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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 "version.h"
44 #include "libavutil/avconfig.h"
45 
46 #if AV_HAVE_BIGENDIAN
47 # define AV_NE(be, le) (be)
48 #else
49 # define AV_NE(be, le) (le)
50 #endif
51 
52 //rounded division & shift
53 #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
54 /* assume b>0 */
55 #define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
56 /* assume a>0 and b>0 */
57 #define FF_CEIL_RSHIFT(a,b) (!av_builtin_constant_p(b) ? -((-(a)) >> (b)) \
58  : ((a) + (1<<(b)) - 1) >> (b))
59 #define FFUDIV(a,b) (((a)>0 ?(a):(a)-(b)+1) / (b))
60 #define FFUMOD(a,b) ((a)-(b)*FFUDIV(a,b))
61 
62 /**
63  * Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they
64  * are not representable as absolute values of their type. This is the same
65  * as with *abs()
66  * @see FFNABS()
67  */
68 #define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
69 #define FFSIGN(a) ((a) > 0 ? 1 : -1)
70 
71 /**
72  * Negative Absolute value.
73  * this works for all integers of all types.
74  * As with many macros, this evaluates its argument twice, it thus must not have
75  * a sideeffect, that is FFNABS(x++) has undefined behavior.
76  */
77 #define FFNABS(a) ((a) <= 0 ? (a) : (-(a)))
78 
79 #define FFMAX(a,b) ((a) > (b) ? (a) : (b))
80 #define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
81 #define FFMIN(a,b) ((a) > (b) ? (b) : (a))
82 #define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)
83 
84 #define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
85 #define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
86 #define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1))
87 
88 /* misc math functions */
89 
90 /**
91  * Reverse the order of the bits of an 8-bits unsigned integer.
92  */
93 #if FF_API_AV_REVERSE
94 extern attribute_deprecated const uint8_t av_reverse[256];
95 #endif
96 
97 #ifdef HAVE_AV_CONFIG_H
98 # include "config.h"
99 # include "intmath.h"
100 #endif
101 
102 /* Pull in unguarded fallback defines at the end of this file. */
103 #include "common.h"
104 
105 #ifndef av_log2
106 av_const int av_log2(unsigned v);
107 #endif
108 
109 #ifndef av_log2_16bit
110 av_const int av_log2_16bit(unsigned v);
111 #endif
112 
113 /**
114  * Clip a signed integer value into the amin-amax range.
115  * @param a value to clip
116  * @param amin minimum value of the clip range
117  * @param amax maximum value of the clip range
118  * @return clipped value
119  */
120 static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
121 {
122 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
123  if (amin > amax) abort();
124 #endif
125  if (a < amin) return amin;
126  else if (a > amax) return amax;
127  else return a;
128 }
129 
130 /**
131  * Clip a signed 64bit integer value into the amin-amax range.
132  * @param a value to clip
133  * @param amin minimum value of the clip range
134  * @param amax maximum value of the clip range
135  * @return clipped value
136  */
137 static av_always_inline av_const int64_t av_clip64_c(int64_t a, int64_t amin, int64_t amax)
138 {
139 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
140  if (amin > amax) abort();
141 #endif
142  if (a < amin) return amin;
143  else if (a > amax) return amax;
144  else return a;
145 }
146 
147 /**
148  * Clip a signed integer value into the 0-255 range.
149  * @param a value to clip
150  * @return clipped value
151  */
153 {
154  if (a&(~0xFF)) return (-a)>>31;
155  else return a;
156 }
157 
158 /**
159  * Clip a signed integer value into the -128,127 range.
160  * @param a value to clip
161  * @return clipped value
162  */
164 {
165  if ((a+0x80U) & ~0xFF) return (a>>31) ^ 0x7F;
166  else return a;
167 }
168 
169 /**
170  * Clip a signed integer value into the 0-65535 range.
171  * @param a value to clip
172  * @return clipped value
173  */
175 {
176  if (a&(~0xFFFF)) return (-a)>>31;
177  else return a;
178 }
179 
180 /**
181  * Clip a signed integer value into the -32768,32767 range.
182  * @param a value to clip
183  * @return clipped value
184  */
186 {
187  if ((a+0x8000U) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
188  else return a;
189 }
190 
191 /**
192  * Clip a signed 64-bit integer value into the -2147483648,2147483647 range.
193  * @param a value to clip
194  * @return clipped value
195  */
197 {
198  if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (int32_t)((a>>63) ^ 0x7FFFFFFF);
199  else return (int32_t)a;
200 }
201 
202 /**
203  * Clip a signed integer into the -(2^p),(2^p-1) range.
204  * @param a value to clip
205  * @param p bit position to clip at
206  * @return clipped value
207  */
209 {
210  if ((a + (1 << p)) & ~((2 << p) - 1))
211  return (a >> 31) ^ ((1 << p) - 1);
212  else
213  return a;
214 }
215 
216 /**
217  * Clip a signed integer to an unsigned power of two range.
