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
113 av_const int av_log2(unsigned v);
114 #endif
115
116 #ifndef av_log2_16bit
117 av_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 */
av_clip_c(int a,int amin,int amax)127 static 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 */
av_clip64_c(int64_t a,int64_t amin,int64_t amax)144 static 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 */
av_clip_uint8_c(int a)159 static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
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 */
av_clip_int8_c(int a)170 static av_always_inline av_const int8_t av_clip_int8_c(int a)
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 */
av_clip_uint16_c(int a)181 static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
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 */
av_clip_int16_c(int a)192 static av_always_inline av_const int16_t av_clip_int16_c(int a)
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 */
av_clipl_int32_c(int64_t a)203 static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
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 */
av_clip_intp2_c(int a,int p)215 static av_always_inline av_const int av_clip_intp2_c(int a, int p)
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 */
av_clip_uintp2_c(int a,int p)229 static 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 */
av_mod_uintp2_c(unsigned a,unsigned p)241 static 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 */
av_sat_add32_c(int a,int b)253 static 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 with signed saturation
264 */
av_sat_dadd32_c(int a,int b)265 static 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 * Clip a float value into the amin-amax range.
272 * @param a value to clip
273 * @param amin minimum value of the clip range
274 * @param amax maximum value of the clip range
275 * @return clipped value
276 */
av_clipf_c(float a,float amin,float amax)277 static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
278 {
279 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
280 if (amin > amax) abort();
281 #endif
282 if (a < amin) return amin;
283 else if (a > amax) return amax;
284 else return a;
285 }
286
287 /**
288 * Clip a double value into the amin-amax range.
289 * @param a value to clip
290 * @param amin minimum value of the clip range
291 * @param amax maximum value of the clip range
292 * @return clipped value
293 */
av_clipd_c(double a,double amin,double amax)294 static av_always_inline av_const double av_clipd_c(double a, double amin, double amax)
295 {
296 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
297 if (amin > amax) abort();
298 #endif
299 if (a < amin) return amin;
300 else if (a > amax) return amax;
301 else return a;
302 }
303
304 /** Compute ceil(log2(x)).
305 * @param x value used to compute ceil(log2(x))
306 * @return computed ceiling of log2(x)
307 */
av_ceil_log2_c(int x)308 static av_always_inline av_const int av_ceil_log2_c(int x)
309 {
310 return av_log2((x - 1) << 1);
311 }
312
313 /**
314 * Count number of bits set to one in x
315 * @param x value to count bits of
316 * @return the number of bits set to one in x
317 */
av_popcount_c(uint32_t x)318 static av_always_inline av_const int av_popcount_c(uint32_t x)
319 {
320 x -= (x >> 1) & 0x55555555;
321 x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
322 x = (x + (x >> 4)) & 0x0F0F0F0F;
323 x += x >> 8;
324 return (x + (x >> 16)) & 0x3F;
325 }
326
327 /**
328 * Count number of bits set to one in x
329 * @param x value to count bits of
330 * @return the number of bits set to one in x
331 */
av_popcount64_c(uint64_t x)332 static av_always_inline av_const int av_popcount64_c(uint64_t x)
333 {
334 return av_popcount((uint32_t)x) + av_popcount((uint32_t)(x >> 32));
335 }
336
av_parity_c(uint32_t v)337 static av_always_inline av_const int av_parity_c(uint32_t v)
338 {
339 return av_popcount(v) & 1;
340 }
341
342 #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
343 #define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))
344
345 /**
346 * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
347 *
348 * @param val Output value, must be an lvalue of type uint32_t.
349 * @param GET_BYTE Expression reading one byte from the input.
350 * Evaluated up to 7 times (4 for the currently
351 * assigned Unicode range). With a memory buffer
352 * input, this could be *ptr++.
353 * @param ERROR Expression to be evaluated on invalid input,
354 * typically a goto statement.
355 *
356 * @warning ERROR should not contain a loop control statement which
357 * could interact with the internal while loop, and should force an
358 * exit from the macro code (e.g. through a goto or a return) in order
359 * to prevent undefined results.
360 */
361 #define GET_UTF8(val, GET_BYTE, ERROR)\
362 val= (GET_BYTE);\
363 {\
364 uint32_t top = (val & 128) >> 1;\
365 if ((val & 0xc0) == 0x80 || val >= 0xFE)\
366 ERROR\
367 while (val & top) {\
368 int tmp= (GET_BYTE) - 128;\
369 if(tmp>>6)\
370 ERROR\
371 val= (val<<6) + tmp;\
372 top <<= 5;\
373 }\
374 val &= (top << 1) - 1;\
375 }
376
377 /**
378 * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
379 *
380 * @param val Output value, must be an lvalue of type uint32_t.
381 * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
382 * to native byte order. Evaluated one or two times.
383 * @param ERROR Expression to be evaluated on invalid input,
384 * typically a goto statement.
