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/*
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 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
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 *
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 * This file is part of FFmpeg.
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 *
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 * 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
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 * 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
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * 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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 */
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/**
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 * @file
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 * common internal and external API header
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 */
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#ifndef AVUTIL_COMMON_H
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#define AVUTIL_COMMON_H
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#include <ctype.h>
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#include <errno.h>
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#include <inttypes.h>
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#include <limits.h>
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#include <math.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "attributes.h"
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#include "libavutil/avconfig.h"
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#if AV_HAVE_BIGENDIAN
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#   define AV_NE(be, le) (be)
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#else
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#   define AV_NE(be, le) (le)
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#endif
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//rounded division & 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 */
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#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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#define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1))
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/* misc math functions */
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extern const uint8_t ff_log2_tab[256];
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extern const uint8_t av_reverse[256];
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static av_always_inline av_const int av_log2_c(unsigned int v)
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{
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    int n = 0;
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    if (v & 0xffff0000) {
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        v >>= 16;
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        n += 16;
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    }
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    if (v & 0xff00) {
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        v >>= 8;
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        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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}
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static av_always_inline av_const int av_log2_16bit_c(unsigned int v)
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{
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    int n = 0;
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    if (v & 0xff00) {
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        v >>= 8;
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        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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}
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#ifdef HAVE_AV_CONFIG_H
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#   include "config.h"
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#   include "intmath.h"
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#endif
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/* Pull in unguarded fallback defines at the end of this file. */
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#include "common.h"
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/**
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 * Clip a signed integer value into the amin-amax range.
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 * @param a value to clip
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 * @param amin minimum value of the clip range
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 * @param amax maximum value of the clip range
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 * @return clipped value
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 */
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static av_always_inline av_const int av_clip_c(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;
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    else               return a;
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}
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/**
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 * Clip a signed integer value into the 0-255 range.
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 * @param a value to clip
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 * @return clipped value
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 */
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static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
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{
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    if (a&(~0xFF)) return (-a)>>31;
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    else           return a;
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}
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/**
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 * Clip a signed integer value into the -128,127 range.
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 * @param a value to clip
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 * @return clipped value
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 */
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static av_always_inline av_const int8_t av_clip_int8_c(int a)
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{
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    if ((a+0x80) & ~0xFF) return (a>>31) ^ 0x7F;
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    else                  return a;
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}
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/**
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 * Clip a signed integer value into the 0-65535 range.
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 * @param a value to clip
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 * @return clipped value
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 */
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static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
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{
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    if (a&(~0xFFFF)) return (-a)>>31;
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    else             return a;
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}
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/**
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 * Clip a signed integer value into the -32768,32767 range.
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 * @param a value to clip
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 * @return clipped value
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 */
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static av_always_inline av_const int16_t av_clip_int16_c(int a)
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{
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    if ((a+0x8000) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
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    else                      return a;
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}
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/**
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 * Clip a signed 64-bit integer value into the -2147483648,2147483647 range.
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 * @param a value to clip
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 * @return clipped value
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 */
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static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
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{
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    if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (a>>63) ^ 0x7FFFFFFF;
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    else                                         return a;
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}
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/**
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 * Clip a float value into the amin-amax range.
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 * @param a value to clip
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 * @param amin minimum value of the clip range
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 * @param amax maximum value of the clip range
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 * @return clipped value
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 */
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static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
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{
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    if      (a < amin) return amin;
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    else if (a > amax) return amax;
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    else               return a;
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}
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/** Compute ceil(log2(x)).
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 * @param x value used to compute ceil(log2(x))
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 * @return computed ceiling of log2(x)
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 */
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static av_always_inline av_const int av_ceil_log2_c(int x)
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{
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    return av_log2((x - 1) << 1);
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}
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/**
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 * Count number of bits set to one in x
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 * @param x value to count bits of
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 * @return the number of bits set to one in x
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 */
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static av_always_inline av_const int av_popcount_c(uint32_t x)
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{
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    x -= (x >> 1) & 0x55555555;
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    x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
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    x = (x + (x >> 4)) & 0x0F0F0F0F;
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    x += x >> 8;
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    return (x + (x >> 16)) & 0x3F;
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}
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#define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((d) << 24))
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#define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((a) << 24))
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/**
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 * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
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 *
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 * @param val      Output value, must be an lvalue of type uint32_t.
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 * @param GET_BYTE Expression reading one byte from the input.
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 *                 Evaluated up to 7 times (4 for the currently
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 *                 assigned Unicode range).  With a memory buffer
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 *                 input, this could be *ptr++.
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 * @param ERROR    Expression to be evaluated on invalid input,
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 *                 typically a goto statement.
