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
45 //rounded division & shift
46 #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
47 /* assume b>0 */
48 #define ROUNDED_DIV(a,b) (((a)>=0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
49 /* Fast a/(1<<b) rounded toward +inf. Assume a>=0 and b>=0 */
50 #define AV_CEIL_RSHIFT(a,b) (!av_builtin_constant_p(b) ? -((-(a)) >> (b)) \
51 : ((a) + (1<<(b)) - 1) >> (b))
52 /* Backwards compat. */
53 #define FF_CEIL_RSHIFT AV_CEIL_RSHIFT
54
55 #define FFUDIV(a,b) (((a)>0 ?(a):(a)-(b)+1) / (b))
56 #define FFUMOD(a,b) ((a)-(b)*FFUDIV(a,b))
57
58 /**
59 * Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they
60 * are not representable as absolute values of their type. This is the same
61 * as with *abs()
62 * @see FFNABS()
63 */
64 #define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
65 #define FFSIGN(a) ((a) > 0 ? 1 : -1)
66
67 /**
68 * Negative Absolute value.
69 * this works for all integers of all types.
70 * As with many macros, this evaluates its argument twice, it thus must not have
71 * a sideeffect, that is FFNABS(x++) has undefined behavior.
72 */
73 #define FFNABS(a) ((a) <= 0 ? (a) : (-(a)))
74
75 /**
76 * Unsigned Absolute value.
77 * This takes the absolute value of a signed int and returns it as a unsigned.
78 * This also works with INT_MIN which would otherwise not be representable
79 * As with many macros, this evaluates its argument twice.
80 */
81 #define FFABSU(a) ((a) <= 0 ? -(unsigned)(a) : (unsigned)(a))
82 #define FFABS64U(a) ((a) <= 0 ? -(uint64_t)(a) : (uint64_t)(a))
83
84 /* misc math functions */
85
86 #ifdef HAVE_AV_CONFIG_H
87 # include "config.h"
88 # include "intmath.h"
89 #endif
90
91 #ifndef av_ceil_log2
92 # define av_ceil_log2 av_ceil_log2_c
93 #endif
94 #ifndef av_clip
95 # define av_clip av_clip_c
96 #endif
97 #ifndef av_clip64
98 # define av_clip64 av_clip64_c
99 #endif
100 #ifndef av_clip_uint8
101 # define av_clip_uint8 av_clip_uint8_c
102 #endif
103 #ifndef av_clip_int8
104 # define av_clip_int8 av_clip_int8_c
105 #endif
106 #ifndef av_clip_uint16
107 # define av_clip_uint16 av_clip_uint16_c
108 #endif
109 #ifndef av_clip_int16
110 # define av_clip_int16 av_clip_int16_c
111 #endif
112 #ifndef av_clipl_int32
113 # define av_clipl_int32 av_clipl_int32_c
114 #endif
115 #ifndef av_clip_intp2
116 # define av_clip_intp2 av_clip_intp2_c
117 #endif
118 #ifndef av_clip_uintp2
119 # define av_clip_uintp2 av_clip_uintp2_c
120 #endif
121 #ifndef av_mod_uintp2
122 # define av_mod_uintp2 av_mod_uintp2_c
123 #endif
124 #ifndef av_sat_add32
125 # define av_sat_add32 av_sat_add32_c
126 #endif
127 #ifndef av_sat_dadd32
128 # define av_sat_dadd32 av_sat_dadd32_c
129 #endif
130 #ifndef av_sat_sub32
131 # define av_sat_sub32 av_sat_sub32_c
132 #endif
133 #ifndef av_sat_dsub32
134 # define av_sat_dsub32 av_sat_dsub32_c
135 #endif
136 #ifndef av_sat_add64
137 # define av_sat_add64 av_sat_add64_c
138 #endif
139 #ifndef av_sat_sub64
140 # define av_sat_sub64 av_sat_sub64_c
141 #endif
142 #ifndef av_clipf
143 # define av_clipf av_clipf_c
144 #endif
145 #ifndef av_clipd
146 # define av_clipd av_clipd_c
147 #endif
148 #ifndef av_popcount
149 # define av_popcount av_popcount_c
150 #endif
151 #ifndef av_popcount64
152 # define av_popcount64 av_popcount64_c
153 #endif
154 #ifndef av_parity
155 # define av_parity av_parity_c
156 #endif
157
158 #ifndef av_log2
159 av_const int av_log2(unsigned v);
160 #endif
161
162 #ifndef av_log2_16bit
163 av_const int av_log2_16bit(unsigned v);
164 #endif
165
166 /**
167 * Clip a signed integer value into the amin-amax range.
