infinity fix by ("Steven M. Schultz" <sms at 2BSD dot COM>)

Originally committed as revision 1310 to svn://svn.ffmpeg.org/ffmpeg/trunk

ffmpeg.c

@@ -31,6 +31,9 @@
 #include <time.h>
 #include <ctype.h>
 
+#if !defined(INFINITY) && defined(HUGE_VAL)
+#define INFINITY HUGE_VAL
+#endif
 
 #define MAXINT64 INT64_C(0x7fffffffffffffff)