+ boost::mutex::scoped_lock lm (_mutex);
+
+ /* Default to turning these subtitles on */
+ only_text()->set_use (true);
+
+ if (iop) {
+ only_text()->set_language (iop->language ());
+ } else if (smpte) {
+ only_text()->set_language (smpte->language().get_value_or (""));
+ }
+