common.h 17 KB

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  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. * @file
  22. * common internal and external API header
  23. */
  24. #ifndef AVUTIL_COMMON_H
  25. #define AVUTIL_COMMON_H
  26. #if defined(__cplusplus) && !defined(__STDC_CONSTANT_MACROS) && !defined(UINT64_C)
  27. #error missing -D__STDC_CONSTANT_MACROS / #define __STDC_CONSTANT_MACROS
  28. #endif
  29. #include <errno.h>
  30. #include <inttypes.h>
  31. #include <limits.h>
  32. #include <math.h>
  33. #include <stdint.h>
  34. #include <stdio.h>
  35. #include <stdlib.h>
  36. #include <string.h>
  37. #include "attributes.h"
  38. #include "error.h"
  39. #include "macros.h"
  40. #include "mem.h"
  41. #ifdef HAVE_AV_CONFIG_H
  42. # include "config.h"
  43. # include "intmath.h"
  44. # include "internal.h"
  45. #endif /* HAVE_AV_CONFIG_H */
  46. //rounded division & shift
  47. #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
  48. /* assume b>0 */
  49. #define ROUNDED_DIV(a,b) (((a)>=0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
  50. /* Fast a/(1<<b) rounded toward +inf. Assume a>=0 and b>=0 */
  51. #define AV_CEIL_RSHIFT(a,b) (!av_builtin_constant_p(b) ? -((-(a)) >> (b)) \
  52. : ((a) + (1<<(b)) - 1) >> (b))
  53. /* Backwards compat. */
  54. #define FF_CEIL_RSHIFT AV_CEIL_RSHIFT
  55. #define FFUDIV(a,b) (((a)>0 ?(a):(a)-(b)+1) / (b))
  56. #define FFUMOD(a,b) ((a)-(b)*FFUDIV(a,b))
  57. /**
  58. * Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they
  59. * are not representable as absolute values of their type. This is the same
  60. * as with *abs()
  61. * @see FFNABS()
  62. */
  63. #define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
  64. #define FFSIGN(a) ((a) > 0 ? 1 : -1)
  65. /**
  66. * Negative Absolute value.
  67. * this works for all integers of all types.
  68. * As with many macros, this evaluates its argument twice, it thus must not have
  69. * a sideeffect, that is FFNABS(x++) has undefined behavior.
  70. */
  71. #define FFNABS(a) ((a) <= 0 ? (a) : (-(a)))
  72. /**
  73. * Unsigned Absolute value.
  74. * This takes the absolute value of a signed int and returns it as a unsigned.
  75. * This also works with INT_MIN which would otherwise not be representable
  76. * As with many macros, this evaluates its argument twice.
  77. */
  78. #define FFABSU(a) ((a) <= 0 ? -(unsigned)(a) : (unsigned)(a))
  79. #define FFABS64U(a) ((a) <= 0 ? -(uint64_t)(a) : (uint64_t)(a))
  80. /* misc math functions */
  81. #ifndef av_ceil_log2
  82. # define av_ceil_log2 av_ceil_log2_c
  83. #endif
  84. #ifndef av_clip
  85. # define av_clip av_clip_c
  86. #endif
  87. #ifndef av_clip64
  88. # define av_clip64 av_clip64_c
  89. #endif
  90. #ifndef av_clip_uint8
  91. # define av_clip_uint8 av_clip_uint8_c
  92. #endif
  93. #ifndef av_clip_int8
  94. # define av_clip_int8 av_clip_int8_c
  95. #endif
  96. #ifndef av_clip_uint16
  97. # define av_clip_uint16 av_clip_uint16_c
  98. #endif
  99. #ifndef av_clip_int16
  100. # define av_clip_int16 av_clip_int16_c
  101. #endif
  102. #ifndef av_clipl_int32
  103. # define av_clipl_int32 av_clipl_int32_c
  104. #endif
  105. #ifndef av_clip_intp2
  106. # define av_clip_intp2 av_clip_intp2_c
  107. #endif
  108. #ifndef av_clip_uintp2
  109. # define av_clip_uintp2 av_clip_uintp2_c
  110. #endif
  111. #ifndef av_mod_uintp2
  112. # define av_mod_uintp2 av_mod_uintp2_c
  113. #endif
  114. #ifndef av_sat_add32
