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