218  * @param a value to clip
219  * @param p bit position to clip at
220  * @return clipped value
221  */
222 static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
223 {
224  if (a & ~((1<<p) - 1)) return -a >> 31 & ((1<<p) - 1);
225  else return a;
226 }
227 
228 /**
229  * Clear high bits from an unsigned integer starting with specific bit position
230  * @param a value to clip
231  * @param p bit position to clip at
232  * @return clipped value
233  */
234 static av_always_inline av_const unsigned av_mod_uintp2_c(unsigned a, unsigned p)
235 {
236  return a & ((1 << p) - 1);
237 }
238 
239 /**
240  * Add two signed 32-bit values with saturation.
241  *
242  * @param a one value
243  * @param b another value
244  * @return sum with signed saturation
245  */
246 static av_always_inline int av_sat_add32_c(int a, int b)
247 {
248  return av_clipl_int32((int64_t)a + b);
249 }
250 
251 /**
252  * Add a doubled value to another value with saturation at both stages.
253  *
254  * @param a first value
255  * @param b value doubled and added to a
256  * @return sum with signed saturation
257  */
258 static av_always_inline int av_sat_dadd32_c(int a, int b)
259 {
260  return av_sat_add32(a, av_sat_add32(b, b));
261 }
262 
263 /**
264  * Clip a float value into the amin-amax range.
265  * @param a value to clip
266  * @param amin minimum value of the clip range
267  * @param amax maximum value of the clip range
268  * @return clipped value
269  */
270 static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
271 {
272 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
273  if (amin > amax) abort();
274 #endif
275  if (a < amin) return amin;
276  else if (a > amax) return amax;
277  else return a;
278 }
279 
280 /**
281  * Clip a double value into the amin-amax range.
282  * @param a value to clip
283  * @param amin minimum value of the clip range
284  * @param amax maximum value of the clip range
285  * @return clipped value
286  */
287 static av_always_inline av_const double av_clipd_c(double a, double amin, double amax)
288 {
289 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
290  if (amin > amax) abort();
291 #endif
292  if (a < amin) return amin;
293  else if (a > amax) return amax;
294  else return a;
295 }
296 
297 /** Compute ceil(log2(x)).
298  * @param x value used to compute ceil(log2(x))
299  * @return computed ceiling of log2(x)
300  */
302 {
303  return av_log2((x - 1) << 1);
304 }
305 
306 /**
307  * Count number of bits set to one in x
308  * @param x value to count bits of
309  * @return the number of bits set to one in x
310  */
312 {
313  x -= (x >> 1) & 0x55555555;
314  x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
315  x = (x + (x >> 4)) & 0x0F0F0F0F;
316  x += x >> 8;
317  return (x + (x >> 16)) & 0x3F;
318 }
319 
320 /**
321  * Count number of bits set to one in x
322  * @param x value to count bits of
323  * @return the number of bits set to one in x
324  */
326 {
327  return av_popcount((uint32_t)x) + av_popcount((uint32_t)(x >> 32));
328 }
329 
330 #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
331 #define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))
332 
333 /**
334  * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
335  *
336  * @param val Output value, must be an lvalue of type uint32_t.
337  * @param GET_BYTE Expression reading one byte from the input.
338  * Evaluated up to 7 times (4 for the currently
339  * assigned Unicode range). With a memory buffer
340  * input, this could be *ptr++.
341  * @param ERROR Expression to be evaluated on invalid input,
342  * typically a goto statement.
343  *
344  * @warning ERROR should not contain a loop control statement which
345  * could interact with the internal while loop, and should force an
346  * exit from the macro code (e.g. through a goto or a return) in order
347  * to prevent undefined results.
348  */
349 #define GET_UTF8(val, GET_BYTE, ERROR)\
350  val= GET_BYTE;\
351  {\
352  uint32_t top = (val & 128) >> 1;\
353  if ((val & 0xc0) == 0x80 || val >= 0xFE)\
354  ERROR\
355  while (val & top) {\
356  int tmp= GET_BYTE - 128;\
357  if(tmp>>6)\
358  ERROR\
359  val= (val<<6) + tmp;\
360  top <<= 5;\
361  }\
362  val &= (top << 1) - 1;\
363  }
364 
365 /**
366  * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
367  *
368  * @param val Output value, must be an lvalue of type uint32_t.
369  * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
370  * to native byte order. Evaluated one or two times.
371  * @param ERROR Expression to be evaluated on invalid input,
372  * typically a goto statement.
373  */
374 #define GET_UTF16(val, GET_16BIT, ERROR)\
375  val = GET_16BIT;\
376  {\
377  unsigned int hi = val - 0xD800;\
378  if (hi < 0x800) {\
379  val = GET_16BIT - 0xDC00;\
380  if (val > 0x3FFU || hi > 0x3FFU)\
381  ERROR\
382  val += (hi<<10) + 0x10000;\
383  }\
384  }\
385 
386 /**
387  * @def PUT_UTF8(val, tmp, PUT_BYTE)
388  * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
389  * @param val is an input-only argument and should be of type uint32_t. It holds
390  * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
391  * val is given as a function it is executed only once.
392  * @param tmp is a temporary variable and should be of type uint8_t. It
393  * represents an intermediate value during conversion that is to be
394  * output by PUT_BYTE.
