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 "error.h"
44#include "macros.h"
45#include "version.h"
46
47#ifdef HAVE_AV_CONFIG_H
48# include "config.h"
49# include "intmath.h"
50# include "internal.h"
51#else
52# include "mem.h"
53#endif /* HAVE_AV_CONFIG_H */
54
55//rounded division & shift
56#define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
57/* assume b>0 */
58#define ROUNDED_DIV(a,b) (((a)>=0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
59/* Fast a/(1<<b) rounded toward +inf. Assume a>=0 and b>=0 */
60#define AV_CEIL_RSHIFT(a,b) (!av_builtin_constant_p(b) ? -((-(a)) >> (b)) \
61 : ((a) + (1<<(b)) - 1) >> (b))
62/* Backwards compat. */
63#define FF_CEIL_RSHIFT AV_CEIL_RSHIFT
64
65#define FFUDIV(a,b) (((a)>0 ?(a):(a)-(b)+1) / (b))
66#define FFUMOD(a,b) ((a)-(b)*FFUDIV(a,b))
67
68/**
69 * Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they
70 * are not representable as absolute values of their type. This is the same
71 * as with *abs()
72 * @see FFNABS()
73 */
74#define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
75#define FFSIGN(a) ((a) > 0 ? 1 : -1)
76
77/**
78 * Negative Absolute value.
79 * this works for all integers of all types.
80 * As with many macros, this evaluates its argument twice, it thus must not have
81 * a sideeffect, that is FFNABS(x++) has undefined behavior.
82 */
83#define FFNABS(a) ((a) <= 0 ? (a) : (-(a)))
84
85/**
86 * Unsigned Absolute value.
87 * This takes the absolute value of a signed int and returns it as a unsigned.
88 * This also works with INT_MIN which would otherwise not be representable
89 * As with many macros, this evaluates its argument twice.
90 */
91#define FFABSU(a) ((a) <= 0 ? -(unsigned)(a) : (unsigned)(a))
92#define FFABS64U(a) ((a) <= 0 ? -(uint64_t)(a) : (uint64_t)(a))
93
94/* misc math functions */
95
96#ifndef av_ceil_log2
97# define av_ceil_log2 av_ceil_log2_c
98#endif
99#ifndef av_clip
100# define av_clip av_clip_c
101#endif
102#ifndef av_clip64
103# define av_clip64 av_clip64_c
104#endif
105#ifndef av_clip_uint8
106# define av_clip_uint8 av_clip_uint8_c
107#endif
108#ifndef av_clip_int8
109# define av_clip_int8 av_clip_int8_c
110#endif
111#ifndef av_clip_uint16
112# define av_clip_uint16 av_clip_uint16_c
113#endif
114#ifndef av_clip_int16
115# define av_clip_int16 av_clip_int16_c
116#endif
117#ifndef av_clipl_int32
118# define av_clipl_int32 av_clipl_int32_c
119#endif
120#ifndef av_clip_intp2
121# define av_clip_intp2 av_clip_intp2_c
122#endif
123#ifndef av_clip_uintp2
124# define av_clip_uintp2 av_clip_uintp2_c
125#endif
126#ifndef av_sat_add32
127# define av_sat_add32 av_sat_add32_c
128#endif
129#ifndef av_sat_dadd32
130# define av_sat_dadd32 av_sat_dadd32_c
131#endif
132#ifndef av_sat_sub32
133# define av_sat_sub32 av_sat_sub32_c
134#endif
135#ifndef av_sat_dsub32
136# define av_sat_dsub32 av_sat_dsub32_c
137#endif
138#ifndef av_sat_add64
139# define av_sat_add64 av_sat_add64_c
140#endif
141#ifndef av_sat_sub64
142# define av_sat_sub64 av_sat_sub64_c
143#endif
144#ifndef av_clipf
145# define av_clipf av_clipf_c
146#endif
147#ifndef av_clipd
148# define av_clipd av_clipd_c
149#endif
150#ifndef av_zero_extend
151# define av_zero_extend av_zero_extend_c
152#endif
153#ifndef av_popcount
154# define av_popcount av_popcount_c
155#endif
156#ifndef av_popcount64
157# define av_popcount64 av_popcount64_c
158#endif
159#ifndef av_parity
160# define av_parity av_parity_c
161#endif
162
163#ifndef av_log2
164av_const int av_log2(unsigned v);
165#endif
166
167#ifndef av_log2_16bit
168av_const int av_log2_16bit(unsigned v);
169#endif
170
171/**
172 * Clip a signed integer value into the amin-amax range.
