+#ifdef DCPOMATIC_WINDOWS
+ return (uint64_t) GetCurrentThreadId ();
+#else
+ return (uint64_t) pthread_self ();
+#endif
+}
+
+int
+avio_open_boost (AVIOContext** s, boost::filesystem::path file, int flags)
+{
+#ifdef DCPOMATIC_WINDOWS
+ int const length = (file.string().length() + 1) * 2;
+ char* utf8 = new char[length];
+ WideCharToMultiByte (CP_UTF8, 0, file.c_str(), -1, utf8, length, 0, 0);
+ int const r = avio_open (s, utf8, flags);
+ delete[] utf8;
+ return r;
+#else
+ return avio_open (s, file.c_str(), flags);
+#endif