1 files changed, 63 insertions, 0 deletions
diff --git a/src/mos.c b/src/mos.c
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--- /dev/null
+++ b/src/mos.c
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+/**
+ * @file src/mos.c  MOS (Mean Opinion Score)
+ *
+ * Copyright (C) 2010 - 2016 Creytiv.com
+ */
+#include <re.h>
+#include <baresip.h>
+#include "core.h"
+
+
+static double rfactor_to_mos(double r)
+{
+	double mos;
+
+	mos = 1 + (0.035) * (r) + (0.000007) * (r) * ((r) - 60) * (100 - (r));
+
+	if (mos > 5)
+		mos = 5;
+
+	return mos;
+}
+
+
+/**
+ * Calculate Pseudo-MOS (Mean Opinion Score)
+ *
+ * @param r_factor          Pointer to where R-factor is written (optional)
+ * @param rtt               Average roundtrip time
+ * @param jitter            Jitter
+ * @param num_packets_lost  Number of packets lost
+ *
+ * @return The calculated MOS value from 1 to 5
+ *
+ * Reference:  https://metacpan.org/pod/Algorithm::MOS
+ */
+double mos_calculate(double *r_factor, double rtt,
+		     double jitter, u_int32_t num_packets_lost)
+{
+	double effective_latency = rtt + (jitter * 2) + 10;
+	double mos_val;
+	double r;
+
+	if (effective_latency < 160) {
+		r = 93.2 - (effective_latency / 40);
+	}
+	else {
+		r = 93.2 - (effective_latency - 120) / 10;
+	}
+
+	r = r - (num_packets_lost * 2.5);
+
+	if (r > 100)
+		r = 100;
+	else if (r < 0)
+		r = 0;
+
+	mos_val = rfactor_to_mos(r);
+
+	if (r_factor)
+		*r_factor = r;
+
+	return mos_val;
+}