385 */
386 #define GET_UTF16(val, GET_16BIT, ERROR)\
387 val = GET_16BIT;\
388 {\
389 unsigned int hi = val - 0xD800;\
390 if (hi < 0x800) {\
391 val = GET_16BIT - 0xDC00;\
392 if (val > 0x3FFU || hi > 0x3FFU)\
393 ERROR\
394 val += (hi<<10) + 0x10000;\
395 }\
396 }\
397
398 /**
399 * @def PUT_UTF8(val, tmp, PUT_BYTE)
400 * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
401 * @param val is an input-only argument and should be of type uint32_t. It holds
402 * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
403 * val is given as a function it is executed only once.
404 * @param tmp is a temporary variable and should be of type uint8_t. It
405 * represents an intermediate value during conversion that is to be
406 * output by PUT_BYTE.
407 * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
408 * It could be a function or a statement, and uses tmp as the input byte.
409 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
410 * executed up to 4 times for values in the valid UTF-8 range and up to
411 * 7 times in the general case, depending on the length of the converted
412 * Unicode character.
413 */
414 #define PUT_UTF8(val, tmp, PUT_BYTE)\
415 {\
416 int bytes, shift;\
417 uint32_t in = val;\
418 if (in < 0x80) {\
419 tmp = in;\
420 PUT_BYTE\
421 } else {\
422 bytes = (av_log2(in) + 4) / 5;\
423 shift = (bytes - 1) * 6;\
424 tmp = (256 - (256 >> bytes)) | (in >> shift);\
425 PUT_BYTE\
426 while (shift >= 6) {\
427 shift -= 6;\
428 tmp = 0x80 | ((in >> shift) & 0x3f);\
429 PUT_BYTE\
430 }\
431 }\
432 }
433
434 /**
435 * @def PUT_UTF16(val, tmp, PUT_16BIT)
436 * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
437 * @param val is an input-only argument and should be of type uint32_t. It holds
438 * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
439 * val is given as a function it is executed only once.
440 * @param tmp is a temporary variable and should be of type uint16_t. It
441 * represents an intermediate value during conversion that is to be
442 * output by PUT_16BIT.
443 * @param PUT_16BIT writes the converted UTF-16 data to any proper destination
444 * in desired endianness. It could be a function or a statement, and uses tmp
445 * as the input byte. For example, PUT_BYTE could be "*output++ = tmp;"
446 * PUT_BYTE will be executed 1 or 2 times depending on input character.
447 */
448 #define PUT_UTF16(val, tmp, PUT_16BIT)\
449 {\
450 uint32_t in = val;\
451 if (in < 0x10000) {\
452 tmp = in;\
453 PUT_16BIT\
454 } else {\
455 tmp = 0xD800 | ((in - 0x10000) >> 10);\
456 PUT_16BIT\
457 tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
458 PUT_16BIT\
459 }\
460 }\
461
462
463
464 #include "mem.h"
465
466 #ifdef HAVE_AV_CONFIG_H
467 # include "internal.h"
468 #endif /* HAVE_AV_CONFIG_H */
469
470 #endif /* AVUTIL_COMMON_H */
471
472 /*
473 * The following definitions are outside the multiple inclusion guard
474 * to ensure they are immediately available in intmath.h.
475 */
476
477 #ifndef av_ceil_log2
478 # define av_ceil_log2 av_ceil_log2_c
479 #endif
480 #ifndef av_clip
481 # define av_clip av_clip_c
482 #endif
483 #ifndef av_clip64
484 # define av_clip64 av_clip64_c
485 #endif
486 #ifndef av_clip_uint8
487 # define av_clip_uint8 av_clip_uint8_c
488 #endif
489 #ifndef av_clip_int8
490 # define av_clip_int8 av_clip_int8_c
491 #endif
492 #ifndef av_clip_uint16
493 # define av_clip_uint16 av_clip_uint16_c
494 #endif
495 #ifndef av_clip_int16
496 # define av_clip_int16 av_clip_int16_c
497 #endif
498 #ifndef av_clipl_int32
499 # define av_clipl_int32 av_clipl_int32_c
500 #endif
501 #ifndef av_clip_intp2
502 # define av_clip_intp2 av_clip_intp2_c
503 #endif
504 #ifndef av_clip_uintp2
505 # define av_clip_uintp2 av_clip_uintp2_c
506 #endif
507 #ifndef av_mod_uintp2
508 # define av_mod_uintp2 av_mod_uintp2_c
509 #endif
510 #ifndef av_sat_add32
511 # define av_sat_add32 av_sat_add32_c
512 #endif
513 #ifndef av_sat_dadd32
514 # define av_sat_dadd32 av_sat_dadd32_c
515 #endif
516 #ifndef av_clipf
517 # define av_clipf av_clipf_c
518 #endif
519 #ifndef av_clipd
520 # define av_clipd av_clipd_c
521 #endif
522 #ifndef av_popcount
523 # define av_popcount av_popcount_c
524 #endif
525 #ifndef av_popcount64
526 # define av_popcount64 av_popcount64_c
527 #endif
528 #ifndef av_parity
529 # define av_parity av_parity_c
530 #endif
531