fix some bugs and g726 wip (only 32 works so far)

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@2459 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/mod/endpoints/mod_dingaling/mod_dingaling.c

@@ -458,7 +458,10 @@ static char *lame(char *in)
 static int do_describe(struct private_object *tech_pvt, int force)
 {
 	ldl_payload_t payloads[5];
-	assert(switch_core_session_get_channel(tech_pvt->session) != NULL);
+
+	if (!tech_pvt->session) {
+		return 0;
+	}
 
 	if (switch_test_flag(tech_pvt, TFLAG_DO_DESC)) {
 		return 1;