add silence gen to wait apps

asterisk.conf's 'transmit_silence' option existed before
this patch, but was limited to only generating silence
while recording and sending DTMF. Now enabling the
transmit_silence option generates silence during wait
times as well.
  
To achieve this, ast_safe_sleep has been modified to
generate silence anytime no other generators are present
and transmit_silence is enabled. Wait apps not using
ast_safe_sleep now generate silence when transmit_silence
is enabled as well.

(closes issue 0016524)
Reported by: kobaz

(closes issue 0016523)
Reported by: kobaz
Tested by: dvossel
  
Review: https://reviewboard.asterisk.org/r/456/


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@239718 65c4cc65-6c06-0410-ace0-fbb531ad65f3

Makefile

@@ -618,7 +618,7 @@ samples: adsi
 		echo ";cache_record_files = yes ; Cache recorded sound files to another directory during recording" ; \
 		echo ";record_cache_dir = /tmp ; Specify cache directory (used in cnjunction with cache_record_files)" ; \
 		echo ";transmit_silence_during_record = yes ; Transmit SLINEAR silence while a channel is being recorded" ; \
-		echo ";transmit_silence = yes ; Transmit SLINEAR silence while a channel is being recorded or DTMF is being generated" ; \
+		echo ";transmit_silence = yes ; Transmit SLINEAR silence while a channel is waiting, being recorded, or DTMF is being generated" ; \
 		echo ";transcode_via_sln = yes ; Build transcode paths via SLINEAR, instead of directly" ; \
 		echo ";runuser = asterisk ; The user to run as" ; \
 		echo ";rungroup = asterisk ; The group to run as" ; \

apps/app_waitforring.c

@@ -57,6 +57,7 @@ static int waitforring_exec(struct ast_channel *chan, void *data)
 {
 	struct ast_module_user *u;
 	struct ast_frame *f;
+	struct ast_silence_generator *silgen = NULL;
 	int res = 0;
 	int ms;
 
@@ -67,6 +68,10 @@ static int waitforring_exec(struct ast_channel *chan, void *data)
 
 	u = ast_module_user_add(chan);
 
+	if (ast_opt_transmit_silence) {
+		silgen = ast_channel_start_silence_generator(chan);
+	}
+
 	ms *= 1000;
 	while(ms > 0) {
 		ms = ast_waitfor(chan, ms);
@@ -114,6 +119,10 @@ static int waitforring_exec(struct ast_channel *chan, void *data)
 	}
 	ast_module_user_remove(u);
 
+	if (silgen) {
+		ast_channel_stop_silence_generator(chan, silgen);
+	}
+
 	return res;
 }
 

apps/app_waitforsilence.c

@@ -164,6 +164,7 @@ static int waitforsilence_exec(struct ast_channel *chan, void *data)
 	int timeout = 0;
 	int iterations = 1, i;
 	time_t waitstart;
+	struct ast_silence_generator *silgen = NULL;
 
 	res = ast_answer(chan); /* Answer the channel */
 
@@ -176,11 +177,18 @@ static int waitforsilence_exec(struct ast_channel *chan, void *data)
 	if (option_verbose > 2)
 		ast_verbose(VERBOSE_PREFIX_3 "Waiting %d time(s) for %d ms silence with %d timeout\n", iterations, silencereqd, timeout);
 
+	if (ast_opt_transmit_silence) {
+		silgen = ast_channel_start_silence_generator(chan);
+	}
 	time(&waitstart);
 	res = 1;
 	for (i=0; (i<iterations) && (res == 1); i++) {
 		res = do_waiting(chan, silencereqd, waitstart, timeout);
 	}
+	if (silgen) {
+		ast_channel_stop_silence_generator(chan, silgen);
+	}
+
 	if (res > 0)
 		res = 0;
 	return res;

main/channel.c

@@ -1204,21 +1204,39 @@ struct ast_channel *ast_walk_channel_by_exten_locked(const struct ast_channel *c
 int ast_safe_sleep_conditional(struct ast_channel *chan, int ms, int (*cond)(void*), void *data)
 {
 	struct ast_frame *f;
+	struct ast_silence_generator *silgen = NULL;
+	int res = 0;
+
+	/* If no other generator is present, start silencegen while waiting */
+	if (ast_opt_transmit_silence && !chan->generatordata) {
+		silgen = ast_channel_start_silence_generator(chan);
+	}
 
 	while (ms > 0) {
-		if (cond && ((*cond)(data) == 0))
-			return 0;
+		if (cond && ((*cond)(data) == 0)) {
+			break;
+		}
 		ms = ast_waitfor(chan, ms);
-		if (ms < 0)
-			return -1;
+		if (ms < 0) {
+			res = -1;
+			break;
+		}
 		if (ms > 0) {
 			f = ast_read(chan);
-			if (!f)
-				return -1;
+			if (!f) {
+				res = -1;
+				break;
+			}
 			ast_frfree(f);
 		}
 	}
-	return 0;
+
+	/* stop silgen if present */
+	if (silgen) {
+		ast_channel_stop_silence_generator(chan, silgen);
+	}
+
+	return res;
 }
 
 /*! \brief Wait, look for hangups */