yading@11: /* yading@11: * copyright (c) 2005-2012 Michael Niedermayer yading@11: * yading@11: * This file is part of FFmpeg. yading@11: * yading@11: * FFmpeg is free software; you can redistribute it and/or yading@11: * modify it under the terms of the GNU Lesser General Public yading@11: * License as published by the Free Software Foundation; either yading@11: * version 2.1 of the License, or (at your option) any later version. yading@11: * yading@11: * FFmpeg is distributed in the hope that it will be useful, yading@11: * but WITHOUT ANY WARRANTY; without even the implied warranty of yading@11: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU yading@11: * Lesser General Public License for more details. yading@11: * yading@11: * You should have received a copy of the GNU Lesser General Public yading@11: * License along with FFmpeg; if not, write to the Free Software yading@11: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA yading@11: */ yading@11: yading@11: #ifndef AVUTIL_MATHEMATICS_H yading@11: #define AVUTIL_MATHEMATICS_H yading@11: yading@11: #include yading@11: #include yading@11: #include "attributes.h" yading@11: #include "rational.h" yading@11: #include "intfloat.h" yading@11: yading@11: #ifndef M_E yading@11: #define M_E 2.7182818284590452354 /* e */ yading@11: #endif yading@11: #ifndef M_LN2 yading@11: #define M_LN2 0.69314718055994530942 /* log_e 2 */ yading@11: #endif yading@11: #ifndef M_LN10 yading@11: #define M_LN10 2.30258509299404568402 /* log_e 10 */ yading@11: #endif yading@11: #ifndef M_LOG2_10 yading@11: #define M_LOG2_10 3.32192809488736234787 /* log_2 10 */ yading@11: #endif yading@11: #ifndef M_PHI yading@11: #define M_PHI 1.61803398874989484820 /* phi / golden ratio */ yading@11: #endif yading@11: #ifndef M_PI yading@11: #define M_PI 3.14159265358979323846 /* pi */ yading@11: #endif yading@11: #ifndef M_SQRT1_2 yading@11: #define M_SQRT1_2 0.70710678118654752440 /* 1/sqrt(2) */ yading@11: #endif yading@11: #ifndef M_SQRT2 yading@11: #define M_SQRT2 1.41421356237309504880 /* sqrt(2) */ yading@11: #endif yading@11: #ifndef NAN yading@11: #define NAN av_int2float(0x7fc00000) yading@11: #endif yading@11: #ifndef INFINITY yading@11: #define INFINITY av_int2float(0x7f800000) yading@11: #endif yading@11: yading@11: /** yading@11: * @addtogroup lavu_math yading@11: * @{ yading@11: */ yading@11: yading@11: yading@11: enum AVRounding { yading@11: AV_ROUND_ZERO = 0, ///< Round toward zero. yading@11: AV_ROUND_INF = 1, ///< Round away from zero. yading@11: AV_ROUND_DOWN = 2, ///< Round toward -infinity. yading@11: AV_ROUND_UP = 3, ///< Round toward +infinity. yading@11: AV_ROUND_NEAR_INF = 5, ///< Round to nearest and halfway cases away from zero. yading@11: AV_ROUND_PASS_MINMAX = 8192, ///< Flag to pass INT64_MIN/MAX through instead of rescaling, this avoids special cases for AV_NOPTS_VALUE yading@11: }; yading@11: yading@11: /** yading@11: * Return the greatest common divisor of a and b. yading@11: * If both a and b are 0 or either or both are <0 then behavior is yading@11: * undefined. yading@11: */ yading@11: int64_t av_const av_gcd(int64_t a, int64_t b); yading@11: yading@11: /** yading@11: * Rescale a 64-bit integer with rounding to nearest. yading@11: * A simple a*b/c isn't possible as it can overflow. yading@11: */ yading@11: int64_t av_rescale(int64_t a, int64_t b, int64_t c) av_const; yading@11: yading@11: /** yading@11: * Rescale a 64-bit integer with specified rounding. yading@11: * A simple a*b/c isn't possible as it can overflow. yading@11: * yading@11: * @return rescaled value a, or if AV_ROUND_PASS_MINMAX is set and a is yading@11: * INT64_MIN or INT64_MAX then a is passed through unchanged. yading@11: */ yading@11: int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding) av_const; yading@11: yading@11: /** yading@11: * Rescale a 64-bit integer by 2 rational numbers. yading@11: */ yading@11: int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) av_const; yading@11: yading@11: /** yading@11: * Rescale a 64-bit integer by 2 rational numbers with specified rounding. yading@11: * yading@11: * @return rescaled value a, or if AV_ROUND_PASS_MINMAX is set and a is yading@11: * INT64_MIN or INT64_MAX then a is passed through unchanged. yading@11: */ yading@11: int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq, yading@11: enum AVRounding) av_const; yading@11: yading@11: /** yading@11: * Compare 2 timestamps each in its own timebases. yading@11: * The result of the function is undefined if one of the timestamps yading@11: * is outside the int64_t range when represented in the others timebase. yading@11: * @return -1 if ts_a is before ts_b, 1 if ts_a is after ts_b or 0 if they represent the same position yading@11: */ yading@11: int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b); yading@11: yading@11: /** yading@11: * Compare 2 integers modulo mod. yading@11: * That is we compare integers a and b for which only the least yading@11: * significant log2(mod) bits are known. yading@11: * yading@11: * @param mod must be a power of 2 yading@11: * @return a negative value if a is smaller than b yading@11: * a positive value if a is greater than b yading@11: * 0 if a equals b yading@11: */ yading@11: int64_t av_compare_mod(uint64_t a, uint64_t b, uint64_t mod); yading@11: yading@11: /** yading@11: * Rescale a timestamp while preserving known durations. yading@11: * yading@11: * @param in_ts Input timestamp yading@11: * @param in_tb Input timesbase yading@11: * @param fs_tb Duration and *last timebase yading@11: * @param duration duration till the next call yading@11: * @param out_tb Output timesbase yading@11: */ yading@11: int64_t av_rescale_delta(AVRational in_tb, int64_t in_ts, AVRational fs_tb, int duration, int64_t *last, AVRational out_tb); yading@11: yading@11: /** yading@11: * @} yading@11: */ yading@11: yading@11: #endif /* AVUTIL_MATHEMATICS_H */