Libav
common.h
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1 /*
2  * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
3  *
4  * This file is part of Libav.
5  *
6  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
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 <stdint.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 
38 #include "attributes.h"
39 #include "macros.h"
40 #include "version.h"
41 #include "libavutil/avconfig.h"
42 
43 #if AV_HAVE_BIGENDIAN
44 # define AV_NE(be, le) (be)
45 #else
46 # define AV_NE(be, le) (le)
47 #endif
48 
49 //rounded division & shift
50 #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
51 /* assume b>0 */
52 #define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
53 
57 #define AV_CEIL_RSHIFT(a, b) \
58  (av_builtin_constant_p(b) ? ((a) + (1 << (b)) - 1) >> (b) \
59  : -((-(a)) >> (b)))
60 
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 
72 /* misc math functions */
73 
74 #ifdef HAVE_AV_CONFIG_H
75 # include "config.h"
76 # include "intmath.h"
77 #endif
78 
79 /* Pull in unguarded fallback defines at the end of this file. */
80 #include "common.h"
81 
82 #ifndef av_log2
83 av_const int av_log2(unsigned v);
84 #endif
85 
86 #ifndef av_log2_16bit
87 av_const int av_log2_16bit(unsigned v);
88 #endif
89 
97 static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
98 {
99  if (a < amin) return amin;
100  else if (a > amax) return amax;
101  else return a;
102 }
103 
110 {
111  if (a&(~0xFF)) return (-a)>>31;
112  else return a;
113 }
114 
121 {
122  if ((a+0x80) & ~0xFF) return (a>>31) ^ 0x7F;
123  else return a;
124 }
125 
132 {
133  if (a&(~0xFFFF)) return (-a)>>31;
134  else return a;
135 }
136 
143 {
144  if ((a+0x8000) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
145  else return a;
146 }
147 
154 {
155  if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (a>>63) ^ 0x7FFFFFFF;
156  else return a;
157 }
158 
166 {
167  if ((a + (1 << p)) & ~((1 << (p + 1)) - 1))
168  return (a >> 31) ^ ((1 << p) - 1);
169  else
170  return a;
171 }
172 
179 static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
180 {
181  if (a & ~((1<<p) - 1)) return -a >> 31 & ((1<<p) - 1);
182  else return a;
183 }
184 
192 static av_always_inline int av_sat_add32_c(int a, int b)
193 {
194  return av_clipl_int32((int64_t)a + b);
195 }
196 
204 static av_always_inline int av_sat_dadd32_c(int a, int b)
205 {
206  return av_sat_add32(a, av_sat_add32(b, b));
207 }
208 
216 static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
217 {
218  if (a < amin) return amin;
219  else if (a > amax) return amax;
220  else return a;
221 }
222 
228 {
229  return av_log2((x - 1) << 1);
230 }
231 
238 {
239  x -= (x >> 1) & 0x55555555;
240  x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
241  x = (x + (x >> 4)) & 0x0F0F0F0F;
242  x += x >> 8;
243  return (x + (x >> 16)) & 0x3F;
244 }
245 
252 {
253  return av_popcount(x) + av_popcount(x >> 32);
254 }
255 
256 #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
257 #define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))
258 
270 #define GET_UTF8(val, GET_BYTE, ERROR)\
271  val= GET_BYTE;\
272  {\
273  uint32_t top = (val & 128) >> 1;\
274  if ((val & 0xc0) == 0x80)\
275  ERROR\
276  while (val & top) {\
277  int tmp= GET_BYTE - 128;\
278  if(tmp>>6)\
279  ERROR\
280  val= (val<<6) + tmp;\
281  top <<= 5;\
282  }\
283  val &= (top << 1) - 1;\
284  }
285 
295 #define GET_UTF16(val, GET_16BIT, ERROR)\
296  val = GET_16BIT;\
297  {\
298  unsigned int hi = val - 0xD800;\
299  if (hi < 0x800) {\
300  val = GET_16BIT - 0xDC00;\
301  if (val > 0x3FFU || hi > 0x3FFU)\
302  ERROR\
303  val += (hi<<10) + 0x10000;\
304  }\
305  }\
306 
307 
323 #define PUT_UTF8(val, tmp, PUT_BYTE)\
324  {\
325  int bytes, shift;\
326  uint32_t in = val;\
327  if (in < 0x80) {\
328  tmp = in;\
329  PUT_BYTE\
330  } else {\
331  bytes = (av_log2(in) + 4) / 5;\
332  shift = (bytes - 1) * 6;\
333  tmp = (256 - (256 >> bytes)) | (in >> shift);\
334  PUT_BYTE\
335  while (shift >= 6) {\
336  shift -= 6;\
337  tmp = 0x80 | ((in >> shift) & 0x3f);\
338  PUT_BYTE\
339  }\
340  }\
341  }
342 
357 #define PUT_UTF16(val, tmp, PUT_16BIT)\
358  {\
359  uint32_t in = val;\
360  if (in < 0x10000) {\
361  tmp = in;\
362  PUT_16BIT\
363  } else {\
364  tmp = 0xD800 | ((in - 0x10000) >> 10);\
365  PUT_16BIT\
366  tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
367  PUT_16BIT\
368  }\
369  }\
370 
371 
372 
373 #include "mem.h"
374 
375 #ifdef HAVE_AV_CONFIG_H
376 # include "internal.h"
377 #endif /* HAVE_AV_CONFIG_H */
378 
379 #endif /* AVUTIL_COMMON_H */
380 
381 /*
382  * The following definitions are outside the multiple inclusion guard
383  * to ensure they are immediately available in intmath.h.
