diff --git a/daemon/codec.c b/daemon/codec.c
index a678f6e8b..2ad173789 100644
--- a/daemon/codec.c
+++ b/daemon/codec.c
@@ -2502,6 +2502,27 @@ static int packet_decode(struct codec_ssrc_handler *ch, struct transcode_packet
 	return ret;
 }
 
+
+static void codec_calc_jitter(struct media_packet *mp, unsigned int clockrate) {
+	if (!mp->ssrc_in)
+		return;
+	struct ssrc_entry_call *sec = mp->ssrc_in->parent;
+
+	// RFC 3550 A.8
+	uint32_t transit = (((timeval_us(&mp->tv) / 1000) * clockrate) / 1000)
+		- ntohl(mp->rtp->timestamp);
+	mutex_lock(&sec->h.lock);
+	int32_t d = 0;
+	if (sec->transit)
+		d = transit - sec->transit;
+	sec->transit = transit;
+	if (d < 0)
+		d = -d;
+	sec->jitter += d - ((sec->jitter + 8) >> 4);
+	mutex_unlock(&sec->h.lock);
+}
+
+
 static int handler_func_transcode(struct codec_handler *h, struct media_packet *mp) {
 	if (G_UNLIKELY(!mp->rtp))
 		return handler_func_passthrough(h, mp);
@@ -2514,6 +2535,8 @@ static int handler_func_transcode(struct codec_handler *h, struct media_packet *
 			ntohl(mp->rtp->ssrc), mp->rtp->m_pt, ntohs(mp->rtp->seq_num),
 			ntohl(mp->rtp->timestamp), mp->payload.len);
 
+	codec_calc_jitter(mp, h->source_pt.clock_rate);
+
 	if (h->stats_entry) {
 		unsigned int idx = rtpe_now.tv_sec & 1;
 		int last_tv_sec = g_atomic_int_get(&h->stats_entry->last_tv_sec[idx]);
diff --git a/daemon/rtcp.c b/daemon/rtcp.c
index ad93119f9..64909ddcd 100644
--- a/daemon/rtcp.c
+++ b/daemon/rtcp.c
@@ -1431,6 +1431,7 @@ GString *rtcp_sender_report(uint32_t ssrc, uint32_t ts, uint32_t packets, uint32
 				tv_diff = timeval_diff(&rtpe_now, &si->received);
 				ntp_middle_bits = si->ntp_middle_bits;
 			}
+			uint32_t jitter = se->jitter;
 			mutex_unlock(&se->h.lock);
 
 			uint64_t lost = atomic64_get(&s->packets_lost);
@@ -1445,8 +1446,8 @@ GString *rtcp_sender_report(uint32_t ssrc, uint32_t ts, uint32_t packets, uint32
 				.high_seq_received = htonl(atomic64_get(&s->last_seq)),
 				.lsr = htonl(ntp_middle_bits),
 				.dlsr = htonl(tv_diff * 65536 / 1000000),
+				.jitter = htonl(jitter >> 4),
 			};
-			// XXX jitter
 			n++;
 		}
 		ssrc_ctx_put(&s);
diff --git a/include/ssrc.h b/include/ssrc.h
index 6698d7c22..fd203bdc1 100644
--- a/include/ssrc.h
+++ b/include/ssrc.h
@@ -98,6 +98,7 @@ struct ssrc_entry_call {
 	// for transcoding
 	// input only
 	packet_sequencer_t sequencer;
+	uint32_t jitter, transit;
 	// output only
 	uint16_t seq_diff;
 };