173 * @param a value to clip
174 * @param amin minimum value of the clip range
175 * @param amax maximum value of the clip range
176 * @return clipped value
177 */
178static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
179{
180#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
181 if (amin > amax) abort();
182#endif
183 if (a < amin) return amin;
184 else if (a > amax) return amax;
185 else return a;
186}
187
188/**
189 * Clip a signed 64bit integer value into the amin-amax range.
190 * @param a value to clip
191 * @param amin minimum value of the clip range
192 * @param amax maximum value of the clip range
193 * @return clipped value
194 */
195static av_always_inline av_const int64_t av_clip64_c(int64_t a, int64_t amin, int64_t amax)
196{
197#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
198 if (amin > amax) abort();
199#endif
200 if (a < amin) return amin;
201 else if (a > amax) return amax;
202 else return a;
203}
204
205/**
206 * Clip a signed integer value into the 0-255 range.
207 * @param a value to clip
208 * @return clipped value
209 */
210static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
211{
212 if (a&(~0xFF)) return (~a)>>31;
213 else return a;
214}
215
216/**
217 * Clip a signed integer value into the -128,127 range.
218 * @param a value to clip
219 * @return clipped value
220 */
221static av_always_inline av_const int8_t av_clip_int8_c(int a)
222{
223 if ((a+0x80U) & ~0xFF) return (a>>31) ^ 0x7F;
224 else return a;
225}
226
227/**
228 * Clip a signed integer value into the 0-65535 range.
229 * @param a value to clip
230 * @return clipped value
231 */
232static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
233{
234 if (a&(~0xFFFF)) return (~a)>>31;
235 else return a;
236}
237
238/**
239 * Clip a signed integer value into the -32768,32767 range.
240 * @param a value to clip
241 * @return clipped value
242 */
243static av_always_inline av_const int16_t av_clip_int16_c(int a)
244{
245 if ((a+0x8000U) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
246 else return a;
247}
248
249/**
250 * Clip a signed 64-bit integer value into the -2147483648,2147483647 range.
251 * @param a value to clip
252 * @return clipped value
253 */
254static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
255{
256 if ((a+UINT64_C(0x80000000)) & ~UINT64_C(0xFFFFFFFF)) return (int32_t)((a>>63) ^ 0x7FFFFFFF);
257 else return (int32_t)a;
258}
259
260/**
261 * Clip a signed integer into the -(2^p),(2^p-1) range.
262 * @param a value to clip
263 * @param p bit position to clip at
264 * @return clipped value
265 */
266static av_always_inline av_const int av_clip_intp2_c(int a, int p)
267{
268 if (((unsigned)a + (1U << p)) & ~((2U << p) - 1))
269 return (a >> 31) ^ ((1 << p) - 1);
270 else
271 return a;
272}
273
274/**
275 * Clip a signed integer to an unsigned power of two range.
276 * @param a value to clip
277 * @param p bit position to clip at
278 * @return clipped value
279 */
280static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
281{
282 if (a & ~((1U<<p) - 1)) return (~a) >> 31 & ((1U<<p) - 1);
283 else return a;
284}
285
286/**
287 * Clear high bits from an unsigned integer starting with specific bit position
288 * @param a value to clip
289 * @param p bit position to clip at. Must be between 0 and 31.
290 * @return clipped value
291 */
292static av_always_inline av_const unsigned av_zero_extend_c(unsigned a, unsigned p)
293{
294#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
295 if (p > 31) abort();
296#endif
297 return a & ((1U << p) - 1);
298}
299
300#if FF_API_MOD_UINTP2
301#ifndef av_mod_uintp2
302# define av_mod_uintp2 av_mod_uintp2_c
303#endif
304attribute_deprecated
305static av_always_inline av_const unsigned av_mod_uintp2_c(unsigned a, unsigned p)
306{
307 return av_zero_extend_c(a, p);
308}
309#endif
310
311/**
312 * Add two signed 32-bit values with saturation.
313 *
314 * @param a one value
315 * @param b another value
316 * @return sum with signed saturation
317 */
318static av_always_inline int av_sat_add32_c(int a, int b)
319{
320 return av_clipl_int32(a: (int64_t)a + b);
321}
322
323/**
324 * Add a doubled value to another value with saturation at both stages.
325 *
326 * @param a first value
327 * @param b value doubled and added to a
328 * @return sum sat(a + sat(2*b)) with signed saturation
329 */
330static av_always_inline int av_sat_dadd32_c(int a, int b)
331{
332 return av_sat_add32(a, av_sat_add32(a: b, b));
333}
334
335/**
336 * Subtract two signed 32-bit values with saturation.
