add sip_append_audio_sdp var

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@16537 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/mod/endpoints/mod_sofia/sofia_glue.c

@@ -130,6 +130,7 @@ void sofia_glue_set_local_sdp(private_object_t *tech_pvt, const char *ip, uint32
 	const char *family;
 	const char *pass_fmtp = switch_channel_get_variable(tech_pvt->channel, "sip_video_fmtp");
 	const char *ov_fmtp = switch_channel_get_variable(tech_pvt->channel, "sip_force_video_fmtp");
+	const char *append_audio = switch_channel_get_variable(tech_pvt->channel, "sip_append_audio_sdp");
 	char srbuf[128] = "";
 	const char *var_val;
 	const char *username = tech_pvt->profile->username;
@@ -289,6 +290,10 @@ void sofia_glue_set_local_sdp(private_object_t *tech_pvt, const char *ip, uint32
 		switch_snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), "a=silenceSupp:off - - - -\n");
 	}
 
+	if (append_audio) {
+		switch_snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), "%s%s", append_audio, end_of(append_audio) == '\n' ? "" : "\n");
+	}
+	
 	if (ptime) {
 		switch_snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), "a=ptime:%d\n", ptime);
 	}