libavutil/mathematics.h

   1 /*
   2  * copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #ifndef FFMPEG_MATHEMATICS_H
  22 #define FFMPEG_MATHEMATICS_H
  23
  24 #include <stdint.h>
  25 #include "rational.h"
  26
  27 enum AVRounding {
  28     AV_ROUND_ZERO     = 0, ///< round toward zero
  29     AV_ROUND_INF      = 1, ///< round away from zero
  30     AV_ROUND_DOWN     = 2, ///< round toward -infinity
  31     AV_ROUND_UP       = 3, ///< round toward +infinity
  32     AV_ROUND_NEAR_INF = 5, ///< round to nearest and halfway cases away from zero
  33 };
  34
  35 /**
  36  * rescale a 64bit integer with rounding to nearest.
  37  * a simple a*b/c isn't possible as it can overflow
  38  */
  39 int64_t av_rescale(int64_t a, int64_t b, int64_t c) av_const;
  40
  41 /**
  42  * rescale a 64bit integer with specified rounding.
  43  * a simple a*b/c isn't possible as it can overflow
  44  */
  45 int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding) av_const;
  46
  47 /**
  48  * rescale a 64bit integer by 2 rational numbers.
  49  */
  50 int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) av_const;
  51
  52 #endif /* FFMPEG_MATHEMATICS_H */