168 * @param a value to clip
169 * @param amin minimum value of the clip range
170 * @param amax maximum value of the clip range
171 * @return clipped value
172 */
av_clip_c(int a,int amin,int amax)173 static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
174 {
175 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
176 if (amin > amax) abort();
177 #endif
178 if (a < amin) return amin;
179 else if (a > amax) return amax;
180 else return a;
181 }
182
183 /**
184 * Clip a signed 64bit integer value into the amin-amax range.
185 * @param a value to clip
186 * @param amin minimum value of the clip range
187 * @param amax maximum value of the clip range
188 * @return clipped value
189 */
av_clip64_c(int64_t a,int64_t amin,int64_t amax)190 static av_always_inline av_const int64_t av_clip64_c(int64_t a, int64_t amin, int64_t amax)
191 {
192 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
193 if (amin > amax) abort();
194 #endif
195 if (a < amin) return amin;
196 else if (a > amax) return amax;
197 else return a;
198 }
199
200 /**
201 * Clip a signed integer value into the 0-255 range.
202 * @param a value to clip
203 * @return clipped value
204 */
av_clip_uint8_c(int a)205 static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
206 {
207 if (a&(~0xFF)) return (~a)>>31;
208 else return a;
209 }
210
211 /**
212 * Clip a signed integer value into the -128,127 range.
213 * @param a value to clip
214 * @return clipped value
215 */
av_clip_int8_c(int a)216 static av_always_inline av_const int8_t av_clip_int8_c(int a)
217 {
218 if ((a+0x80U) & ~0xFF) return (a>>31) ^ 0x7F;
219 else return a;
220 }
221
222 /**
223 * Clip a signed integer value into the 0-65535 range.
224 * @param a value to clip
225 * @return clipped value
226 */
av_clip_uint16_c(int a)227 static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
228 {
229 if (a&(~0xFFFF)) return (~a)>>31;
230 else return a;
231 }
232
233 /**
234 * Clip a signed integer value into the -32768,32767 range.
235 * @param a value to clip
236 * @return clipped value
237 */
av_clip_int16_c(int a)238 static av_always_inline av_const int16_t av_clip_int16_c(int a)
239 {
240 if ((a+0x8000U) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
241 else return a;
242 }
243
244 /**
245 * Clip a signed 64-bit integer value into the -2147483648,2147483647 range.
246 * @param a value to clip
247 * @return clipped value
248 */
av_clipl_int32_c(int64_t a)249 static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
250 {
251 if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (int32_t)((a>>63) ^ 0x7FFFFFFF);
252 else return (int32_t)a;
253 }
254
255 /**
256 * Clip a signed integer into the -(2^p),(2^p-1) range.
257 * @param a value to clip
258 * @param p bit position to clip at
259 * @return clipped value
260 */
av_clip_intp2_c(int a,int p)261 static av_always_inline av_const int av_clip_intp2_c(int a, int p)
262 {
263 if (((unsigned)a + (1 << p)) & ~((2 << p) - 1))
264 return (a >> 31) ^ ((1 << p) - 1);
265 else
266 return a;
267 }
268
269 /**
270 * Clip a signed integer to an unsigned power of two range.
271 * @param a value to clip
272 * @param p bit position to clip at
273 * @return clipped value
274 */
av_clip_uintp2_c(int a,int p)275 static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
276 {
277 if (a & ~((1<<p) - 1)) return (~a) >> 31 & ((1<<p) - 1);
278 else return a;
279 }
280
281 /**
282 * Clear high bits from an unsigned integer starting with specific bit position
283 * @param a value to clip
284 * @param p bit position to clip at
285 * @return clipped value
286 */
av_mod_uintp2_c(unsigned a,unsigned p)287 static av_always_inline av_const unsigned av_mod_uintp2_c(unsigned a, unsigned p)
288 {
289 return a & ((1U << p) - 1);
290 }
291
292 /**
293 * Add two signed 32-bit values with saturation.
294 *
295 * @param a one value
296 * @param b another value
297 * @return sum with signed saturation
298 */
av_sat_add32_c(int a,int b)299 static av_always_inline int av_sat_add32_c(int a, int b)
300 {
301 return av_clipl_int32((int64_t)a + b);
302 }
303
304 /**
305 * Add a doubled value to another value with saturation at both stages.
306 *
307 * @param a first value
308 * @param b value doubled and added to a
309 * @return sum sat(a + sat(2*b)) with signed saturation
310 */
av_sat_dadd32_c(int a,int b)311 static av_always_inline int av_sat_dadd32_c(int a, int b)
312 {
313 return av_sat_add32(a, av_sat_add32(b, b));
314 }
315
316 /**
317 * Subtract two signed 32-bit values with saturation.
318 *
319 * @param a one value
320 * @param b another value
321 * @return difference with signed saturation
322 */
av_sat_sub32_c(int a,int b)323 static av_always_inline int av_sat_sub32_c(int a, int b)
324 {
325 return av_clipl_int32((int64_t)a - b);
326 }
327
328 /**
329 * Subtract a doubled value from another value with saturation at both stages.
