FFmpeg: libavutil/common.h Source File

FFmpeg
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 "version.h"
44 #include "libavutil/avconfig.h"
45 
46 #if AV_HAVE_BIGENDIAN
47 # define AV_NE(be, le) (be)
48 #else
49  # define AV_NE(be, le) (le)
50 #endif
51 
52 //rounded division & shift
53  #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
54 /* assume b>0 */
55  #define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
56 /* assume a>0 and b>0 */
57  #define FF_CEIL_RSHIFT(a,b) (!av_builtin_constant_p(b) ? -((-(a)) >> (b)) \
58  : ((a) + (1<<(b)) - 1) >> (b))
59  #define FFUDIV(a,b) (((a)>0 ?(a):(a)-(b)+1) / (b))
60  #define FFUMOD(a,b) ((a)-(b)*FFUDIV(a,b))
61  #define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
62  #define FFSIGN(a) ((a) > 0 ? 1 : -1)
63 
64  #define FFMAX(a,b) ((a) > (b) ? (a) : (b))
65  #define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
66  #define FFMIN(a,b) ((a) > (b) ? (b) : (a))
67  #define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)
68 
69  #define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
70  #define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
71  #define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1))
72 
73 /* misc math functions */
74 
75 /**
76  * Reverse the order of the bits of an 8-bits unsigned integer.
77  */
78 #if FF_API_AV_REVERSE
79 extern attribute_deprecated const uint8_t av_reverse[256];
80 #endif
81 
82 #ifdef HAVE_AV_CONFIG_H
83 # include "config.h"
84 # include "intmath.h"
85 #endif
86 
87 /* Pull in unguarded fallback defines at the end of this file. */
88 #include "common.h"
89 
90 #ifndef av_log2
91 av_const int av_log2(unsigned v);
92 #endif
93 
94 #ifndef av_log2_16bit
95 av_const int av_log2_16bit(unsigned v);
96 #endif
97 
98 /**
99  * Clip a signed integer value into the amin-amax range.
100  * @param a value to clip
101  * @param amin minimum value of the clip range
102  * @param amax maximum value of the clip range
103  * @return clipped value
104  */
105  static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
106 {
107 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
108  if (amin > amax) abort();
109 #endif
110  if (a < amin) return amin;
111  else if (a > amax) return amax;
112  else return a;
113 }
114 
115 /**
116  * Clip a signed 64bit integer value into the amin-amax range.
117  * @param a value to clip
118  * @param amin minimum value of the clip range
119  * @param amax maximum value of the clip range
120  * @return clipped value
121  */
122  static av_always_inline av_const int64_t av_clip64_c(int64_t a, int64_t amin, int64_t amax)
123 {
124 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
125  if (amin > amax) abort();
126 #endif
127  if (a < amin) return amin;
128  else if (a > amax) return amax;
129  else return a;
130 }
131 
132 /**
133  * Clip a signed integer value into the 0-255 range.
134  * @param a value to clip
135  * @return clipped value
136  */
137  static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
138 {
139  if (a&(~0xFF)) return (-a)>>31;
140  else return a;
141 }
142 
143 /**
144  * Clip a signed integer value into the -128,127 range.
145  * @param a value to clip
146  * @return clipped value
147  */
148  static av_always_inline av_const int8_t av_clip_int8_c(int a)
149 {
150  if ((a+0x80U) & ~0xFF) return (a>>31) ^ 0x7F;
151  else return a;
152 }
153 
154 /**
155  * Clip a signed integer value into the 0-65535 range.
156  * @param a value to clip
157  * @return clipped value
158  */
159  static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
160 {
161  if (a&(~0xFFFF)) return (-a)>>31;
162  else return a;
163 }
164 
165 /**
166  * Clip a signed integer value into the -32768,32767 range.
167  * @param a value to clip
168  * @return clipped value
169  */
170  static av_always_inline av_const int16_t av_clip_int16_c(int a)
171 {
172  if ((a+0x8000U) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
173  else return a;
174 }
175 
176 /**
177  * Clip a signed 64-bit integer value into the -2147483648,2147483647 range.
178  * @param a value to clip
179  * @return clipped value
180  */
181  static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
182 {
183  if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (int32_t)((a>>63) ^ 0x7FFFFFFF);
184  else return (int32_t)a;
185 }
186 
187 /**
188  * Clip a signed integer into the -(2^p),(2^p-1) range.
189  * @param a value to clip
190  * @param p bit position to clip at
191  * @return clipped value
192  */
193  static av_always_inline av_const int av_clip_intp2_c(int a, int p)
194 {
195  if ((a + (1 << p)) & ~((2 << p) - 1))
196  return (a >> 31) ^ ((1 << p) - 1);
197  else
198  return a;
199 }
200 
201 /**
202  * Clip a signed integer to an unsigned power of two range.
