common.h (16541B)
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 "macros.h" 44 #include "version.h" 45 #include "libavutil/avconfig.h" 46 47 #if AV_HAVE_BIGENDIAN 48 # define AV_NE(be, le) (be) 49 #else 50 # define AV_NE(be, le) (le) 51 #endif 52 53 //rounded division & shift 54 #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b)) 55 /* assume b>0 */ 56 #define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b)) 57 /* Fast a/(1<<b) rounded toward +inf. Assume a>=0 and b>=0 */ 58 #define AV_CEIL_RSHIFT(a,b) (!av_builtin_constant_p(b) ? -((-(a)) >> (b)) \ 59 : ((a) + (1<<(b)) - 1) >> (b)) 60 /* Backwards compat. */ 61 #define FF_CEIL_RSHIFT AV_CEIL_RSHIFT 62 63 #define FFUDIV(a,b) (((a)>0 ?(a):(a)-(b)+1) / (b)) 64 #define FFUMOD(a,b) ((a)-(b)*FFUDIV(a,b)) 65 66 /** 67 * Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they 68 * are not representable as absolute values of their type. This is the same 69 * as with *abs() 70 * @see FFNABS() 71 */ 72 #define FFABS(a) ((a) >= 0 ? (a) : (-(a))) 73 #define FFSIGN(a) ((a) > 0 ? 1 : -1) 74 75 /** 76 * Negative Absolute value. 77 * this works for all integers of all types. 78 * As with many macros, this evaluates its argument twice, it thus must not have 79 * a sideeffect, that is FFNABS(x++) has undefined behavior. 80 */ 81 #define FFNABS(a) ((a) <= 0 ? (a) : (-(a))) 82 83 /** 84 * Comparator. 85 * For two numerical expressions x and y, gives 1 if x > y, -1 if x < y, and 0 86 * if x == y. This is useful for instance in a qsort comparator callback. 87 * Furthermore, compilers are able to optimize this to branchless code, and 88 * there is no risk of overflow with signed types. 89 * As with many macros, this evaluates its argument multiple times, it thus 90 * must not have a side-effect. 91 */ 92 #define FFDIFFSIGN(x,y) (((x)>(y)) - ((x)<(y))) 93 94 #define FFMAX(a,b) ((a) > (b) ? (a) : (b)) 95 #define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c) 96 #define FFMIN(a,b) ((a) > (b) ? (b) : (a)) 97 #define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c) 98 99 #define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0) 100 #define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0])) 101 102 /* misc math functions */ 103 104 #ifdef HAVE_AV_CONFIG_H 105 # include "config.h" 106 # include "intmath.h" 107 #endif 108 109 /* Pull in unguarded fallback defines at the end of this file. */ 110 #include "common.h" 111 112 #ifndef av_log2 113 av_const int av_log2(unsigned v); 114 #endif 115 116 #ifndef av_log2_16bit 117 av_const int av_log2_16bit(unsigned v); 118 #endif 119 120 /** 121 * Clip a signed integer value into the amin-amax range. 122 * @param a value to clip 123 * @param amin minimum value of the clip range 124 * @param amax maximum value of the clip range 125 * @return clipped value 126 */ 127 static av_always_inline av_const int av_clip_c(int a, int amin, int amax) 128 { 129 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2 130 if (amin > amax) abort(); 131 #endif 132 if (a < amin) return amin; 133 else if (a > amax) return amax; 134 else return a; 135 } 136 137 /** 138 * Clip a signed 64bit integer value into the amin-amax range. 139 * @param a value to clip 140 * @param amin minimum value of the clip range 141 * @param amax maximum value of the clip range 142 * @return clipped value 143 */ 144 static av_always_inline av_const int64_t av_clip64_c(int64_t a, int64_t amin, int64_t amax) 145 { 146 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2 147 if (amin > amax) abort(); 148 #endif 149 if (a < amin) return amin; 150 else if (a > amax) return amax; 151 else return a; 152 } 153 154 /** 155 * Clip a signed integer value into the 0-255 range. 156 * @param a value to clip 157 * @return clipped value 158 */ 159 static av_always_inline av_const uint8_t av_clip_uint8_c(int a) 160 { 161 if (a&(~0xFF)) return (~a)>>31; 162 else return a; 163 } 164 165 /** 166 * Clip a signed integer value into the -128,127 range. 