gfiber / vendor / opensource / ffmpeg / a08e27a935844c13e4090bbd0fd2b626cd862a2b / . / libavutil / mathematics.h

/* | |

* copyright (c) 2005 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 | |

*/ | |

#ifndef AVUTIL_MATHEMATICS_H | |

#define AVUTIL_MATHEMATICS_H | |

#include <stdint.h> | |

#include <math.h> | |

#include "common.h" | |

#include "rational.h" | |

#ifndef M_E | |

#define M_E 2.7182818284590452354 /* e */ | |

#endif | |

#ifndef M_LN2 | |

#define M_LN2 0.69314718055994530942 /* log_e 2 */ | |

#endif | |

#ifndef M_LN10 | |

#define M_LN10 2.30258509299404568402 /* log_e 10 */ | |

#endif | |

#ifndef M_PI | |

#define M_PI 3.14159265358979323846 /* pi */ | |

#endif | |

#ifndef M_SQRT1_2 | |

#define M_SQRT1_2 0.70710678118654752440 /* 1/sqrt(2) */ | |

#endif | |

enum AVRounding { | |

AV_ROUND_ZERO = 0, ///< Round toward zero. | |

AV_ROUND_INF = 1, ///< Round away from zero. | |

AV_ROUND_DOWN = 2, ///< Round toward -infinity. | |

AV_ROUND_UP = 3, ///< Round toward +infinity. | |

AV_ROUND_NEAR_INF = 5, ///< Round to nearest and halfway cases away from zero. | |

}; | |

int64_t av_const av_gcd(int64_t a, int64_t b); | |

/** | |

* Rescales a 64-bit integer with rounding to nearest. | |

* A simple a*b/c isn't possible as it can overflow. | |

*/ | |

int64_t av_rescale(int64_t a, int64_t b, int64_t c) av_const; | |

/** | |

* Rescales a 64-bit integer with specified rounding. | |

* A simple a*b/c isn't possible as it can overflow. | |

*/ | |

int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding) av_const; | |

/** | |

* Rescales a 64-bit integer by 2 rational numbers. | |

*/ | |

int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) av_const; | |

#endif /* AVUTIL_MATHEMATICS_H */ |