FFmpeg  2.8.7
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 /**
80  * Comparator.
81  * For two numerical expressions x and y, gives 1 if x > y, -1 if x < y, and 0
82  * if x == y. This is useful for instance in a qsort comparator callback.
83  * Furthermore, compilers are able to optimize this to branchless code, and
84  * there is no risk of overflow with signed types.
85  * As with many macros, this evaluates its argument multiple times, it thus
86  * must not have a side-effect.
87  */
88 #define FFDIFFSIGN(x,y) (((x)>(y)) - ((x)<(y)))
89 
90 #define FFMAX(a,b) ((a) > (b) ? (a) : (b))
91 #define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
92 #define FFMIN(a,b) ((a) > (b) ? (b) : (a))
93 #define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)
94 
95 #define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
96 #define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
97 #define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1))
98 
99 /* misc math functions */
100 
101 /**
102  * Reverse the order of the bits of an 8-bits unsigned integer.
103  */
104 #if FF_API_AV_REVERSE
105 extern attribute_deprecated const uint8_t av_reverse[256];
106 #endif
107 
108 #ifdef HAVE_AV_CONFIG_H
109 # include "config.h"
110 # include "intmath.h"
111 #endif
112 
113 /* Pull in unguarded fallback defines at the end of this file. */
114 #include "common.h"
115 
116 #ifndef av_log2
117 av_const int av_log2(unsigned v);
118 #endif
119 
120 #ifndef av_log2_16bit
121 av_const int av_log2_16bit(unsigned v);
122 #endif
123 
124 /**
125  * Clip a signed integer value into the amin-amax range.
126  * @param a value to clip
127  * @param amin minimum value of the clip range
128  * @param amax maximum value of the clip range
129  * @return clipped value
130  */
131 static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
132 {
133 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
134  if (amin > amax) abort();
135 #endif
136  if (a < amin) return amin;
137  else if (a > amax) return amax;
138  else return a;
139 }
140 
141 /**
142  * Clip a signed 64bit integer value into the amin-amax range.
143  * @param a value to clip
144  * @param amin minimum value of the clip range
145  * @param amax maximum value of the clip range
146  * @return clipped value
147  */
148 static av_always_inline av_const int64_t av_clip64_c(int64_t a, int64_t amin, int64_t amax)
149 {
150 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
151  if (amin > amax) abort();
152 #endif
153  if (a < amin) return amin;
154  else if (a > amax) return amax;
155  else return a;
156 }
157 
158 /**
159  * Clip a signed integer value into the 0-255 range.
160  * @param a value to clip
161  * @return clipped value
162  */
164 {
165  if (a&(~0xFF)) return (-a)>>31;
166  else return a;
167 }
168 
169 /**
170  * Clip a signed integer value into the -128,127 range.
171  * @param a value to clip
172  * @return clipped value
173  */
175 {
176  if ((a+0x80U) & ~0xFF) return (a>>31) ^ 0x7F;
177  else return a;
178 }
179 
180 /**
181  * Clip a signed integer value into the 0-65535 range.
182  * @param a value to clip
183  * @return clipped value
184  */
186 {
187  if (a&(~0xFFFF)) return (-a)>>31;
188  else return a;
189 }
190 
191 /**
192  * Clip a signed integer value into the -32768,32767 range.
193  * @param a value to clip
194  * @return clipped value
195  */
197 {
198  if ((a+0x8000U) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
199  else return a;
200 }
201 
202 /**
203  * Clip a signed 64-bit integer value into the -2147483648,2147483647 range.
204  * @param a value to clip
205  * @return clipped value
206  */
207 static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
208 {
209  if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (int32_t)((a>>63) ^ 0x7FFFFFFF);
210  else return (int32_t)a;
211 }
212 
213 /**
214  * Clip a signed integer into the -(2^p),(2^p-1) range.
215  * @param a value to clip
216  * @param p bit position to clip at
217  * @return clipped value
218  */
219 static av_always_inline av_const int av_clip_intp2_c(int a, int p)
220 {
221  if ((a + (1 << p)) & ~((2 << p) - 1))
222  return (a >> 31) ^ ((1 << p) - 1);
223  else
224  return a;
225 }
226 
227 /**
228  * Clip a signed integer to an unsigned power of two range.
229  * @param a value to clip
230  * @param p bit position to clip at
231  * @return clipped value
232  */
233 static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
234 {
235  if (a & ~((1<<p) - 1)) return -a >> 31 & ((1<<p) - 1);
236  else return a;
237 }
238 
239 /**
240  * Clear high bits from an unsigned integer starting with specific bit position
241  * @param a value to clip
242  * @param p bit position to clip at
243  * @return clipped value
244  */
245 static av_always_inline av_const unsigned av_mod_uintp2_c(unsigned a, unsigned p)
246 {
247  return a & ((1 << p) - 1);
248 }
249 
250 /**
251  * Add two signed 32-bit values with saturation.
