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 /* assume a>0 and b>0 */
58 #define FF_CEIL_RSHIFT(a,b) (!av_builtin_constant_p(b) ? -((-(a)) >> (b)) \
59 : ((a) + (1<<(b)) - 1) >> (b))
60 #define FFUDIV(a,b) (((a)>0 ?(a):(a)-(b)+1) / (b))
61 #define FFUMOD(a,b) ((a)-(b)*FFUDIV(a,b))
62
63 /**
64 * Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they
65 * are not representable as absolute values of their type. This is the same
66 * as with *abs()
67 * @see FFNABS()
68 */
69 #define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
70 #define FFSIGN(a) ((a) > 0 ? 1 : -1)
71
72 /**
73 * Negative Absolute value.
74 * this works for all integers of all types.
75 * As with many macros, this evaluates its argument twice, it thus must not have
76 * a sideeffect, that is FFNABS(x++) has undefined behavior.
77 */
78 #define FFNABS(a) ((a) <= 0 ? (a) : (-(a)))
79
80 /**
81 * Comparator.
82 * For two numerical expressions x and y, gives 1 if x > y, -1 if x < y, and 0
83 * if x == y. This is useful for instance in a qsort comparator callback.
84 * Furthermore, compilers are able to optimize this to branchless code, and
85 * there is no risk of overflow with signed types.
86 * As with many macros, this evaluates its argument multiple times, it thus
87 * must not have a side-effect.
88 */
89 #define FFDIFFSIGN(x,y) (((x)>(y)) - ((x)<(y)))
90
91 #define FFMAX(a,b) ((a) > (b) ? (a) : (b))
92 #define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
93 #define FFMIN(a,b) ((a) > (b) ? (b) : (a))
94 #define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)
95
96 #define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
97 #define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
98
99 /* misc math functions */
100
101 #ifdef HAVE_AV_CONFIG_H
102 # include "config.h"
103 # include "intmath.h"
104 #endif
105
106 /* Pull in unguarded fallback defines at the end of this file. */
107 #include "common.h"
108
109 #ifndef av_log2
110 av_const int av_log2(unsigned v);
111 #endif
112
113 #ifndef av_log2_16bit
114 av_const int av_log2_16bit(unsigned v);
115 #endif
116
117 /**
118 * Clip a signed integer value into the amin-amax range.
119 * @param a value to clip
120 * @param amin minimum value of the clip range
121 * @param amax maximum value of the clip range
122 * @return clipped value
123 */
av_clip_c(int a,int amin,int amax)124 static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
125 {
126 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
127 if (amin > amax) abort();
128 #endif
129 if (a < amin) return amin;
130 else if (a > amax) return amax;
131 else return a;
132 }
133
134 /**
135 * Clip a signed 64bit integer value into the amin-amax range.
136 * @param a value to clip
137 * @param amin minimum value of the clip range
138 * @param amax maximum value of the clip range
139 * @return clipped value
140 */
av_clip64_c(int64_t a,int64_t amin,int64_t amax)141 static av_always_inline av_const int64_t av_clip64_c(int64_t a, int64_t amin, int64_t amax)
142 {
143 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
144 if (amin > amax) abort();
145 #endif
146 if (a < amin) return amin;
147 else if (a > amax) return amax;
148 else return a;
149 }
150
151 /**
152 * Clip a signed integer value into the 0-255 range.
153 * @param a value to clip
154 * @return clipped value
155 */
av_clip_uint8_c(int a)156 static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
157 {
158 if (a&(~0xFF)) return (-a)>>31;
159 else return a;
160 }
161
162 /**
163 * Clip a signed integer value into the -128,127 range.
164 * @param a value to clip
165 * @return clipped value
166 */
av_clip_int8_c(int a)167 static av_always_inline av_const int8_t av_clip_int8_c(int a)
168 {
169 if ((a+0x80U) & ~0xFF) return (a>>31) ^ 0x7F;
170 else return a;
171 }
172
173 /**
174 * Clip a signed integer value into the 0-65535 range.
