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 * Unsigned Absolute value.
85 * This takes the absolute value of a signed int and returns it as a unsigned.
86 * This also works with INT_MIN which would otherwise not be representable
87 * As with many macros, this evaluates its argument twice.
88 */
89#define FFABSU(a) ((a) <= 0 ? -(unsigned)(a) : (unsigned)(a))
90#define FFABS64U(a) ((a) <= 0 ? -(uint64_t)(a) : (uint64_t)(a))
91
92/**
93 * Comparator.
94 * For two numerical expressions x and y, gives 1 if x > y, -1 if x < y, and 0
95 * if x == y. This is useful for instance in a qsort comparator callback.
96 * Furthermore, compilers are able to optimize this to branchless code, and
97 * there is no risk of overflow with signed types.
98 * As with many macros, this evaluates its argument multiple times, it thus
99 * must not have a side-effect.
100 */
101#define FFDIFFSIGN(x,y) (((x)>(y)) - ((x)<(y)))
102
103#define FFMAX(a,b) ((a) > (b) ? (a) : (b))
104#define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
105#define FFMIN(a,b) ((a) > (b) ? (b) : (a))
106#define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)
107
108#define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
109#define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
110
111/* misc math functions */
112
113#ifdef HAVE_AV_CONFIG_H
114# include "config.h"
115# include "intmath.h"
116#endif
117
118#ifndef av_ceil_log2
119# define av_ceil_log2 av_ceil_log2_c
120#endif
121#ifndef av_clip
122# define av_clip av_clip_c
123#endif
124#ifndef av_clip64
125# define av_clip64 av_clip64_c
126#endif
127#ifndef av_clip_uint8
128# define av_clip_uint8 av_clip_uint8_c
129#endif
130#ifndef av_clip_int8
131# define av_clip_int8 av_clip_int8_c
132#endif
133#ifndef av_clip_uint16
134# define av_clip_uint16 av_clip_uint16_c
135#endif
136#ifndef av_clip_int16
137# define av_clip_int16 av_clip_int16_c
138#endif
139#ifndef av_clipl_int32
140# define av_clipl_int32 av_clipl_int32_c
141#endif
142#ifndef av_clip_intp2
143# define av_clip_intp2 av_clip_intp2_c
144#endif
145#ifndef av_clip_uintp2
146# define av_clip_uintp2 av_clip_uintp2_c
147#endif
148#ifndef av_mod_uintp2
149# define av_mod_uintp2 av_mod_uintp2_c
150#endif
151#ifndef av_sat_add32
152# define av_sat_add32 av_sat_add32_c
153#endif
154#ifndef av_sat_dadd32
155# define av_sat_dadd32 av_sat_dadd32_c
156#endif
157#ifndef av_sat_sub32
158# define av_sat_sub32 av_sat_sub32_c
159#endif
160#ifndef av_sat_dsub32
161# define av_sat_dsub32 av_sat_dsub32_c
162#endif
163#ifndef av_sat_add64
164# define av_sat_add64 av_sat_add64_c
165#endif
166#ifndef av_sat_sub64
167# define av_sat_sub64 av_sat_sub64_c
168#endif
169#ifndef av_clipf
170# define av_clipf av_clipf_c
171#endif
172#ifndef av_clipd
173# define av_clipd av_clipd_c
174#endif
175#ifndef av_popcount
176# define av_popcount av_popcount_c
177#endif
178#ifndef av_popcount64
179# define av_popcount64 av_popcount64_c
180#endif
181#ifndef av_parity
182# define av_parity av_parity_c
183#endif
184
185#ifndef av_log2
186av_const int av_log2(unsigned v);
187#endif
188
189#ifndef av_log2_16bit
190av_const int av_log2_16bit(unsigned v);
191#endif
192
193/**
194 * Clip a signed integer value into the amin-amax range.
195 * @param a value to clip
196 * @param amin minimum value of the clip range
197 * @param amax maximum value of the clip range
198 * @return clipped value
199 */
200static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
201{
202#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
203 if (amin > amax) abort();
204#endif
205 if (a < amin) return amin;
206 else if (a > amax) return amax;
207 else return a;
208}
209
210/**
211 * Clip a signed 64bit integer value into the amin-amax range.
