diff options
Diffstat (limited to 'libavutil/mathematics.h')
| -rw-r--r-- | libavutil/mathematics.h | 63 |
1 files changed, 58 insertions, 5 deletions
diff --git a/libavutil/mathematics.h b/libavutil/mathematics.h index 043dd0fafe..ac94488729 100644 --- a/libavutil/mathematics.h +++ b/libavutil/mathematics.h @@ -1,20 +1,20 @@ /* - * copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at> + * copyright (c) 2005-2012 Michael Niedermayer <michaelni@gmx.at> * - * This file is part of Libav. + * This file is part of FFmpeg. * - * Libav is free software; you can redistribute it and/or + * 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. * - * Libav is distributed in the hope that it will be useful, + * 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 Libav; if not, write to the Free Software + * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ @@ -27,12 +27,33 @@ #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 @@ -52,6 +73,7 @@ enum AVRounding { 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 }; /** @@ -70,6 +92,9 @@ 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; @@ -80,6 +105,9 @@ 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; @@ -105,6 +133,31 @@ int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_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); + + + /** * @} */ |