avgtone/(BUSY_PERCENT*2) >= avgsilence)
+			if (avgtone + avgtone*BUSY_PERCENT/100 >= avgsilence)
 				res = 1;
 		}
 #else
 		res = 1;
 #endif
 	}
+	/* If we know the expected busy tone length, check we are in the range */
+	if (res && (dsp->busy_tonelength > 0)) {
+		if (abs(avgtone - dsp->busy_tonelength) > (dsp->busy_tonelength*BUSY_PERCENT/200)) {
+#if 0
+			ast_log(LOG_NOTICE, "busy detector: avgtone of %d not close enough to desired %d\n",
+						avgtone, dsp->busy_tonelength);
+#endif
+			res = 0;
+		}
+	}
+	/* If we know the expected busy tone silent-period length, check we are in the range */
+	if (res && (dsp->busy_quietlength > 0)) {
+		if (abs(avgsilence - dsp->busy_quietlength) > (dsp->busy_quietlength*BUSY_PERCENT/200)) {
 #if 0
+			ast_log(LOG_NOTICE, "busy detector: avgsilence of %d not close enough to desired %d\n",
+						avgsilence, dsp->busy_quietlength);
+#endif
+			res = 0;
+		}
+	}
+#if 1
 	if (res)
-		ast_log(LOG_NOTICE, "detected busy, avgtone: %d, avgsilence %d\n", avgtone, avgsilence);
+		ast_log(LOG_NOTICE, "ast_dsp_busydetect detected busy, avgtone: %d, avgsilence %d\n", avgtone, avgsilence);
 #endif
 	return res;
 }
@@ -1574,6 +1599,13 @@
 	if (cadences > DSP_HISTORY)
 		cadences = DSP_HISTORY;
 	dsp->busycount = cadences;
+}
+
+void ast_dsp_set_busy_pattern(struct ast_dsp *dsp, int tonelength, int quietlength)
+{
+	dsp->busy_tonelength = tonelength;
+	dsp->busy_quietlength = quietlength;
+	ast_log(LOG_NOTICE, "dsp busy pattern set to %d,%d\n", tonelength, quietlength);
 }
 
 void ast_dsp_digitreset(struct ast_dsp *dsp)
Index: channels/chan_zap.c
===================================================================
RCS file: /usr/cvsroot/asterisk/channels/chan_zap.c,v
retrieving revision 1.482
diff -u -r1.482 chan_zap.c
--- channels/chan_zap.c	25 Jul 2005 22:16:35 -0000	1.482
+++ channels/chan_zap.c	27 Jul 2005 17:27:20 -0000
@@ -234,6 +235,8 @@
 static int busydetect = 0;
 
 static int busycount = 3;
+static int busy_tonelength = 0;
+static int busy_quietlength = 0;
 
 static int callprogress = 0;
 
@@ -611,6 +614,8 @@
 	int echotraining;
 	char echorest[20];
 	int busycount;
+	int busy_tonelength;
+	int busy_quietlength;
 	int callprogress;
 	struct timeval flashtime;			/* Last flash-hook time */
 	struct ast_dsp *dsp;
@@ -4824,6 +4829,7 @@
 						ast_dsp_set_call_progress_zone(i->dsp, progzone);
 					if (i->busydetect && CANBUSYDETECT(i)) {
 						ast_dsp_set_busy_count(i->dsp, i->busycount);
+						ast_dsp_set_busy_pattern(i->dsp, i->busy_tonelength, i->busy_quietlength);
 					}
 				}
 			}
@@ -6871,6 +6877,8 @@
 		tmp->echocanbridged = echocanbridged;
 		tmp->busydetect = busydetect;
 		tmp->busycount = busycount;
+		tmp->busy_tonelength = busy_tonelength;
+		tmp->busy_quietlength = busy_quietlength;
 		tmp->callprogress = callprogress;
 		tmp->cancallforward = cancallforward;
 		tmp->dtmfrelax = relaxdtmf;
@@ -10054,6 +10062,10 @@
 			busydetect = ast_true(v->value);
 		} else if (!strcasecmp(v->name, "busycount")) {
 			busycount = atoi(v->value);
+		} else if (!strcasecmp(v->name, "busypattern")) {
+			if (sscanf(v->value, "%d,%d", &busy_tonelength, &busy_quietlength) != 2) {
+				ast_log(LOG_ERROR, "busypattern= expects busypattern=tonelength,quietlength\n");
+			}
 		} else if (!strcasecmp(v->name, "callprogress")) {
 			if (ast_true(v->value))
 				callprogress |= 1;
Index: configs/zapata.conf.sample
===================================================================
RCS file: /usr/cvsroot/asterisk/configs/zapata.conf.sample,v
retrieving revision 1.49
diff -u -r1.49 zapata.conf.sample
--- configs/zapata.conf.sample	19 Jul 2005 13:30:37 -0000	1.49
+++ configs/zapata.conf.sample	27 Jul 2005 17:27:21 -0000
@@ -366,17 +366,35 @@
 ;
 ; On trunk interfaces (FXS) and E&M interfaces (E&M, Wink, Feature Group D
 ; etc, it can be useful to perform busy detection either in an effort to 
-; detect hangup or for detecting busies
+; detect hangup or for detecting busies.  This enables listening for
+; the beep-beep busy pattern.
 ;
 ;busydetect=yes
 ;
 ; If busydetect is enabled, is also possible to specify how many
-; busy tones to wait before hanging up. The default is 4, but
+; busy tones to wait for before hanging up. The default is 4, but
 ; better results can be achieved if set to 6 or even 8. Mind that
 ; higher the number, more time is needed to hangup a channel, but
 ; lower is probability to get random hangups
 ;
-;busycount=4
+;busycount=4
+;
+; If busydetect is enabled, is also possible to specify the
+; cadence of your busy signal.  In many countries it is 500mec
+; on, 500msec off.
+; Without busypattern specified, we'll accept any regular
+; sound-silence pattern than repeats busycount times as a busy
+; signal.
+; If you specify busypattern then we'll further check the length
+; of the sound (tone) and silence, which will further reduce the
+; chance of a false positive.
+;
+;busypattern=500,500
+;
+; NOTE: In the Asterisk Makefile you'll find further options to tweak
+; the busy detector.  If your country has a busy tone with the same
+; lengh tone and silence (as many countries do), consider defining
+; the -DBUSYDETECT_COMPARE_TONE_AND_SILENCE option.
 ;
 ; Use a polarity reversal to mark when a outgoing call is answered by the
 ; remote party.
Index: include/asterisk/dsp.h
===================================================================
RCS file: /usr/cvsroot/asterisk/include/asterisk/dsp.h,v
retrieving revision 1.7
diff -u -r1.7 dsp.h
--- include/asterisk/dsp.h	28 Jun 2005 14:36:56 -0000	1.7
+++ include/asterisk/dsp.h	27 Jul 2005 17:27:22 -0000
@@ -53,6 +53,9 @@
 /* Set number of required cadences for busy */
 void ast_dsp_set_busy_count(struct ast_dsp *dsp, int cadences);
 
+/* Set expected lengths of the busy tone */
+void ast_dsp_set_busy_pattern(struct ast_dsp *dsp, int tonelength, int quietlength);
+
 /* Scans for progress indication in audio */
 int ast_dsp_call_progress(struct ast_dsp *dsp, struct ast_frame *inf);