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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 #include <errno.h>
30 #include <inttypes.h>
31 #include <limits.h>
32 #include <math.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 
37 #include "attributes.h"
38 #include "version.h"
39 #include "libavutil/avconfig.h"
40 
41 #if AV_HAVE_BIGENDIAN
42 # define AV_NE(be, le) (be)
43 #else
44 # define AV_NE(be, le) (le)
45 #endif
46 
47 //rounded division & shift
48 #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
49 /* assume b>0 */
50 #define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
51 /* assume a>0 and b>0 */
52 #define FF_CEIL_RSHIFT(a,b) (!av_builtin_constant_p(b) ? -((-(a)) >> (b)) \
53  : ((a) + (1<<(b)) - 1) >> (b))
54 #define FFUDIV(a,b) (((a)>0 ?(a):(a)-(b)+1) / (b))
55 #define FFUMOD(a,b) ((a)-(b)*FFUDIV(a,b))
56 #define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
57 #define FFSIGN(a) ((a) > 0 ? 1 : -1)
58 
59 #define FFMAX(a,b) ((a) > (b) ? (a) : (b))
60 #define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
61 #define FFMIN(a,b) ((a) > (b) ? (b) : (a))
62 #define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)
63 
64 #define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
65 #define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
66 #define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1))
67 
68 /* misc math functions */
69 
70 /**
71  * Reverse the order of the bits of an 8-bits unsigned integer.
72  */
73 #if FF_API_AV_REVERSE
74 extern attribute_deprecated const uint8_t av_reverse[256];
75 #endif
76 
77 #ifdef HAVE_AV_CONFIG_H
78 # include "config.h"
79 # include "intmath.h"
80 #endif
81 
82 /* Pull in unguarded fallback defines at the end of this file. */
83 #include "common.h"
84 
85 #ifndef av_log2
86 av_const int av_log2(unsigned v);
87 #endif
88 
89 #ifndef av_log2_16bit
90 av_const int av_log2_16bit(unsigned v);
91 #endif
92 
93 /**
94  * Clip a signed integer value into the amin-amax range.
95  * @param a value to clip
96  * @param amin minimum value of the clip range
97  * @param amax maximum value of the clip range
98  * @return clipped value
99  */
100 static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
101 {
102 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
103  if (amin > amax) abort();
104 #endif
105  if (a < amin) return amin;
106  else if (a > amax) return amax;
107  else return a;
108 }
109 
110 /**
111  * Clip a signed 64bit integer value into the amin-amax range.
112  * @param a value to clip
113  * @param amin minimum value of the clip range
114  * @param amax maximum value of the clip range
115  * @return clipped value
116  */
117 static av_always_inline av_const int64_t av_clip64_c(int64_t a, int64_t amin, int64_t amax)
118 {
119 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
120  if (amin > amax) abort();
121 #endif
122  if (a < amin) return amin;
123  else if (a > amax) return amax;
124  else return a;
125 }
126 
127 /**
128  * Clip a signed integer value into the 0-255 range.
129  * @param a value to clip
130  * @return clipped value
131  */
133 {
134  if (a&(~0xFF)) return (-a)>>31;
135  else return a;
136 }
137 
138 /**
139  * Clip a signed integer value into the -128,127 range.
140  * @param a value to clip
141  * @return clipped value
142  */
144 {
145  if ((a+0x80) & ~0xFF) return (a>>31) ^ 0x7F;
146  else return a;
147 }
148 
149 /**
150  * Clip a signed integer value into the 0-65535 range.
151  * @param a value to clip
152  * @return clipped value
153  */
155 {
156  if (a&(~0xFFFF)) return (-a)>>31;
157  else return a;
158 }
159 
160 /**
161  * Clip a signed integer value into the -32768,32767 range.
162  * @param a value to clip
163  * @return clipped value
164  */
166 {
167  if ((a+0x8000) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
168  else return a;
169 }
170 
171 /**
172  * Clip a signed 64-bit integer value into the -2147483648,2147483647 range.
173  * @param a value to clip
174  * @return clipped value
175  */
177 {
178  if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (int32_t)((a>>63) ^ 0x7FFFFFFF);
179  else return (int32_t)a;
180 }
181 
182 /**
183  * Clip a signed integer to an unsigned power of two range.
