Make av_d2q() manage the case in which the value to convert is inf.

Originally committed as revision 25332 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavutil/avutil.h

@@ -41,7 +41,7 @@
 
 #define LIBAVUTIL_VERSION_MAJOR 50
 #define LIBAVUTIL_VERSION_MINOR 32
-#define LIBAVUTIL_VERSION_MICRO  0
+#define LIBAVUTIL_VERSION_MICRO  1
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
                                                LIBAVUTIL_VERSION_MINOR, \

libavutil/rational.c

@@ -100,6 +100,8 @@ AVRational av_d2q(double d, int max){
     int64_t den;
     if (isnan(d))
         return (AVRational){0,0};
+    if (isinf(d))
+        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, (int64_t)(d * den + 0.5), den, max);

libavutil/rational.h

@@ -107,6 +107,8 @@ AVRational av_sub_q(AVRational b, AVRational c) av_const;
 
 /**
  * Convert a double precision floating point number to a rational.
+ * inf is expressed as {1,0} or {-1,0} depending on the sign.
+ *
  * @param d double to convert
  * @param max the maximum allowed numerator and denominator
  * @return (AVRational) d