bridge_softmix: Use removed stream spots when renegotiating.
authorJoshua Colp <jcolp@digium.com>
Sun, 16 Jul 2017 17:31:35 +0000 (17:31 +0000)
committerJoshua Colp <jcolp@digium.com>
Sun, 16 Jul 2017 17:31:35 +0000 (17:31 +0000)
Streams are never truly removed in SDP, they still occupy
a location within the SDP. This location can be reused by
another stream if it so chooses.

This change takes advantage of this such that if a new stream
is needing to be added for a new participant any removed streams
are instead replaced first. This reduces the size of the SDP
and the number of streams.

ASTERISK-27134

Change-Id: I95cdcfd55cf47e02ea52abb5d94008db3fb68b1d

bridges/bridge_softmix.c

index ae877eb..3801ccb 100644 (file)
@@ -524,15 +524,32 @@ static int append_all_streams(struct ast_stream_topology *dest,
        const struct ast_stream_topology *source)
 {
        int i;
+       int dest_index = 0;
 
        for (i = 0; i < ast_stream_topology_get_count(source); ++i) {
                struct ast_stream *clone;
+               int added = 0;
 
                clone = ast_stream_clone(ast_stream_topology_get_stream(source, i), NULL);
                if (!clone) {
                        return -1;
                }
-               if (ast_stream_topology_append_stream(dest, clone) < 0) {
+
+               /* If we can reuse an existing removed stream then do so */
+               while (dest_index < ast_stream_topology_get_count(dest)) {
+                       struct ast_stream *stream = ast_stream_topology_get_stream(dest, dest_index);
+
+                       dest_index++;
+
+                       if (ast_stream_get_state(stream) == AST_STREAM_STATE_REMOVED) {
+                               ast_stream_topology_set_stream(dest, dest_index - 1, clone);
+                               added = 1;
+                               break;
+                       }
+               }
+
+               /* If no removed stream exists that we took the place of append the stream */
+               if (!added && ast_stream_topology_append_stream(dest, clone) < 0) {
                        ast_stream_free(clone);
                        return -1;
                }