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 */
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#define GET_UTF8(val, GET_BYTE, ERROR)\
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    val= GET_BYTE;\
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    {\
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        int ones= 7 - av_log2(val ^ 255);\
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        if(ones==1)\
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            ERROR\
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        val&= 127>>ones;\
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        while(--ones > 0){\
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            int tmp= GET_BYTE - 128;\
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            if(tmp>>6)\
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                ERROR\
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            val= (val<<6) + tmp;\
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        }\
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    }
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/**
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 * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
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 *
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 * @param val       Output value, must be an lvalue of type uint32_t.
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 * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
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 *                  to native byte order.  Evaluated one or two times.
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 * @param ERROR     Expression to be evaluated on invalid input,
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 *                  typically a goto statement.
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 */
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#define GET_UTF16(val, GET_16BIT, ERROR)\
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    val = GET_16BIT;\
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    {\
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        unsigned int hi = val - 0xD800;\
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        if (hi < 0x800) {\
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            val = GET_16BIT - 0xDC00;\
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            if (val > 0x3FFU || hi > 0x3FFU)\
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                ERROR\
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            val += (hi<<10) + 0x10000;\
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        }\
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    }\
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/*!
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 * \def PUT_UTF8(val, tmp, PUT_BYTE)
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 * Convert 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 UCS-4 encoded Unicode character that is to be converted to UTF-8. If
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 * val is given as a function it is executed only once.
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 * \param tmp is a temporary variable and should be of type uint8_t. It
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 * represents an intermediate value during conversion that is to be
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 * output 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.
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 * 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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 */
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#define PUT_UTF8(val, tmp, PUT_BYTE)\
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    {\
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        int bytes, shift;\
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        uint32_t in = val;\
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        if (in < 0x80) {\
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            tmp = in;\
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            PUT_BYTE\
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        } else {\
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            bytes = (av_log2(in) + 4) / 5;\
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            shift = (bytes - 1) * 6;\
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            tmp = (256 - (256 >> bytes)) | (in >> shift);\
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            PUT_BYTE\
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            while (shift >= 6) {\
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                shift -= 6;\
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                tmp = 0x80 | ((in >> shift) & 0x3f);\
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                PUT_BYTE\
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            }\
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        }\
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    }
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/*!
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 * \def PUT_UTF16(val, tmp, PUT_16BIT)
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 * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
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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 UCS-4 encoded Unicode character that is to be converted to UTF-16. If
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 * val is given as a function it is executed only once.
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 * \param tmp is a temporary variable and should be of type uint16_t. It
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 * represents an intermediate value during conversion that is to be
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 * output by PUT_16BIT.
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 * \param PUT_16BIT writes the converted UTF-16 data to any proper destination
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 * in desired endianness. It could be a function or a statement, and uses tmp
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 * as the input byte.  For example, PUT_BYTE could be "*output++ = tmp;"
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 * PUT_BYTE will be executed 1 or 2 times depending on input character.
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 */
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#define PUT_UTF16(val, tmp, PUT_16BIT)\
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    {\
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        uint32_t in = val;\
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        if (in < 0x10000) {\
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            tmp = in;\
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            PUT_16BIT\
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        } else {\
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            tmp = 0xD800 | ((in - 0x10000) >> 10);\
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            PUT_16BIT\
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            tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
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            PUT_16BIT\
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        }\
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    }\
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#include "mem.h"
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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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#endif /* AVUTIL_COMMON_H */
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/*
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 * The following definitions are outside the multiple inclusion guard
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 * to ensure they are immediately available in intmath.h.
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 */
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#ifndef av_log2
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#   define av_log2       av_log2_c
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#endif
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#ifndef av_log2_16bit
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#   define av_log2_16bit av_log2_16bit_c
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#endif
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#ifndef av_ceil_log2
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#   define av_ceil_log2     av_ceil_log2_c
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#endif
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#ifndef av_clip
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#   define av_clip          av_clip_c
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#endif
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#ifndef av_clip_uint8
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#   define av_clip_uint8    av_clip_uint8_c
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#endif
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#ifndef av_clip_int8
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#   define av_clip_int8     av_clip_int8_c
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#endif
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#ifndef av_clip_uint16
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#   define av_clip_uint16   av_clip_uint16_c
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#endif
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#ifndef av_clip_int16
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#   define av_clip_int16    av_clip_int16_c
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#endif
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#ifndef av_clipl_int32
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#   define av_clipl_int32   av_clipl_int32_c
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#endif
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#ifndef av_clipf
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#   define av_clipf         av_clipf_c
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#endif
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#ifndef av_popcount
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#   define av_popcount      av_popcount_c
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#endif