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 "error.h"
  44 #include "macros.h"
  45 #include "version.h"
  46
  47 #ifdef HAVE_AV_CONFIG_H
  48 #   include "config.h"
  49 #   include "intmath.h"
  50 #   include "internal.h"
  51 #else
  52 #   include "mem.h"
  53 #endif /* HAVE_AV_CONFIG_H */
  54
  55 //rounded division & shift
  56 #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
  57 /* assume b>0 */
  58 #define ROUNDED_DIV(a,b) (((a)>=0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
  59 /* Fast a/(1<<b) rounded toward +inf. Assume a>=0 and b>=0 */
  60 #define AV_CEIL_RSHIFT(a,b) (!av_builtin_constant_p(b) ? -((-(a)) >> (b)) \
  61                                                        : ((a) + (1<<(b)) - 1) >> (b))
  62 /* Backwards compat. */
  63 #define FF_CEIL_RSHIFT AV_CEIL_RSHIFT
  64
  65 #define FFUDIV(a,b) (((a)>0 ?(a):(a)-(b)+1) / (b))
  66 #define FFUMOD(a,b) ((a)-(b)*FFUDIV(a,b))
  67
  68 /**
  69  * Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they
  70  * are not representable as absolute values of their type. This is the same
  71  * as with *abs()
  72  * @see FFNABS()
  73  */
  74 #define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
  75 #define FFSIGN(a) ((a) > 0 ? 1 : -1)
  76
  77 /**
  78  * Negative Absolute value.
  79  * this works for all integers of all types.
  80  * As with many macros, this evaluates its argument twice, it thus must not have
  81  * a sideeffect, that is FFNABS(x++) has undefined behavior.
  82  */
  83 #define FFNABS(a) ((a) <= 0 ? (a) : (-(a)))
  84
  85 /**
  86  * Unsigned Absolute value.
  87  * This takes the absolute value of a signed int and returns it as a unsigned.
  88  * This also works with INT_MIN which would otherwise not be representable
  89  * As with many macros, this evaluates its argument twice.
  90  */
  91 #define FFABSU(a) ((a) <= 0 ? -(unsigned)(a) : (unsigned)(a))
  92 #define FFABS64U(a) ((a) <= 0 ? -(uint64_t)(a) : (uint64_t)(a))
  93
  94 /* misc math functions */
  95
  96 #ifndef av_ceil_log2
  97 #   define av_ceil_log2     av_ceil_log2_c
  98 #endif
  99 #ifndef av_clip
 100 #   define av_clip          av_clip_c
 101 #endif
 102 #ifndef av_clip64
 103 #   define av_clip64        av_clip64_c
 104 #endif
 105 #ifndef av_clip_uint8
 106 #   define av_clip_uint8    av_clip_uint8_c
 107 #endif
 108 #ifndef av_clip_int8
 109 #   define av_clip_int8     av_clip_int8_c
 110 #endif
 111 #ifndef av_clip_uint16
 112 #   define av_clip_uint16   av_clip_uint16_c
 113 #endif
 114 #ifndef av_clip_int16
 115 #   define av_clip_int16    av_clip_int16_c
 116 #endif
 117 #ifndef av_clipl_int32
 118 #   define av_clipl_int32   av_clipl_int32_c
 119 #endif
 120 #ifndef av_clip_intp2
 121 #   define av_clip_intp2    av_clip_intp2_c
 122 #endif
 123 #ifndef av_clip_uintp2
 124 #   define av_clip_uintp2   av_clip_uintp2_c
 125 #endif
 126 #ifndef av_sat_add32
 127 #   define av_sat_add32     av_sat_add32_c
 128 #endif
 129 #ifndef av_sat_dadd32
 130 #   define av_sat_dadd32    av_sat_dadd32_c
 131 #endif
 132 #ifndef av_sat_sub32
 133 #   define av_sat_sub32     av_sat_sub32_c
 134 #endif
 135 #ifndef av_sat_dsub32
 136 #   define av_sat_dsub32    av_sat_dsub32_c
 137 #endif
 138 #ifndef av_sat_add64
 139 #   define av_sat_add64     av_sat_add64_c
 140 #endif
 141 #ifndef av_sat_sub64
 142 #   define av_sat_sub64     av_sat_sub64_c
 143 #endif
 144 #ifndef av_clipf
 145 #   define av_clipf         av_clipf_c
 146 #endif
 147 #ifndef av_clipd
 148 #   define av_clipd         av_clipd_c
 149 #endif
 150 #ifndef av_zero_extend
 151 #   define av_zero_extend   av_zero_extend_c
 152 #endif
 153 #ifndef av_popcount
 154 #   define av_popcount      av_popcount_c
 155 #endif
 156 #ifndef av_popcount64
 157 #   define av_popcount64    av_popcount64_c
 158 #endif
 159 #ifndef av_parity
 160 #   define av_parity        av_parity_c
 161 #endif
 162
 163 #ifndef av_log2
 164 av_const int av_log2(unsigned v);
 165 #endif
 166
 167 #ifndef av_log2_16bit
 168 av_const int av_log2_16bit(unsigned v);
 169 #endif
 170
 171 /**
 172  * Clip a signed integer value into the amin-amax range.