167 * @param a value to clip 168 * @return clipped value 169 */ 170 static av_always_inline av_const int8_t av_clip_int8_c(int a) 171 { 172 if ((a+0x80U) & ~0xFF) return (a>>31) ^ 0x7F; 173 else return a; 174 } 175 176 /** 177 * Clip a signed integer value into the 0-65535 range. 178 * @param a value to clip 179 * @return clipped value 180 */ 181 static av_always_inline av_const uint16_t av_clip_uint16_c(int a) 182 { 183 if (a&(~0xFFFF)) return (~a)>>31; 184 else return a; 185 } 186 187 /** 188 * Clip a signed integer value into the -32768,32767 range. 189 * @param a value to clip 190 * @return clipped value 191 */ 192 static av_always_inline av_const int16_t av_clip_int16_c(int a) 193 { 194 if ((a+0x8000U) & ~0xFFFF) return (a>>31) ^ 0x7FFF; 195 else return a; 196 } 197 198 /** 199 * Clip a signed 64-bit integer value into the -2147483648,2147483647 range. 200 * @param a value to clip 201 * @return clipped value 202 */ 203 static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a) 204 { 205 if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (int32_t)((a>>63) ^ 0x7FFFFFFF); 206 else return (int32_t)a; 207 } 208 209 /** 210 * Clip a signed integer into the -(2^p),(2^p-1) range. 211 * @param a value to clip 212 * @param p bit position to clip at 213 * @return clipped value 214 */ 215 static av_always_inline av_const int av_clip_intp2_c(int a, int p) 216 { 217 if (((unsigned)a + (1 << p)) & ~((2 << p) - 1)) 218 return (a >> 31) ^ ((1 << p) - 1); 219 else 220 return a; 221 } 222 223 /** 224 * Clip a signed integer to an unsigned power of two range. 225 * @param a value to clip 226 * @param p bit position to clip at 227 * @return clipped value 228 */ 229 static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p) 230 { 231 if (a & ~((1<<p) - 1)) return -a >> 31 & ((1<<p) - 1); 232 else return a; 233 } 234 235 /** 236 * Clear high bits from an unsigned integer starting with specific bit position 237 * @param a value to clip 238 * @param p bit position to clip at 239 * @return clipped value 240 */ 241 static av_always_inline av_const unsigned av_mod_uintp2_c(unsigned a, unsigned p) 242 { 243 return a & ((1 << p) - 1); 244 } 245 246 /** 247 * Add two signed 32-bit values with saturation. 248 * 249 * @param a one value 250 * @param b another value 251 * @return sum with signed saturation 252 */ 253 static av_always_inline int av_sat_add32_c(int a, int b) 254 { 255 return av_clipl_int32((int64_t)a + b); 256 } 257 258 /** 259 * Add a doubled value to another value with saturation at both stages. 260 * 261 * @param a first value 262 * @param b value doubled and added to a 263 * @return sum sat(a + sat(2*b)) with signed saturation 264 */ 265 static av_always_inline int av_sat_dadd32_c(int a, int b) 266 { 267 return av_sat_add32(a, av_sat_add32(b, b)); 268 } 269 270 /** 271 * Subtract two signed 32-bit values with saturation. 272 * 273 * @param a one value 274 * @param b another value 275 * @return difference with signed saturation 276 */ 277 static av_always_inline int av_sat_sub32_c(int a, int b) 278 { 279 return av_clipl_int32((int64_t)a - b); 280 } 281 282 /** 283 * Subtract a doubled value from another value with saturation at both stages. 284 * 285 * @param a first value 286 * @param b value doubled and subtracted from a 287 * @return difference sat(a - sat(2*b)) with signed saturation 288 */ 289 static av_always_inline int av_sat_dsub32_c(int a, int b) 290 { 291 return av_sat_sub32(a, av_sat_add32(b, b)); 292 } 293 294 /** 295 * Clip a float value into the amin-amax range. 296 * @param a value to clip 297 * @param amin minimum value of the clip range 298 * @param amax maximum value of the clip range 299 * @return clipped value 300 */ 301 static av_always_inline av_const float av_clipf_c(float a, float amin, float amax) 302 { 303 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2 304 if (amin > amax) abort(); 305 #endif 306 if (a < amin) return amin; 307 else if (a > amax) return amax; 308 else return a; 309 } 310 311 /** 312 * Clip a double value into the amin-amax range. 