ffmpeg/libavutil/common.h

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