337 *
338 * @param a one value
339 * @param b another value
340 * @return difference with signed saturation
341 */
342static av_always_inline int av_sat_sub32_c(int a, int b)
343{
344 return av_clipl_int32(a: (int64_t)a - b);
345}
346
347/**
348 * Subtract a doubled value from another value with saturation at both stages.
349 *
350 * @param a first value
351 * @param b value doubled and subtracted from a
352 * @return difference sat(a - sat(2*b)) with signed saturation
353 */
354static av_always_inline int av_sat_dsub32_c(int a, int b)
355{
356 return av_sat_sub32(a, av_sat_add32(a: b, b));
357}
358
359/**
360 * Add two signed 64-bit values with saturation.
361 *
362 * @param a one value
363 * @param b another value
364 * @return sum with signed saturation
365 */
366static av_always_inline int64_t av_sat_add64_c(int64_t a, int64_t b) {
367#if (!defined(__INTEL_COMPILER) && AV_GCC_VERSION_AT_LEAST(5,1)) || AV_HAS_BUILTIN(__builtin_add_overflow)
368 int64_t tmp;
369 return !__builtin_add_overflow(a, b, &tmp) ? tmp : (tmp < 0 ? INT64_MAX : INT64_MIN);
370#else
371 int64_t s = a+(uint64_t)b;
372 if ((int64_t)(a^b | ~s^b) >= 0)
373 return INT64_MAX ^ (b >> 63);
374 return s;
375#endif
376}
377
378/**
379 * Subtract two signed 64-bit values with saturation.
380 *
381 * @param a one value
382 * @param b another value
383 * @return difference with signed saturation
384 */
385static av_always_inline int64_t av_sat_sub64_c(int64_t a, int64_t b) {
386#if (!defined(__INTEL_COMPILER) && AV_GCC_VERSION_AT_LEAST(5,1)) || AV_HAS_BUILTIN(__builtin_sub_overflow)
387 int64_t tmp;
388 return !__builtin_sub_overflow(a, b, &tmp) ? tmp : (tmp < 0 ? INT64_MAX : INT64_MIN);
389#else
390 if (b <= 0 && a >= INT64_MAX + b)
391 return INT64_MAX;
392 if (b >= 0 && a <= INT64_MIN + b)
393 return INT64_MIN;
394 return a - b;
395#endif
396}
397
398/**
399 * Clip a float value into the amin-amax range.
400 * If a is nan or -inf amin will be returned.
401 * If a is +inf amax will be returned.
402 * @param a value to clip
403 * @param amin minimum value of the clip range
404 * @param amax maximum value of the clip range
405 * @return clipped value
406 */
407static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
408{
409#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
410 if (amin > amax) abort();
411#endif
412 return FFMIN(FFMAX(a, amin), amax);
413}
414
415/**
416 * Clip a double value into the amin-amax range.
417 * If a is nan or -inf amin will be returned.
418 * If a is +inf amax will be returned.
419 * @param a value to clip
420 * @param amin minimum value of the clip range
421 * @param amax maximum value of the clip range
422 * @return clipped value
423 */
424static av_always_inline av_const double av_clipd_c(double a, double amin, double amax)
425{
426#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
427 if (amin > amax) abort();
428#endif
429 return FFMIN(FFMAX(a, amin), amax);
430}
431
432/** Compute ceil(log2(x)).
433 * @param x value used to compute ceil(log2(x))
434 * @return computed ceiling of log2(x)
435 */
436static av_always_inline av_const int av_ceil_log2_c(int x)
437{
438 return av_log2(v: (x - 1U) << 1);
439}
440
441/**
442 * Count number of bits set to one in x
443 * @param x value to count bits of
444 * @return the number of bits set to one in x
445 */
446static av_always_inline av_const int av_popcount_c(uint32_t x)
447{
448 x -= (x >> 1) & 0x55555555;
449 x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
450 x = (x + (x >> 4)) & 0x0F0F0F0F;
451 x += x >> 8;
452 return (x + (x >> 16)) & 0x3F;
453}
454
455/**
456 * Count number of bits set to one in x
457 * @param x value to count bits of
458 * @return the number of bits set to one in x
459 */
460static av_always_inline av_const int av_popcount64_c(uint64_t x)
461{
462 return av_popcount(x: (uint32_t)x) + av_popcount(x: (uint32_t)(x >> 32));
463}
464
465static av_always_inline av_const int av_parity_c(uint32_t v)
466{
467 return av_popcount(x: v) & 1;
468}
469
470/**
471 * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
472 *
473 * @param val Output value, must be an lvalue of type uint32_t.
