#if !defined(WIN32) || defined(__MINGW32__)
// some versions of FFMPEG assume a C99 compiler, and don't define INT64_C
-#if !defined INT64_C || !defined UINT64_C
-#define INT64_C
-#define UINT64_C
- #define __STDC_CONSTANT_MACROS
-// force re-inclusion of stdint.h to get INT64_C macro
-#undef _STDINT_H
#include <stdint.h>
+
+// some versions of FFMPEG assume a C99 compiler, and don't define INT64_C
+#ifndef INT64_C
+#define INT64_C(c) (c##LL)
#endif
+
+#ifndef UINT64_C
+#define UINT64_C(c) (c##ULL)
+#endif
+
#include <errno.h>
#endif