212 * @param a value to clip
213 * @param amin minimum value of the clip range
214 * @param amax maximum value of the clip range
215 * @return clipped value
216 */
217static av_always_inline av_const int64_t av_clip64_c(int64_t a, int64_t amin, int64_t amax)
218{
219#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
220 if (amin > amax) abort();
221#endif
222 if (a < amin) return amin;
223 else if (a > amax) return amax;
224 else return a;
225}
226
227/**
228 * Clip a signed integer value into the 0-255 range.
229 * @param a value to clip
230 * @return clipped value
231 */
232static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
233{
234 if (a&(~0xFF)) return (~a)>>31;
235 else return a;
236}
237
238/**
239 * Clip a signed integer value into the -128,127 range.
240 * @param a value to clip
241 * @return clipped value
242 */
243static av_always_inline av_const int8_t av_clip_int8_c(int a)
244{
245 if ((a+0x80U) & ~0xFF) return (a>>31) ^ 0x7F;
246 else return a;
247}
248
249/**
250 * Clip a signed integer value into the 0-65535 range.
251 * @param a value to clip
252 * @return clipped value
253 */
254static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
255{
256 if (a&(~0xFFFF)) return (~a)>>31;
257 else return a;
258}
259
260/**
261 * Clip a signed integer value into the -32768,32767 range.
262 * @param a value to clip
263 * @return clipped value
264 */
265static av_always_inline av_const int16_t av_clip_int16_c(int a)
266{
267 if ((a+0x8000U) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
268 else return a;
269}
270
271/**
272 * Clip a signed 64-bit integer value into the -2147483648,2147483647 range.
273 * @param a value to clip
274 * @return clipped value
275 */
276static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
277{
278 if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (int32_t)((a>>63) ^ 0x7FFFFFFF);
279 else return (int32_t)a;
280}
281
282/**
283 * Clip a signed integer into the -(2^p),(2^p-1) range.
284 * @param a value to clip
285 * @param p bit position to clip at
286 * @return clipped value
287 */
288static av_always_inline av_const int av_clip_intp2_c(int a, int p)
289{
290 if (((unsigned)a + (1 << p)) & ~((2 << p) - 1))
291 return (a >> 31) ^ ((1 << p) - 1);
292 else
293 return a;
294}
295
296/**
297 * Clip a signed integer to an unsigned power of two range.
298 * @param a value to clip
299 * @param p bit position to clip at
300 * @return clipped value
301 */
302static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
303{
304 if (a & ~((1<<p) - 1)) return (~a) >> 31 & ((1<<p) - 1);
305 else return a;
306}
307
308/**
309 * Clear high bits from an unsigned integer starting with specific bit position
310 * @param a value to clip
311 * @param p bit position to clip at
312 * @return clipped value
313 */
314static av_always_inline av_const unsigned av_mod_uintp2_c(unsigned a, unsigned p)
315{
316 return a & ((1U << p) - 1);
317}
318
319/**
320 * Add two signed 32-bit values with saturation.
321 *
322 * @param a one value
323 * @param b another value
324 * @return sum with signed saturation
325 */
326static av_always_inline int av_sat_add32_c(int a, int b)
327{
328 return av_clipl_int32(a: (int64_t)a + b);
329}
330
331/**
332 * Add a doubled value to another value with saturation at both stages.
333 *
334 * @param a first value
335 * @param b value doubled and added to a
336 * @return sum sat(a + sat(2*b)) with signed saturation
337 */
338static av_always_inline int av_sat_dadd32_c(int a, int b)
339{
340 return av_sat_add32(a, av_sat_add32(a: b, b));
341}
342
343/**
344 * Subtract two signed 32-bit values with saturation.
345 *
346 * @param a one value
347 * @param b another value
348 * @return difference with signed saturation
349 */
350static av_always_inline int av_sat_sub32_c(int a, int b)
351{
352 return av_clipl_int32(a: (int64_t)a - b);
353}
354
355/**
356 * Subtract a doubled value from another value with saturation at both stages.
357 *
358 * @param a first value
359 * @param b value doubled and subtracted from a
360 * @return difference sat(a - sat(2*b)) with signed saturation
361 */
362static av_always_inline int av_sat_dsub32_c(int a, int b)
363{
364 return av_sat_sub32(a, av_sat_add32(a: b, b));
365}
366
367/**
368 * Add two signed 64-bit values with saturation.