 173  * @param a value to clip
 174  * @param amin minimum value of the clip range
 175  * @param amax maximum value of the clip range
 176  * @return clipped value
 177  */
 178 static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
 179 {
 180 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
 181     if (amin > amax) abort();
 182 #endif
 183     if      (a < amin) return amin;
 184     else if (a > amax) return amax;
 185     else               return a;
 186 }
 187
 188 /**
 189  * Clip a signed 64bit integer value into the amin-amax range.
 190  * @param a value to clip
 191  * @param amin minimum value of the clip range
 192  * @param amax maximum value of the clip range
 193  * @return clipped value
 194  */
 195 static av_always_inline av_const int64_t av_clip64_c(int64_t a, int64_t amin, int64_t amax)
 196 {
 197 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
 198     if (amin > amax) abort();
 199 #endif
 200     if      (a < amin) return amin;
 201     else if (a > amax) return amax;
 202     else               return a;
 203 }
 204
 205 /**
 206  * Clip a signed integer value into the 0-255 range.
 207  * @param a value to clip
 208  * @return clipped value
 209  */
 210 static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
 211 {
 212     if (a&(~0xFF)) return (~a)>>31;
 213     else           return a;
 214 }
 215
 216 /**
 217  * Clip a signed integer value into the -128,127 range.
 218  * @param a value to clip
 219  * @return clipped value
 220  */
 221 static av_always_inline av_const int8_t av_clip_int8_c(int a)
 222 {
 223     if ((a+0x80U) & ~0xFF) return (a>>31) ^ 0x7F;
 224     else                  return a;
 225 }
 226
 227 /**
 228  * Clip a signed integer value into the 0-65535 range.
 229  * @param a value to clip
 230  * @return clipped value
 231  */
 232 static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
 233 {
 234     if (a&(~0xFFFF)) return (~a)>>31;
 235     else             return a;
 236 }
 237
 238 /**
 239  * Clip a signed integer value into the -32768,32767 range.
 240  * @param a value to clip
 241  * @return clipped value
 242  */
 243 static av_always_inline av_const int16_t av_clip_int16_c(int a)
 244 {
 245     if ((a+0x8000U) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
 246     else                      return a;
 247 }
 248
 249 /**
 250  * Clip a signed 64-bit integer value into the -2147483648,2147483647 range.
 251  * @param a value to clip
 252  * @return clipped value
 253  */
 254 static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
 255 {
 256     if ((a+UINT64_C(0x80000000)) & ~UINT64_C(0xFFFFFFFF)) return (int32_t)((a>>63) ^ 0x7FFFFFFF);
 257     else                                                  return (int32_t)a;
 258 }
 259
 260 /**
 261  * Clip a signed integer into the -(2^p),(2^p-1) range.
