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 */
av_clip_c(int a,int amin,int amax)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 */
av_clip64_c(int64_t a,int64_t amin,int64_t amax)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 */
av_clip_uint8_c(int a)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 */
av_clip_int8_c(int a)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 */
av_clip_uint16_c(int a)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 */
av_clip_int16_c(int a)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 */
av_clipl_int32_c(int64_t a)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 */
av_clip_intp2_c(int a,int p)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 */
av_clip_uintp2_c(int a,int p)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 */
av_mod_uintp2_c(unsigned a,unsigned p)241 static av_always_inline av_const unsigned av_mod_uintp2_c(unsigned a, unsigned p)
242 {
243 return a & ((1U << 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 */
av_sat_add32_c(int a,int b)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 */
av_sat_dadd32_c(int a,int b)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 */
av_sat_sub32_c(int a,int b)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 */
av_sat_dsub32_c(int a,int b)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 * Add two signed 64-bit values with saturation.
296 *
297 * @param a one value
298 * @param b another value
299 * @return sum with signed saturation
300 */
av_sat_add64_c(int64_t a,int64_t b)301 static av_always_inline int64_t av_sat_add64_c(int64_t a, int64_t b) {
302 #if (!defined(__INTEL_COMPILER) && AV_GCC_VERSION_AT_LEAST(5,1)) || AV_HAS_BUILTIN(__builtin_add_overflow)
303 int64_t tmp;
304 return !__builtin_add_overflow(a, b, &tmp) ? tmp : (tmp < 0 ? INT64_MAX : INT64_MIN);
305 #else
306 if (b >= 0 && a >= INT64_MAX - b)
307 return INT64_MAX;
308 if (b <= 0 && a <= INT64_MIN - b)
309 return INT64_MIN;
310 return a + b;
311 #endif
312 }
313
314 /**
315 * Subtract two signed 64-bit values with saturation.
316 *
317 * @param a one value
318 * @param b another value
319 * @return difference with signed saturation
320 */
av_sat_sub64_c(int64_t a,int64_t b)321 static av_always_inline int64_t av_sat_sub64_c(int64_t a, int64_t b) {
322 #if (!defined(__INTEL_COMPILER) && AV_GCC_VERSION_AT_LEAST(5,1)) || AV_HAS_BUILTIN(__builtin_sub_overflow)
323 int64_t tmp;
324 return !__builtin_sub_overflow(a, b, &tmp) ? tmp : (tmp < 0 ? INT64_MAX : INT64_MIN);
325 #else
326 if (b <= 0 && a >= INT64_MAX + b)
327 return INT64_MAX;
328 if (b >= 0 && a <= INT64_MIN + b)
329 return INT64_MIN;
330 return a - b;
331 #endif
332 }
333
334 /**
335 * Clip a float value into the amin-amax range.
336 * @param a value to clip
337 * @param amin minimum value of the clip range
338 * @param amax maximum value of the clip range
339 * @return clipped value
340 */
av_clipf_c(float a,float amin,float amax)341 static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
342 {
343 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
344 if (amin > amax) abort();
345 #endif
346 if (a < amin) return amin;
347 else if (a > amax) return amax;
348 else return a;
349 }
350
351 /**
352 * Clip a double value into the amin-amax range.
353 * @param a value to clip
354 * @param amin minimum value of the clip range
355 * @param amax maximum value of the clip range
356 * @return clipped value
357 */
av_clipd_c(double a,double amin,double amax)358 static av_always_inline av_const double av_clipd_c(double a, double amin, double amax)
359 {
360 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
361 if (amin > amax) abort();
362 #endif
363 if (a < amin) return amin;
364 else if (a > amax) return amax;
365 else return a;
366 }
367
368 /** Compute ceil(log2(x)).
