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common.h
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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 /**
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  */
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  */
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  */
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  */
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  */
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  */
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 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  * Clip a float value into the amin-amax range.
272  * @param a value to clip
273  * @param amin minimum value of the clip range
274  * @param amax maximum value of the clip range
275  * @return clipped value
276  */
277 static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
278 {
279 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
280  if (amin > amax) abort();
281 #endif
282  if (a < amin) return amin;
283  else if (a > amax) return amax;
284  else return a;
285 }
286 
287 /**
288  * Clip a double value into the amin-amax range.
289  * @param a value to clip
290  * @param amin minimum value of the clip range
291  * @param amax maximum value of the clip range
292  * @return clipped value
293  */
294 static av_always_inline av_const double av_clipd_c(double a, double amin, double amax)
295 {
296 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
297  if (amin > amax) abort();
298 #endif
299  if (a < amin) return amin;
300  else if (a > amax) return amax;
301  else return a;
302 }
303 
304 /** Compute ceil(log2(x)).
305  * @param x value used to compute ceil(log2(x))
306  * @return computed ceiling of log2(x)
307  */
309 {
310  return av_log2((x - 1) << 1);
311 }
312 
313 /**
314  * Count number of bits set to one in x
315  * @param x value to count bits of
316  * @return the number of bits set to one in x
317  */
319 {
320  x -= (x >> 1) & 0x55555555;
321  x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
322  x = (x + (x >> 4)) & 0x0F0F0F0F;
323  x += x >> 8;
324  return (x + (x >> 16)) & 0x3F;
325 }
326 
327 /**
328  * Count number of bits set to one in x
329  * @param x value to count bits of
330  * @return the number of bits set to one in x
331  */
333 {
334  return av_popcount((uint32_t)x) + av_popcount((uint32_t)(x >> 32));
335 }
336 
337 static av_always_inline av_const int av_parity_c(uint32_t v)
338 {
339  return av_popcount(v) & 1;
340 }
341 
342 #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
343 #define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))
344 
345 /**
346  * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
347  *
348  * @param val Output value, must be an lvalue of type uint32_t.
349  * @param GET_BYTE Expression reading one byte from the input.
350  * Evaluated up to 7 times (4 for the currently
351  * assigned Unicode range). With a memory buffer
352  * input, this could be *ptr++.
353  * @param ERROR Expression to be evaluated on invalid input,
354  * typically a goto statement.
355  *
356  * @warning ERROR should not contain a loop control statement which
357  * could interact with the internal while loop, and should force an
358  * exit from the macro code (e.g. through a goto or a return) in order
359  * to prevent undefined results.
360  */
361 #define GET_UTF8(val, GET_BYTE, ERROR)\
362  val= (GET_BYTE);\
363  {\
364  uint32_t top = (val & 128) >> 1;\
365  if ((val & 0xc0) == 0x80 || val >= 0xFE)\
366  ERROR\
367  while (val & top) {\
368  int tmp= (GET_BYTE) - 128;\
369  if(tmp>>6)\
370  ERROR\
371  val= (val<<6) + tmp;\
372  top <<= 5;\
373  }\
374  val &= (top << 1) - 1;\
375  }
376 
377 /**
378  * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
379  *
380  * @param val Output value, must be an lvalue of type uint32_t.
381  * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
382  * to native byte order. Evaluated one or two times.
383  * @param ERROR Expression to be evaluated on invalid input,
384  * typically a goto statement.
385  */
386 #define GET_UTF16(val, GET_16BIT, ERROR)\
387  val = GET_16BIT;\
388  {\
389  unsigned int hi = val - 0xD800;\
390  if (hi < 0x800) {\
391  val = GET_16BIT - 0xDC00;\
392  if (val > 0x3FFU || hi > 0x3FFU)\
393  ERROR\
394  val += (hi<<10) + 0x10000;\
395  }\
396  }\
397 
398 /**
399  * @def PUT_UTF8(val, tmp, PUT_BYTE)
400  * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
401  * @param val is an input-only argument and should be of type uint32_t. It holds
402  * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
403  * val is given as a function it is executed only once.
404  * @param tmp is a temporary variable and should be of type uint8_t. It
405  * represents an intermediate value during conversion that is to be
406  * output by PUT_BYTE.
407  * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
408  * It could be a function or a statement, and uses tmp as the input byte.
409  * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
410  * executed up to 4 times for values in the valid UTF-8 range and up to
411  * 7 times in the general case, depending on the length of the converted
412  * Unicode character.
413  */
414 #define PUT_UTF8(val, tmp, PUT_BYTE)\
415  {\
416  int bytes, shift;\
417  uint32_t in = val;\
418  if (in < 0x80) {\
419  tmp = in;\
420  PUT_BYTE\
421  } else {\
422  bytes = (av_log2(in) + 4) / 5;\
423  shift = (bytes - 1) * 6;\
424  tmp = (256 - (256 >> bytes)) | (in >> shift);\
425  PUT_BYTE\
426  while (shift >= 6) {\
427  shift -= 6;\
428  tmp = 0x80 | ((in >> shift) & 0x3f);\
429  PUT_BYTE\
430  }\
431  }\
432  }
433 
434 /**
435  * @def PUT_UTF16(val, tmp, PUT_16BIT)
436  * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
437  * @param val is an input-only argument and should be of type uint32_t. It holds
438  * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
439  * val is given as a function it is executed only once.
440  * @param tmp is a temporary variable and should be of type uint16_t. It
441  * represents an intermediate value during conversion that is to be
442  * output by PUT_16BIT.