395  * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
396  * It could be a function or a statement, and uses tmp as the input byte.
397  * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
398  * executed up to 4 times for values in the valid UTF-8 range and up to
399  * 7 times in the general case, depending on the length of the converted
400  * Unicode character.
401  */
402 #define PUT_UTF8(val, tmp, PUT_BYTE)\
403  {\
404  int bytes, shift;\
405  uint32_t in = val;\
406  if (in < 0x80) {\
407  tmp = in;\
408  PUT_BYTE\
409  } else {\
410  bytes = (av_log2(in) + 4) / 5;\
411  shift = (bytes - 1) * 6;\
412  tmp = (256 - (256 >> bytes)) | (in >> shift);\
413  PUT_BYTE\
414  while (shift >= 6) {\
415  shift -= 6;\
416  tmp = 0x80 | ((in >> shift) & 0x3f);\
417  PUT_BYTE\
418  }\
419  }\
420  }
421 
422 /**
423  * @def PUT_UTF16(val, tmp, PUT_16BIT)
424  * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
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-16. 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 uint16_t. It
429  * represents an intermediate value during conversion that is to be
430  * output by PUT_16BIT.
431  * @param PUT_16BIT writes the converted UTF-16 data to any proper destination
432  * in desired endianness. It could be a function or a statement, and uses tmp
433  * as the input byte. For example, PUT_BYTE could be "*output++ = tmp;"
434  * PUT_BYTE will be executed 1 or 2 times depending on input character.
435  */
436 #define PUT_UTF16(val, tmp, PUT_16BIT)\
437  {\
438  uint32_t in = val;\
439  if (in < 0x10000) {\
440  tmp = in;\
441  PUT_16BIT\
442  } else {\
443  tmp = 0xD800 | ((in - 0x10000) >> 10);\
444  PUT_16BIT\
445  tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
446  PUT_16BIT\
447  }\
448  }\
449 
450 
451 
452 #include "mem.h"
453 
454 #ifdef HAVE_AV_CONFIG_H
455 # include "internal.h"
456 #endif /* HAVE_AV_CONFIG_H */
457 
458 #endif /* AVUTIL_COMMON_H */
459 
460 /*
461  * The following definitions are outside the multiple inclusion guard
462  * to ensure they are immediately available in intmath.h.
463  */
464 
465 #ifndef av_ceil_log2
466 # define av_ceil_log2 av_ceil_log2_c
467 #endif
468 #ifndef av_clip
469 # define av_clip av_clip_c
470 #endif
471 #ifndef av_clip64
472 # define av_clip64 av_clip64_c
473 #endif
474 #ifndef av_clip_uint8
475 # define av_clip_uint8 av_clip_uint8_c
476 #endif
477 #ifndef av_clip_int8
478 # define av_clip_int8 av_clip_int8_c
479 #endif
480 #ifndef av_clip_uint16
481 # define av_clip_uint16 av_clip_uint16_c
482 #endif
483 #ifndef av_clip_int16
484 # define av_clip_int16 av_clip_int16_c
485 #endif
486 #ifndef av_clipl_int32
487 # define av_clipl_int32 av_clipl_int32_c
488 #endif
489 #ifndef av_clip_intp2
490 # define av_clip_intp2 av_clip_intp2_c
491 #endif
492 #ifndef av_clip_uintp2
493 # define av_clip_uintp2 av_clip_uintp2_c
494 #endif
495 #ifndef av_mod_uintp2
496 # define av_mod_uintp2 av_mod_uintp2_c
497 #endif
498 #ifndef av_sat_add32
499 # define av_sat_add32 av_sat_add32_c
500 #endif
501 #ifndef av_sat_dadd32
502 # define av_sat_dadd32 av_sat_dadd32_c
503 #endif
504 #ifndef av_clipf
505 # define av_clipf av_clipf_c
506 #endif
507 #ifndef av_clipd
508 # define av_clipd av_clipd_c
509 #endif
510 #ifndef av_popcount
511 # define av_popcount av_popcount_c
512 #endif
513 #ifndef av_popcount64
514 # define av_popcount64 av_popcount64_c
515 #endif
#define av_const
Definition: attributes.h:68
float v
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:196
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:270
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:234
memory handling functions
const char * b
Definition: vf_curves.c:109
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:163
int av_log2_16bit(unsigned v)
Definition: intmath.c:31
Macro definitions for various function/variable attributes.
uint8_t
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:120
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:174
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:152
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:287
#define av_log2
Definition: intmath.h:100
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:208
attribute_deprecated const uint8_t av_reverse[256]
Reverse the order of the bits of an 8-bits unsigned integer.
Definition: mathematics.c:35
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:185
#define attribute_deprecated
Definition: attributes.h:86
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:311
static av_always_inline int av_sat_add32_c(int a, int b)
Add two signed 32-bit values with saturation.
Definition: common.h:246
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:325
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:258
#define av_always_inline
Definition: attributes.h:37
static av_always_inline av_const int av_ceil_log2_c(int x)
Compute ceil(log2(x)).
Definition: common.h:301
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:137
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:222