--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/libavutil/rational.h	Tue Dec 31 14:52:14 2013 +0000
@@ -0,0 +1,155 @@
+/*
+ * rational numbers
+ * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * rational numbers
+ * @author Michael Niedermayer <michaelni@gmx.at>
+ */
+
+#ifndef AVUTIL_RATIONAL_H
+#define AVUTIL_RATIONAL_H
+
+#include <stdint.h>
+#include <limits.h>
+#include "attributes.h"
+
+/**
+ * @addtogroup lavu_math
+ * @{
+ */
+
+/**
+ * rational number numerator/denominator
+ */
+typedef struct AVRational{
+    int num; ///< numerator
+    int den; ///< denominator
+} AVRational;
+
+/**
+ * Compare two rationals.
+ * @param a first rational
+ * @param b second rational
+ * @return 0 if a==b, 1 if a>b, -1 if a<b, and INT_MIN if one of the
+ * values is of the form 0/0
+ */
+static inline int av_cmp_q(AVRational a, AVRational b){
+    const int64_t tmp= a.num * (int64_t)b.den - b.num * (int64_t)a.den;
+
+    if(tmp) return ((tmp ^ a.den ^ b.den)>>63)|1;
+    else if(b.den && a.den) return 0;
+    else if(a.num && b.num) return (a.num>>31) - (b.num>>31);
+    else                    return INT_MIN;
+}
+
+/**
+ * Convert rational to double.
+ * @param a rational to convert
+ * @return (double) a
+ */
+static inline double av_q2d(AVRational a){
+    return a.num / (double) a.den;
+}
+
+/**
+ * Reduce a fraction.
+ * This is useful for framerate calculations.
+ * @param dst_num destination numerator
+ * @param dst_den destination denominator
+ * @param num source numerator
+ * @param den source denominator
+ * @param max the maximum allowed for dst_num & dst_den
+ * @return 1 if exact, 0 otherwise
+ */
+int av_reduce(int *dst_num, int *dst_den, int64_t num, int64_t den, int64_t max);
+
+/**
+ * Multiply two rationals.
+ * @param b first rational
+ * @param c second rational
+ * @return b*c
+ */
+AVRational av_mul_q(AVRational b, AVRational c) av_const;
+
+/**
+ * Divide one rational by another.
+ * @param b first rational
+ * @param c second rational
+ * @return b/c
+ */
+AVRational av_div_q(AVRational b, AVRational c) av_const;
+
+/**
+ * Add two rationals.
+ * @param b first rational
+ * @param c second rational
+ * @return b+c
+ */
+AVRational av_add_q(AVRational b, AVRational c) av_const;
+
+/**
+ * Subtract one rational from another.
+ * @param b first rational
+ * @param c second rational
+ * @return b-c
+ */
+AVRational av_sub_q(AVRational b, AVRational c) av_const;
+
+/**
+ * Invert a rational.
+ * @param q value
+ * @return 1 / q
+ */
+static av_always_inline AVRational av_inv_q(AVRational q)
+{
+    AVRational r = { q.den, q.num };
+    return r;
+}
+
+/**
+ * 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
+ */
+AVRational av_d2q(double d, int max) av_const;
+
+/**
+ * @return 1 if q1 is nearer to q than q2, -1 if q2 is nearer
+ * than q1, 0 if they have the same distance.
+ */
+int av_nearer_q(AVRational q, AVRational q1, AVRational q2);
+
+/**
+ * Find the nearest value in q_list to q.
+ * @param q_list an array of rationals terminated by {0, 0}
+ * @return the index of the nearest value found in the array
+ */
+int av_find_nearest_q_idx(AVRational q, const AVRational* q_list);
+
+/**
+ * @}
+ */
+
+#endif /* AVUTIL_RATIONAL_H */