mathops.h 4.99 KB
Newer Older
1 2
/*
 * simple math operations
3
 * Copyright (c) 2001, 2002 Fabrice Bellard
4 5
 * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> et al
 *
6 7 8
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
9 10
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
11
 * version 2.1 of the License, or (at your option) any later version.
12
 *
13
 * FFmpeg is distributed in the hope that it will be useful,
14 15 16 17 18
 * 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
19
 * License along with FFmpeg; if not, write to the Free Software
20 21
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */
22 23
#ifndef AVCODEC_MATHOPS_H
#define AVCODEC_MATHOPS_H
24

25 26
#include <stdint.h>

27
#include "libavutil/common.h"
28
#include "config.h"
29

30
extern const uint32_t ff_inverse[257];
31
extern const uint8_t  ff_reverse[256];
32 33
extern const uint8_t ff_sqrt_tab[256];

34
#if   ARCH_ARM
35
#   include "arm/mathops.h"
36 37
#elif ARCH_AVR32
#   include "avr32/mathops.h"
38
#elif ARCH_BFIN
39
#   include "bfin/mathops.h"
40 41
#elif ARCH_MIPS
#   include "mips/mathops.h"
42 43 44 45
#elif ARCH_PPC
#   include "ppc/mathops.h"
#elif ARCH_X86
#   include "x86/mathops.h"
46 47 48 49
#endif

/* generic implementation */

50 51 52 53
#ifndef MUL64
#   define MUL64(a,b) ((int64_t)(a) * (int64_t)(b))
#endif

54
#ifndef MULL
55
#   define MULL(a,b,s) (MUL64(a, b) >> (s))
56 57 58
#endif

#ifndef MULH
59
static av_always_inline int MULH(int a, int b){
60
    return MUL64(a, b) >> 32;
61 62 63
}
#endif

Måns Rullgård's avatar
Måns Rullgård committed
64 65 66 67 68 69
#ifndef UMULH
static av_always_inline unsigned UMULH(unsigned a, unsigned b){
    return ((uint64_t)(a) * (uint64_t)(b))>>32;
}
#endif

70 71 72 73 74 75 76 77
#ifndef MAC64
#   define MAC64(d, a, b) ((d) += MUL64(a, b))
#endif

#ifndef MLS64
#   define MLS64(d, a, b) ((d) -= MUL64(a, b))
#endif

78 79 80 81 82 83 84 85 86 87
/* signed 16x16 -> 32 multiply add accumulate */
#ifndef MAC16
#   define MAC16(rt, ra, rb) rt += (ra) * (rb)
#endif

/* signed 16x16 -> 32 multiply */
#ifndef MUL16
#   define MUL16(ra, rb) ((ra) * (rb))
#endif

88 89 90 91
#ifndef MLS16
#   define MLS16(rt, ra, rb) ((rt) -= (ra) * (rb))
#endif

92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121
/* median of 3 */
#ifndef mid_pred
#define mid_pred mid_pred
static inline av_const int mid_pred(int a, int b, int c)
{
#if 0
    int t= (a-b)&((a-b)>>31);
    a-=t;
    b+=t;
    b-= (b-c)&((b-c)>>31);
    b+= (a-b)&((a-b)>>31);

    return b;
#else
    if(a>b){
        if(c>b){
            if(c>a) b=a;
            else    b=c;
        }
    }else{
        if(b>c){
            if(c>a) b=c;
            else    b=a;
        }
    }
    return b;
#endif
}
#endif

122 123 124
#ifndef sign_extend
static inline av_const int sign_extend(int val, unsigned bits)
{
125 126 127
    unsigned shift = 8 * sizeof(int) - bits;
    union { unsigned u; int s; } v = { (unsigned) val << shift };
    return v.s >> shift;
128 129 130
}
#endif

131 132 133
#ifndef zero_extend
static inline av_const unsigned zero_extend(unsigned val, unsigned bits)
{
134
    return (val << ((8 * sizeof(int)) - bits)) >> ((8 * sizeof(int)) - bits);
135 136 137
}
#endif

138 139 140 141 142 143 144 145 146
#ifndef COPY3_IF_LT
#define COPY3_IF_LT(x, y, a, b, c, d)\
if ((y) < (x)) {\
    (x) = (y);\
    (a) = (b);\
    (c) = (d);\
}
#endif

147 148 149 150 151 152 153
#ifndef MASK_ABS
#define MASK_ABS(mask, level) do {              \
        mask  = level >> 31;                    \
        level = (level ^ mask) - mask;          \
    } while (0)
#endif

154 155 156 157 158 159 160 161
#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

162 163 164
#if HAVE_BIGENDIAN
# ifndef PACK_2U8
#   define PACK_2U8(a,b)     (((a) <<  8) | (b))
165
# endif
166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191
# ifndef PACK_4U8
#   define PACK_4U8(a,b,c,d) (((a) << 24) | ((b) << 16) | ((c) << 8) | (d))
# endif
# ifndef PACK_2U16
#   define PACK_2U16(a,b)    (((a) << 16) | (b))
# endif
#else
# ifndef PACK_2U8
#   define PACK_2U8(a,b)     (((b) <<  8) | (a))
# endif
# ifndef PACK_4U2
#   define PACK_4U8(a,b,c,d) (((d) << 24) | ((c) << 16) | ((b) << 8) | (a))
# endif
# ifndef PACK_2U16
#   define PACK_2U16(a,b)    (((b) << 16) | (a))
# endif
#endif

#ifndef PACK_2S8
#   define PACK_2S8(a,b)     PACK_2U8((a)&255, (b)&255)
#endif
#ifndef PACK_4S8
#   define PACK_4S8(a,b,c,d) PACK_4U8((a)&255, (b)&255, (c)&255, (d)&255)
#endif
#ifndef PACK_2S16
#   define PACK_2S16(a,b)    PACK_2U16((a)&0xffff, (b)&0xffff)
192 193
#endif

194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217
#ifndef FASTDIV
#   define FASTDIV(a,b) ((uint32_t)((((uint64_t)a) * ff_inverse[b]) >> 32))
#endif /* FASTDIV */

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);
}

218
#endif /* AVCODEC_MATHOPS_H */