 262  * @param  a value to clip
 263  * @param  p bit position to clip at
 264  * @return clipped value
 265  */
 266 static av_always_inline av_const int av_clip_intp2_c(int a, int p)
 267 {
 268     if (((unsigned)a + (1U << p)) & ~((2U << p) - 1))
 269         return (a >> 31) ^ ((1 << p) - 1);
 270     else
 271         return a;
 272 }
 273
 274 /**
 275  * Clip a signed integer to an unsigned power of two range.
 276  * @param  a value to clip
 277  * @param  p bit position to clip at
 278  * @return clipped value
 279  */
 280 static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
 281 {
 282     if (a & ~((1U<<p) - 1)) return (~a) >> 31 & ((1U<<p) - 1);
 283     else                    return  a;
 284 }
 285
 286 /**
 287  * Clear high bits from an unsigned integer starting with specific bit position
 288  * @param  a value to clip
 289  * @param  p bit position to clip at. Must be between 0 and 31.
 290  * @return clipped value
 291  */
 292 static av_always_inline av_const unsigned av_zero_extend_c(unsigned a, unsigned p)
 293 {
 294 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
 295     if (p > 31) abort();
 296 #endif
 297     return a & ((1U << p) - 1);
 298 }
 299
 300 #if FF_API_MOD_UINTP2
 301 #ifndef av_mod_uintp2
 302 #   define av_mod_uintp2 av_mod_uintp2_c
 303 #endif
 304 attribute_deprecated
 305 static av_always_inline av_const unsigned av_mod_uintp2_c(unsigned a, unsigned p)
 306 {
 307     return av_zero_extend_c(a, p);
 308 }
 309 #endif
 310
 311 /**
 312  * Add two signed 32-bit values with saturation.
 313  *
 314  * @param  a one value
 315  * @param  b another value
 316  * @return sum with signed saturation
 317  */
 318 static av_always_inline int av_sat_add32_c(int a, int b)
 319 {
 320     return av_clipl_int32((int64_t)a + b);
 321 }
 322
 323 /**
 324  * Add a doubled value to another value with saturation at both stages.
 325  *
 326  * @param  a first value
 327  * @param  b value doubled and added to a
 328  * @return sum sat(a + sat(2*b)) with signed saturation
 329  */
 330 static av_always_inline int av_sat_dadd32_c(int a, int b)
 331 {
 332     return av_sat_add32(a, av_sat_add32(b, b));
 333 }
 334
 335 /**
 336  * Subtract two signed 32-bit values with saturation.
 337  *
 338  * @param  a one value
 339  * @param  b another value
 340  * @return difference with signed saturation
 341  */
 342 static av_always_inline int av_sat_sub32_c(int a, int b)
 343 {
 344     return av_clipl_int32((int64_t)a - b);
 345 }
 346
 347 /**
 348  * Subtract a doubled value from another value with saturation at both stages.
 349  *
 350  * @param  a first value
 351  * @param  b value doubled and subtracted from a
 352  * @return difference sat(a - sat(2*b)) with signed saturation
 353  */
 354 static av_always_inline int av_sat_dsub32_c(int a, int b)
 355 {
 356     return av_sat_sub32(a, av_sat_add32(b, b));
 357 }
 358
 359 /**
 360  * Add two signed 64-bit values with saturation.
 361  *
 362  * @param  a one value
 363  * @param  b another value
 364  * @return sum with signed saturation
 365  */
 366 static av_always_inline int64_t av_sat_add64_c(int64_t a, int64_t b) {
 367 #if (!defined(__INTEL_COMPILER) && AV_GCC_VERSION_AT_LEAST(5,1)) || AV_HAS_BUILTIN(__builtin_add_overflow)
 368     int64_t tmp;
 369     return !__builtin_add_overflow(a, b, &tmp) ? tmp : (tmp < 0 ? INT64_MAX : INT64_MIN);
 370 #else
 371     int64_t s = a+(uint64_t)b;
 372     if ((int64_t)(a^b | ~s^b) >= 0)
 373         return INT64_MAX ^ (b >> 63);
 374     return s;
 375 #endif
 376 }
 377
 378 /**
 379  * Subtract two signed 64-bit values with saturation.
