TT#98901 add limit to length of DTX processing

Change-Id: I6fba28b985ff63de6185dccc2ca16f4264a0493d

daemon/codec.c

@@ -74,6 +74,7 @@ struct dtx_buffer {
 	int tspp; // timestamp increment per packet
 	struct call *call;
 	unsigned long ts;
+	time_t start;
 };
 struct dtx_entry {
 	struct timerthread_queue_entry ttq_entry;
@@ -1908,9 +1909,10 @@ static void __dtx_send_later(struct timerthread_queue *ttq, void *p) {
 		unsigned long dtxe_ts = dtxe->ts;
 
 		mutex_lock(&dtxb->lock);
+		unsigned int diff = rtpe_now.tv_sec - dtxb->start;
 		unsigned long dtxb_ts = dtxb->ts;
 
-		if (dtxe_ts == dtxb_ts) {
+		if (dtxe_ts == dtxb_ts && (rtpe_config.max_dtx <= 0 || diff < rtpe_config.max_dtx)) {
 			ilog(LOG_DEBUG, "RTP media for TS %lu+ missing, triggering DTX",
 					dtxe_ts);
 
@@ -2301,6 +2303,7 @@ static int packet_decode(struct codec_ssrc_handler *ch, struct transcode_packet
 		mutex_lock(&dtxb->lock);
 		if (ts != dtxb->ts)
 			dtxb->ts = ts;
+		dtxb->start = rtpe_now.tv_sec;
 		mutex_unlock(&dtxb->lock);
 
 		struct dtx_entry *dtxe = g_slice_alloc0(sizeof(*dtxe));

daemon/main.c

@@ -79,6 +79,7 @@ struct rtpengine_config rtpe_config = {
 	.media_num_threads = -1,
 	.dtls_rsa_key_size = 2048,
 	.dtls_signature = 256,
+	.max_dtx = 30,
 };
 
 static void sighandler(gpointer x) {
@@ -461,6 +462,7 @@ static void options(int *argc, char ***argv) {
 		{ "http-threads", 0,0,	G_OPTION_ARG_INT,	&rtpe_config.http_threads,"Number of worker threads for HTTP and WS","INT"},
 #ifdef WITH_TRANSCODING
 		{ "dtx-delay",	0,0,	G_OPTION_ARG_INT,	&rtpe_config.dtx_delay,	"Delay in milliseconds to trigger DTX handling","INT"},
+		{ "max-dtx",	0,0,	G_OPTION_ARG_INT,	&rtpe_config.max_dtx,	"Maximum duration of DTX handling",	"INT"},
 #endif
 
 		{ NULL, }

daemon/rtpengine.pod

@@ -738,6 +738,13 @@ time during a transmission gap, for example by generating comfort noise. The
 delay should be configured to just slightly more than the expected incoming
 jitter.
 
+=item B<--max-dtx=>I<INT>
+
+Maximum duration for DTX handling in seconds. If no further RTP media is
+received within this time frame, then DTX processing will stop. Can be set to
+zero or negative to disable and keep DTX processing on indefinitely. Defaults
+to 30 seconds.
+
 =back
 
 =head1 INTERFACES

include/main.h

@@ -107,6 +107,7 @@ struct rtpengine_config {
 	char			*https_key;
 	int			http_threads;
 	int			dtx_delay;
+	int			max_dtx;
 };