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Diffstat (limited to 'media/ffvpx/libavutil/mathematics.h')
-rw-r--r-- | media/ffvpx/libavutil/mathematics.h | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/media/ffvpx/libavutil/mathematics.h b/media/ffvpx/libavutil/mathematics.h new file mode 100644 index 000000000..57c44f845 --- /dev/null +++ b/media/ffvpx/libavutil/mathematics.h @@ -0,0 +1,165 @@ +/* + * copyright (c) 2005-2012 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 "attributes.h" +#include "rational.h" +#include "intfloat.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_LOG2_10 +#define M_LOG2_10 3.32192809488736234787 /* log_2 10 */ +#endif +#ifndef M_PHI +#define M_PHI 1.61803398874989484820 /* phi / golden ratio */ +#endif +#ifndef M_PI +#define M_PI 3.14159265358979323846 /* pi */ +#endif +#ifndef M_PI_2 +#define M_PI_2 1.57079632679489661923 /* pi/2 */ +#endif +#ifndef M_SQRT1_2 +#define M_SQRT1_2 0.70710678118654752440 /* 1/sqrt(2) */ +#endif +#ifndef M_SQRT2 +#define M_SQRT2 1.41421356237309504880 /* sqrt(2) */ +#endif +#ifndef NAN +#define NAN av_int2float(0x7fc00000) +#endif +#ifndef INFINITY +#define INFINITY av_int2float(0x7f800000) +#endif + +/** + * @addtogroup lavu_math + * @{ + */ + + +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. + AV_ROUND_PASS_MINMAX = 8192, ///< Flag to pass INT64_MIN/MAX through instead of rescaling, this avoids special cases for AV_NOPTS_VALUE +}; + +/** + * Compute the greatest common divisor of a and b. + * + * @return gcd of a and b up to sign; if a >= 0 and b >= 0, return value is >= 0; + * if a == 0 and b == 0, returns 0. + */ +int64_t av_const av_gcd(int64_t a, int64_t b); + +/** + * Rescale 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; + +/** + * Rescale a 64-bit integer with specified rounding. + * A simple a*b/c isn't possible as it can overflow. + * + * @return rescaled value a, or if AV_ROUND_PASS_MINMAX is set and a is + * INT64_MIN or INT64_MAX then a is passed through unchanged. + */ +int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding) av_const; + +/** + * Rescale a 64-bit integer by 2 rational numbers. + */ +int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) av_const; + +/** + * Rescale a 64-bit integer by 2 rational numbers with specified rounding. + * + * @return rescaled value a, or if AV_ROUND_PASS_MINMAX is set and a is + * INT64_MIN or INT64_MAX then a is passed through unchanged. + */ +int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq, + enum AVRounding) av_const; + +/** + * Compare 2 timestamps each in its own timebases. + * The result of the function is undefined if one of the timestamps + * is outside the int64_t range when represented in the others timebase. + * @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 + */ +int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b); + +/** + * Compare 2 integers modulo mod. + * That is we compare integers a and b for which only the least + * significant log2(mod) bits are known. + * + * @param mod must be a power of 2 + * @return a negative value if a is smaller than b + * a positive value if a is greater than b + * 0 if a equals b + */ +int64_t av_compare_mod(uint64_t a, uint64_t b, uint64_t mod); + +/** + * Rescale a timestamp while preserving known durations. + * + * @param in_ts Input timestamp + * @param in_tb Input timebase + * @param fs_tb Duration and *last timebase + * @param duration duration till the next call + * @param out_tb Output timebase + */ +int64_t av_rescale_delta(AVRational in_tb, int64_t in_ts, AVRational fs_tb, int duration, int64_t *last, AVRational out_tb); + +/** + * Add a value to a timestamp. + * + * This function guarantees that when the same value is repeatly added that + * no accumulation of rounding errors occurs. + * + * @param ts Input timestamp + * @param ts_tb Input timestamp timebase + * @param inc value to add to ts + * @param inc_tb inc timebase + */ +int64_t av_add_stable(AVRational ts_tb, int64_t ts, AVRational inc_tb, int64_t inc); + + + /** + * @} + */ + +#endif /* AVUTIL_MATHEMATICS_H */ |