--- main/channel.c	(Asterisk 13.38.0)
+++ main/channel.c	(working copy)
@@ -5787,2 +5787,7 @@ static int set_format(struct ast_channel
 
+	cap_native = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
+	if (!cap_native) {
+		return -1;
+	}
+
 	/* See if the underlying channel driver is capable of performing transcoding for us */
@@ -5794,7 +5799,3 @@ static int set_format(struct ast_channel
 
-		ast_channel_lock(chan);
-		cap_native = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
-		if (!cap_native
-			|| ast_format_cap_append(cap_native, best_set_fmt, 0)) {
-			ast_channel_unlock(chan);
+		if (ast_format_cap_append(cap_native, best_set_fmt, 0)) {
 			ao2_cleanup(cap_native);
@@ -5802,2 +5803,3 @@ static int set_format(struct ast_channel
 		}
+		ast_channel_lock(chan);
 		ast_channel_nativeformats_set(chan, cap_native);
@@ -5830,5 +5832,10 @@ static int set_format(struct ast_channel
 
-	cap_native = ast_channel_nativeformats(chan);
+	if (ast_format_cap_append_from_cap(cap_native, ast_channel_nativeformats(chan), AST_MEDIA_TYPE_AUDIO)) {
+		ast_channel_unlock(chan);
+		ao2_cleanup(cap_native);
+		return -1;
+	}
 	if (ast_format_cap_empty(cap_native)) {
 		ast_channel_unlock(chan);
+		ao2_cleanup(cap_native);
 		ast_log(LOG_ERROR, "Unable to set format because channel %s supports no formats\n",
@@ -5852,2 +5859,3 @@ static int set_format(struct ast_channel
 		ast_channel_unlock(chan);
+		ao2_cleanup(cap_native);
 		ast_format_cap_get_names(cap_set, &codec_set);
@@ -5866,2 +5874,3 @@ static int set_format(struct ast_channel
 		ast_channel_unlock(chan);
+		ao2_cleanup(cap_native);
 		return 0;
@@ -5915,2 +5924,4 @@ static int set_format(struct ast_channel
 
+	ao2_cleanup(cap_native);
+
 	return res;
--- channels/chan_sip.c	(Asterisk 13.38.0)
+++ channels/chan_sip.c	(working copy)
@@ -11159,11 +11159,11 @@ static int process_sdp(struct sip_pvt *p
 				ast_format_cap_get_names(ast_channel_nativeformats(p->owner), &cap_buf));
 		}
 
 		caps = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
 		if (caps) {
-			tmp_fmt = ast_format_cap_get_format(p->jointcaps, 0);
+			tmp_fmt = ast_format_cap_get_best_by_type(p->jointcaps, AST_MEDIA_TYPE_AUDIO);
 			framing = ast_format_cap_get_format_framing(p->jointcaps, tmp_fmt);
 			ast_format_cap_append(caps, tmp_fmt, framing);
 			ast_format_cap_append_from_cap(caps, vpeercapability, AST_MEDIA_TYPE_VIDEO);
 			ast_format_cap_append_from_cap(caps, tpeercapability, AST_MEDIA_TYPE_TEXT);
 			ast_channel_nativeformats_set(p->owner, caps);