Sunshine/third-party/cbs/mathops.h

/*
 * simple math operations
 * Copyright (c) 2001, 2002 Fabrice Bellard
 * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> et al
 *
 * 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 AVCODEC_MATHOPS_H
#define AVCODEC_MATHOPS_H

#include "config.h"

#include <stdint.h>

#include <libavutil/common.h>

#define MAX_NEG_CROP 1024

extern const uint8_t ff_reverse[256];
extern const uint32_t ff_inverse[257];
extern const uint8_t ff_sqrt_tab[256];
extern const uint8_t ff_crop_tab[256 + 2 * MAX_NEG_CROP];
extern const uint8_t ff_zigzag_direct[64];
extern const uint8_t ff_zigzag_scan[16 + 1];

#ifndef MUL64
#define MUL64(a, b) ((int64_t)(a) * (int64_t)(b))
#endif

#ifndef MULL
#define MULL(a, b, s) (MUL64(a, b) >> (s))
#endif

#ifndef MULH
static av_always_inline int MULH(int a, int b) {
  return MUL64(a, b) >> 32;
}
#endif

#ifndef UMULH
static av_always_inline unsigned UMULH(unsigned a, unsigned b) {
  return ((uint64_t)(a) * (uint64_t)(b)) >> 32;
}
#endif

#ifndef MAC64
#define MAC64(d, a, b) ((d) += MUL64(a, b))
#endif

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

/* 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

#ifndef MLS16
#define MLS16(rt, ra, rb) ((rt) -= (ra) * (rb))
#endif

/* 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(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

#ifndef median4
#define median4 median4
static inline av_const int median4(int a, int b, int c, int d) {
  if(a < b) {
    if(c < d) return (FFMIN(b, d) + FFMAX(a, c)) / 2;
    else
      return (FFMIN(b, c) + FFMAX(a, d)) / 2;
  }
  else {
    if(c < d) return (FFMIN(a, d) + FFMAX(b, c)) / 2;
    else
      return (FFMIN(a, c) + FFMAX(b, d)) / 2;
  }
}
#endif

#ifndef sign_extend
static inline av_const 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;
}
#endif

#ifndef zero_extend
static inline av_const unsigned zero_extend(unsigned val, unsigned bits) {
  return (val << ((8 * sizeof(int)) - bits)) >> ((8 * sizeof(int)) - bits);
}
#endif

#ifndef COPY3_IF_LT
#define COPY3_IF_LT(x, y, a, b, c, d) \
  if((y) < (x)) {                     \
    (x) = (y);                        \
    (a) = (b);                        \
    (c) = (d);                        \
  }
#endif

#ifndef MASK_ABS
#define MASK_ABS(mask, level)      \
  do {                             \
    mask  = level >> 31;           \
    level = (level ^ mask) - mask; \
  } while(0)
#endif

#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

#if HAVE_BIGENDIAN
#ifndef PACK_2U8
#define PACK_2U8(a, b) (((a) << 8) | (b))
#endif
#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)
#endif

#ifndef FASTDIV
#define FASTDIV(a, b) ((uint32_t)((((uint64_t)a) * ff_inverse[b]) >> 32))
#endif /* FASTDIV */

#ifndef ff_sqrt
#define ff_sqrt ff_sqrt
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

static inline av_const float ff_sqrf(float a) {
  return a * a;
}

static inline int8_t ff_u8_to_s8(uint8_t a) {
  union {
    uint8_t u8;
    int8_t s8;
  } b;
  b.u8 = a;
  return b.s8;
}

static av_always_inline uint32_t bitswap_32(uint32_t x) {
  return (uint32_t)ff_reverse[x & 0xFF] << 24 |
         (uint32_t)ff_reverse[(x >> 8) & 0xFF] << 16 |
         (uint32_t)ff_reverse[(x >> 16) & 0xFF] << 8 |
         (uint32_t)ff_reverse[x >> 24];
}

#endif /* AVCODEC_MATHOPS_H */