+
+string
+FFmpegContent::identifier () const
+{
+ stringstream s;
+
+ s << VideoContent::identifier();
+
+ boost::mutex::scoped_lock lm (_mutex);
+
+ if (_subtitle_stream) {
+ s << "_" << _subtitle_stream->id;
+ }
+
+ for (vector<Filter const *>::const_iterator i = _filters.begin(); i != _filters.end(); ++i) {
+ s << "_" << (*i)->id ();
+ }
+
+ return s.str ();
+}