avutil/rational: avoid llrint() and rint()

This should workaround issues with these functions on ia64 and sparc64

Fixes Ticket2713
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavutil/rational.c

@@ -114,9 +114,10 @@ AVRational av_d2q(double d, int max)
         return (AVRational) { d < 0 ? -1 : 1, 0 };
     exponent = FFMAX( (int)(log(fabs(d) + 1e-20)/LOG2), 0);
     den = 1LL << (61 - exponent);
-    av_reduce(&a.num, &a.den, rint(d * den), den, max);
+    // (int64_t)rint() and llrint() do not work with gcc on ia64 and sparc64
+    av_reduce(&a.num, &a.den, floor(d * den + 0.5), den, max);
     if ((!a.num || !a.den) && d && max>0 && max<INT_MAX)
-        av_reduce(&a.num, &a.den, llrint(d * den), den, INT_MAX);
+        av_reduce(&a.num, &a.den, floor(d * den + 0.5), den, INT_MAX);
 
     return a;
 }