From 3eae4b3af3829a5a9a888ddd8cb06f748e25e055 Mon Sep 17 00:00:00 2001
From: Richard Fuchs <rfuchs@sipwise.com>
Date: Thu, 10 Jun 2021 14:59:49 -0400
Subject: [PATCH] TT#14008 add MOS-LQ option

Change-Id: I2cacceda1f910fb2ed74ccd9f17cde1bf50031b0
---
 daemon/main.c        | 10 ++++++++++
 daemon/rtpengine.pod |  7 +++++++
 daemon/ssrc.c        |  5 ++++-
 include/main.h       |  4 ++++
 4 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/daemon/main.c b/daemon/main.c
index 153290ad2..513e211b2 100644
--- a/daemon/main.c
+++ b/daemon/main.c
@@ -434,6 +434,7 @@ static void options(int *argc, char ***argv) {
 #ifdef HAVE_MQTT
 	AUTO_CLEANUP_GBUF(mqtt_publish_scope);
 #endif
+	AUTO_CLEANUP_GBUF(mos);
 
 	rwlock_lock_w(&rtpe_config.config_lock);
 
@@ -554,6 +555,7 @@ static void options(int *argc, char ***argv) {
 		{ "mqtt-publish-interval",0,0,G_OPTION_ARG_INT,	&rtpe_config.mqtt_publish_interval,"Publish timer interval",	"MILLISECONDS"},
 		{ "mqtt-publish-scope",0,0,G_OPTION_ARG_STRING,	&mqtt_publish_scope,	"Scope for published mosquitto messages","global|call|media"},
 #endif
+		{ "mos",0,0,		G_OPTION_ARG_STRING,	&mos,		"Type of MOS calculation","CQ|LQ"},
 
 		{ NULL, }
 	};
@@ -820,6 +822,14 @@ static void options(int *argc, char ***argv) {
 			die("Invalid --mqtt-publish-scope option ('%s')", mqtt_publish_scope);
 	}
 #endif
+	if (mos) {
+		if (!strcasecmp(mos, "cq"))
+			rtpe_config.mos = MOS_CQ;
+		else if (!strcmp(mos, "lq"))
+			rtpe_config.mos = MOS_LQ;
+		else
+			die("Invalid --mos option ('%s')", mos);
+	}
 
 	rwlock_unlock_w(&rtpe_config.config_lock);
 }
diff --git a/daemon/rtpengine.pod b/daemon/rtpengine.pod
index 6c07df321..60888e11b 100644
--- a/daemon/rtpengine.pod
+++ b/daemon/rtpengine.pod
@@ -978,6 +978,13 @@ call participant, so usually 2 media per call) will be published to Mosquitto
 with stats for that call media every I<interval> milliseconds, plus one message
 every I<interval> milliseconds with global stats.
 
+=item B<--mos=>B<CQ>|B<LQ>
+
+MOS calculation formula. Defaults to B<CQ> (conversational quality) which takes
+RTT into account and therefore requires peers to correctly send RTCP. If set to
+B<LQ> (listening quality) RTT is ignored, allowing a MOS to be calculated in
+the absence of RTCP.
+
 =back
 
 =head1 INTERFACES
diff --git a/daemon/ssrc.c b/daemon/ssrc.c
index 315df6069..dfc9f230f 100644
--- a/daemon/ssrc.c
+++ b/daemon/ssrc.c
@@ -61,8 +61,11 @@ static void ssrc_entry_put(void *ep) {
 
 // returned as mos * 10 (i.e. 10 - 50 for 1.0 to 5.0)
 static void mos_calc(struct ssrc_stats_block *ssb) {
-	if (!ssb->rtt)
+	uint64_t rtt = ssb->rtt;
+	if (rtpe_config.mos == MOS_CQ && !rtt)
 		return; // can not compute the MOS-CQ unless we have a valid RTT
+	else if (rtpe_config.mos == MOS_LQ)
+		rtt = 0; // ignore RTT
 
 	// as per https://www.pingman.com/kb/article/how-is-mos-calculated-in-pingplotter-pro-50.html
 	int eff_rtt = ssb->rtt / 1000 + ssb->jitter * 2 + 10;
diff --git a/include/main.h b/include/main.h
index cfdecc226..e33330984 100644
--- a/include/main.h
+++ b/include/main.h
@@ -143,6 +143,10 @@ struct rtpengine_config {
 		MPS_CALL,
 		MPS_MEDIA,
 	}			mqtt_publish_scope;
+	enum {
+		MOS_CQ = 0,
+		MOS_LQ,
+	}			mos;
 };