184  * @param a value to clip
185  * @param p bit position to clip at
186  * @return clipped value
187  */
188 static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
189 {
190  if (a & ~((1<<p) - 1)) return -a >> 31 & ((1<<p) - 1);
191  else return a;
192 }
193 
194 /**
195  * Add two signed 32-bit values with saturation.
196  *
197  * @param a one value
198  * @param b another value
199  * @return sum with signed saturation
200  */
201 static av_always_inline int av_sat_add32_c(int a, int b)
202 {
203  return av_clipl_int32((int64_t)a + b);
204 }
205 
206 /**
207  * Add a doubled value to another value with saturation at both stages.
208  *
209  * @param a first value
210  * @param b value doubled and added to a
211  * @return sum with signed saturation
212  */
213 static av_always_inline int av_sat_dadd32_c(int a, int b)
214 {
215  return av_sat_add32(a, av_sat_add32(b, b));
216 }
217 
218 /**
219  * Clip a float value into the amin-amax range.
220  * @param a value to clip
221  * @param amin minimum value of the clip range
222  * @param amax maximum value of the clip range
223  * @return clipped value
224  */
225 static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
226 {
227 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
228  if (amin > amax) abort();
229 #endif
230  if (a < amin) return amin;
231  else if (a > amax) return amax;
232  else return a;
233 }
234 
235 /**
236  * Clip a double value into the amin-amax range.
237  * @param a value to clip
238  * @param amin minimum value of the clip range
239  * @param amax maximum value of the clip range
240  * @return clipped value
241  */
242 static av_always_inline av_const double av_clipd_c(double a, double amin, double amax)
243 {
244 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
245  if (amin > amax) abort();
246 #endif
247  if (a < amin) return amin;
248  else if (a > amax) return amax;
249  else return a;
250 }
251 
252 /** Compute ceil(log2(x)).
253  * @param x value used to compute ceil(log2(x))
254  * @return computed ceiling of log2(x)
255  */
257 {
258  return av_log2((x - 1) << 1);
259 }
260 
261 /**
262  * Count number of bits set to one in x
263  * @param x value to count bits of
264  * @return the number of bits set to one in x
265  */
267 {
268  x -= (x >> 1) & 0x55555555;
269  x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
270  x = (x + (x >> 4)) & 0x0F0F0F0F;
271  x += x >> 8;
272  return (x + (x >> 16)) & 0x3F;
273 }
274 
275 /**
276  * Count number of bits set to one in x
277  * @param x value to count bits of
278  * @return the number of bits set to one in x
279  */
281 {
282  return av_popcount((uint32_t)x) + av_popcount((uint32_t)(x >> 32));
283 }
284 
285 #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
286 #define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))
287 
288 /**
289  * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
290  *
291  * @param val Output value, must be an lvalue of type uint32_t.
292  * @param GET_BYTE Expression reading one byte from the input.
293  * Evaluated up to 7 times (4 for the currently
294  * assigned Unicode range). With a memory buffer
295  * input, this could be *ptr++.
296  * @param ERROR Expression to be evaluated on invalid input,
297  * typically a goto statement.
298  *
299  * @warning ERROR should not contain a loop control statement which
300  * could interact with the internal while loop, and should force an
301  * exit from the macro code (e.g. through a goto or a return) in order
302  * to prevent undefined results.
303  */
304 #define GET_UTF8(val, GET_BYTE, ERROR)\
305  val= GET_BYTE;\
306  {\
307  uint32_t top = (val & 128) >> 1;\
308  if ((val & 0xc0) == 0x80 || val >= 0xFE)\
309  ERROR\
310  while (val & top) {\
311  int tmp= GET_BYTE - 128;\
312  if(tmp>>6)\
313  ERROR\
314  val= (val<<6) + tmp;\
315  top <<= 5;\
316  }\
317  val &= (top << 1) - 1;\
318  }
319 
320 /**
321  * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
322  *
323  * @param val Output value, must be an lvalue of type uint32_t.
324  * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
325  * to native byte order. Evaluated one or two times.
326  * @param ERROR Expression to be evaluated on invalid input,
327  * typically a goto statement.
328  */
329 #define GET_UTF16(val, GET_16BIT, ERROR)\
330  val = GET_16BIT;\
331  {\
332  unsigned int hi = val - 0xD800;\
333  if (hi < 0x800) {\
334  val = GET_16BIT - 0xDC00;\
335  if (val > 0x3FFU || hi > 0x3FFU)\
336  ERROR\
337  val += (hi<<10) + 0x10000;\
338  }\
339  }\
340 
341 /**
342  * @def PUT_UTF8(val, tmp, PUT_BYTE)
343  * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
344  * @param val is an input-only argument and should be of type uint32_t. It holds
345  * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
346  * val is given as a function it is executed only once.