330 *
331 * @param a first value
332 * @param b value doubled and subtracted from a
333 * @return difference sat(a - sat(2*b)) with signed saturation
334 */
av_sat_dsub32_c(int a,int b)335 static av_always_inline int av_sat_dsub32_c(int a, int b)
336 {
337 return av_sat_sub32(a, av_sat_add32(b, b));
338 }
339
340 /**
341 * Add two signed 64-bit values with saturation.
342 *
343 * @param a one value
344 * @param b another value
345 * @return sum with signed saturation
346 */
av_sat_add64_c(int64_t a,int64_t b)347 static av_always_inline int64_t av_sat_add64_c(int64_t a, int64_t b) {
348 #if (!defined(__INTEL_COMPILER) && AV_GCC_VERSION_AT_LEAST(5,1)) || AV_HAS_BUILTIN(__builtin_add_overflow)
349 int64_t tmp;
350 return !__builtin_add_overflow(a, b, &tmp) ? tmp : (tmp < 0 ? INT64_MAX : INT64_MIN);
351 #else
352 int64_t s = a+(uint64_t)b;
353 if ((int64_t)(a^b | ~s^b) >= 0)
354 return INT64_MAX ^ (b >> 63);
355 return s;
356 #endif
357 }
358
359 /**
360 * Subtract two signed 64-bit values with saturation.
361 *
362 * @param a one value
363 * @param b another value
364 * @return difference with signed saturation
365 */
av_sat_sub64_c(int64_t a,int64_t b)366 static av_always_inline int64_t av_sat_sub64_c(int64_t a, int64_t b) {
367 #if (!defined(__INTEL_COMPILER) && AV_GCC_VERSION_AT_LEAST(5,1)) || AV_HAS_BUILTIN(__builtin_sub_overflow)
368 int64_t tmp;
369 return !__builtin_sub_overflow(a, b, &tmp) ? tmp : (tmp < 0 ? INT64_MAX : INT64_MIN);
370 #else
371 if (b <= 0 && a >= INT64_MAX + b)
372 return INT64_MAX;
373 if (b >= 0 && a <= INT64_MIN + b)
374 return INT64_MIN;
375 return a - b;
376 #endif
377 }
378
379 /**
380 * Clip a float value into the amin-amax range.
381 * If a is nan or -inf amin will be returned.
382 * If a is +inf amax will be returned.
383 * @param a value to clip
384 * @param amin minimum value of the clip range
385 * @param amax maximum value of the clip range
386 * @return clipped value
387 */
av_clipf_c(float a,float amin,float amax)388 static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
389 {
390 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
391 if (amin > amax) abort();
392 #endif
393 return FFMIN(FFMAX(a, amin), amax);
394 }
395
396 /**
397 * Clip a double value into the amin-amax range.
398 * If a is nan or -inf amin will be returned.
399 * If a is +inf amax will be returned.
400 * @param a value to clip
401 * @param amin minimum value of the clip range
402 * @param amax maximum value of the clip range
403 * @return clipped value
404 */
av_clipd_c(double a,double amin,double amax)405 static av_always_inline av_const double av_clipd_c(double a, double amin, double amax)
406 {
407 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
408 if (amin > amax) abort();
409 #endif
410 return FFMIN(FFMAX(a, amin), amax);
411 }
412
413 /** Compute ceil(log2(x)).
414 * @param x value used to compute ceil(log2(x))
415 * @return computed ceiling of log2(x)
416 */
av_ceil_log2_c(int x)417 static av_always_inline av_const int av_ceil_log2_c(int x)
418 {
419 return av_log2((x - 1U) << 1);
420 }
421
422 /**
423 * Count number of bits set to one in x
424 * @param x value to count bits of
425 * @return the number of bits set to one in x
426 */
av_popcount_c(uint32_t x)427 static av_always_inline av_const int av_popcount_c(uint32_t x)
428 {
429 x -= (x >> 1) & 0x55555555;
430 x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
431 x = (x + (x >> 4)) & 0x0F0F0F0F;
432 x += x >> 8;
433 return (x + (x >> 16)) & 0x3F;
434 }
435
436 /**
437 * Count number of bits set to one in x
438 * @param x value to count bits of
439 * @return the number of bits set to one in x
440 */
av_popcount64_c(uint64_t x)441 static av_always_inline av_const int av_popcount64_c(uint64_t x)
442 {
443 return av_popcount((uint32_t)x) + av_popcount((uint32_t)(x >> 32));
444 }
445
av_parity_c(uint32_t v)446 static av_always_inline av_const int av_parity_c(uint32_t v)
447 {
448 return av_popcount(v) & 1;
449 }
450
451 /**
452 * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
453 *
454 * @param val Output value, must be an lvalue of type uint32_t.
