Index: main/rtp.c
===================================================================
--- main/rtp.c  (revision 58347)
+++ main/rtp.c  (working copy)
@@ -1533,7 +1533,7 @@
        struct ast_rtp_protocol *destpr = NULL, *srcpr = NULL;
        enum ast_rtp_get_result audio_dest_res = AST_RTP_GET_FAILED, video_dest_res = AST_RTP_GET_FAILED;
        enum ast_rtp_get_result audio_src_res = AST_RTP_GET_FAILED, video_src_res = AST_RTP_GET_FAILED;
-       int srccodec;
+       int srccodec, destcodec;

        /* Lock channels */
        ast_channel_lock(dest);
@@ -1565,9 +1565,19 @@
        audio_src_res = srcpr->get_rtp_info(src, &srcp);
        video_src_res = srcpr->get_vrtp_info ? srcpr->get_vrtp_info(src, &vsrcp) : AST_RTP_GET_FAILED;

+       /* Ensure we have at least one matching codec */
+       if (srcpr->get_codec)
+               srccodec = srcpr->get_codec(src);
+       else
+               srccodec = 0;
+       if (destpr->get_codec)
+               destcodec = destpr->get_codec(dest);
+       else
+               destcodec = 0;
+
        /* Check if bridge is still possible (In SIP canreinvite=no stops this, like NAT) */
-       if (audio_dest_res != AST_RTP_TRY_NATIVE || audio_src_res != AST_RTP_TRY_NATIVE) {
-               /* Somebody doesn't want to play... */
+       if (audio_dest_res != AST_RTP_TRY_NATIVE || audio_src_res != AST_RTP_TRY_NATIVE || !(srccodec & destcodec)) {
+               /* Somebody doesn't want to play or we have no matching codec... */
                ast_channel_unlock(dest);
                ast_channel_unlock(src);
                return 0;
@@ -1575,10 +1585,6 @@
        ast_rtp_pt_copy(destp, srcp);
        if (vdestp && vsrcp)
                ast_rtp_pt_copy(vdestp, vsrcp);
-       if (srcpr->get_codec)
-               srccodec = srcpr->get_codec(src);
-       else
-               srccodec = 0;
        if (media) {
                /* Bridge early */
                if (destpr->set_rtp_peer(dest, srcp, vsrcp, srccodec, ast_test_flag(srcp, FLAG_NAT_ACTIVE)))