  115. # define av_sat_add32 av_sat_add32_c
  116. #endif
  117. #ifndef av_sat_dadd32
  118. # define av_sat_dadd32 av_sat_dadd32_c
  119. #endif
  120. #ifndef av_sat_sub32
  121. # define av_sat_sub32 av_sat_sub32_c
  122. #endif
  123. #ifndef av_sat_dsub32
  124. # define av_sat_dsub32 av_sat_dsub32_c
  125. #endif
  126. #ifndef av_sat_add64
  127. # define av_sat_add64 av_sat_add64_c
  128. #endif
  129. #ifndef av_sat_sub64
  130. # define av_sat_sub64 av_sat_sub64_c
  131. #endif
  132. #ifndef av_clipf
  133. # define av_clipf av_clipf_c
  134. #endif
  135. #ifndef av_clipd
  136. # define av_clipd av_clipd_c
  137. #endif
  138. #ifndef av_popcount
  139. # define av_popcount av_popcount_c
  140. #endif
  141. #ifndef av_popcount64
  142. # define av_popcount64 av_popcount64_c
  143. #endif
  144. #ifndef av_parity
  145. # define av_parity av_parity_c
  146. #endif
  147. #ifndef av_log2
  148. av_const int av_log2(unsigned v);
  149. #endif
  150. #ifndef av_log2_16bit
  151. av_const int av_log2_16bit(unsigned v);
  152. #endif
  153. /**
  154. * Clip a signed integer value into the amin-amax range.
  155. * @param a value to clip
  156. * @param amin minimum value of the clip range
  157. * @param amax maximum value of the clip range
  158. * @return clipped value
  159. */
  160. static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
  161. {
  162. #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
  163. if (amin > amax) abort();
  164. #endif
  165. if (a < amin) return amin;
  166. else if (a > amax) return amax;
  167. else return a;
  168. }
  169. /**
  170. * Clip a signed 64bit integer value into the amin-amax range.
  171. * @param a value to clip
  172. * @param amin minimum value of the clip range
  173. * @param amax maximum value of the clip range
  174. * @return clipped value
  175. */
  176. static av_always_inline av_const int64_t av_clip64_c(int64_t a, int64_t amin, int64_t amax)
  177. {
  178. #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
  179. if (amin > amax) abort();
  180. #endif
  181. if (a < amin) return amin;
  182. else if (a > amax) return amax;
  183. else return a;
  184. }
  185. /**
  186. * Clip a signed integer value into the 0-255 range.
  187. * @param a value to clip
  188. * @return clipped value
  189. */
  190. static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
  191. {
  192. if (a&(~0xFF)) return (~a)>>31;
  193. else return a;
  194. }
  195. /**
  196. * Clip a signed integer value into the -128,127 range.
  197. * @param a value to clip
  198. * @return clipped value
  199. */
  200. static av_always_inline av_const int8_t av_clip_int8_c(int a)
  201. {
  202. if ((a+0x80U) & ~0xFF) return (a>>31) ^ 0x7F;
  203. else return a;
  204. }
  205. /**
  206. * Clip a signed integer value into the 0-65535 range.
  207. * @param a value to clip
  208. * @return clipped value
  209. */
  210. static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
  211. {
  212. if (a&(~0xFFFF)) return (~a)>>31;
  213. else return a;
  214. }
  215. /**
  216. * Clip a signed integer value into the -32768,32767 range.
  217. * @param a value to clip
  218. * @return clipped value
  219. */
  220. static av_always_inline av_const int16_t av_clip_int16_c(int a)
  221. {
  222. if ((a+0x8000U) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
  223. else return a;
  224. }
  225. /**
  226. * Clip a signed 64-bit integer value into the -2147483648,2147483647 range.