203  * @param a value to clip
204  * @param p bit position to clip at
205  * @return clipped value
206  */
207  static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
208 {
209  if (a & ~((1<<p) - 1)) return -a >> 31 & ((1<<p) - 1);
210  else return a;
211 }
212 
213 /**
214  * Add two signed 32-bit values with saturation.
215  *
216  * @param a one value
217  * @param b another value
218  * @return sum with signed saturation
219  */
220  static av_always_inline int av_sat_add32_c(int a, int b)
221 {
222  return av_clipl_int32((int64_t)a + b);
223 }
224 
225 /**
226  * Add a doubled value to another value with saturation at both stages.
227  *
228  * @param a first value
229  * @param b value doubled and added to a
230  * @return sum with signed saturation
231  */
232  static av_always_inline int av_sat_dadd32_c(int a, int b)
233 {
234  return av_sat_add32(a, av_sat_add32(b, b));
235 }
236 
237 /**
238  * Clip a float value into the amin-amax range.
239  * @param a value to clip
240  * @param amin minimum value of the clip range
241  * @param amax maximum value of the clip range
242  * @return clipped value
243  */
244  static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
245 {
246 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
247  if (amin > amax) abort();
248 #endif
249  if (a < amin) return amin;
250  else if (a > amax) return amax;
251  else return a;
252 }
253 
254 /**
255  * Clip a double value into the amin-amax range.
256  * @param a value to clip
257  * @param amin minimum value of the clip range
258  * @param amax maximum value of the clip range
259  * @return clipped value
260  */
261  static av_always_inline av_const double av_clipd_c(double a, double amin, double amax)
262 {
263 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
264  if (amin > amax) abort();
265 #endif
266  if (a < amin) return amin;
267  else if (a > amax) return amax;
268  else return a;
269 }
270 
271 /** Compute ceil(log2(x)).
272  * @param x value used to compute ceil(log2(x))
273  * @return computed ceiling of log2(x)
274  */
275  static av_always_inline av_const int av_ceil_log2_c(int x)
276 {
277  return av_log2((x - 1) << 1);
278 }
279 
280 /**
281  * Count number of bits set to one in x
282  * @param x value to count bits of
283  * @return the number of bits set to one in x
284  */
285  static av_always_inline av_const int av_popcount_c(uint32_t x)
286 {
287  x -= (x >> 1) & 0x55555555;
288  x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
289  x = (x + (x >> 4)) & 0x0F0F0F0F;
290  x += x >> 8;
291  return (x + (x >> 16)) & 0x3F;
292 }
293 
294 /**
295  * Count number of bits set to one in x
296  * @param x value to count bits of
297  * @return the number of bits set to one in x
298  */
299  static av_always_inline av_const int av_popcount64_c(uint64_t x)
300 {
301  return av_popcount((uint32_t)x) + av_popcount((uint32_t)(x >> 32));
302 }
303 
304  #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
305  #define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))
306 
307 /**
308  * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
309  *
310  * @param val Output value, must be an lvalue of type uint32_t.
311  * @param GET_BYTE Expression reading one byte from the input.
312  * Evaluated up to 7 times (4 for the currently
313  * assigned Unicode range). With a memory buffer
314  * input, this could be *ptr++.
315  * @param ERROR Expression to be evaluated on invalid input,
316  * typically a goto statement.
317  *
318  * @warning ERROR should not contain a loop control statement which
319  * could interact with the internal while loop, and should force an
320  * exit from the macro code (e.g. through a goto or a return) in order
321  * to prevent undefined results.
322  */
323  #define GET_UTF8(val, GET_BYTE, ERROR)\
324  val= GET_BYTE;\
325  {\
326  uint32_t top = (val & 128) >> 1;\
327  if ((val & 0xc0) == 0x80 || val >= 0xFE)\
328  ERROR\
329  while (val & top) {\
330  int tmp= GET_BYTE - 128;\
331  if(tmp>>6)\
332  ERROR\
333  val= (val<<6) + tmp;\
334  top <<= 5;\
335  }\
336  val &= (top << 1) - 1;\
337  }
338 
339 /**
340  * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
341  *
342  * @param val Output value, must be an lvalue of type uint32_t.
343  * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
344  * to native byte order. Evaluated one or two times.
345  * @param ERROR Expression to be evaluated on invalid input,
346  * typically a goto statement.
