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      1 /*
      2  * copyright (c) 2006 Michael Niedermayer <michaelni (at) gmx.at>
      3  *
      4  * This file is part of FFmpeg.
      5  *
      6  * FFmpeg is free software; you can redistribute it and/or
      7  * modify it under the terms of the GNU Lesser General Public
      8  * License as published by the Free Software Foundation; either
      9  * version 2.1 of the License, or (at your option) any later version.
     10  *
     11  * FFmpeg is distributed in the hope that it will be useful,
     12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     14  * Lesser General Public License for more details.
     15  *
     16  * You should have received a copy of the GNU Lesser General Public
     17  * License along with FFmpeg; if not, write to the Free Software
     18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
     19  */
     20 
     21 /**
     22  * @file
     23  * common internal and external API header
     24  */
     25 
     26 #ifndef AVUTIL_COMMON_H
     27 #define AVUTIL_COMMON_H
     28 
     29 #include <errno.h>
     30 #include <inttypes.h>
     31 #include <limits.h>
     32 #include <math.h>
     33 #include <stdio.h>
     34 #include <stdlib.h>
     35 #include <string.h>
     36 
     37 #include "attributes.h"
     38 #include "version.h"
     39 #include "libavutil/avconfig.h"
     40 
     41 #if AV_HAVE_BIGENDIAN
     42 #   define AV_NE(be, le) (be)
     43 #else
     44 #   define AV_NE(be, le) (le)
     45 #endif
     46 
     47 //rounded division & shift
     48 #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
     49 /* assume b>0 */
     50 #define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
     51 /* assume a>0 and b>0 */
     52 #define FF_CEIL_RSHIFT(a,b) (!av_builtin_constant_p(b) ? -((-(a)) >> (b)) \
     53                                                        : ((a) + (1<<(b)) - 1) >> (b))
     54 #define FFUDIV(a,b) (((a)>0 ?(a):(a)-(b)+1) / (b))
     55 #define FFUMOD(a,b) ((a)-(b)*FFUDIV(a,b))
     56 #define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
     57 #define FFSIGN(a) ((a) > 0 ? 1 : -1)
     58 
     59 #define FFMAX(a,b) ((a) > (b) ? (a) : (b))
     60 #define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
     61 #define FFMIN(a,b) ((a) > (b) ? (b) : (a))
     62 #define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)
     63 
     64 #define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
     65 #define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
     66 #define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1))
     67 
     68 /* misc math functions */
     69 
     70 /**
     71  * Reverse the order of the bits of an 8-bits unsigned integer.
     72  */
     73 #if FF_API_AV_REVERSE
     74 extern attribute_deprecated const uint8_t av_reverse[256];
     75 #endif
     76 
     77 #ifdef HAVE_AV_CONFIG_H
     78 #   include "config.h"
     79 #   include "intmath.h"
     80 #endif
     81 
     82 /* Pull in unguarded fallback defines at the end of this file. */
     83 #include "common.h"
     84 
     85 #ifndef av_log2
     86 av_const int av_log2(unsigned v);
     87 #endif
     88 
     89 #ifndef av_log2_16bit
     90 av_const int av_log2_16bit(unsigned v);
     91 #endif
     92 
     93 /**
     94  * Clip a signed integer value into the amin-amax range.
     95  * @param a value to clip
     96  * @param amin minimum value of the clip range
     97  * @param amax maximum value of the clip range
     98  * @return clipped value
     99  */
    100 static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
    101 {
    102 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
    103     if (amin > amax) abort();
    104 #endif
    105     if      (a < amin) return amin;
    106     else if (a > amax) return amax;
    107     else               return a;
    108 }
    109 
    110 /**
    111  * Clip a signed 64bit integer value into the amin-amax range.