  227. * @param a value to clip
  228. * @return clipped value
  229. */
  230. static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
  231. {
  232. if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (int32_t)((a>>63) ^ 0x7FFFFFFF);
  233. else return (int32_t)a;
  234. }
  235. /**
  236. * Clip a signed integer into the -(2^p),(2^p-1) range.
  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 int av_clip_intp2_c(int a, int p)
  242. {
  243. if (((unsigned)a + (1 << p)) & ~((2 << p) - 1))
  244. return (a >> 31) ^ ((1 << p) - 1);
  245. else
  246. return a;
  247. }
  248. /**
  249. * Clip a signed integer to an unsigned power of two range.
  250. * @param a value to clip
  251. * @param p bit position to clip at
  252. * @return clipped value
  253. */
  254. static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
  255. {
  256. if (a & ~((1<<p) - 1)) return (~a) >> 31 & ((1<<p) - 1);
  257. else return a;
  258. }
  259. /**
  260. * Clear high bits from an unsigned integer starting with specific bit position
  261. * @param a value to clip
  262. * @param p bit position to clip at
  263. * @return clipped value
  264. */
  265. static av_always_inline av_const unsigned av_mod_uintp2_c(unsigned a, unsigned p)
  266. {
  267. return a & ((1U << p) - 1);
  268. }
  269. /**
  270. * Add two signed 32-bit values with saturation.
  271. *
  272. * @param a one value
  273. * @param b another value
  274. * @return sum with signed saturation
  275. */
  276. static av_always_inline int av_sat_add32_c(int a, int b)
  277. {
  278. return av_clipl_int32((int64_t)a + b);
  279. }
  280. /**
  281. * Add a doubled value to another value with saturation at both stages.
  282. *
  283. * @param a first value
  284. * @param b value doubled and added to a
  285. * @return sum sat(a + sat(2*b)) with signed saturation
  286. */
  287. static av_always_inline int av_sat_dadd32_c(int a, int b)
  288. {
  289. return av_sat_add32(a, av_sat_add32(b, b));
  290. }
  291. /**
  292. * Subtract two signed 32-bit values with saturation.
  293. *
  294. * @param a one value
  295. * @param b another value
  296. * @return difference with signed saturation
  297. */
  298. static av_always_inline int av_sat_sub32_c(int a, int b)
  299. {
  300. return av_clipl_int32((int64_t)a - b);
  301. }
  302. /**
  303. * Subtract a doubled value from another value with saturation at both stages.
  304. *
  305. * @param a first value
  306. * @param b value doubled and subtracted from a
  307. * @return difference sat(a - sat(2*b)) with signed saturation
  308. */
  309. static av_always_inline int av_sat_dsub32_c(int a, int b)
  310. {
  311. return av_sat_sub32(a, av_sat_add32(b, b));
  312. }
  313. /**
  314. * Add two signed 64-bit values with saturation.
  315. *
  316. * @param a one value
  317. * @param b another value
  318. * @return sum with signed saturation
  319. */
  320. static av_always_inline int64_t av_sat_add64_c(int64_t a, int64_t b) {
  321. #if (!defined(__INTEL_COMPILER) && AV_GCC_VERSION_AT_LEAST(5,1)) || AV_HAS_BUILTIN(__builtin_add_overflow)
  322. int64_t tmp;
  323. return !__builtin_add_overflow(a, b, &tmp) ? tmp : (tmp < 0 ? INT64_MAX : INT64_MIN);
  324. #else
  325. int64_t s = a+(uint64_t)b;
  326. if ((int64_t)(a^b | ~s^b) >= 0)
  327. return INT64_MAX ^ (b >> 63);
  328. return s;
  329. #endif
  330. }
  331. /**
  332. * Subtract two signed 64-bit values with saturation.
