extern FILE * fopen_boost (boost::filesystem::path, std::string);
extern int dcpomatic_fseek (FILE *, int64_t, int);
extern void start_batch_converter (boost::filesystem::path dcpomatic);
-extern int thread_id ();
+extern uint64_t thread_id ();
/** @class Waker
* @brief A class which tries to keep the computer awake on various operating systems.