scalos/include/ffmpeg/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 AVUTIL_MATHEMATICS_H
  22 #define AVUTIL_MATHEMATICS_H
  23
  24 #include <stdint.h>
  25 #include <math.h>
  26 #include "rational.h"
  27
  28 #ifndef M_E
  29 #define M_E            2.7182818284590452354   /* e */
  30 #endif
  31 #ifndef M_LN2
  32 #define M_LN2          0.69314718055994530942  /* log_e 2 */
  33 #endif
  34 #ifndef M_LN10
  35 #define M_LN10         2.30258509299404568402  /* log_e 10 */
  36 #endif
  37 #ifndef M_PI
  38 #define M_PI           3.14159265358979323846  /* pi */
  39 #endif
  40 #ifndef M_SQRT1_2
  41 #define M_SQRT1_2      0.70710678118654752440  /* 1/sqrt(2) */
  42 #endif
  43
  44 enum AVRounding {
  45     AV_ROUND_ZERO     = 0, ///< round toward zero
  46     AV_ROUND_INF      = 1, ///< round away from zero
  47     AV_ROUND_DOWN     = 2, ///< round toward -infinity
  48     AV_ROUND_UP       = 3, ///< round toward +infinity
  49     AV_ROUND_NEAR_INF = 5, ///< round to nearest and halfway cases away from zero
  50 };
  51
  52 /**
  53  * rescale a 64bit integer with rounding to nearest.
  54  * a simple a*b/c isn't possible as it can overflow
  55  */
  56 int64_t av_rescale(int64_t a, int64_t b, int64_t c) av_const;
  57
  58 /**
  59  * rescale a 64bit integer with specified rounding.
  60  * a simple a*b/c isn't possible as it can overflow
  61  */
  62 int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding) av_const;
  63
  64 /**
  65  * rescale a 64bit integer by 2 rational numbers.
  66  */
  67 int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) av_const;
  68
  69 #endif /* AVUTIL_MATHEMATICS_H */