175 * @param a value to clip
176 * @return clipped value
177 */
av_clip_uint16_c(int a)178 static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
179 {
180 if (a&(~0xFFFF)) return (-a)>>31;
181 else return a;
182 }
183
184 /**
185 * Clip a signed integer value into the -32768,32767 range.
186 * @param a value to clip
187 * @return clipped value
188 */
av_clip_int16_c(int a)189 static av_always_inline av_const int16_t av_clip_int16_c(int a)
190 {
191 if ((a+0x8000U) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
192 else return a;
193 }
194
195 /**
196 * Clip a signed 64-bit integer value into the -2147483648,2147483647 range.
197 * @param a value to clip
198 * @return clipped value
199 */
av_clipl_int32_c(int64_t a)200 static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
201 {
202 if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (int32_t)((a>>63) ^ 0x7FFFFFFF);
203 else return (int32_t)a;
204 }
205
206 /**
207 * Clip a signed integer into the -(2^p),(2^p-1) range.
208 * @param a value to clip
209 * @param p bit position to clip at
210 * @return clipped value
211 */
av_clip_intp2_c(int a,int p)212 static av_always_inline av_const int av_clip_intp2_c(int a, int p)
213 {
214 if ((a + (1 << p)) & ~((2 << p) - 1))
215 return (a >> 31) ^ ((1 << p) - 1);
216 else
217 return a;
218 }
219
220 /**
221 * Clip a signed integer to an unsigned power of two range.
222 * @param a value to clip
223 * @param p bit position to clip at
224 * @return clipped value
225 */
av_clip_uintp2_c(int a,int p)226 static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
227 {
228 if (a & ~((1<<p) - 1)) return -a >> 31 & ((1<<p) - 1);
229 else return a;
230 }
231
232 /**
233 * Clear high bits from an unsigned integer starting with specific bit position
234 * @param a value to clip
235 * @param p bit position to clip at
236 * @return clipped value
237 */
av_mod_uintp2_c(unsigned a,unsigned p)238 static av_always_inline av_const unsigned av_mod_uintp2_c(unsigned a, unsigned p)
239 {
240 return a & ((1 << p) - 1);
241 }
242
243 /**
244 * Add two signed 32-bit values with saturation.
245 *
246 * @param a one value
247 * @param b another value
248 * @return sum with signed saturation
249 */
av_sat_add32_c(int a,int b)250 static av_always_inline int av_sat_add32_c(int a, int b)
251 {
252 return av_clipl_int32((int64_t)a + b);
253 }
254
255 /**
256 * Add a doubled value to another value with saturation at both stages.
257 *
258 * @param a first value
259 * @param b value doubled and added to a
260 * @return sum with signed saturation
261 */
av_sat_dadd32_c(int a,int b)262 static av_always_inline int av_sat_dadd32_c(int a, int b)
263 {
264 return av_sat_add32(a, av_sat_add32(b, b));
265 }
266
267 /**
268 * Clip a float value into the amin-amax range.
269 * @param a value to clip
270 * @param amin minimum value of the clip range
271 * @param amax maximum value of the clip range
272 * @return clipped value
273 */
av_clipf_c(float a,float amin,float amax)274 static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
275 {
276 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
277 if (amin > amax) abort();
278 #endif
279 if (a < amin) return amin;
280 else if (a > amax) return amax;
281 else return a;
282 }
283
284 /**
285 * Clip a double value into the amin-amax range.
286 * @param a value to clip
287 * @param amin minimum value of the clip range
288 * @param amax maximum value of the clip range
289 * @return clipped value
290 */
av_clipd_c(double a,double amin,double amax)291 static av_always_inline av_const double av_clipd_c(double a, double amin, double amax)
292 {
293 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
294 if (amin > amax) abort();
295 #endif
296 if (a < amin) return amin;
297 else if (a > amax) return amax;
298 else return a;
299 }
300
301 /** Compute ceil(log2(x)).