369 * @param x value used to compute ceil(log2(x))
370 * @return computed ceiling of log2(x)
371 */
av_ceil_log2_c(int x)372 static av_always_inline av_const int av_ceil_log2_c(int x)
373 {
374 return av_log2((x - 1U) << 1);
375 }
376
377 /**
378 * Count number of bits set to one in x
379 * @param x value to count bits of
380 * @return the number of bits set to one in x
381 */
av_popcount_c(uint32_t x)382 static av_always_inline av_const int av_popcount_c(uint32_t x)
383 {
384 x -= (x >> 1) & 0x55555555;
385 x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
386 x = (x + (x >> 4)) & 0x0F0F0F0F;
387 x += x >> 8;
388 return (x + (x >> 16)) & 0x3F;
389 }
390
391 /**
392 * Count number of bits set to one in x
393 * @param x value to count bits of
394 * @return the number of bits set to one in x
395 */
av_popcount64_c(uint64_t x)396 static av_always_inline av_const int av_popcount64_c(uint64_t x)
397 {
398 return av_popcount((uint32_t)x) + av_popcount((uint32_t)(x >> 32));
399 }
400
av_parity_c(uint32_t v)401 static av_always_inline av_const int av_parity_c(uint32_t v)
402 {
403 return av_popcount(v) & 1;
404 }
405
406 #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
407 #define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))
408
409 /**
410 * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
411 *
412 * @param val Output value, must be an lvalue of type uint32_t.
413 * @param GET_BYTE Expression reading one byte from the input.
414 * Evaluated up to 7 times (4 for the currently
415 * assigned Unicode range). With a memory buffer
416 * input, this could be *ptr++, or if you want to make sure
417 * that *ptr stops at the end of a NULL terminated string then
418 * *ptr ? *ptr++ : 0
419 * @param ERROR Expression to be evaluated on invalid input,
420 * typically a goto statement.
421 *
422 * @warning ERROR should not contain a loop control statement which
423 * could interact with the internal while loop, and should force an
424 * exit from the macro code (e.g. through a goto or a return) in order
425 * to prevent undefined results.
426 */
427 #define GET_UTF8(val, GET_BYTE, ERROR)\
428 val= (GET_BYTE);\
429 {\
430 uint32_t top = (val & 128) >> 1;\
431 if ((val & 0xc0) == 0x80 || val >= 0xFE)\
432 {ERROR}\
433 while (val & top) {\
434 unsigned int tmp = (GET_BYTE) - 128;\
435 if(tmp>>6)\
436 {ERROR}\
437 val= (val<<6) + tmp;\
438 top <<= 5;\
439 }\
440 val &= (top << 1) - 1;\
441 }
442
443 /**
444 * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
445 *
446 * @param val Output value, must be an lvalue of type uint32_t.
447 * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
448 * to native byte order. Evaluated one or two times.
449 * @param ERROR Expression to be evaluated on invalid input,
450 * typically a goto statement.
451 */
452 #define GET_UTF16(val, GET_16BIT, ERROR)\
453 val = (GET_16BIT);\
454 {\
455 unsigned int hi = val - 0xD800;\
456 if (hi < 0x800) {\
457 val = (GET_16BIT) - 0xDC00;\
458 if (val > 0x3FFU || hi > 0x3FFU)\
459 {ERROR}\
460 val += (hi<<10) + 0x10000;\
461 }\
462 }\
463
464 /**
465 * @def PUT_UTF8(val, tmp, PUT_BYTE)
466 * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
467 * @param val is an input-only argument and should be of type uint32_t. It holds
468 * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
469 * val is given as a function it is executed only once.
470 * @param tmp is a temporary variable and should be of type uint8_t. It
471 * represents an intermediate value during conversion that is to be
472 * output by PUT_BYTE.
473 * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
474 * It could be a function or a statement, and uses tmp as the input byte.
475 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
476 * executed up to 4 times for values in the valid UTF-8 range and up to
477 * 7 times in the general case, depending on the length of the converted
478 * Unicode character.
