libavutil/common.h

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/*
 * copyright (c) 2006 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
 */

#ifndef AVUTIL_COMMON_H
#define AVUTIL_COMMON_H

#include <ctype.h>
#include <errno.h>
#include <inttypes.h>
#include <limits.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "attributes.h"
#include "libavutil/avconfig.h"

#if AV_HAVE_BIGENDIAN
#   define AV_NE(be, le) (be)
#else
#   define AV_NE(be, le) (le)
#endif

//rounded division & shift
#define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
/* assume b>0 */
#define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
#define FFUDIV(a,b) (((a)>0 ?(a):(a)-(b)+1) / (b))
#define FFUMOD(a,b) ((a)-(b)*FFUDIV(a,b))
#define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
#define FFSIGN(a) ((a) > 0 ? 1 : -1)

#define FFMAX(a,b) ((a) > (b) ? (a) : (b))
#define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
#define FFMIN(a,b) ((a) > (b) ? (b) : (a))
#define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)

#define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
#define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
#define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1))

/* misc math functions */
extern const uint8_t ff_log2_tab[256];

extern const uint8_t av_reverse[256];

static av_always_inline av_const int av_log2_c(unsigned int v)
{
    int n = 0;
    if (v & 0xffff0000) {
        v >>= 16;
        n += 16;
    }
    if (v & 0xff00) {
        v >>= 8;
        n += 8;
    }
    n += ff_log2_tab[v];

    return n;
}

static av_always_inline av_const int av_log2_16bit_c(unsigned int v)
{
    int n = 0;
    if (v & 0xff00) {
        v >>= 8;
        n += 8;
    }
    n += ff_log2_tab[v];

    return n;
}

#ifdef HAVE_AV_CONFIG_H
#   include "config.h"
#   include "intmath.h"
#endif

/* Pull in unguarded fallback defines at the end of this file. */
#include "common.h"

static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
{
    if      (a < amin) return amin;
    else if (a > amax) return amax;
    else               return a;
}

static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
{
    if (a&(~0xFF)) return (-a)>>31;
    else           return a;
}

static av_always_inline av_const int8_t av_clip_int8_c(int a)
{
    if ((a+0x80) & ~0xFF) return (a>>31) ^ 0x7F;
    else                  return a;
}

static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
{
    if (a&(~0xFFFF)) return (-a)>>31;
    else             return a;
}

static av_always_inline av_const int16_t av_clip_int16_c(int a)
{
    if ((a+0x8000) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
    else                      return a;
}

static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
{
    if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (a>>63) ^ 0x7FFFFFFF;
    else                                         return a;
}

static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
{
    if (a & ~((1<<p) - 1)) return -a >> 31 & ((1<<p) - 1);
    else                   return  a;
}

static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
{
    if      (a < amin) return amin;
    else if (a > amax) return amax;
    else               return a;
}

static av_always_inline av_const int av_ceil_log2_c(int x)
{
    return av_log2((x - 1) << 1);
}

static av_always_inline av_const int av_popcount_c(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;
}

#define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
#define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))

#define GET_UTF8(val, GET_BYTE, ERROR)\
    val= GET_BYTE;\
    {\
        int ones= 7 - av_log2(val ^ 255);\
        if(ones==1)\
            ERROR\
        val&= 127>>ones;\
        while(--ones > 0){\
            int tmp= GET_BYTE - 128;\
            if(tmp>>6)\
                ERROR\
            val= (val<<6) + tmp;\
        }\
    }

#define GET_UTF16(val, GET_16BIT, ERROR)\
    val = GET_16BIT;\
    {\
        unsigned int hi = val - 0xD800;\
        if (hi < 0x800) {\
            val = GET_16BIT - 0xDC00;\
            if (val > 0x3FFU || hi > 0x3FFU)\
                ERROR\
            val += (hi<<10) + 0x10000;\
        }\
    }\


#define PUT_UTF8(val, tmp, PUT_BYTE)\
    {\
        int bytes, shift;\
        uint32_t in = val;\
        if (in < 0x80) {\
            tmp = in;\
            PUT_BYTE\
        } else {\
            bytes = (av_log2(in) + 4) / 5;\
            shift = (bytes - 1) * 6;\
            tmp = (256 - (256 >> bytes)) | (in >> shift);\
            PUT_BYTE\
            while (shift >= 6) {\
                shift -= 6;\
                tmp = 0x80 | ((in >> shift) & 0x3f);\
                PUT_BYTE\
            }\
        }\
    }

#define PUT_UTF16(val, tmp, PUT_16BIT)\
    {\
        uint32_t in = val;\
        if (in < 0x10000) {\
            tmp = in;\
            PUT_16BIT\
        } else {\
            tmp = 0xD800 | ((in - 0x10000) >> 10);\
            PUT_16BIT\
            tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
            PUT_16BIT\
        }\
    }\



#include "mem.h"

#ifdef HAVE_AV_CONFIG_H
#    include "internal.h"
#endif /* HAVE_AV_CONFIG_H */

#endif /* AVUTIL_COMMON_H */

/*
 * The following definitions are outside the multiple inclusion guard
 * to ensure they are immediately available in intmath.h.
 */

#ifndef av_log2
#   define av_log2       av_log2_c
#endif
#ifndef av_log2_16bit
#   define av_log2_16bit av_log2_16bit_c
#endif
#ifndef av_ceil_log2
#   define av_ceil_log2     av_ceil_log2_c
#endif
#ifndef av_clip
#   define av_clip          av_clip_c
#endif
#ifndef av_clip_uint8
#   define av_clip_uint8    av_clip_uint8_c
#endif
#ifndef av_clip_int8
#   define av_clip_int8     av_clip_int8_c
#endif
#ifndef av_clip_uint16
#   define av_clip_uint16   av_clip_uint16_c
#endif
#ifndef av_clip_int16
#   define av_clip_int16    av_clip_int16_c
#endif
#ifndef av_clipl_int32
#   define av_clipl_int32   av_clipl_int32_c
#endif
#ifndef av_clip_uintp2
#   define av_clip_uintp2   av_clip_uintp2_c
#endif
#ifndef av_clipf
#   define av_clipf         av_clipf_c
#endif
#ifndef av_popcount
#   define av_popcount      av_popcount_c
#endif

---