bridge: Don't try to match audio formats.

When bridging channels we were trying to match the audio
formats of both sides in combination with the configured
formats. While this is allowed in SDP in practice this
causes extra reinvites and problems. This change ensures
that audio streams use the formats of the first existing
active audio stream. It is only when other stream types
(like video) exist that this will result in re-negotiation
occurring for those streams only.

ASTERISK-28871

Change-Id: I22f5a3e7db29e00c165e74d05d10856f6086fe47

bridges/bridge_native_rtp.c

@@ -886,8 +886,6 @@ static struct ast_stream_topology *native_rtp_request_stream_topology_update(
 
 	if (audio_formats) {
 		for (i = 0; i < ast_stream_topology_get_count(new_topology); ++i) {
-			struct ast_format_cap *joint;
-
 			stream = ast_stream_topology_get_stream(new_topology, i);
 
 			if (ast_stream_get_type(stream) != AST_MEDIA_TYPE_AUDIO ||
@@ -895,16 +893,8 @@ static struct ast_stream_topology *native_rtp_request_stream_topology_update(
 				continue;
 			}
 
-			joint = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
-			if (!joint) {
-				continue;
-			}
-
-			ast_format_cap_append_from_cap(joint, ast_stream_get_formats(stream),
-				AST_MEDIA_TYPE_AUDIO);
-			ast_format_cap_append_from_cap(joint, audio_formats, AST_MEDIA_TYPE_AUDIO);
-			ast_stream_set_formats(stream, joint);
-			ao2_ref(joint, -1);
+			/* We haven't actually modified audio_formats so this is safe */
+			ast_stream_set_formats(stream, (struct ast_format_cap *)audio_formats);
 		}
 	}
 

bridges/bridge_simple.c

@@ -90,8 +90,6 @@ static struct ast_stream_topology *simple_bridge_request_stream_topology_update(
 
 	if (audio_formats) {
 		for (i = 0; i < ast_stream_topology_get_count(new_topology); ++i) {
-			struct ast_format_cap *joint;
-
 			stream = ast_stream_topology_get_stream(new_topology, i);
 
 			if (ast_stream_get_type(stream) != AST_MEDIA_TYPE_AUDIO ||
@@ -99,16 +97,8 @@ static struct ast_stream_topology *simple_bridge_request_stream_topology_update(
 				continue;
 			}
 
-			joint = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
-			if (!joint) {
-				continue;
-			}
-
-			ast_format_cap_append_from_cap(joint, ast_stream_get_formats(stream),
-				AST_MEDIA_TYPE_AUDIO);
-			ast_format_cap_append_from_cap(joint, audio_formats, AST_MEDIA_TYPE_AUDIO);
-			ast_stream_set_formats(stream, joint);
-			ao2_ref(joint, -1);
+			/* We haven't actually modified audio_formats so this is safe */
+			ast_stream_set_formats(stream, (struct ast_format_cap *)audio_formats);
 		}
 	}