313 * @param a value to clip 314 * @param amin minimum value of the clip range 315 * @param amax maximum value of the clip range 316 * @return clipped value 317 */ 318 static av_always_inline av_const double av_clipd_c(double a, double amin, double amax) 319 { 320 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2 321 if (amin > amax) abort(); 322 #endif 323 if (a < amin) return amin; 324 else if (a > amax) return amax; 325 else return a; 326 } 327 328 /** Compute ceil(log2(x)). 329 * @param x value used to compute ceil(log2(x)) 330 * @return computed ceiling of log2(x) 331 */ 332 static av_always_inline av_const int av_ceil_log2_c(int x) 333 { 334 return av_log2((x - 1) << 1); 335 } 336 337 /** 338 * Count number of bits set to one in x 339 * @param x value to count bits of 340 * @return the number of bits set to one in x 341 */ 342 static av_always_inline av_const int av_popcount_c(uint32_t x) 343 { 344 x -= (x >> 1) & 0x55555555; 345 x = (x & 0x33333333) + ((x >> 2) & 0x33333333); 346 x = (x + (x >> 4)) & 0x0F0F0F0F; 347 x += x >> 8; 348 return (x + (x >> 16)) & 0x3F; 349 } 350 351 /** 352 * Count number of bits set to one in x 353 * @param x value to count bits of 354 * @return the number of bits set to one in x 355 */ 356 static av_always_inline av_const int av_popcount64_c(uint64_t x) 357 { 358 return av_popcount((uint32_t)x) + av_popcount((uint32_t)(x >> 32)); 359 } 360 361 static av_always_inline av_const int av_parity_c(uint32_t v) 362 { 363 return av_popcount(v) & 1; 364 } 365 366 #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24)) 367 #define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24)) 368 369 /** 370 * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form. 371 * 372 * @param val Output value, must be an lvalue of type uint32_t. 373 * @param GET_BYTE Expression reading one byte from the input. 374 * Evaluated up to 7 times (4 for the currently 375 * assigned Unicode range). With a memory buffer 376 * input, this could be *ptr++. 377 * @param ERROR Expression to be evaluated on invalid input, 378 * typically a goto statement. 379 * 380 * @warning ERROR should not contain a loop control statement which 381 * could interact with the internal while loop, and should force an 382 * exit from the macro code (e.g. through a goto or a return) in order 383 * to prevent undefined results. 384 */ 385 #define GET_UTF8(val, GET_BYTE, ERROR)\ 386 val= (GET_BYTE);\ 387 {\ 388 uint32_t top = (val & 128) >> 1;\ 389 if ((val & 0xc0) == 0x80 || val >= 0xFE)\ 390 ERROR\ 391 while (val & top) {\ 392 int tmp= (GET_BYTE) - 128;\ 393 if(tmp>>6)\ 394 ERROR\ 395 val= (val<<6) + tmp;\ 396 top <<= 5;\ 397 }\ 398 val &= (top << 1) - 1;\ 399 } 400 401 /** 402 * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form. 403 * 404 * @param val Output value, must be an lvalue of type uint32_t. 405 * @param GET_16BIT Expression returning two bytes of UTF-16 data converted 406 * to native byte order. Evaluated one or two times. 407 * @param ERROR Expression to be evaluated on invalid input, 408 * typically a goto statement. 409 */ 410 #define GET_UTF16(val, GET_16BIT, ERROR)\ 411 val = GET_16BIT;\ 412 {\ 413 unsigned int hi = val - 0xD800;\ 414 if (hi < 0x800) {\ 415 val = GET_16BIT - 0xDC00;\ 416 if (val > 0x3FFU || hi > 0x3FFU)\ 417 ERROR\ 418 val += (hi<<10) + 0x10000;\ 419 }\ 420 }\ 421 422 /** 423 * @def PUT_UTF8(val, tmp, PUT_BYTE) 424 * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long). 