  333. *
  334. * @param a one value
  335. * @param b another value
  336. * @return difference with signed saturation
  337. */
  338. static av_always_inline int64_t av_sat_sub64_c(int64_t a, int64_t b) {
  339. #if (!defined(__INTEL_COMPILER) && AV_GCC_VERSION_AT_LEAST(5,1)) || AV_HAS_BUILTIN(__builtin_sub_overflow)
  340. int64_t tmp;
  341. return !__builtin_sub_overflow(a, b, &tmp) ? tmp : (tmp < 0 ? INT64_MAX : INT64_MIN);
  342. #else
  343. if (b <= 0 && a >= INT64_MAX + b)
  344. return INT64_MAX;
  345. if (b >= 0 && a <= INT64_MIN + b)
  346. return INT64_MIN;
  347. return a - b;
  348. #endif
  349. }
  350. /**
  351. * Clip a float value into the amin-amax range.
  352. * If a is nan or -inf amin will be returned.
  353. * If a is +inf amax will be returned.
  354. * @param a value to clip
  355. * @param amin minimum value of the clip range
  356. * @param amax maximum value of the clip range
  357. * @return clipped value
  358. */
  359. static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
  360. {
  361. #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
  362. if (amin > amax) abort();
  363. #endif
  364. return FFMIN(FFMAX(a, amin), amax);
  365. }
  366. /**
  367. * Clip a double value into the amin-amax range.
  368. * If a is nan or -inf amin will be returned.
  369. * If a is +inf amax will be returned.
  370. * @param a value to clip
  371. * @param amin minimum value of the clip range
  372. * @param amax maximum value of the clip range
  373. * @return clipped value
  374. */
  375. static av_always_inline av_const double av_clipd_c(double a, double amin, double amax)
  376. {
  377. #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
  378. if (amin > amax) abort();
  379. #endif
  380. return FFMIN(FFMAX(a, amin), amax);
  381. }
  382. /** Compute ceil(log2(x)).
  383. * @param x value used to compute ceil(log2(x))
  384. * @return computed ceiling of log2(x)
  385. */
  386. static av_always_inline av_const int av_ceil_log2_c(int x)
  387. {
  388. return av_log2((x - 1U) << 1);
  389. }
  390. /**
  391. * Count number of bits set to one in x
  392. * @param x value to count bits of
  393. * @return the number of bits set to one in x
  394. */
  395. static av_always_inline av_const int av_popcount_c(uint32_t x)
  396. {
  397. x -= (x >> 1) & 0x55555555;
  398. x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
  399. x = (x + (x >> 4)) & 0x0F0F0F0F;
  400. x += x >> 8;
  401. return (x + (x >> 16)) & 0x3F;
  402. }
  403. /**
  404. * Count number of bits set to one in x
  405. * @param x value to count bits of
  406. * @return the number of bits set to one in x
  407. */
  408. static av_always_inline av_const int av_popcount64_c(uint64_t x)
  409. {
  410. return av_popcount((uint32_t)x) + av_popcount((uint32_t)(x >> 32));
  411. }
  412. static av_always_inline av_const int av_parity_c(uint32_t v)
  413. {
  414. return av_popcount(v) & 1;
  415. }
  416. /**
  417. * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
  418. *
  419. * @param val Output value, must be an lvalue of type uint32_t.
  420. * @param GET_BYTE Expression reading one byte from the input.
  421. * Evaluated up to 7 times (4 for the currently
  422. * assigned Unicode range). With a memory buffer
  423. * input, this could be *ptr++, or if you want to make sure
  424. * that *ptr stops at the end of a NULL terminated string then
  425. * *ptr ? *ptr++ : 0
  426. * @param ERROR Expression to be evaluated on invalid input,
  427. * typically a goto statement.
  428. *
  429. * @warning ERROR should not contain a loop control statement which
  430. * could interact with the internal while loop, and should force an
  431. * exit from the macro code (e.g. through a goto or a return) in order
  432. * to prevent undefined results.