455 * @param GET_BYTE Expression reading one byte from the input.
456 * Evaluated up to 7 times (4 for the currently
457 * assigned Unicode range). With a memory buffer
458 * input, this could be *ptr++, or if you want to make sure
459 * that *ptr stops at the end of a NULL terminated string then
460 * *ptr ? *ptr++ : 0
461 * @param ERROR Expression to be evaluated on invalid input,
462 * typically a goto statement.
463 *
464 * @warning ERROR should not contain a loop control statement which
465 * could interact with the internal while loop, and should force an
466 * exit from the macro code (e.g. through a goto or a return) in order
467 * to prevent undefined results.
468 */
469 #define GET_UTF8(val, GET_BYTE, ERROR)\
470 val= (GET_BYTE);\
471 {\
472 uint32_t top = (val & 128) >> 1;\
473 if ((val & 0xc0) == 0x80 || val >= 0xFE)\
474 {ERROR}\
475 while (val & top) {\
476 unsigned int tmp = (GET_BYTE) - 128;\
477 if(tmp>>6)\
478 {ERROR}\
479 val= (val<<6) + tmp;\
480 top <<= 5;\
481 }\
482 val &= (top << 1) - 1;\
483 }
484
485 /**
486 * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
487 *
488 * @param val Output value, must be an lvalue of type uint32_t.
489 * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
490 * to native byte order. Evaluated one or two times.
491 * @param ERROR Expression to be evaluated on invalid input,
492 * typically a goto statement.
493 */
494 #define GET_UTF16(val, GET_16BIT, ERROR)\
495 val = (GET_16BIT);\
496 {\
497 unsigned int hi = val - 0xD800;\
498 if (hi < 0x800) {\
499 val = (GET_16BIT) - 0xDC00;\
500 if (val > 0x3FFU || hi > 0x3FFU)\
501 {ERROR}\
502 val += (hi<<10) + 0x10000;\
503 }\
504 }\
505
506 /**
507 * @def PUT_UTF8(val, tmp, PUT_BYTE)
508 * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
509 * @param val is an input-only argument and should be of type uint32_t. It holds
510 * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
511 * val is given as a function it is executed only once.
512 * @param tmp is a temporary variable and should be of type uint8_t. It
513 * represents an intermediate value during conversion that is to be
514 * output by PUT_BYTE.
515 * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
516 * It could be a function or a statement, and uses tmp as the input byte.
517 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
518 * executed up to 4 times for values in the valid UTF-8 range and up to
519 * 7 times in the general case, depending on the length of the converted
520 * Unicode character.
521 */
522 #define PUT_UTF8(val, tmp, PUT_BYTE)\
523 {\
524 int bytes, shift;\
525 uint32_t in = val;\
526 if (in < 0x80) {\
527 tmp = in;\
528 PUT_BYTE\
529 } else {\
530 bytes = (av_log2(in) + 4) / 5;\
531 shift = (bytes - 1) * 6;\
532 tmp = (256 - (256 >> bytes)) | (in >> shift);\
533 PUT_BYTE\
534 while (shift >= 6) {\
535 shift -= 6;\
536 tmp = 0x80 | ((in >> shift) & 0x3f);\
537 PUT_BYTE\
538 }\
539 }\
540 }
541
542 /**
543 * @def PUT_UTF16(val, tmp, PUT_16BIT)
544 * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
545 * @param val is an input-only argument and should be of type uint32_t. It holds
546 * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
547 * val is given as a function it is executed only once.
548 * @param tmp is a temporary variable and should be of type uint16_t. It
549 * represents an intermediate value during conversion that is to be
550 * output by PUT_16BIT.
551 * @param PUT_16BIT writes the converted UTF-16 data to any proper destination
552 * in desired endianness. It could be a function or a statement, and uses tmp
553 * as the input byte. For example, PUT_BYTE could be "*output++ = tmp;"
554 * PUT_BYTE will be executed 1 or 2 times depending on input character.
555 */
556 #define PUT_UTF16(val, tmp, PUT_16BIT)\
557 {\
558 uint32_t in = val;\
559 if (in < 0x10000) {\
560 tmp = in;\
561 PUT_16BIT\
562 } else {\
563 tmp = 0xD800 | ((in - 0x10000) >> 10);\
564 PUT_16BIT\
565 tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
566 PUT_16BIT\
567 }\
568 }\
569
570
571
572 #include "mem.h"
573
574 #ifdef HAVE_AV_CONFIG_H
575 # include "internal.h"
576 #endif /* HAVE_AV_CONFIG_H */
577
578 #endif /* AVUTIL_COMMON_H */
579