--- res/res_pjsip_sdp_rtp.c	(Asterisk 13.15.0)
+++ res/res_pjsip_sdp_rtp.c	(working copy)
@@ -431,2 +431,3 @@
 {
+	extern pj_bool_t pjsip_use_compact_form;
 	pjmedia_sdp_rtpmap rtpmap;
@@ -439,2 +440,7 @@
 	pj_strdup2(pool, &media->desc.fmt[media->desc.fmt_count++], tmp);
+
+	if (35 > rtp_code && pjsip_use_compact_form) {
+		return NULL;
+	}
+
 	rtpmap.pt = media->desc.fmt[media->desc.fmt_count - 1];
@@ -1230,7 +1236,5 @@
 
-		if (!(attr = generate_rtpmap_attr(session, media, pool, rtp_code, 1, format, 0))) {
-			ao2_ref(format, -1);
-			continue;
+		if ((attr = generate_rtpmap_attr(session, media, pool, rtp_code, 1, format, 0))) {
+			media->attr[media->attr_count++] = attr;
 		}
-		media->attr[media->attr_count++] = attr;
 
@@ -1263,8 +1267,6 @@
 
-			if (!(attr = generate_rtpmap_attr(session, media, pool, rtp_code, 0, NULL, index))) {
-				continue;
+			if ((attr = generate_rtpmap_attr(session, media, pool, rtp_code, 0, NULL, index))) {
+				media->attr[media->attr_count++] = attr;
 			}
 
-			media->attr[media->attr_count++] = attr;
-
 			if (index == AST_RTP_DTMF) {