    112  * @param a value to clip
    113  * @param amin minimum value of the clip range
    114  * @param amax maximum value of the clip range
    115  * @return clipped value
    116  */
    117 static av_always_inline av_const int64_t av_clip64_c(int64_t a, int64_t amin, int64_t amax)
    118 {
    119 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
    120     if (amin > amax) abort();
    121 #endif
    122     if      (a < amin) return amin;
    123     else if (a > amax) return amax;
    124     else               return a;
    125 }
    126 
    127 /**
    128  * Clip a signed integer value into the 0-255 range.
    129  * @param a value to clip
    130  * @return clipped value
    131  */
    132 static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
    133 {
    134     if (a&(~0xFF)) return (-a)>>31;
    135     else           return a;
    136 }
    137 
    138 /**
    139  * Clip a signed integer value into the -128,127 range.
    140  * @param a value to clip
    141  * @return clipped value
    142  */
    143 static av_always_inline av_const int8_t av_clip_int8_c(int a)
    144 {
    145     if ((a+0x80) & ~0xFF) return (a>>31) ^ 0x7F;
    146     else                  return a;
    147 }
    148 
    149 /**
    150  * Clip a signed integer value into the 0-65535 range.
    151  * @param a value to clip
    152  * @return clipped value
    153  */
    154 static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
    155 {
    156     if (a&(~0xFFFF)) return (-a)>>31;
    157     else             return a;
    158 }
    159 
    160 /**
    161  * Clip a signed integer value into the -32768,32767 range.
    162  * @param a value to clip
    163  * @return clipped value
    164  */
    165 static av_always_inline av_const int16_t av_clip_int16_c(int a)
    166 {
    167     if ((a+0x8000) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
    168     else                      return a;
    169 }
    170 
    171 /**
    172  * Clip a signed 64-bit integer value into the -2147483648,2147483647 range.
    173  * @param a value to clip
    174  * @return clipped value
    175  */
    176 static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
    177 {
    178     if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (a>>63) ^ 0x7FFFFFFF;
    179     else                                         return (int32_t)a;
    180 }
    181 
    182 /**
    183  * Clip a signed integer to an unsigned power of two range.
    184  * @param  a value to clip
    185  * @param  p bit position to clip at
    186  * @return clipped value
    187  */
    188 static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
    189 {
    190     if (a & ~((1<<p) - 1)) return -a >> 31 & ((1<<p) - 1);
    191     else                   return  a;
    192 }
    193 
    194 /**
    195  * Add two signed 32-bit values with saturation.
    196  *
    197  * @param  a one value
    198  * @param  b another value
    199  * @return sum with signed saturation
    200  */
    201 static av_always_inline int av_sat_add32_c(int a, int b)
    202 {
    203     return av_clipl_int32((int64_t)a + b);
    204 }
    205 
    206 /**
    207  * Add a doubled value to another value with saturation at both stages.
    208  *
    209  * @param  a first value
    210  * @param  b value doubled and added to a
    211  * @return sum with signed saturation
    212  */
    213 static av_always_inline int av_sat_dadd32_c(int a, int b)
    214 {
    215     return av_sat_add32(a, av_sat_add32(b, b));
    216 }
    217 
    218 /**
    219  * Clip a float value into the amin-amax range.
    220  * @param a value to clip
    221  * @param amin minimum value of the clip range
    222  * @param amax maximum value of the clip range
    223  * @return clipped value
    224  */
    225 static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
    226 {
    227 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
    228     if (amin > amax) abort();
    229 #endif
    230     if      (a < amin) return amin;
    231     else if (a > amax) return amax;
    232     else               return a;
    233 }
    234 
    235 /**
    236  * Clip a double value into the amin-amax range.
    237  * @param a value to clip
    238  * @param amin minimum value of the clip range
    239  * @param amax maximum value of the clip range
    240  * @return clipped value
    241  */
    242 static av_always_inline av_const double av_clipd_c(double a, double amin, double amax)
    243 {
    244 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
    245     if (amin > amax) abort();
    246 #endif
    247     if      (a < amin) return amin;
    248     else if (a > amax) return amax;
    249     else               return a;
    250 }
    251 
    252 /** Compute ceil(log2(x)).