474 * @param GET_BYTE Expression reading one byte from the input.
475 * Evaluated up to 7 times (4 for the currently
476 * assigned Unicode range). With a memory buffer
477 * input, this could be *ptr++, or if you want to make sure
478 * that *ptr stops at the end of a NULL terminated string then
479 * *ptr ? *ptr++ : 0
480 * @param ERROR Expression to be evaluated on invalid input,
481 * typically a goto statement.
482 *
483 * @warning ERROR should not contain a loop control statement which
484 * could interact with the internal while loop, and should force an
485 * exit from the macro code (e.g. through a goto or a return) in order
486 * to prevent undefined results.
487 */
488#define GET_UTF8(val, GET_BYTE, ERROR)\
489 val= (uint8_t)(GET_BYTE);\
490 {\
491 uint32_t top = (val & 128) >> 1;\
492 if ((val & 0xc0) == 0x80 || val >= 0xFE)\
493 {ERROR}\
494 while (val & top) {\
495 unsigned int tmp = (uint8_t)(GET_BYTE) - 128;\
496 if(tmp>>6)\
497 {ERROR}\
498 val= (val<<6) + tmp;\
499 top <<= 5;\
500 }\
501 val &= (top << 1) - 1;\
502 }
503
504/**
505 * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
506 *
507 * @param val Output value, must be an lvalue of type uint32_t.
508 * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
509 * to native byte order. Evaluated one or two times.
510 * @param ERROR Expression to be evaluated on invalid input,
511 * typically a goto statement.
512 */
513#define GET_UTF16(val, GET_16BIT, ERROR)\
514 val = (uint16_t)(GET_16BIT);\
515 {\
516 unsigned int hi = val - 0xD800;\
517 if (hi < 0x800) {\
518 val = (uint16_t)(GET_16BIT) - 0xDC00;\
519 if (val > 0x3FFU || hi > 0x3FFU)\
520 {ERROR}\
521 val += (hi<<10) + 0x10000;\
522 }\
523 }\
524
525/**
526 * @def PUT_UTF8(val, tmp, PUT_BYTE)
527 * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
528 * @param val is an input-only argument and should be of type uint32_t. It holds
529 * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
530 * val is given as a function it is executed only once.
531 * @param tmp is a temporary variable and should be of type uint8_t. It
532 * represents an intermediate value during conversion that is to be
533 * output by PUT_BYTE.
534 * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
535 * It could be a function or a statement, and uses tmp as the input byte.
536 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
537 * executed up to 4 times for values in the valid UTF-8 range and up to
538 * 7 times in the general case, depending on the length of the converted
539 * Unicode character.
540 */
541#define PUT_UTF8(val, tmp, PUT_BYTE)\
542 {\
543 int bytes, shift;\
544 uint32_t in = val;\
545 if (in < 0x80) {\
546 tmp = in;\
547 PUT_BYTE\
548 } else {\
549 bytes = (av_log2(in) + 4) / 5;\
550 shift = (bytes - 1) * 6;\
551 tmp = (256 - (256 >> bytes)) | (in >> shift);\
552 PUT_BYTE\
553 while (shift >= 6) {\
554 shift -= 6;\
555 tmp = 0x80 | ((in >> shift) & 0x3f);\
556 PUT_BYTE\
557 }\
558 }\
559 }
560
561/**
562 * @def PUT_UTF16(val, tmp, PUT_16BIT)
563 * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
564 * @param val is an input-only argument and should be of type uint32_t. It holds
565 * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
566 * val is given as a function it is executed only once.
567 * @param tmp is a temporary variable and should be of type uint16_t. It
568 * represents an intermediate value during conversion that is to be
569 * output by PUT_16BIT.
570 * @param PUT_16BIT writes the converted UTF-16 data to any proper destination
571 * in desired endianness. It could be a function or a statement, and uses tmp
572 * as the input byte. For example, PUT_BYTE could be "*output++ = tmp;"
573 * PUT_BYTE will be executed 1 or 2 times depending on input character.
574 */
575#define PUT_UTF16(val, tmp, PUT_16BIT)\
576 {\
577 uint32_t in = val;\
578 if (in < 0x10000) {\
579 tmp = in;\
580 PUT_16BIT\
581 } else {\
582 tmp = 0xD800 | ((in - 0x10000) >> 10);\
583 PUT_16BIT\
584 tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
585 PUT_16BIT\
586 }\
587 }\
588
589#endif /* AVUTIL_COMMON_H */
590