libavutil/mathematics.h

   1 #ifndef MATHEMATICS_H
   2 #define MATHEMATICS_H
   3
   4 #include "rational.h"
   5
   6 enum AVRounding {
   7     AV_ROUND_ZERO     = 0, ///< round toward zero
   8     AV_ROUND_INF      = 1, ///< round away from zero
   9     AV_ROUND_DOWN     = 2, ///< round toward -infinity
  10     AV_ROUND_UP       = 3, ///< round toward +infinity
  11     AV_ROUND_NEAR_INF = 5, ///< round to nearest and halfway cases away from zero
  12 };
  13
  14 /**
  15  * rescale a 64bit integer with rounding to nearest.
  16  * a simple a*b/c isn't possible as it can overflow
  17  */
  18 int64_t av_rescale(int64_t a, int64_t b, int64_t c);
  19
  20 /**
  21  * rescale a 64bit integer with specified rounding.
  22  * a simple a*b/c isn't possible as it can overflow
  23  */
  24 int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding);
  25
  26 /**
  27  * rescale a 64bit integer by 2 rational numbers.
  28  */
  29 int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq);
  30
  31 #endif /* MATHEMATICS_H */