 380  *
 381  * @param  a one value
 382  * @param  b another value
 383  * @return difference with signed saturation
 384  */
 385 static av_always_inline int64_t av_sat_sub64_c(int64_t a, int64_t b) {
 386 #if (!defined(__INTEL_COMPILER) && AV_GCC_VERSION_AT_LEAST(5,1)) || AV_HAS_BUILTIN(__builtin_sub_overflow)
 387     int64_t tmp;
 388     return !__builtin_sub_overflow(a, b, &tmp) ? tmp : (tmp < 0 ? INT64_MAX : INT64_MIN);
 389 #else
 390     if (b <= 0 && a >= INT64_MAX + b)
 391         return INT64_MAX;
 392     if (b >= 0 && a <= INT64_MIN + b)
 393         return INT64_MIN;
 394     return a - b;
 395 #endif
 396 }
 397
 398 /**
 399  * Clip a float value into the amin-amax range.
 400  * If a is nan or -inf amin will be returned.
 401  * If a is +inf amax will be returned.
 402  * @param a value to clip
 403  * @param amin minimum value of the clip range
 404  * @param amax maximum value of the clip range
 405  * @return clipped value
 406  */
 407 static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
 408 {
 409 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
 410     if (amin > amax) abort();
 411 #endif
 412     return FFMIN(FFMAX(a, amin), amax);
 413 }
 414
 415 /**
 416  * Clip a double value into the amin-amax range.
 417  * If a is nan or -inf amin will be returned.
 418  * If a is +inf amax will be returned.
 419  * @param a value to clip
 420  * @param amin minimum value of the clip range
 421  * @param amax maximum value of the clip range
 422  * @return clipped value
 423  */
 424 static av_always_inline av_const double av_clipd_c(double a, double amin, double amax)
 425 {
 426 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
 427     if (amin > amax) abort();
 428 #endif
 429     return FFMIN(FFMAX(a, amin), amax);
 430 }
 431
 432 /** Compute ceil(log2(x)).
 433  * @param x value used to compute ceil(log2(x))
 434  * @return computed ceiling of log2(x)
 435  */
 436 static av_always_inline av_const int av_ceil_log2_c(int x)
 437 {
 438     return av_log2((x - 1U) << 1);
 439 }
 440
 441 /**
 442  * Count number of bits set to one in x
 443  * @param x value to count bits of
 444  * @return the number of bits set to one in x
 445  */
 446 static av_always_inline av_const int av_popcount_c(uint32_t x)
 447 {
 448     x -= (x >> 1) & 0x55555555;
 449     x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
 450     x = (x + (x >> 4)) & 0x0F0F0F0F;
 451     x += x >> 8;
 452     return (x + (x >> 16)) & 0x3F;
 453 }
 454
 455 /**
 456  * Count number of bits set to one in x
 457  * @param x value to count bits of
 458  * @return the number of bits set to one in x
 459  */
 460 static av_always_inline av_const int av_popcount64_c(uint64_t x)
 461 {
 462     return av_popcount((uint32_t)x) + av_popcount((uint32_t)(x >> 32));
 463 }
 464
 465 static av_always_inline av_const int av_parity_c(uint32_t v)
 466 {
 467     return av_popcount(v) & 1;
 468 }
 469
 470 /**
 471  * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
 472  *
 473  * @param val      Output value, must be an lvalue of type uint32_t.
 474  * @param GET_BYTE Expression reading one byte from the input.
 475  *                 Evaluated up to 7 times (4 for the currently
 476  *                 assigned Unicode range).  With a memory buffer
 477  *                 input, this could be *ptr++, or if you want to make sure
 478  *                 that *ptr stops at the end of a NULL terminated string then
 479  *                 *ptr ? *ptr++ : 0
 480  * @param ERROR    Expression to be evaluated on invalid input,
 481  *                 typically a goto statement.
 482  *
 483  * @warning ERROR should not contain a loop control statement which
 484  * could interact with the internal while loop, and should force an
 485  * exit from the macro code (e.g. through a goto or a return) in order
 486  * to prevent undefined results.
