ppsspp/ext/at3_standalone/mathematics.h
2024-04-11 14:39:59 +02:00

314 lines
8.1 KiB
C

/*
* 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
*/
#pragma once
#include <stdint.h>
#include <math.h>
#include <limits.h>
#include "compat.h"
#if HAVE_FAST_CLZ
#if AV_GCC_VERSION_AT_LEAST(3,4)
#ifndef ff_log2
# define ff_log2(x) (31 - __builtin_clz((x)|1))
# ifndef ff_log2_16bit
# define ff_log2_16bit av_log2
# endif
#endif /* ff_log2 */
#endif /* AV_GCC_VERSION_AT_LEAST(3,4) */
#endif
int av_log2(unsigned int v);
int av_log2_16bit(unsigned int v);
/**
* @addtogroup lavu_math
* @{
*/
#if HAVE_FAST_CLZ
#if AV_GCC_VERSION_AT_LEAST(3,4)
#ifndef ff_ctz
#define ff_ctz(v) __builtin_ctz(v)
#endif
#ifndef ff_ctzll
#define ff_ctzll(v) __builtin_ctzll(v)
#endif
#ifndef ff_clz
#define ff_clz(v) __builtin_clz(v)
#endif
#endif
#endif
#ifndef ff_ctz
#define ff_ctz ff_ctz_c
/**
* Trailing zero bit count.
*
* @param v input value. If v is 0, the result is undefined.
* @return the number of trailing 0-bits
*/
/* We use the De-Bruijn method outlined in:
* http://supertech.csail.mit.edu/papers/debruijn.pdf. */
static av_always_inline av_const int ff_ctz_c(int v)
{
static const uint8_t debruijn_ctz32[32] = {
0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8,
31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9
};
return debruijn_ctz32[(uint32_t)((v & -v) * 0x077CB531U) >> 27];
}
#endif
#ifndef ff_ctzll
#define ff_ctzll ff_ctzll_c
/* We use the De-Bruijn method outlined in:
* http://supertech.csail.mit.edu/papers/debruijn.pdf. */
static av_always_inline av_const int ff_ctzll_c(long long v)
{
static const uint8_t debruijn_ctz64[64] = {
0, 1, 2, 53, 3, 7, 54, 27, 4, 38, 41, 8, 34, 55, 48, 28,
62, 5, 39, 46, 44, 42, 22, 9, 24, 35, 59, 56, 49, 18, 29, 11,
63, 52, 6, 26, 37, 40, 33, 47, 61, 45, 43, 21, 23, 58, 17, 10,
51, 25, 36, 32, 60, 20, 57, 16, 50, 31, 19, 15, 30, 14, 13, 12
};
return debruijn_ctz64[(uint64_t)((v & -v) * 0x022FDD63CC95386DU) >> 58];
}
#endif
static inline int sign_extend(int val, unsigned bits)
{
unsigned shift = 8 * sizeof(int) - bits;
union { unsigned u; int s; } v = { (unsigned)val << shift };
return v.s >> shift;
}
static inline unsigned zero_extend(unsigned val, unsigned bits)
{
return (val << ((8 * sizeof(int)) - bits)) >> ((8 * sizeof(int)) - bits);
}
#ifndef NEG_SSR32
# define NEG_SSR32(a,s) ((( int32_t)(a))>>(32-(s)))
#endif
#ifndef NEG_USR32
# define NEG_USR32(a,s) (((uint32_t)(a))>>(32-(s)))
#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
/**
* @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
};
/**
* rational number numerator/denominator
*/
typedef struct AVRational {
int num; ///< numerator
int den; ///< denominator
} AVRational;
/**
* 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_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);
/**
* 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, AVRounding);
/**
* Rescale a 64-bit integer by 2 rational numbers.
*/
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq);
/**
* 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, AVRounding);
/**
* Create a rational.
* Useful for compilers that do not support compound literals.
* @note The return value is not reduced.
*/
static inline AVRational av_make_q(int num, int den)
{
AVRational r = { num, den };
return r;
}
/**
* Compare two rationals.
* @param a first rational
* @param b second rational
* @return 0 if a==b, 1 if a>b, -1 if a<b, and INT_MIN if one of the
* values is of the form 0/0
*/
static inline int av_cmp_q(AVRational a, AVRational b) {
const int64_t tmp = a.num * (int64_t)b.den - b.num * (int64_t)a.den;
if (tmp) return (int)((tmp ^ a.den ^ b.den) >> 63) | 1;
else if (b.den && a.den) return 0;
else if (a.num && b.num) return (a.num >> 31) - (b.num >> 31);
else return INT_MIN;
}
/**
* Convert rational to double.
* @param a rational to convert
* @return (double) a
*/
static inline double av_q2d(AVRational a) {
return a.num / (double)a.den;
}
/**
* Reduce a fraction.
* This is useful for framerate calculations.
* @param dst_num destination numerator
* @param dst_den destination denominator
* @param num source numerator
* @param den source denominator
* @param max the maximum allowed for dst_num & dst_den
* @return 1 if exact, 0 otherwise
*/
int av_reduce(int *dst_num, int *dst_den, int64_t num, int64_t den, int64_t max);
/**
* Multiply two rationals.
* @param b first rational
* @param c second rational
* @return b*c
*/
AVRational av_mul_q(AVRational b, AVRational c);
/**
* Divide one rational by another.
* @param b first rational
* @param c second rational
* @return b/c
*/
AVRational av_div_q(AVRational b, AVRational c);
/**
* Add two rationals.
* @param b first rational
* @param c second rational
* @return b+c
*/
AVRational av_add_q(AVRational b, AVRational c);
/**
* Invert a rational.
* @param q value
* @return 1 / q
*/
static inline AVRational av_inv_q(AVRational q)
{
AVRational r = { q.den, q.num };
return r;
}
/**
* Clear high bits from an unsigned integer starting with specific bit position
* @param a value to clip
* @param p bit position to clip at
* @return clipped value
*/
static inline unsigned av_mod_uintp2(unsigned a, unsigned p)
{
return a & ((1 << p) - 1);
}
/**
* Count number of bits set to one in x
* @param x value to count bits of
* @return the number of bits set to one in x
*/
static inline int av_popcount(uint32_t x)
{
x -= (x >> 1) & 0x55555555;
x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
x = (x + (x >> 4)) & 0x0F0F0F0F;
x += x >> 8;
return (x + (x >> 16)) & 0x3F;
}
/**
* Count number of bits set to one in x
* @param x value to count bits of
* @return the number of bits set to one in x
*/
static inline int av_popcount64(uint64_t x)
{
return av_popcount((uint32_t)x) + av_popcount((uint32_t)(x >> 32));
}