384  */
385 
386 #ifndef av_ceil_log2
387 # define av_ceil_log2 av_ceil_log2_c
388 #endif
389 #ifndef av_clip
390 # define av_clip av_clip_c
391 #endif
392 #ifndef av_clip_uint8
393 # define av_clip_uint8 av_clip_uint8_c
394 #endif
395 #ifndef av_clip_int8
396 # define av_clip_int8 av_clip_int8_c
397 #endif
398 #ifndef av_clip_uint16
399 # define av_clip_uint16 av_clip_uint16_c
400 #endif
401 #ifndef av_clip_int16
402 # define av_clip_int16 av_clip_int16_c
403 #endif
404 #ifndef av_clipl_int32
405 # define av_clipl_int32 av_clipl_int32_c
406 #endif
407 #ifndef av_clip_intp2
408 # define av_clip_intp2 av_clip_intp2_c
409 #endif
410 #ifndef av_clip_uintp2
411 # define av_clip_uintp2 av_clip_uintp2_c
412 #endif
413 #ifndef av_sat_add32
414 # define av_sat_add32 av_sat_add32_c
415 #endif
416 #ifndef av_sat_dadd32
417 # define av_sat_dadd32 av_sat_dadd32_c
418 #endif
419 #ifndef av_clipf
420 # define av_clipf av_clipf_c
421 #endif
422 #ifndef av_popcount
423 # define av_popcount av_popcount_c
424 #endif
425 #ifndef av_popcount64
426 # define av_popcount64 av_popcount64_c
427 #endif
#define av_const
Definition: attributes.h:60
static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
Clip a signed 64-bit integer value into the -2147483648,2147483647 range.
Definition: common.h:153
static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
Clip a float value into the amin-amax range.
Definition: common.h:216
memory handling functions
static av_always_inline av_const int8_t av_clip_int8_c(int a)
Clip a signed integer value into the -128,127 range.
Definition: common.h:120
av_const int av_log2_16bit(unsigned v)
Definition: intmath.c:31
Macro definitions for various function/variable attributes.
uint8_t
#define b
Definition: input.c:52
Utility Preprocessor macros.
static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
Clip a signed integer value into the amin-amax range.
Definition: common.h:97
Libavutil version macros.
static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
Clip a signed integer value into the 0-65535 range.
Definition: common.h:131
static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
Clip a signed integer value into the 0-255 range.
Definition: common.h:109
int32_t
static av_always_inline av_const int av_clip_intp2_c(int a, int p)
Clip a signed integer into the -(2^p),(2^p-1) range.
Definition: common.h:165
av_const int av_log2(unsigned v)
Definition: intmath.c:26
static av_always_inline av_const int16_t av_clip_int16_c(int a)
Clip a signed integer value into the -32768,32767 range.
Definition: common.h:142
common internal and external API header
static av_always_inline av_const int av_popcount_c(uint32_t x)
Count number of bits set to one in x.
Definition: common.h:237
static av_always_inline int av_sat_add32_c(int a, int b)
Add two signed 32-bit values with saturation.
Definition: common.h:192
static av_always_inline av_const int av_popcount64_c(uint64_t x)
Count number of bits set to one in x.
Definition: common.h:251
static av_always_inline int av_sat_dadd32_c(int a, int b)
Add a doubled value to another value with saturation at both stages.
Definition: common.h:204
#define av_always_inline
Definition: attributes.h:40
static av_always_inline av_const int av_ceil_log2_c(int x)
Compute ceil(log2(x)).
Definition: common.h:227
static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
Clip a signed integer to an unsigned power of two range.
Definition: common.h:179