 487  */
 488 #define GET_UTF8(val, GET_BYTE, ERROR)\
 489     val= (uint8_t)(GET_BYTE);\
 490     {\
 491         uint32_t top = (val & 128) >> 1;\
 492         if ((val & 0xc0) == 0x80 || val >= 0xFE)\
 493             {ERROR}\
 494         while (val & top) {\
 495             unsigned int tmp = (uint8_t)(GET_BYTE) - 128;\
 496             if(tmp>>6)\
 497                 {ERROR}\
 498             val= (val<<6) + tmp;\
 499             top <<= 5;\
 500         }\
 501         val &= (top << 1) - 1;\
 502     }
 503
 504 /**
 505  * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
 506  *
 507  * @param val       Output value, must be an lvalue of type uint32_t.
 508  * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
 509  *                  to native byte order.  Evaluated one or two times.
 510  * @param ERROR     Expression to be evaluated on invalid input,
 511  *                  typically a goto statement.
 512  */
 513 #define GET_UTF16(val, GET_16BIT, ERROR)\
 514     val = (uint16_t)(GET_16BIT);\
 515     {\
 516         unsigned int hi = val - 0xD800;\
 517         if (hi < 0x800) {\
 518             val = (uint16_t)(GET_16BIT) - 0xDC00;\
 519             if (val > 0x3FFU || hi > 0x3FFU)\
 520                 {ERROR}\
 521             val += (hi<<10) + 0x10000;\
 522         }\
 523     }\
 524
 525 /**
 526  * @def PUT_UTF8(val, tmp, PUT_BYTE)
 527  * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
 528  * @param val is an input-only argument and should be of type uint32_t. It holds
 529  * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
 530  * val is given as a function it is executed only once.
 531  * @param tmp is a temporary variable and should be of type uint8_t. It
 532  * represents an intermediate value during conversion that is to be
 533  * output by PUT_BYTE.
 534  * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
 535  * It could be a function or a statement, and uses tmp as the input byte.
 536  * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
 537  * executed up to 4 times for values in the valid UTF-8 range and up to
 538  * 7 times in the general case, depending on the length of the converted
 539  * Unicode character.
 540  */
 541 #define PUT_UTF8(val, tmp, PUT_BYTE)\
 542     {\
 543         int bytes, shift;\
 544         uint32_t in = val;\
 545         if (in < 0x80) {\
 546             tmp = in;\
 547             PUT_BYTE\
 548         } else {\
 549             bytes = (av_log2(in) + 4) / 5;\
 550             shift = (bytes - 1) * 6;\
 551             tmp = (256 - (256 >> bytes)) | (in >> shift);\
 552             PUT_BYTE\
 553             while (shift >= 6) {\
 554                 shift -= 6;\
 555                 tmp = 0x80 | ((in >> shift) & 0x3f);\
 556                 PUT_BYTE\
 557             }\
 558         }\
 559     }
 560
 561 /**
 562  * @def PUT_UTF16(val, tmp, PUT_16BIT)
 563  * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
 564  * @param val is an input-only argument and should be of type uint32_t. It holds
 565  * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
 566  * val is given as a function it is executed only once.
 567  * @param tmp is a temporary variable and should be of type uint16_t. It
 568  * represents an intermediate value during conversion that is to be
 569  * output by PUT_16BIT.
 570  * @param PUT_16BIT writes the converted UTF-16 data to any proper destination
 571  * in desired endianness. It could be a function or a statement, and uses tmp
 572  * as the input byte.  For example, PUT_BYTE could be "*output++ = tmp;"
 573  * PUT_BYTE will be executed 1 or 2 times depending on input character.
 574  */
 575 #define PUT_UTF16(val, tmp, PUT_16BIT)\
 576     {\
 577         uint32_t in = val;\
 578         if (in < 0x10000) {\
 579             tmp = in;\
 580             PUT_16BIT\
 581         } else {\
 582             tmp = 0xD800 | ((in - 0x10000) >> 10);\
 583             PUT_16BIT\
 584             tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
 585             PUT_16BIT\
 586         }\
 587     }\
 588
 589 #endif /* AVUTIL_COMMON_H */