347  * @param tmp is a temporary variable and should be of type uint8_t. It
348  * represents an intermediate value during conversion that is to be
349  * output by PUT_BYTE.
350  * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
351  * It could be a function or a statement, and uses tmp as the input byte.
352  * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
353  * executed up to 4 times for values in the valid UTF-8 range and up to
354  * 7 times in the general case, depending on the length of the converted
355  * Unicode character.
356  */
357 #define PUT_UTF8(val, tmp, PUT_BYTE)\
358  {\
359  int bytes, shift;\
360  uint32_t in = val;\
361  if (in < 0x80) {\
362  tmp = in;\
363  PUT_BYTE\
364  } else {\
365  bytes = (av_log2(in) + 4) / 5;\
366  shift = (bytes - 1) * 6;\
367  tmp = (256 - (256 >> bytes)) | (in >> shift);\
368  PUT_BYTE\
369  while (shift >= 6) {\
370  shift -= 6;\
371  tmp = 0x80 | ((in >> shift) & 0x3f);\
372  PUT_BYTE\
373  }\
374  }\
375  }
376 
377 /**
378  * @def PUT_UTF16(val, tmp, PUT_16BIT)
379  * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
380  * @param val is an input-only argument and should be of type uint32_t. It holds
381  * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
382  * val is given as a function it is executed only once.
383  * @param tmp is a temporary variable and should be of type uint16_t. It
384  * represents an intermediate value during conversion that is to be
385  * output by PUT_16BIT.
386  * @param PUT_16BIT writes the converted UTF-16 data to any proper destination
387  * in desired endianness. It could be a function or a statement, and uses tmp
388  * as the input byte. For example, PUT_BYTE could be "*output++ = tmp;"
389  * PUT_BYTE will be executed 1 or 2 times depending on input character.
390  */
391 #define PUT_UTF16(val, tmp, PUT_16BIT)\
392  {\
393  uint32_t in = val;\
394  if (in < 0x10000) {\
395  tmp = in;\
396  PUT_16BIT\
397  } else {\
398  tmp = 0xD800 | ((in - 0x10000) >> 10);\
399  PUT_16BIT\
400  tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
401  PUT_16BIT\
402  }\
403  }\
404 
405 
406 
407 #include "mem.h"
408 
409 #ifdef HAVE_AV_CONFIG_H
410 # include "internal.h"
411 #endif /* HAVE_AV_CONFIG_H */
412 
413 #endif /* AVUTIL_COMMON_H */
414 
415 /*
416  * The following definitions are outside the multiple inclusion guard
417  * to ensure they are immediately available in intmath.h.
418  */
419 
420 #ifndef av_ceil_log2
421 # define av_ceil_log2 av_ceil_log2_c
422 #endif
423 #ifndef av_clip
424 # define av_clip av_clip_c
425 #endif
426 #ifndef av_clip64
427 # define av_clip64 av_clip64_c
428 #endif
429 #ifndef av_clip_uint8
430 # define av_clip_uint8 av_clip_uint8_c
431 #endif
432 #ifndef av_clip_int8
433 # define av_clip_int8 av_clip_int8_c
434 #endif
435 #ifndef av_clip_uint16
436 # define av_clip_uint16 av_clip_uint16_c
437 #endif
438 #ifndef av_clip_int16
439 # define av_clip_int16 av_clip_int16_c
440 #endif
441 #ifndef av_clipl_int32
442 # define av_clipl_int32 av_clipl_int32_c
443 #endif
444 #ifndef av_clip_uintp2
445 # define av_clip_uintp2 av_clip_uintp2_c
446 #endif
447 #ifndef av_sat_add32
448 # define av_sat_add32 av_sat_add32_c
449 #endif
450 #ifndef av_sat_dadd32
451 # define av_sat_dadd32 av_sat_dadd32_c
452 #endif
453 #ifndef av_clipf
454 # define av_clipf av_clipf_c
455 #endif
456 #ifndef av_clipd
457 # define av_clipd av_clipd_c
458 #endif
459 #ifndef av_popcount
460 # define av_popcount av_popcount_c
461 #endif
462 #ifndef av_popcount64
463 # define av_popcount64 av_popcount64_c
464 #endif