347  */
348  #define GET_UTF16(val, GET_16BIT, ERROR)\
349  val = GET_16BIT;\
350  {\
351  unsigned int hi = val - 0xD800;\
352  if (hi < 0x800) {\
353  val = GET_16BIT - 0xDC00;\
354  if (val > 0x3FFU || hi > 0x3FFU)\
355  ERROR\
356  val += (hi<<10) + 0x10000;\
357  }\
358  }\
359 
360 /**
361  * @def PUT_UTF8(val, tmp, PUT_BYTE)
362  * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
363  * @param val is an input-only argument and should be of type uint32_t. It holds
364  * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
365  * val is given as a function it is executed only once.
366  * @param tmp is a temporary variable and should be of type uint8_t. It
367  * represents an intermediate value during conversion that is to be
368  * output by PUT_BYTE.
369  * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
370  * It could be a function or a statement, and uses tmp as the input byte.
371  * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
372  * executed up to 4 times for values in the valid UTF-8 range and up to
373  * 7 times in the general case, depending on the length of the converted
374  * Unicode character.
375  */
376  #define PUT_UTF8(val, tmp, PUT_BYTE)\
377  {\
378  int bytes, shift;\
379  uint32_t in = val;\
380  if (in < 0x80) {\
381  tmp = in;\
382  PUT_BYTE\
383  } else {\
384  bytes = (av_log2(in) + 4) / 5;\
385  shift = (bytes - 1) * 6;\
386  tmp = (256 - (256 >> bytes)) | (in >> shift);\
387  PUT_BYTE\
388  while (shift >= 6) {\
389  shift -= 6;\
390  tmp = 0x80 | ((in >> shift) & 0x3f);\
391  PUT_BYTE\
392  }\
393  }\
394  }
395 
396 /**
397  * @def PUT_UTF16(val, tmp, PUT_16BIT)
398  * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
399  * @param val is an input-only argument and should be of type uint32_t. It holds
400  * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
401  * val is given as a function it is executed only once.
402  * @param tmp is a temporary variable and should be of type uint16_t. It
403  * represents an intermediate value during conversion that is to be
404  * output by PUT_16BIT.
405  * @param PUT_16BIT writes the converted UTF-16 data to any proper destination
406  * in desired endianness. It could be a function or a statement, and uses tmp
407  * as the input byte. For example, PUT_BYTE could be "*output++ = tmp;"
408  * PUT_BYTE will be executed 1 or 2 times depending on input character.
409  */
410  #define PUT_UTF16(val, tmp, PUT_16BIT)\
411  {\
412  uint32_t in = val;\
413  if (in < 0x10000) {\
414  tmp = in;\
415  PUT_16BIT\
416  } else {\
417  tmp = 0xD800 | ((in - 0x10000) >> 10);\
418  PUT_16BIT\
419  tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
420  PUT_16BIT\
421  }\
422  }\
423 
424 
425 
426 #include "mem.h"
427 
428 #ifdef HAVE_AV_CONFIG_H
429 # include "internal.h"
430 #endif /* HAVE_AV_CONFIG_H */
431 
432 #endif /* AVUTIL_COMMON_H */
433 
434 /*
435  * The following definitions are outside the multiple inclusion guard
436  * to ensure they are immediately available in intmath.h.
437  */
438 
439 #ifndef av_ceil_log2
440 # define av_ceil_log2 av_ceil_log2_c
441 #endif
442 #ifndef av_clip
443 # define av_clip av_clip_c
444 #endif
445 #ifndef av_clip64
446 # define av_clip64 av_clip64_c
447 #endif
448 #ifndef av_clip_uint8
449 # define av_clip_uint8 av_clip_uint8_c
450 #endif
451 #ifndef av_clip_int8
452 # define av_clip_int8 av_clip_int8_c
453 #endif
454 #ifndef av_clip_uint16
455 # define av_clip_uint16 av_clip_uint16_c
456 #endif
457 #ifndef av_clip_int16
458 # define av_clip_int16 av_clip_int16_c
459 #endif
460 #ifndef av_clipl_int32
461 # define av_clipl_int32 av_clipl_int32_c
462 #endif
463 #ifndef av_clip_intp2
464 # define av_clip_intp2 av_clip_intp2_c
465 #endif
466 #ifndef av_clip_uintp2
467 # define av_clip_uintp2 av_clip_uintp2_c
468 #endif
469 #ifndef av_sat_add32
470 # define av_sat_add32 av_sat_add32_c
471 #endif
472 #ifndef av_sat_dadd32
473 # define av_sat_dadd32 av_sat_dadd32_c
474 #endif
475 #ifndef av_clipf
476 # define av_clipf av_clipf_c
477 #endif
478 #ifndef av_clipd
479 # define av_clipd av_clipd_c
480 #endif
481 #ifndef av_popcount
482 # define av_popcount av_popcount_c
483 #endif
484 #ifndef av_popcount64
485 # define av_popcount64 av_popcount64_c
486 #endif
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