    253  * @param x value used to compute ceil(log2(x))
    254  * @return computed ceiling of log2(x)
    255  */
    256 static av_always_inline av_const int av_ceil_log2_c(int x)
    257 {
    258     return av_log2((x - 1) << 1);
    259 }
    260 
    261 /**
    262  * Count number of bits set to one in x
    263  * @param x value to count bits of
    264  * @return the number of bits set to one in x
    265  */
    266 static av_always_inline av_const int av_popcount_c(uint32_t x)
    267 {
    268     x -= (x >> 1) & 0x55555555;
    269     x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
    270     x = (x + (x >> 4)) & 0x0F0F0F0F;
    271     x += x >> 8;
    272     return (x + (x >> 16)) & 0x3F;
    273 }
    274 
    275 /**
    276  * Count number of bits set to one in x
    277  * @param x value to count bits of
    278  * @return the number of bits set to one in x
    279  */
    280 static av_always_inline av_const int av_popcount64_c(uint64_t x)
    281 {
    282     return av_popcount((uint32_t)x) + av_popcount(x >> 32);
    283 }
    284 
    285 #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
    286 #define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))
    287 
    288 /**
    289  * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
    290  *
    291  * @param val      Output value, must be an lvalue of type uint32_t.
    292  * @param GET_BYTE Expression reading one byte from the input.
    293  *                 Evaluated up to 7 times (4 for the currently
    294  *                 assigned Unicode range).  With a memory buffer
    295  *                 input, this could be *ptr++.
    296  * @param ERROR    Expression to be evaluated on invalid input,
    297  *                 typically a goto statement.
    298  */
    299 #define GET_UTF8(val, GET_BYTE, ERROR)\
    300     val= GET_BYTE;\
    301     {\
    302         uint32_t top = (val & 128) >> 1;\
    303         if ((val & 0xc0) == 0x80 || val >= 0xFE)\
    304             ERROR\
    305         while (val & top) {\
    306             int tmp= GET_BYTE - 128;\
    307             if(tmp>>6)\
    308                 ERROR\
    309             val= (val<<6) + tmp;\
    310             top <<= 5;\
    311         }\
    312         val &= (top << 1) - 1;\
    313     }
    314 
    315 /**
    316  * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
    317  *
    318  * @param val       Output value, must be an lvalue of type uint32_t.
    319  * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
    320  *                  to native byte order.  Evaluated one or two times.
    321  * @param ERROR     Expression to be evaluated on invalid input,
    322  *                  typically a goto statement.
    323  */
    324 #define GET_UTF16(val, GET_16BIT, ERROR)\
    325     val = GET_16BIT;\
    326     {\
    327         unsigned int hi = val - 0xD800;\
    328         if (hi < 0x800) {\
    329             val = GET_16BIT - 0xDC00;\
    330             if (val > 0x3FFU || hi > 0x3FFU)\
    331                 ERROR\
    332             val += (hi<<10) + 0x10000;\
    333         }\
    334     }\
    335 
    336 /**
    337  * @def PUT_UTF8(val, tmp, PUT_BYTE)
    338  * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
    339  * @param val is an input-only argument and should be of type uint32_t. It holds
    340  * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
    341  * val is given as a function it is executed only once.
    342  * @param tmp is a temporary variable and should be of type uint8_t. It
    343  * represents an intermediate value during conversion that is to be
    344  * output by PUT_BYTE.
    345  * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
    346  * It could be a function or a statement, and uses tmp as the input byte.
    347  * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
    348  * executed up to 4 times for values in the valid UTF-8 range and up to
    349  * 7 times in the general case, depending on the length of the converted
    350  * Unicode character.
