mirror of https://github.com/FFmpeg/FFmpeg.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
81 lines
2.0 KiB
81 lines
2.0 KiB
/* |
|
* Copyright (c) 2010 Mans Rullgard <mans@mansr.com> |
|
* |
|
* This file is part of Libav. |
|
* |
|
* Libav 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, |
|
* 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 |
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
|
*/ |
|
|
|
#ifndef AVUTIL_INTMATH_H |
|
#define AVUTIL_INTMATH_H |
|
|
|
#include <stdint.h> |
|
#include "config.h" |
|
#include "attributes.h" |
|
|
|
/** |
|
* @addtogroup lavu_internal |
|
* @{ |
|
*/ |
|
|
|
extern const uint32_t ff_inverse[257]; |
|
|
|
#if ARCH_ARM |
|
# include "arm/intmath.h" |
|
#endif |
|
|
|
#if HAVE_FAST_CLZ && AV_GCC_VERSION_AT_LEAST(3,4) |
|
|
|
#ifndef av_log2 |
|
# define av_log2(x) (31 - __builtin_clz((x)|1)) |
|
# ifndef av_log2_16bit |
|
# define av_log2_16bit av_log2 |
|
# endif |
|
#endif /* av_log2 */ |
|
|
|
#endif /* AV_GCC_VERSION_AT_LEAST(3,4) */ |
|
|
|
#ifndef FASTDIV |
|
# define FASTDIV(a,b) ((uint32_t)((((uint64_t)a) * ff_inverse[b]) >> 32)) |
|
#endif /* FASTDIV */ |
|
|
|
#include "common.h" |
|
|
|
extern const uint8_t ff_sqrt_tab[256]; |
|
|
|
static inline av_const unsigned int ff_sqrt(unsigned int a) |
|
{ |
|
unsigned int b; |
|
|
|
if (a < 255) return (ff_sqrt_tab[a + 1] - 1) >> 4; |
|
else if (a < (1 << 12)) b = ff_sqrt_tab[a >> 4] >> 2; |
|
#if !CONFIG_SMALL |
|
else if (a < (1 << 14)) b = ff_sqrt_tab[a >> 6] >> 1; |
|
else if (a < (1 << 16)) b = ff_sqrt_tab[a >> 8] ; |
|
#endif |
|
else { |
|
int s = av_log2_16bit(a >> 16) >> 1; |
|
unsigned int c = a >> (s + 2); |
|
b = ff_sqrt_tab[c >> (s + 8)]; |
|
b = FASTDIV(c,b) + (b << s); |
|
} |
|
|
|
return b - (a < b * b); |
|
} |
|
|
|
/** |
|
* @} |
|
*/ |
|
#endif /* AVUTIL_INTMATH_H */
|
|
|