302 * @param x value used to compute ceil(log2(x))
303 * @return computed ceiling of log2(x)
304 */
av_ceil_log2_c(int x)305 static av_always_inline av_const int av_ceil_log2_c(int x)
306 {
307 return av_log2((x - 1) << 1);
308 }
309
310 /**
311 * Count number of bits set to one in x
312 * @param x value to count bits of
313 * @return the number of bits set to one in x
314 */
av_popcount_c(uint32_t x)315 static av_always_inline av_const int av_popcount_c(uint32_t x)
316 {
317 x -= (x >> 1) & 0x55555555;
318 x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
319 x = (x + (x >> 4)) & 0x0F0F0F0F;
320 x += x >> 8;
321 return (x + (x >> 16)) & 0x3F;
322 }
323
324 /**
325 * Count number of bits set to one in x
326 * @param x value to count bits of
327 * @return the number of bits set to one in x
328 */
av_popcount64_c(uint64_t x)329 static av_always_inline av_const int av_popcount64_c(uint64_t x)
330 {
331 return av_popcount((uint32_t)x) + av_popcount((uint32_t)(x >> 32));
332 }
333
334 #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
335 #define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))
336
337 /**
338 * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
339 *
340 * @param val Output value, must be an lvalue of type uint32_t.
341 * @param GET_BYTE Expression reading one byte from the input.
342 * Evaluated up to 7 times (4 for the currently
343 * assigned Unicode range). With a memory buffer
344 * input, this could be *ptr++.
345 * @param ERROR Expression to be evaluated on invalid input,
346 * typically a goto statement.
347 *
348 * @warning ERROR should not contain a loop control statement which
349 * could interact with the internal while loop, and should force an
350 * exit from the macro code (e.g. through a goto or a return) in order
351 * to prevent undefined results.
352 */
353 #define GET_UTF8(val, GET_BYTE, ERROR)\
354 val= GET_BYTE;\
355 {\
356 uint32_t top = (val & 128) >> 1;\
357 if ((val & 0xc0) == 0x80 || val >= 0xFE)\
358 ERROR\
359 while (val & top) {\
360 int tmp= GET_BYTE - 128;\
361 if(tmp>>6)\
362 ERROR\
363 val= (val<<6) + tmp;\
364 top <<= 5;\
365 }\
366 val &= (top << 1) - 1;\
367 }
368
369 /**
370 * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
371 *
372 * @param val Output value, must be an lvalue of type uint32_t.
373 * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
374 * to native byte order. Evaluated one or two times.
375 * @param ERROR Expression to be evaluated on invalid input,
376 * typically a goto statement.
377 */
378 #define GET_UTF16(val, GET_16BIT, ERROR)\
379 val = GET_16BIT;\
380 {\
381 unsigned int hi = val - 0xD800;\
382 if (hi < 0x800) {\
383 val = GET_16BIT - 0xDC00;\
384 if (val > 0x3FFU || hi > 0x3FFU)\
385 ERROR\
386 val += (hi<<10) + 0x10000;\
387 }\
388 }\
389
390 /**
391 * @def PUT_UTF8(val, tmp, PUT_BYTE)
392 * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
393 * @param val is an input-only argument and should be of type uint32_t. It holds
394 * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
395 * val is given as a function it is executed only once.
396 * @param tmp is a temporary variable and should be of type uint8_t. It
397 * represents an intermediate value during conversion that is to be
398 * output by PUT_BYTE.
399 * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
400 * It could be a function or a statement, and uses tmp as the input byte.
401 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
402 * executed up to 4 times for values in the valid UTF-8 range and up to
403 * 7 times in the general case, depending on the length of the converted
404 * Unicode character.