    351  */
    352 #define PUT_UTF8(val, tmp, PUT_BYTE)\
    353     {\
    354         int bytes, shift;\
    355         uint32_t in = val;\
    356         if (in < 0x80) {\
    357             tmp = in;\
    358             PUT_BYTE\
    359         } else {\
    360             bytes = (av_log2(in) + 4) / 5;\
    361             shift = (bytes - 1) * 6;\
    362             tmp = (256 - (256 >> bytes)) | (in >> shift);\
    363             PUT_BYTE\
    364             while (shift >= 6) {\
    365                 shift -= 6;\
    366                 tmp = 0x80 | ((in >> shift) & 0x3f);\
    367                 PUT_BYTE\
    368             }\
    369         }\
    370     }
    371 
    372 /**
    373  * @def PUT_UTF16(val, tmp, PUT_16BIT)
    374  * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
    375  * @param val is an input-only argument and should be of type uint32_t. It holds
    376  * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
    377  * val is given as a function it is executed only once.
    378  * @param tmp is a temporary variable and should be of type uint16_t. It
    379  * represents an intermediate value during conversion that is to be
    380  * output by PUT_16BIT.
    381  * @param PUT_16BIT writes the converted UTF-16 data to any proper destination
    382  * in desired endianness. It could be a function or a statement, and uses tmp
    383  * as the input byte.  For example, PUT_BYTE could be "*output++ = tmp;"
    384  * PUT_BYTE will be executed 1 or 2 times depending on input character.
    385  */
    386 #define PUT_UTF16(val, tmp, PUT_16BIT)\
    387     {\
    388         uint32_t in = val;\
    389         if (in < 0x10000) {\
    390             tmp = in;\
    391             PUT_16BIT\
    392         } else {\
    393             tmp = 0xD800 | ((in - 0x10000) >> 10);\
    394             PUT_16BIT\
    395             tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
    396             PUT_16BIT\
    397         }\
    398     }\
    399 
    400 
    401 
    402 #include "mem.h"
    403 
    404 #ifdef HAVE_AV_CONFIG_H
    405 #    include "internal.h"
    406 #endif /* HAVE_AV_CONFIG_H */
    407 
    408 #endif /* AVUTIL_COMMON_H */
    409 
    410 /*
    411  * The following definitions are outside the multiple inclusion guard
    412  * to ensure they are immediately available in intmath.h.
    413  */
    414 
    415 #ifndef av_ceil_log2
    416 #   define av_ceil_log2     av_ceil_log2_c
    417 #endif
    418 #ifndef av_clip
    419 #   define av_clip          av_clip_c
    420 #endif
    421 #ifndef av_clip64
    422 #   define av_clip64        av_clip64_c
    423 #endif
    424 #ifndef av_clip_uint8
    425 #   define av_clip_uint8    av_clip_uint8_c
    426 #endif
    427 #ifndef av_clip_int8
    428 #   define av_clip_int8     av_clip_int8_c
    429 #endif
    430 #ifndef av_clip_uint16
    431 #   define av_clip_uint16   av_clip_uint16_c
    432 #endif
    433 #ifndef av_clip_int16
    434 #   define av_clip_int16    av_clip_int16_c
    435 #endif
    436 #ifndef av_clipl_int32
    437 #   define av_clipl_int32   av_clipl_int32_c
    438 #endif
    439 #ifndef av_clip_uintp2
    440 #   define av_clip_uintp2   av_clip_uintp2_c
    441 #endif
    442 #ifndef av_sat_add32
    443 #   define av_sat_add32     av_sat_add32_c
    444 #endif
    445 #ifndef av_sat_dadd32
    446 #   define av_sat_dadd32    av_sat_dadd32_c
    447 #endif
    448 #ifndef av_clipf
    449 #   define av_clipf         av_clipf_c
    450 #endif
    451 #ifndef av_clipd
    452 #   define av_clipd         av_clipd_c
    453 #endif
    454 #ifndef av_popcount
    455 #   define av_popcount      av_popcount_c
    456 #endif
    457 #ifndef av_popcount64
    458 #   define av_popcount64    av_popcount64_c
    459 #endif
    460