425 * @param val is an input-only argument and should be of type uint32_t. It holds 426 * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If 427 * val is given as a function it is executed only once. 428 * @param tmp is a temporary variable and should be of type uint8_t. It 429 * represents an intermediate value during conversion that is to be 430 * output by PUT_BYTE. 431 * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination. 432 * It could be a function or a statement, and uses tmp as the input byte. 433 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be 434 * executed up to 4 times for values in the valid UTF-8 range and up to 435 * 7 times in the general case, depending on the length of the converted 436 * Unicode character. 437 */ 438 #define PUT_UTF8(val, tmp, PUT_BYTE)\ 439 {\ 440 int bytes, shift;\ 441 uint32_t in = val;\ 442 if (in < 0x80) {\ 443 tmp = in;\ 444 PUT_BYTE\ 445 } else {\ 446 bytes = (av_log2(in) + 4) / 5;\ 447 shift = (bytes - 1) * 6;\ 448 tmp = (256 - (256 >> bytes)) | (in >> shift);\ 449 PUT_BYTE\ 450 while (shift >= 6) {\ 451 shift -= 6;\ 452 tmp = 0x80 | ((in >> shift) & 0x3f);\ 453 PUT_BYTE\ 454 }\ 455 }\ 456 } 457 458 /** 459 * @def PUT_UTF16(val, tmp, PUT_16BIT) 460 * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes). 461 * @param val is an input-only argument and should be of type uint32_t. It holds 462 * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If 463 * val is given as a function it is executed only once. 464 * @param tmp is a temporary variable and should be of type uint16_t. It 465 * represents an intermediate value during conversion that is to be 466 * output by PUT_16BIT. 467 * @param PUT_16BIT writes the converted UTF-16 data to any proper destination 468 * in desired endianness. It could be a function or a statement, and uses tmp 469 * as the input byte. For example, PUT_BYTE could be "*output++ = tmp;" 470 * PUT_BYTE will be executed 1 or 2 times depending on input character. 471 */ 472 #define PUT_UTF16(val, tmp, PUT_16BIT)\ 473 {\ 474 uint32_t in = val;\ 475 if (in < 0x10000) {\ 476 tmp = in;\ 477 PUT_16BIT\ 478 } else {\ 479 tmp = 0xD800 | ((in - 0x10000) >> 10);\ 480 PUT_16BIT\ 481 tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\ 482 PUT_16BIT\ 483 }\ 484 }\ 485 486 487 488 #include "mem.h" 489 490 #ifdef HAVE_AV_CONFIG_H 491 # include "internal.h" 492 #endif /* HAVE_AV_CONFIG_H */ 493 494 #endif /* AVUTIL_COMMON_H */ 495 496 /* 497 * The following definitions are outside the multiple inclusion guard 498 * to ensure they are immediately available in intmath.h. 499 */ 500 501 #ifndef av_ceil_log2 502 # define av_ceil_log2 av_ceil_log2_c 503 #endif 504 #ifndef av_clip 505 # define av_clip av_clip_c 506 #endif 507 #ifndef av_clip64 508 # define av_clip64 av_clip64_c 509 #endif 510 #ifndef av_clip_uint8 511 # define av_clip_uint8 av_clip_uint8_c 512 #endif 513 #ifndef av_clip_int8 514 # define av_clip_int8 av_clip_int8_c 515 #endif 516 #ifndef av_clip_uint16 517 # define av_clip_uint16 av_clip_uint16_c 518 #endif 519 #ifndef av_clip_int16 520 # define av_clip_int16 av_clip_int16_c 521 #endif 522 #ifndef av_clipl_int32 523 # define av_clipl_int32 av_clipl_int32_c 524 #endif 525 #ifndef av_clip_intp2 526 # define av_clip_intp2 av_clip_intp2_c 527 #endif 528 #ifndef av_clip_uintp2 529 # define av_clip_uintp2 av_clip_uintp2_c 530 #endif 531 #ifndef av_mod_uintp2 532 # define av_mod_uintp2 av_mod_uintp2_c 533 #endif 534 #ifndef av_sat_add32 535 # define av_sat_add32 av_sat_add32_c 536 #endif 537 #ifndef av_sat_dadd32 538 # define av_sat_dadd32 av_sat_dadd32_c 539 #endif 540 #ifndef av_sat_sub32 541 # define av_sat_sub32 av_sat_sub32_c 542 #endif 543 #ifndef av_sat_dsub32 544 # define av_sat_dsub32 av_sat_dsub32_c 545 #endif 546 #ifndef av_clipf 547 # define av_clipf av_clipf_c 548 #endif 549 #ifndef av_clipd 550 # define av_clipd av_clipd_c 551 #endif 552 #ifndef av_popcount 553 # define av_popcount av_popcount_c 554 #endif 555 #ifndef av_popcount64 556 # define av_popcount64 av_popcount64_c 557 #endif 558 #ifndef av_parity 559 # define av_parity av_parity_c 560 #endif