FFmpeg 4.2.2
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
113av_const int av_log2(unsigned v);
114#endif
115
116#ifndef av_log2_16bit
117av_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 */
127static 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 */
144static 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 */
229static 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 */
241static 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 */
253static 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 sat(a + sat(2*b)) with signed saturation
264 */
265static 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 * Subtract two signed 32-bit values with saturation.
272 *
273 * @param a one value
274 * @param b another value
275 * @return difference with signed saturation
276 */
277static av_always_inline int av_sat_sub32_c(int a, int b)
278{
279 return av_clipl_int32((int64_t)a - b);
280}
281
282/**
283 * Subtract a doubled value from another value with saturation at both stages.
284 *
285 * @param a first value
286 * @param b value doubled and subtracted from a
287 * @return difference sat(a - sat(2*b)) with signed saturation
288 */
289static av_always_inline int av_sat_dsub32_c(int a, int b)
290{
291 return av_sat_sub32(a, av_sat_add32(b, b));
292}
293
294/**
295 * Clip a float value into the amin-amax range.
296 * @param a value to clip
297 * @param amin minimum value of the clip range
298 * @param amax maximum value of the clip range
299 * @return clipped value
300 */
301static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
302{
303#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
304 if (amin > amax) abort();
305#endif
306 if (a < amin) return amin;
307 else if (a > amax) return amax;
308 else return a;
309}
310
311/**
312 * Clip a double value into the amin-amax range.
313 * @param a value to clip
314 * @param amin minimum value of the clip range
315 * @param amax maximum value of the clip range
316 * @return clipped value
317 */
318static av_always_inline av_const double av_clipd_c(double a, double amin, double amax)
319{
320#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
321 if (amin > amax) abort();
322#endif
323 if (a < amin) return amin;
324 else if (a > amax) return amax;
325 else return a;
326}
327
328/** Compute ceil(log2(x)).
329 * @param x value used to compute ceil(log2(x))
330 * @return computed ceiling of log2(x)
331 */
333{
334 return av_log2((x - 1) << 1);
335}
336
337/**
338 * Count number of bits set to one in x
339 * @param x value to count bits of
340 * @return the number of bits set to one in x
341 */
343{
344 x -= (x >> 1) & 0x55555555;
345 x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
346 x = (x + (x >> 4)) & 0x0F0F0F0F;
347 x += x >> 8;
348 return (x + (x >> 16)) & 0x3F;
349}
350
351/**
352 * Count number of bits set to one in x
353 * @param x value to count bits of
354 * @return the number of bits set to one in x
355 */
357{
358 return av_popcount((uint32_t)x) + av_popcount((uint32_t)(x >> 32));
359}
360
362{
363 return av_popcount(v) & 1;
364}
365
366#define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
367#define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))
368
369/**
370 * Convert a UTF-8 character (up to 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_BYTE Expression reading one byte from the input.
374 * Evaluated up to 7 times (4 for the currently
375 * assigned Unicode range). With a memory buffer
376 * input, this could be *ptr++.
377 * @param ERROR Expression to be evaluated on invalid input,
378 * typically a goto statement.
379 *
380 * @warning ERROR should not contain a loop control statement which
381 * could interact with the internal while loop, and should force an
382 * exit from the macro code (e.g. through a goto or a return) in order
383 * to prevent undefined results.
384 */
385#define GET_UTF8(val, GET_BYTE, ERROR)\
386 val= (GET_BYTE);\
387 {\
388 uint32_t top = (val & 128) >> 1;\
389 if ((val & 0xc0) == 0x80 || val >= 0xFE)\
390 ERROR\
391 while (val & top) {\
392 int tmp= (GET_BYTE) - 128;\
393 if(tmp>>6)\
394 ERROR\
395 val= (val<<6) + tmp;\
396 top <<= 5;\
397 }\
398 val &= (top << 1) - 1;\
399 }
400
401/**
402 * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
403 *
404 * @param val Output value, must be an lvalue of type uint32_t.
405 * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
406 * to native byte order. Evaluated one or two times.
407 * @param ERROR Expression to be evaluated on invalid input,
408 * typically a goto statement.
409 */
410#define GET_UTF16(val, GET_16BIT, ERROR)\
411 val = GET_16BIT;\
412 {\
413 unsigned int hi = val - 0xD800;\
414 if (hi < 0x800) {\
415 val = GET_16BIT - 0xDC00;\
416 if (val > 0x3FFU || hi > 0x3FFU)\
417 ERROR\
418 val += (hi<<10) + 0x10000;\
419 }\
420 }\
421
422/**
423 * @def PUT_UTF8(val, tmp, PUT_BYTE)
424 * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
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-8. 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 uint8_t. It
429 * represents an intermediate value during conversion that is to be
430 * output by PUT_BYTE.
431 * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
432 * It could be a function or a statement, and uses tmp as the input byte.
433 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
434 * executed up to 4 times for values in the valid UTF-8 range and up to
435 * 7 times in the general case, depending on the length of the converted
436 * Unicode character.