405 */
406 #define PUT_UTF8(val, tmp, PUT_BYTE)\
407 {\
408 int bytes, shift;\
409 uint32_t in = val;\
410 if (in < 0x80) {\
411 tmp = in;\
412 PUT_BYTE\
413 } else {\
414 bytes = (av_log2(in) + 4) / 5;\
415 shift = (bytes - 1) * 6;\
416 tmp = (256 - (256 >> bytes)) | (in >> shift);\
417 PUT_BYTE\
418 while (shift >= 6) {\
419 shift -= 6;\
420 tmp = 0x80 | ((in >> shift) & 0x3f);\
421 PUT_BYTE\
422 }\
423 }\
424 }
425
426 /**
427 * @def PUT_UTF16(val, tmp, PUT_16BIT)
428 * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
429 * @param val is an input-only argument and should be of type uint32_t. It holds
430 * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
431 * val is given as a function it is executed only once.
432 * @param tmp is a temporary variable and should be of type uint16_t. It
433 * represents an intermediate value during conversion that is to be
434 * output by PUT_16BIT.
435 * @param PUT_16BIT writes the converted UTF-16 data to any proper destination
436 * in desired endianness. It could be a function or a statement, and uses tmp
437 * as the input byte. For example, PUT_BYTE could be "*output++ = tmp;"
438 * PUT_BYTE will be executed 1 or 2 times depending on input character.
439 */
440 #define PUT_UTF16(val, tmp, PUT_16BIT)\
441 {\
442 uint32_t in = val;\
443 if (in < 0x10000) {\
444 tmp = in;\
445 PUT_16BIT\
446 } else {\
447 tmp = 0xD800 | ((in - 0x10000) >> 10);\
448 PUT_16BIT\
449 tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
450 PUT_16BIT\
451 }\
452 }\
453
454
455
456 #include "mem.h"
457
458 #ifdef HAVE_AV_CONFIG_H
459 # include "internal.h"
460 #endif /* HAVE_AV_CONFIG_H */
461
462 #endif /* AVUTIL_COMMON_H */
463
464 /*
465 * The following definitions are outside the multiple inclusion guard
466 * to ensure they are immediately available in intmath.h.
467 */
468
469 #ifndef av_ceil_log2
470 # define av_ceil_log2 av_ceil_log2_c
471 #endif
472 #ifndef av_clip
473 # define av_clip av_clip_c
474 #endif
475 #ifndef av_clip64
476 # define av_clip64 av_clip64_c
477 #endif
478 #ifndef av_clip_uint8
479 # define av_clip_uint8 av_clip_uint8_c
480 #endif
481 #ifndef av_clip_int8
482 # define av_clip_int8 av_clip_int8_c
483 #endif
484 #ifndef av_clip_uint16
485 # define av_clip_uint16 av_clip_uint16_c
486 #endif
487 #ifndef av_clip_int16
488 # define av_clip_int16 av_clip_int16_c
489 #endif
490 #ifndef av_clipl_int32
491 # define av_clipl_int32 av_clipl_int32_c
492 #endif
493 #ifndef av_clip_intp2
494 # define av_clip_intp2 av_clip_intp2_c
495 #endif
496 #ifndef av_clip_uintp2
497 # define av_clip_uintp2 av_clip_uintp2_c
498 #endif
499 #ifndef av_mod_uintp2
500 # define av_mod_uintp2 av_mod_uintp2_c
501 #endif
502 #ifndef av_sat_add32
503 # define av_sat_add32 av_sat_add32_c
504 #endif
505 #ifndef av_sat_dadd32
506 # define av_sat_dadd32 av_sat_dadd32_c
507 #endif
508 #ifndef av_clipf
509 # define av_clipf av_clipf_c
510 #endif
511 #ifndef av_clipd
512 # define av_clipd av_clipd_c
513 #endif
514 #ifndef av_popcount
515 # define av_popcount av_popcount_c
516 #endif
517 #ifndef av_popcount64
518 # define av_popcount64 av_popcount64_c
519 #endif
520