252  *
253  * @param a one value
254  * @param b another value
255  * @return sum with signed saturation
256  */
257 static av_always_inline int av_sat_add32_c(int a, int b)
258 {
259  return av_clipl_int32((int64_t)a + b);
260 }
261 
262 /**
263  * Add a doubled value to another value with saturation at both stages.
264  *
265  * @param a first value
266  * @param b value doubled and added to a
267  * @return sum with signed saturation
268  */
269 static av_always_inline int av_sat_dadd32_c(int a, int b)
270 {
271  return av_sat_add32(a, av_sat_add32(b, b));
272 }
273 
274 /**
275  * Clip a float value into the amin-amax range.
276  * @param a value to clip
277  * @param amin minimum value of the clip range
278  * @param amax maximum value of the clip range
279  * @return clipped value
280  */
281 static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
282 {
283 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
284  if (amin > amax) abort();
285 #endif
286  if (a < amin) return amin;
287  else if (a > amax) return amax;
288  else return a;
289 }
290 
291 /**
292  * Clip a double value into the amin-amax range.
293  * @param a value to clip
294  * @param amin minimum value of the clip range
295  * @param amax maximum value of the clip range
296  * @return clipped value
297  */
298 static av_always_inline av_const double av_clipd_c(double a, double amin, double amax)
299 {
300 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
301  if (amin > amax) abort();
302 #endif
303  if (a < amin) return amin;
304  else if (a > amax) return amax;
305  else return a;
306 }
307 
308 /** Compute ceil(log2(x)).
309  * @param x value used to compute ceil(log2(x))
310  * @return computed ceiling of log2(x)
311  */
313 {
314  return av_log2((x - 1) << 1);
315 }
316 
317 /**
318  * Count number of bits set to one in x
319  * @param x value to count bits of
320  * @return the number of bits set to one in x
321  */
323 {
324  x -= (x >> 1) & 0x55555555;
325  x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
326  x = (x + (x >> 4)) & 0x0F0F0F0F;
327  x += x >> 8;
328  return (x + (x >> 16)) & 0x3F;
329 }
330 
331 /**
332  * Count number of bits set to one in x
333  * @param x value to count bits of
334  * @return the number of bits set to one in x
335  */
337 {
338  return av_popcount((uint32_t)x) + av_popcount((uint32_t)(x >> 32));
339 }
340 
341 #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
342 #define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))
343 
344 /**
345  * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
346  *
347  * @param val Output value, must be an lvalue of type uint32_t.
348  * @param GET_BYTE Expression reading one byte from the input.
349  * Evaluated up to 7 times (4 for the currently
350  * assigned Unicode range). With a memory buffer
351  * input, this could be *ptr++.
352  * @param ERROR Expression to be evaluated on invalid input,
353  * typically a goto statement.
354  *
355  * @warning ERROR should not contain a loop control statement which
356  * could interact with the internal while loop, and should force an
357  * exit from the macro code (e.g. through a goto or a return) in order
358  * to prevent undefined results.
359  */
360 #define GET_UTF8(val, GET_BYTE, ERROR)\
361  val= GET_BYTE;\
362  {\
363  uint32_t top = (val & 128) >> 1;\
364  if ((val & 0xc0) == 0x80 || val >= 0xFE)\
365  ERROR\
366  while (val & top) {\
367  int tmp= GET_BYTE - 128;\
368  if(tmp>>6)\
369  ERROR\
370  val= (val<<6) + tmp;\
371  top <<= 5;\
372  }\
373  val &= (top << 1) - 1;\
374  }
375 
376 /**
377  * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
378  *
379  * @param val Output value, must be an lvalue of type uint32_t.
380  * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
381  * to native byte order. Evaluated one or two times.
382  * @param ERROR Expression to be evaluated on invalid input,
383  * typically a goto statement.
384  */
385 #define GET_UTF16(val, GET_16BIT, ERROR)\
386  val = GET_16BIT;\
387  {\
388  unsigned int hi = val - 0xD800;\
389  if (hi < 0x800) {\
390  val = GET_16BIT - 0xDC00;\
391  if (val > 0x3FFU || hi > 0x3FFU)\
392  ERROR\
393  val += (hi<<10) + 0x10000;\
394  }\
395  }\
396 
397 /**
398  * @def PUT_UTF8(val, tmp, PUT_BYTE)
399  * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
400  * @param val is an input-only argument and should be of type uint32_t. It holds
401  * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
402  * val is given as a function it is executed only once.
403  * @param tmp is a temporary variable and should be of type uint8_t. It
404  * represents an intermediate value during conversion that is to be
405  * output by PUT_BYTE.
406  * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
407  * It could be a function or a statement, and uses tmp as the input byte.