437 */
438#define PUT_UTF8(val, tmp, PUT_BYTE)\
439 {\
440 int bytes, shift;\
441 uint32_t in = val;\
442 if (in < 0x80) {\
443 tmp = in;\
444 PUT_BYTE\
445 } else {\
446 bytes = (av_log2(in) + 4) / 5;\
447 shift = (bytes - 1) * 6;\
448 tmp = (256 - (256 >> bytes)) | (in >> shift);\
449 PUT_BYTE\
450 while (shift >= 6) {\
451 shift -= 6;\
452 tmp = 0x80 | ((in >> shift) & 0x3f);\
453 PUT_BYTE\
454 }\
455 }\
456 }
457
458/**
459 * @def PUT_UTF16(val, tmp, PUT_16BIT)
460 * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
461 * @param val is an input-only argument and should be of type uint32_t. It holds
462 * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
463 * val is given as a function it is executed only once.
464 * @param tmp is a temporary variable and should be of type uint16_t. It
465 * represents an intermediate value during conversion that is to be
466 * output by PUT_16BIT.
467 * @param PUT_16BIT writes the converted UTF-16 data to any proper destination
468 * in desired endianness. It could be a function or a statement, and uses tmp
469 * as the input byte. For example, PUT_BYTE could be "*output++ = tmp;"
470 * PUT_BYTE will be executed 1 or 2 times depending on input character.
471 */
472#define PUT_UTF16(val, tmp, PUT_16BIT)\
473 {\
474 uint32_t in = val;\
475 if (in < 0x10000) {\
476 tmp = in;\
477 PUT_16BIT\
478 } else {\
479 tmp = 0xD800 | ((in - 0x10000) >> 10);\
480 PUT_16BIT\
481 tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
482 PUT_16BIT\
483 }\
484 }\
485
486
487
488#include "mem.h"
489
490#ifdef HAVE_AV_CONFIG_H
491# include "internal.h"
492#endif /* HAVE_AV_CONFIG_H */
493
494#endif /* AVUTIL_COMMON_H */
495
496/*
497 * The following definitions are outside the multiple inclusion guard
498 * to ensure they are immediately available in intmath.h.
499 */
500
501#ifndef av_ceil_log2
502# define av_ceil_log2 av_ceil_log2_c
503#endif
504#ifndef av_clip
505# define av_clip av_clip_c
506#endif
507#ifndef av_clip64
508# define av_clip64 av_clip64_c
509#endif
510#ifndef av_clip_uint8
511# define av_clip_uint8 av_clip_uint8_c
512#endif
513#ifndef av_clip_int8
514# define av_clip_int8 av_clip_int8_c
515#endif
516#ifndef av_clip_uint16
517# define av_clip_uint16 av_clip_uint16_c
518#endif
519#ifndef av_clip_int16
520# define av_clip_int16 av_clip_int16_c
521#endif
522#ifndef av_clipl_int32
523# define av_clipl_int32 av_clipl_int32_c
524#endif
525#ifndef av_clip_intp2
526# define av_clip_intp2 av_clip_intp2_c
527#endif
528#ifndef av_clip_uintp2
529# define av_clip_uintp2 av_clip_uintp2_c
530#endif
531#ifndef av_mod_uintp2
532# define av_mod_uintp2 av_mod_uintp2_c
533#endif
534#ifndef av_sat_add32
535# define av_sat_add32 av_sat_add32_c
536#endif
537#ifndef av_sat_dadd32
538# define av_sat_dadd32 av_sat_dadd32_c
539#endif
540#ifndef av_sat_sub32
541# define av_sat_sub32 av_sat_sub32_c
542#endif
543#ifndef av_sat_dsub32
544# define av_sat_dsub32 av_sat_dsub32_c
545#endif
546#ifndef av_clipf
547# define av_clipf av_clipf_c
548#endif
549#ifndef av_clipd
550# define av_clipd av_clipd_c
551#endif
552#ifndef av_popcount
553# define av_popcount av_popcount_c
554#endif
555#ifndef av_popcount64
556# define av_popcount64 av_popcount64_c
557#endif
558#ifndef av_parity
559# define av_parity av_parity_c
560#endif
Macro definitions for various function/variable attributes.
#define av_always_inline
Definition: attributes.h:39
#define av_const
Definition: attributes.h:76
common internal and external API header
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:356
av_const int av_log2(unsigned v)
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 int8_t av_clip_int8_c(int a)
Clip a signed integer value into the -128,127 range.
Definition: common.h:170
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
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
static av_always_inline int av_sat_dsub32_c(int a, int b)
Subtract a doubled value from another value with saturation at both stages.
Definition: common.h:289
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 int av_popcount_c(uint32_t x)
Count number of bits set to one in x.
Definition: common.h:342
static av_always_inline int av_sat_sub32_c(int a, int b)
Subtract two signed 32-bit values with saturation.
Definition: common.h:277
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:301
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
av_const int av_log2_16bit(unsigned v)
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
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:318
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 int16_t av_clip_int16_c(int a)
Clip a signed integer value into the -32768,32767 range.
Definition: common.h:192
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 int av_ceil_log2_c(int x)
Compute ceil(log2(x)).
Definition: common.h:332
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 int av_parity_c(uint32_t v)
Definition: common.h:361
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
swscale version macros
Utility Preprocessor macros.
Memory handling functions.