369 *
370 * @param a one value
371 * @param b another value
372 * @return sum with signed saturation
373 */
374static av_always_inline int64_t av_sat_add64_c(int64_t a, int64_t b) {
375#if (!defined(__INTEL_COMPILER) && AV_GCC_VERSION_AT_LEAST(5,1)) || AV_HAS_BUILTIN(__builtin_add_overflow)
376 int64_t tmp;
377 return !__builtin_add_overflow(a, b, &tmp) ? tmp : (tmp < 0 ? INT64_MAX : INT64_MIN);
378#else
379 int64_t s = a+(uint64_t)b;
380 if ((int64_t)(a^b | ~s^b) >= 0)
381 return INT64_MAX ^ (b >> 63);
382 return s;
383#endif
384}
385
386/**
387 * Subtract two signed 64-bit values with saturation.
388 *
389 * @param a one value
390 * @param b another value
391 * @return difference with signed saturation
392 */
393static av_always_inline int64_t av_sat_sub64_c(int64_t a, int64_t b) {
394#if (!defined(__INTEL_COMPILER) && AV_GCC_VERSION_AT_LEAST(5,1)) || AV_HAS_BUILTIN(__builtin_sub_overflow)
395 int64_t tmp;
396 return !__builtin_sub_overflow(a, b, &tmp) ? tmp : (tmp < 0 ? INT64_MAX : INT64_MIN);
397#else
398 if (b <= 0 && a >= INT64_MAX + b)
399 return INT64_MAX;
400 if (b >= 0 && a <= INT64_MIN + b)
401 return INT64_MIN;
402 return a - b;
403#endif
404}
405
406/**
407 * Clip a float value into the amin-amax range.
408 * @param a value to clip
409 * @param amin minimum value of the clip range
410 * @param amax maximum value of the clip range
411 * @return clipped value
412 */
413static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
414{
415#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
416 if (amin > amax) abort();
417#endif
418 if (a < amin) return amin;
419 else if (a > amax) return amax;
420 else return a;
421}
422
423/**
424 * Clip a double value into the amin-amax range.
425 * @param a value to clip
426 * @param amin minimum value of the clip range
427 * @param amax maximum value of the clip range
428 * @return clipped value
429 */
430static av_always_inline av_const double av_clipd_c(double a, double amin, double amax)
431{
432#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
433 if (amin > amax) abort();
434#endif
435 if (a < amin) return amin;
436 else if (a > amax) return amax;
437 else return a;
438}
439
440/** Compute ceil(log2(x)).
441 * @param x value used to compute ceil(log2(x))
442 * @return computed ceiling of log2(x)
443 */
444static av_always_inline av_const int av_ceil_log2_c(int x)
445{
446 return av_log2(v: (x - 1U) << 1);
447}
448
449/**
450 * Count number of bits set to one in x
451 * @param x value to count bits of
452 * @return the number of bits set to one in x
453 */
454static av_always_inline av_const int av_popcount_c(uint32_t x)
455{
456 x -= (x >> 1) & 0x55555555;
457 x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
458 x = (x + (x >> 4)) & 0x0F0F0F0F;
459 x += x >> 8;
460 return (x + (x >> 16)) & 0x3F;
461}
462
463/**
464 * Count number of bits set to one in x
465 * @param x value to count bits of
466 * @return the number of bits set to one in x
467 */
468static av_always_inline av_const int av_popcount64_c(uint64_t x)
469{
470 return av_popcount(x: (uint32_t)x) + av_popcount(x: (uint32_t)(x >> 32));
471}
472
473static av_always_inline av_const int av_parity_c(uint32_t v)
474{
475 return av_popcount(x: v) & 1;
476}
477
478#define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
479#define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))
480
481/**
482 * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
483 *
484 * @param val Output value, must be an lvalue of type uint32_t.
485 * @param GET_BYTE Expression reading one byte from the input.
486 * Evaluated up to 7 times (4 for the currently
487 * assigned Unicode range). With a memory buffer
488 * input, this could be *ptr++, or if you want to make sure
489 * that *ptr stops at the end of a NULL terminated string then
490 * *ptr ? *ptr++ : 0
491 * @param ERROR Expression to be evaluated on invalid input,
492 * typically a goto statement.
