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 <ctype.h>
30 #include <errno.h>
31 #include <inttypes.h>
32 #include <limits.h>
33 #include <math.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include "attributes.h"
38 #include "libavutil/avconfig.h"
39 
40 #if AV_HAVE_BIGENDIAN
41 # define AV_NE(be, le) (be)
42 #else
43 # define AV_NE(be, le) (le)
44 #endif
45 
46 //rounded division & shift
47 #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
48 /* assume b>0 */
49 #define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
50 #define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
51 #define FFSIGN(a) ((a) > 0 ? 1 : -1)
52 
53 #define FFMAX(a,b) ((a) > (b) ? (a) : (b))
54 #define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
55 #define FFMIN(a,b) ((a) > (b) ? (b) : (a))
56 #define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)
57 
58 #define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
59 #define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
60 #define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1))
61 
62 /* misc math functions */
63 extern const uint8_t ff_log2_tab[256];
64 
65 extern const uint8_t av_reverse[256];
66 
67 static av_always_inline av_const int av_log2_c(unsigned int v)
68 {
69  int n = 0;
70  if (v & 0xffff0000) {
71  v >>= 16;
72  n += 16;
73  }
74  if (v & 0xff00) {
75  v >>= 8;
76  n += 8;
77  }
78  n += ff_log2_tab[v];
79 
80  return n;
81 }
82 
83 static av_always_inline av_const int av_log2_16bit_c(unsigned int v)
84 {
85  int n = 0;
86  if (v & 0xff00) {
87  v >>= 8;
88  n += 8;
89  }
90  n += ff_log2_tab[v];
91 
92  return n;
93 }
94 
95 #ifdef HAVE_AV_CONFIG_H
96 # include "config.h"
97 # include "intmath.h"
98 #endif
99 
100 /* Pull in unguarded fallback defines at the end of this file. */
101 #include "common.h"
102 
110 static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
111 {
112  if (a < amin) return amin;
113  else if (a > amax) return amax;
114  else return a;
115 }
116 
123 {
124  if (a&(~0xFF)) return (-a)>>31;
125  else return a;
126 }
127 
134 {
135  if ((a+0x80) & ~0xFF) return (a>>31) ^ 0x7F;
136  else return a;
137 }
138 
145 {
146  if (a&(~0xFFFF)) return (-a)>>31;
147  else return a;
148 }
149 
156 {
157  if ((a+0x8000) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
158  else return a;
159 }
160 
166 static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
167 {
168  if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (a>>63) ^ 0x7FFFFFFF;
169  else return a;
170 }
171 
178 static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
179 {
180  if (a & ~((1<<p) - 1)) return -a >> 31 & ((1<<p) - 1);
181  else return a;
182 }
183 
191 static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
192 {
193  if (a < amin) return amin;
194  else if (a > amax) return amax;
195  else return a;
196 }
197 
203 {
204  return av_log2((x - 1) << 1);
205 }
206 
213 {
214  x -= (x >> 1) & 0x55555555;
215  x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
216  x = (x + (x >> 4)) & 0x0F0F0F0F;
217  x += x >> 8;
218  return (x + (x >> 16)) & 0x3F;
219 }
220 
227 {
228  return av_popcount(x) + av_popcount(x >> 32);
229 }
230 
231 #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
232 #define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))
233 
245 #define GET_UTF8(val, GET_BYTE, ERROR)\
246  val= GET_BYTE;\
247  {\
248  int ones= 7 - av_log2(val ^ 255);\
249  if(ones==1)\
250  ERROR\
251  val&= 127>>ones;\
252  while(--ones > 0){\
253  int tmp= GET_BYTE - 128;\
254  if(tmp>>6)\
255  ERROR\
256  val= (val<<6) + tmp;\
257  }\
258  }
259 
269 #define GET_UTF16(val, GET_16BIT, ERROR)\
270  val = GET_16BIT;\
271  {\
272  unsigned int hi = val - 0xD800;\
273  if (hi < 0x800) {\
274  val = GET_16BIT - 0xDC00;\
275  if (val > 0x3FFU || hi > 0x3FFU)\
276  ERROR\
277  val += (hi<<10) + 0x10000;\
278  }\
279  }\
280 
281 
297 #define PUT_UTF8(val, tmp, PUT_BYTE)\
298  {\
299  int bytes, shift;\
300  uint32_t in = val;\
301  if (in < 0x80) {\
302  tmp = in;\
303  PUT_BYTE\
304  } else {\
305  bytes = (av_log2(in) + 4) / 5;\
306  shift = (bytes - 1) * 6;\
307  tmp = (256 - (256 >> bytes)) | (in >> shift);\
308  PUT_BYTE\
309  while (shift >= 6) {\
310  shift -= 6;\
311  tmp = 0x80 | ((in >> shift) & 0x3f);\
312  PUT_BYTE\
313  }\
314  }\
315  }
316 
331 #define PUT_UTF16(val, tmp, PUT_16BIT)\
332  {\
333  uint32_t in = val;\
334  if (in < 0x10000) {\
335  tmp = in;\
336  PUT_16BIT\
337  } else {\
338  tmp = 0xD800 | ((in - 0x10000) >> 10);\
339  PUT_16BIT\
340  tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
341  PUT_16BIT\
342  }\
343  }\
344 
345 
346 
347 #include "mem.h"
348 
349 #ifdef HAVE_AV_CONFIG_H
350 # include "internal.h"
351 #endif /* HAVE_AV_CONFIG_H */
352 
353 #endif /* AVUTIL_COMMON_H */
354 
355 /*
356  * The following definitions are outside the multiple inclusion guard
357  * to ensure they are immediately available in intmath.h.
358  */
359 
360 #ifndef av_log2
361 # define av_log2 av_log2_c
362 #endif
363 #ifndef av_log2_16bit
364 # define av_log2_16bit av_log2_16bit_c
365 #endif
366 #ifndef av_ceil_log2
367 # define av_ceil_log2 av_ceil_log2_c
368 #endif
369 #ifndef av_clip
370 # define av_clip av_clip_c
371 #endif
372 #ifndef av_clip_uint8
373 # define av_clip_uint8 av_clip_uint8_c
374 #endif
375 #ifndef av_clip_int8
376 # define av_clip_int8 av_clip_int8_c
377 #endif
378 #ifndef av_clip_uint16
379 # define av_clip_uint16 av_clip_uint16_c
380 #endif
381 #ifndef av_clip_int16
382 # define av_clip_int16 av_clip_int16_c
383 #endif
384 #ifndef av_clipl_int32
385 # define av_clipl_int32 av_clipl_int32_c
386 #endif
387 #ifndef av_clip_uintp2
388 # define av_clip_uintp2 av_clip_uintp2_c
389 #endif
390 #ifndef av_clipf
391 # define av_clipf av_clipf_c
392 #endif
393 #ifndef av_popcount
394 # define av_popcount av_popcount_c
395 #endif
396 #ifndef av_popcount64
397 # define av_popcount64 av_popcount64_c
398 #endif