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/*
 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
 *
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 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * 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
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

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/**
 * @file common.h
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 * common internal and external API header
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 */

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#ifndef AVUTIL_COMMON_H
#define AVUTIL_COMMON_H
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#include <inttypes.h>

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#ifdef HAVE_AV_CONFIG_H
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/* only include the following when compiling package */
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#    include "config.h"

#    include <stdlib.h>
#    include <stdio.h>
#    include <string.h>
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#    include <ctype.h>
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#    include <limits.h>
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#    include <errno.h>
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#    include <math.h>
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#endif /* HAVE_AV_CONFIG_H */

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#define AV_GCC_VERSION_AT_LEAST(x,y) (defined(__GNUC__) && (__GNUC__ > x || __GNUC__ == x && __GNUC_MINOR__ >= y))

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#ifndef av_always_inline
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#if AV_GCC_VERSION_AT_LEAST(3,1)
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#    define av_always_inline __attribute__((always_inline)) inline
#else
#    define av_always_inline inline
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#endif
#endif

#ifndef av_noinline
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#if AV_GCC_VERSION_AT_LEAST(3,1)
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#    define av_noinline __attribute__((noinline))
#else
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#    define av_noinline
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#endif
#endif

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#ifndef av_pure
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#if AV_GCC_VERSION_AT_LEAST(3,1)
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#    define av_pure __attribute__((pure))
#else
#    define av_pure
#endif
#endif

#ifndef av_const
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#if AV_GCC_VERSION_AT_LEAST(2,6)
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#    define av_const __attribute__((const))
#else
#    define av_const
#endif
#endif

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#ifndef av_cold
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#if (!defined(__ICC) || __ICC > 1100) && AV_GCC_VERSION_AT_LEAST(4,3)
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#    define av_cold __attribute__((cold))
#else
#    define av_cold
#endif
#endif

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#ifdef HAVE_AV_CONFIG_H
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#    include "internal.h"
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#endif /* HAVE_AV_CONFIG_H */
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#ifndef attribute_deprecated
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#if AV_GCC_VERSION_AT_LEAST(3,1)
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#    define attribute_deprecated __attribute__((deprecated))
#else
#    define attribute_deprecated
#endif
#endif

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#ifndef av_unused
#if defined(__GNUC__)
#    define av_unused __attribute__((unused))
#else
#    define av_unused
#endif
#endif

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#include "mem.h"

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//rounded divison & shift
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#define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
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/* assume b>0 */
#define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
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#define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
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#define FFSIGN(a) ((a) > 0 ? 1 : -1)
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#define FFMAX(a,b) ((a) > (b) ? (a) : (b))
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#define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
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#define FFMIN(a,b) ((a) > (b) ? (b) : (a))
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#define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)
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#define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
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#define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
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/* misc math functions */
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extern const uint8_t ff_log2_tab[256];
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static inline av_const int av_log2(unsigned int v)
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{
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    int n = 0;
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    if (v & 0xffff0000) {
        v >>= 16;
        n += 16;
    }
    if (v & 0xff00) {
        v >>= 8;
        n += 8;
    }
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    n += ff_log2_tab[v];

    return n;
}

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static inline av_const int av_log2_16bit(unsigned int v)
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{
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    int n = 0;
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    if (v & 0xff00) {
        v >>= 8;
        n += 8;
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    }
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    n += ff_log2_tab[v];

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    return n;
}

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/* median of 3 */
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static inline av_const int mid_pred(int a, int b, int c)
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{
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#if HAVE_CMOV
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    int i=b;
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    __asm__ volatile(
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        "cmp    %2, %1 \n\t"
        "cmovg  %1, %0 \n\t"
        "cmovg  %2, %1 \n\t"
        "cmp    %3, %1 \n\t"
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        "cmovl  %3, %1 \n\t"
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        "cmp    %1, %0 \n\t"
        "cmovg  %1, %0 \n\t"
        :"+&r"(i), "+&r"(a)
        :"r"(b), "r"(c)
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    );
    return i;
#elif 0
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    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
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}

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/**
 * clip a signed integer value into the amin-amax range
 * @param a value to clip
 * @param amin minimum value of the clip range
 * @param amax maximum value of the clip range
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 * @return clipped value
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 */
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static inline av_const int av_clip(int a, int amin, int amax)
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{
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    if      (a < amin) return amin;
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    else if (a > amax) return amax;
    else               return a;
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}

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/**
 * clip a signed integer value into the 0-255 range
 * @param a value to clip
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 * @return clipped value
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 */
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static inline av_const uint8_t av_clip_uint8(int a)
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{
    if (a&(~255)) return (-a)>>31;
    else          return a;
}

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/**
 * clip a signed integer value into the -32768,32767 range
 * @param a value to clip
 * @return clipped value
 */
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static inline av_const int16_t av_clip_int16(int a)
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{
    if ((a+32768) & ~65535) return (a>>31) ^ 32767;
    else                    return a;
}

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/**
 * clip a float value into the amin-amax range
 * @param a value to clip
 * @param amin minimum value of the clip range
 * @param amax maximum value of the clip range
 * @return clipped value
 */
static inline av_const float av_clipf(float a, float amin, float amax)
{
    if      (a < amin) return amin;
    else if (a > amax) return amax;
    else               return a;
}

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/* math */
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int64_t av_const ff_gcd(int64_t a, int64_t b);
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/**
 * converts fourcc string to int
 */
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static inline av_pure int ff_get_fourcc(const char *s){
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#ifdef HAVE_AV_CONFIG_H
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    assert( strlen(s)==4 );
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#endif
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    return (s[0]) + (s[1]<<8) + (s[2]<<16) + (s[3]<<24);
}

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

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/*!
 * \def GET_UTF8(val, GET_BYTE, ERROR)
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 * converts a UTF-8 character (up to 4 bytes long) to its 32-bit UCS-4 encoded form
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 * \param val is the output and should be of type uint32_t. It holds the converted
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 * UCS-4 character and should be a left value.
 * \param GET_BYTE gets UTF-8 encoded bytes from any proper source. It can be
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 * a function or a statement whose return value or evaluated value is of type
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 * uint8_t. It will be executed up to 4 times for values in the valid UTF-8 range,
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 * and up to 7 times in the general case.
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 * \param ERROR action that should be taken when an invalid UTF-8 byte is returned
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 * from GET_BYTE. It should be a statement that jumps out of the macro,
 * like exit(), goto, return, break, or continue.
 */
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#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;\
        }\
    }
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/*!
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 * \def PUT_UTF8(val, tmp, PUT_BYTE)
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 * converts a 32-bit unicode character to its UTF-8 encoded form (up to 4 bytes long).
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 * \param val is an input only argument and should be of type uint32_t. It holds
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 * a ucs4 encoded unicode character that is to be converted to UTF-8. If
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 * val is given as a function it's executed only once.
 * \param tmp is a temporary variable and should be of type uint8_t. It
 * represents an intermediate value during conversion that is to be
 * outputted by PUT_BYTE.
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 * \param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
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 * It could be a function or a statement, and uses tmp as the input byte.
 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
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 * executed up to 4 times for values in the valid UTF-8 range and up to
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 * 7 times in the general case, depending on the length of the converted
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 * unicode character.
 */
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#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\
            }\
        }\
    }

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#endif /* AVUTIL_COMMON_H */