443  * @param PUT_16BIT writes the converted UTF-16 data to any proper destination
444  * in desired endianness. It could be a function or a statement, and uses tmp
445  * as the input byte. For example, PUT_BYTE could be "*output++ = tmp;"
446  * PUT_BYTE will be executed 1 or 2 times depending on input character.
447  */
448 #define PUT_UTF16(val, tmp, PUT_16BIT)\
449  {\
450  uint32_t in = val;\
451  if (in < 0x10000) {\
452  tmp = in;\
453  PUT_16BIT\
454  } else {\
455  tmp = 0xD800 | ((in - 0x10000) >> 10);\
456  PUT_16BIT\
457  tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
458  PUT_16BIT\
459  }\
460  }\
461 
462 
463 
464 #include "mem.h"
465 
466 #ifdef HAVE_AV_CONFIG_H
467 # include "internal.h"
468 #endif /* HAVE_AV_CONFIG_H */
469 
470 #endif /* AVUTIL_COMMON_H */
471 
472 /*
473  * The following definitions are outside the multiple inclusion guard
474  * to ensure they are immediately available in intmath.h.
475  */
476 
477 #ifndef av_ceil_log2
478 # define av_ceil_log2 av_ceil_log2_c
479 #endif
480 #ifndef av_clip
481 # define av_clip av_clip_c
482 #endif
483 #ifndef av_clip64
484 # define av_clip64 av_clip64_c
485 #endif
486 #ifndef av_clip_uint8
487 # define av_clip_uint8 av_clip_uint8_c
488 #endif
489 #ifndef av_clip_int8
490 # define av_clip_int8 av_clip_int8_c
491 #endif
492 #ifndef av_clip_uint16
493 # define av_clip_uint16 av_clip_uint16_c
494 #endif
495 #ifndef av_clip_int16
496 # define av_clip_int16 av_clip_int16_c
497 #endif
498 #ifndef av_clipl_int32
499 # define av_clipl_int32 av_clipl_int32_c
500 #endif
501 #ifndef av_clip_intp2
502 # define av_clip_intp2 av_clip_intp2_c
503 #endif
504 #ifndef av_clip_uintp2
505 # define av_clip_uintp2 av_clip_uintp2_c
506 #endif
507 #ifndef av_mod_uintp2
508 # define av_mod_uintp2 av_mod_uintp2_c
509 #endif
510 #ifndef av_sat_add32
511 # define av_sat_add32 av_sat_add32_c
512 #endif
513 #ifndef av_sat_dadd32
514 # define av_sat_dadd32 av_sat_dadd32_c
515 #endif
516 #ifndef av_clipf
517 # define av_clipf av_clipf_c
518 #endif
519 #ifndef av_clipd
520 # define av_clipd av_clipd_c
521 #endif
522 #ifndef av_popcount
523 # define av_popcount av_popcount_c
524 #endif
525 #ifndef av_popcount64
526 # define av_popcount64 av_popcount64_c
527 #endif
528 #ifndef av_parity
529 # define av_parity av_parity_c
530 #endif
#define av_const
Definition: attributes.h:76
static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
Clip a signed 64-bit integer value into the -2147483648,2147483647 range.
Definition: common.h:203
static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
Clip a float value into the amin-amax range.
Definition: common.h:277
static av_always_inline av_const unsigned av_mod_uintp2_c(unsigned a, unsigned p)
Clear high bits from an unsigned integer starting with specific bit position.
Definition: common.h:241
memory handling functions
const char * b
Definition: vf_curves.c:113
int av_log2(unsigned v)
Definition: intmath.c:26
static av_always_inline av_const int8_t av_clip_int8_c(int a)
Clip a signed integer value into the -128,127 range.
Definition: common.h:170
int av_log2_16bit(unsigned v)
Definition: intmath.c:31
Macro definitions for various function/variable attributes.
uint8_t
Utility Preprocessor macros.
static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
Clip a signed integer value into the amin-amax range.
Definition: common.h:127
Libavutil version macros.
static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
Clip a signed integer value into the 0-65535 range.
Definition: common.h:181
static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
Clip a signed integer value into the 0-255 range.
Definition: common.h:159
common internal API header
int32_t
static av_always_inline av_const double av_clipd_c(double a, double amin, double amax)
Clip a double value into the amin-amax range.
Definition: common.h:294
static av_always_inline av_const int av_clip_intp2_c(int a, int p)
Clip a signed integer into the -(2^p),(2^p-1) range.
Definition: common.h:215
static av_always_inline av_const int16_t av_clip_int16_c(int a)
Clip a signed integer value into the -32768,32767 range.
Definition: common.h:192
common internal and external API header
static av_always_inline av_const int av_popcount_c(uint32_t x)
Count number of bits set to one in x.
Definition: common.h:318
static av_always_inline int av_sat_add32_c(int a, int b)
Add two signed 32-bit values with saturation.
Definition: common.h:253
static av_always_inline av_const int av_popcount64_c(uint64_t x)
Count number of bits set to one in x.
Definition: common.h:332
static av_always_inline av_const int av_parity_c(uint32_t v)
Definition: common.h:337
static av_always_inline int av_sat_dadd32_c(int a, int b)
Add a doubled value to another value with saturation at both stages.
Definition: common.h:265
#define av_always_inline
Definition: attributes.h:39
static av_always_inline av_const int av_ceil_log2_c(int x)
Compute ceil(log2(x)).
Definition: common.h:308
static av_always_inline av_const int64_t av_clip64_c(int64_t a, int64_t amin, int64_t amax)
Clip a signed 64bit integer value into the amin-amax range.
Definition: common.h:144
static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
Clip a signed integer to an unsigned power of two range.
Definition: common.h:229