493 *
494 * @warning ERROR should not contain a loop control statement which
495 * could interact with the internal while loop, and should force an
496 * exit from the macro code (e.g. through a goto or a return) in order
497 * to prevent undefined results.
498 */
499#define GET_UTF8(val, GET_BYTE, ERROR)\
500 val= (GET_BYTE);\
501 {\
502 uint32_t top = (val & 128) >> 1;\
503 if ((val & 0xc0) == 0x80 || val >= 0xFE)\
504 {ERROR}\
505 while (val & top) {\
506 unsigned int tmp = (GET_BYTE) - 128;\
507 if(tmp>>6)\
508 {ERROR}\
509 val= (val<<6) + tmp;\
510 top <<= 5;\
511 }\
512 val &= (top << 1) - 1;\
513 }
514
515/**
516 * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
517 *
518 * @param val Output value, must be an lvalue of type uint32_t.
519 * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
520 * to native byte order. Evaluated one or two times.
521 * @param ERROR Expression to be evaluated on invalid input,
522 * typically a goto statement.
523 */
524#define GET_UTF16(val, GET_16BIT, ERROR)\
525 val = (GET_16BIT);\
526 {\
527 unsigned int hi = val - 0xD800;\
528 if (hi < 0x800) {\
529 val = (GET_16BIT) - 0xDC00;\
530 if (val > 0x3FFU || hi > 0x3FFU)\
531 {ERROR}\
532 val += (hi<<10) + 0x10000;\
533 }\
534 }\
535
536/**
537 * @def PUT_UTF8(val, tmp, PUT_BYTE)
538 * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
539 * @param val is an input-only argument and should be of type uint32_t. It holds
540 * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
541 * val is given as a function it is executed only once.
542 * @param tmp is a temporary variable and should be of type uint8_t. It
543 * represents an intermediate value during conversion that is to be
544 * output by PUT_BYTE.
545 * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
546 * It could be a function or a statement, and uses tmp as the input byte.
547 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
548 * executed up to 4 times for values in the valid UTF-8 range and up to
549 * 7 times in the general case, depending on the length of the converted
550 * Unicode character.
551 */
552#define PUT_UTF8(val, tmp, PUT_BYTE)\
553 {\
554 int bytes, shift;\
555 uint32_t in = val;\
556 if (in < 0x80) {\
557 tmp = in;\
558 PUT_BYTE\
559 } else {\
560 bytes = (av_log2(in) + 4) / 5;\
561 shift = (bytes - 1) * 6;\
562 tmp = (256 - (256 >> bytes)) | (in >> shift);\
563 PUT_BYTE\
564 while (shift >= 6) {\
565 shift -= 6;\
566 tmp = 0x80 | ((in >> shift) & 0x3f);\
567 PUT_BYTE\
568 }\
569 }\
570 }
571
572/**
573 * @def PUT_UTF16(val, tmp, PUT_16BIT)
574 * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
575 * @param val is an input-only argument and should be of type uint32_t. It holds
576 * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
577 * val is given as a function it is executed only once.
578 * @param tmp is a temporary variable and should be of type uint16_t. It
579 * represents an intermediate value during conversion that is to be
580 * output by PUT_16BIT.
581 * @param PUT_16BIT writes the converted UTF-16 data to any proper destination
582 * in desired endianness. It could be a function or a statement, and uses tmp
583 * as the input byte. For example, PUT_BYTE could be "*output++ = tmp;"
584 * PUT_BYTE will be executed 1 or 2 times depending on input character.
585 */
586#define PUT_UTF16(val, tmp, PUT_16BIT)\
587 {\
588 uint32_t in = val;\
589 if (in < 0x10000) {\
590 tmp = in;\
591 PUT_16BIT\
592 } else {\
593 tmp = 0xD800 | ((in - 0x10000) >> 10);\
594 PUT_16BIT\
595 tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
596 PUT_16BIT\
597 }\
598 }\
599
600
601
602#include "mem.h"
603
604#ifdef HAVE_AV_CONFIG_H
605# include "internal.h"
606#endif /* HAVE_AV_CONFIG_H */
607
608#endif /* AVUTIL_COMMON_H */
609

source code of include/x86_64-linux-gnu/libavutil/common.h