408  * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
409  * executed up to 4 times for values in the valid UTF-8 range and up to
410  * 7 times in the general case, depending on the length of the converted
411  * Unicode character.
412  */
413 #define PUT_UTF8(val, tmp, PUT_BYTE)\
414  {\
415  int bytes, shift;\
416  uint32_t in = val;\
417  if (in < 0x80) {\
418  tmp = in;\
419  PUT_BYTE\
420  } else {\
421  bytes = (av_log2(in) + 4) / 5;\
422  shift = (bytes - 1) * 6;\
423  tmp = (256 - (256 >> bytes)) | (in >> shift);\
424  PUT_BYTE\
425  while (shift >= 6) {\
426  shift -= 6;\
427  tmp = 0x80 | ((in >> shift) & 0x3f);\
428  PUT_BYTE\
429  }\
430  }\
431  }
432 
433 /**
434  * @def PUT_UTF16(val, tmp, PUT_16BIT)
435  * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
436  * @param val is an input-only argument and should be of type uint32_t. It holds
437  * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
438  * val is given as a function it is executed only once.
439  * @param tmp is a temporary variable and should be of type uint16_t. It
440  * represents an intermediate value during conversion that is to be
441  * output by PUT_16BIT.
442  * @param PUT_16BIT writes the converted UTF-16 data to any proper destination
443  * in desired endianness. It could be a function or a statement, and uses tmp
444  * as the input byte. For example, PUT_BYTE could be "*output++ = tmp;"
445  * PUT_BYTE will be executed 1 or 2 times depending on input character.
446  */
447 #define PUT_UTF16(val, tmp, PUT_16BIT)\
448  {\
449  uint32_t in = val;\
450  if (in < 0x10000) {\
451  tmp = in;\
452  PUT_16BIT\
453  } else {\
454  tmp = 0xD800 | ((in - 0x10000) >> 10);\
455  PUT_16BIT\
456  tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
457  PUT_16BIT\
458  }\
459  }\
460 
461 
462 
463 #include "mem.h"
464 
465 #ifdef HAVE_AV_CONFIG_H
466 # include "internal.h"
467 #endif /* HAVE_AV_CONFIG_H */
468 
469 #endif /* AVUTIL_COMMON_H */
470 
471 /*
472  * The following definitions are outside the multiple inclusion guard
473  * to ensure they are immediately available in intmath.h.
474  */
475 
476 #ifndef av_ceil_log2
477 # define av_ceil_log2 av_ceil_log2_c
478 #endif
479 #ifndef av_clip
480 # define av_clip av_clip_c
481 #endif
482 #ifndef av_clip64
483 # define av_clip64 av_clip64_c
484 #endif
485 #ifndef av_clip_uint8
486 # define av_clip_uint8 av_clip_uint8_c
487 #endif
488 #ifndef av_clip_int8
489 # define av_clip_int8 av_clip_int8_c
490 #endif
491 #ifndef av_clip_uint16
492 # define av_clip_uint16 av_clip_uint16_c
493 #endif
494 #ifndef av_clip_int16
495 # define av_clip_int16 av_clip_int16_c
496 #endif
497 #ifndef av_clipl_int32
498 # define av_clipl_int32 av_clipl_int32_c
499 #endif
500 #ifndef av_clip_intp2
501 # define av_clip_intp2 av_clip_intp2_c
502 #endif
503 #ifndef av_clip_uintp2
504 # define av_clip_uintp2 av_clip_uintp2_c
505 #endif
506 #ifndef av_mod_uintp2
507 # define av_mod_uintp2 av_mod_uintp2_c
508 #endif
509 #ifndef av_sat_add32
510 # define av_sat_add32 av_sat_add32_c
511 #endif
512 #ifndef av_sat_dadd32
513 # define av_sat_dadd32 av_sat_dadd32_c
514 #endif
515 #ifndef av_clipf
516 # define av_clipf av_clipf_c
517 #endif
518 #ifndef av_clipd
519 # define av_clipd av_clipd_c
520 #endif
521 #ifndef av_popcount
522 # define av_popcount av_popcount_c
523 #endif
524 #ifndef av_popcount64
525 # define av_popcount64 av_popcount64_c
526 #endif
#define av_const
Definition: attributes.h:68
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:207
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:281
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:245
memory handling functions
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:174
av_const int av_log2_16bit(unsigned v)
Macro definitions for various function/variable attributes.
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:131
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:185
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:163
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:298
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:219
av_const int av_log2(unsigned v)
attribute_deprecated const uint8_t av_reverse[256]
Reverse the order of the bits of an 8-bits unsigned integer.
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:196
#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:322
static av_always_inline int av_sat_add32_c(int a, int b)
Add two signed 32-bit values with saturation.
Definition: common.h:257
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:336
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:269
#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:312
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:148
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:233