diff --git a/libavcodec/os_support.h b/libavcodec/os_support.h
deleted file mode 100644
index ef895b1d51..0000000000
--- a/libavcodec/os_support.h
+++ /dev/null
@@ -1,38 +0,0 @@
-#ifndef _OS_SUPPORT_H
-#define _OS_SUPPORT_H
-
-/**
- * @file os_support.h
- * miscellaneous OS support macros and functions.
- *
- * - usleep() (Win32, BeOS, OS/2)
- * - floatf() (OS/2)
- * - strcasecmp() (OS/2)
- */
-
-#ifdef __MINGW32__
-#  undef DATADIR /* clashes with /usr/include/w32api/objidl.h */
-__declspec(dllimport) void __stdcall Sleep(unsigned long dwMilliseconds);
-// #  include <windows.h>
-#  define usleep(t)    Sleep((t) / 1000)
-#endif
-
-#ifdef __BEOS__
-#  ifndef usleep
-#    include <OS.h>
-#    define usleep(t)  snooze((bigtime_t)(t))
-#  endif
-#endif
-
-#if defined(CONFIG_OS2)
-#include <stdlib.h>
-static inline int usleep(unsigned int t) { return _sleep2(t / 1000); }
-static inline float floorf(float f) { return floor(f); }
-static inline int strcasecmp(const char* s1, const char* s2) { return stricmp(s1,s2); }
-#endif
-
-#if defined(CONFIG_SUNOS)
-static inline float floorf(float f) { return floor(f); }
-#endif
-
-#endif /* _OS_SUPPORT_H */