+extern void start_batch_converter (boost::filesystem::path dcpomatic);
+extern void start_player (boost::filesystem::path dcpomatic);
+extern uint64_t thread_id ();
+extern int avio_open_boost (AVIOContext** s, boost::filesystem::path file, int flags);
+extern boost::filesystem::path home_directory ();
+extern std::string command_and_read (std::string cmd);