  433. */
  434. #define GET_UTF8(val, GET_BYTE, ERROR)\
  435. val= (GET_BYTE);\
  436. {\
  437. uint32_t top = (val & 128) >> 1;\
  438. if ((val & 0xc0) == 0x80 || val >= 0xFE)\
  439. {ERROR}\
  440. while (val & top) {\
  441. unsigned int tmp = (GET_BYTE) - 128;\
  442. if(tmp>>6)\
  443. {ERROR}\
  444. val= (val<<6) + tmp;\
  445. top <<= 5;\
  446. }\
  447. val &= (top << 1) - 1;\
  448. }
  449. /**
  450. * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
  451. *
  452. * @param val Output value, must be an lvalue of type uint32_t.
  453. * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
  454. * to native byte order. Evaluated one or two times.
  455. * @param ERROR Expression to be evaluated on invalid input,
  456. * typically a goto statement.
  457. */
  458. #define GET_UTF16(val, GET_16BIT, ERROR)\
  459. val = (GET_16BIT);\
  460. {\
  461. unsigned int hi = val - 0xD800;\
  462. if (hi < 0x800) {\
  463. val = (GET_16BIT) - 0xDC00;\
  464. if (val > 0x3FFU || hi > 0x3FFU)\
  465. {ERROR}\
  466. val += (hi<<10) + 0x10000;\
  467. }\
  468. }\
  469. /**
  470. * @def PUT_UTF8(val, tmp, PUT_BYTE)
  471. * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
  472. * @param val is an input-only argument and should be of type uint32_t. It holds
  473. * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
  474. * val is given as a function it is executed only once.
  475. * @param tmp is a temporary variable and should be of type uint8_t. It
  476. * represents an intermediate value during conversion that is to be
  477. * output by PUT_BYTE.
  478. * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
  479. * It could be a function or a statement, and uses tmp as the input byte.
  480. * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
  481. * executed up to 4 times for values in the valid UTF-8 range and up to
  482. * 7 times in the general case, depending on the length of the converted
  483. * Unicode character.
  484. */
  485. #define PUT_UTF8(val, tmp, PUT_BYTE)\
  486. {\
  487. int bytes, shift;\
  488. uint32_t in = val;\
  489. if (in < 0x80) {\
  490. tmp = in;\
  491. PUT_BYTE\
  492. } else {\
  493. bytes = (av_log2(in) + 4) / 5;\
  494. shift = (bytes - 1) * 6;\
  495. tmp = (256 - (256 >> bytes)) | (in >> shift);\
  496. PUT_BYTE\
  497. while (shift >= 6) {\
  498. shift -= 6;\
  499. tmp = 0x80 | ((in >> shift) & 0x3f);\
  500. PUT_BYTE\
  501. }\
  502. }\
  503. }
  504. /**
  505. * @def PUT_UTF16(val, tmp, PUT_16BIT)
  506. * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
  507. * @param val is an input-only argument and should be of type uint32_t. It holds
  508. * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
  509. * val is given as a function it is executed only once.
  510. * @param tmp is a temporary variable and should be of type uint16_t. It
  511. * represents an intermediate value during conversion that is to be
  512. * output by PUT_16BIT.
  513. * @param PUT_16BIT writes the converted UTF-16 data to any proper destination
  514. * in desired endianness. It could be a function or a statement, and uses tmp
  515. * as the input byte. For example, PUT_BYTE could be "*output++ = tmp;"
  516. * PUT_BYTE will be executed 1 or 2 times depending on input character.
  517. */
  518. #define PUT_UTF16(val, tmp, PUT_16BIT)\
  519. {\
  520. uint32_t in = val;\
  521. if (in < 0x10000) {\
  522. tmp = in;\
  523. PUT_16BIT\
  524. } else {\
  525. tmp = 0xD800 | ((in - 0x10000) >> 10);\
  526. PUT_16BIT\
  527. tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
  528. PUT_16BIT\
  529. }\
  530. }\
  531. #endif /* AVUTIL_COMMON_H */