479 */
480 #define PUT_UTF8(val, tmp, PUT_BYTE)\
481 {\
482 int bytes, shift;\
483 uint32_t in = val;\
484 if (in < 0x80) {\
485 tmp = in;\
486 PUT_BYTE\
487 } else {\
488 bytes = (av_log2(in) + 4) / 5;\
489 shift = (bytes - 1) * 6;\
490 tmp = (256 - (256 >> bytes)) | (in >> shift);\
491 PUT_BYTE\
492 while (shift >= 6) {\
493 shift -= 6;\
494 tmp = 0x80 | ((in >> shift) & 0x3f);\
495 PUT_BYTE\
496 }\
497 }\
498 }
499
500 /**
501 * @def PUT_UTF16(val, tmp, PUT_16BIT)
502 * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
503 * @param val is an input-only argument and should be of type uint32_t. It holds
504 * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
505 * val is given as a function it is executed only once.
506 * @param tmp is a temporary variable and should be of type uint16_t. It
507 * represents an intermediate value during conversion that is to be
508 * output by PUT_16BIT.
509 * @param PUT_16BIT writes the converted UTF-16 data to any proper destination
510 * in desired endianness. It could be a function or a statement, and uses tmp
511 * as the input byte. For example, PUT_BYTE could be "*output++ = tmp;"
512 * PUT_BYTE will be executed 1 or 2 times depending on input character.
513 */
514 #define PUT_UTF16(val, tmp, PUT_16BIT)\
515 {\
516 uint32_t in = val;\
517 if (in < 0x10000) {\
518 tmp = in;\
519 PUT_16BIT\
520 } else {\
521 tmp = 0xD800 | ((in - 0x10000) >> 10);\
522 PUT_16BIT\
523 tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
524 PUT_16BIT\
525 }\
526 }\
527
528
529
530 #include "mem.h"
531
532 #ifdef HAVE_AV_CONFIG_H
533 # include "internal.h"
534 #endif /* HAVE_AV_CONFIG_H */
535
536 #endif /* AVUTIL_COMMON_H */
537
538 /*
539 * The following definitions are outside the multiple inclusion guard
540 * to ensure they are immediately available in intmath.h.
541 */
542
543 #ifndef av_ceil_log2
544 # define av_ceil_log2 av_ceil_log2_c
545 #endif
546 #ifndef av_clip
547 # define av_clip av_clip_c
548 #endif
549 #ifndef av_clip64
550 # define av_clip64 av_clip64_c
551 #endif
552 #ifndef av_clip_uint8
553 # define av_clip_uint8 av_clip_uint8_c
554 #endif
555 #ifndef av_clip_int8
556 # define av_clip_int8 av_clip_int8_c
557 #endif
558 #ifndef av_clip_uint16
559 # define av_clip_uint16 av_clip_uint16_c
560 #endif
561 #ifndef av_clip_int16
562 # define av_clip_int16 av_clip_int16_c
563 #endif
564 #ifndef av_clipl_int32
565 # define av_clipl_int32 av_clipl_int32_c
566 #endif
567 #ifndef av_clip_intp2
568 # define av_clip_intp2 av_clip_intp2_c
569 #endif
570 #ifndef av_clip_uintp2
571 # define av_clip_uintp2 av_clip_uintp2_c
572 #endif
573 #ifndef av_mod_uintp2
574 # define av_mod_uintp2 av_mod_uintp2_c
575 #endif
576 #ifndef av_sat_add32
577 # define av_sat_add32 av_sat_add32_c
578 #endif
579 #ifndef av_sat_dadd32
580 # define av_sat_dadd32 av_sat_dadd32_c
581 #endif
582 #ifndef av_sat_sub32
583 # define av_sat_sub32 av_sat_sub32_c
584 #endif
585 #ifndef av_sat_dsub32
586 # define av_sat_dsub32 av_sat_dsub32_c
587 #endif
588 #ifndef av_sat_add64
589 # define av_sat_add64 av_sat_add64_c
590 #endif
591 #ifndef av_sat_sub64
592 # define av_sat_sub64 av_sat_sub64_c
593 #endif
594 #ifndef av_clipf
595 # define av_clipf av_clipf_c
596 #endif
597 #ifndef av_clipd
598 # define av_clipd av_clipd_c
599 #endif
600 #ifndef av_popcount
601 # define av_popcount av_popcount_c
602 #endif
603 #ifndef av_popcount64
604 # define av_popcount64 av_popcount64_c
605 #endif
606 #ifndef av_parity
607 # define av_parity av_parity_c
608 #endif
609