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
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 <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
av_log2_c(unsigned int v)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
av_log2_16bit_c(unsigned int v)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
103 /**
104 * Clip a signed integer value into the amin-amax range.
105 * @param a value to clip
106 * @param amin minimum value of the clip range
107 * @param amax maximum value of the clip range
108 * @return clipped value
109 */
av_clip_c(int a,int amin,int amax)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
117 /**
118 * Clip a signed integer value into the 0-255 range.
119 * @param a value to clip
120 * @return clipped value
121 */
av_clip_uint8_c(int a)122 static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
123 {
124 if (a&(~0xFF)) return (-a)>>31;
125 else return a;
126 }
127
128 /**
129 * Clip a signed integer value into the -128,127 range.
130 * @param a value to clip
131 * @return clipped value
132 */
av_clip_int8_c(int a)133 static av_always_inline av_const int8_t av_clip_int8_c(int a)
134 {
135 if ((a+0x80) & ~0xFF) return (a>>31) ^ 0x7F;
136 else return a;
137 }
138
139 /**
140 * Clip a signed integer value into the 0-65535 range.
141 * @param a value to clip
142 * @return clipped value
143 */
av_clip_uint16_c(int a)144 static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
145 {
146 if (a&(~0xFFFF)) return (-a)>>31;
147 else return a;
148 }
149
150 /**
151 * Clip a signed integer value into the -32768,32767 range.
152 * @param a value to clip
153 * @return clipped value
154 */
av_clip_int16_c(int a)155 static av_always_inline av_const int16_t av_clip_int16_c(int a)
156 {
157 if ((a+0x8000) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
158 else return a;
159 }
160
161 /**
162 * Clip a signed 64-bit integer value into the -2147483648,2147483647 range.
163 * @param a value to clip
164 * @return clipped value
165 */
av_clipl_int32_c(int64_t a)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
172 /**
173 * Clip a signed integer to an unsigned power of two range.
174 * @param a value to clip
175 * @param p bit position to clip at
176 * @return clipped value
177 */
av_clip_uintp2_c(int a,int p)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
184 /**
185 * Clip a float value into the amin-amax range.
186 * @param a value to clip
187 * @param amin minimum value of the clip range
188 * @param amax maximum value of the clip range
189 * @return clipped value
190 */
av_clipf_c(float a,float amin,float amax)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
198 /** Compute ceil(log2(x)).
199 * @param x value used to compute ceil(log2(x))
200 * @return computed ceiling of log2(x)
201 */
av_ceil_log2_c(int x)202 static av_always_inline av_const int av_ceil_log2_c(int x)
203 {
204 return av_log2((x - 1) << 1);
205 }
206
207 /**
208 * Count number of bits set to one in x
209 * @param x value to count bits of
210 * @return the number of bits set to one in x
211 */
av_popcount_c(uint32_t x)212 static av_always_inline av_const int av_popcount_c(uint32_t x)
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
221 /**
222 * Count number of bits set to one in x
223 * @param x value to count bits of
224 * @return the number of bits set to one in x
225 */
av_popcount64_c(uint64_t x)226 static av_always_inline av_const int av_popcount64_c(uint64_t x)
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
234 /**
235 * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
236 *
237 * @param val Output value, must be an lvalue of type uint32_t.
238 * @param GET_BYTE Expression reading one byte from the input.
239 * Evaluated up to 7 times (4 for the currently
240 * assigned Unicode range). With a memory buffer
241 * input, this could be *ptr++.
242 * @param ERROR Expression to be evaluated on invalid input,
243 * typically a goto statement.
244 */
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
260 /**
261 * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
262 *
263 * @param val Output value, must be an lvalue of type uint32_t.
264 * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
265 * to native byte order. Evaluated one or two times.
266 * @param ERROR Expression to be evaluated on invalid input,
267 * typically a goto statement.
268 */
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 /**
282 * @def PUT_UTF8(val, tmp, PUT_BYTE)
283 * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
284 * @param val is an input-only argument and should be of type uint32_t. It holds
285 * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
286 * val is given as a function it is executed only once.
287 * @param tmp is a temporary variable and should be of type uint8_t. It
288 * represents an intermediate value during conversion that is to be
289 * output by PUT_BYTE.
290 * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
291 * It could be a function or a statement, and uses tmp as the input byte.
292 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
293 * executed up to 4 times for values in the valid UTF-8 range and up to
294 * 7 times in the general case, depending on the length of the converted
295 * Unicode character.
296 */
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
317 /**
318 * @def PUT_UTF16(val, tmp, PUT_16BIT)
319 * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
320 * @param val is an input-only argument and should be of type uint32_t. It holds
321 * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
322 * val is given as a function it is executed only once.
323 * @param tmp is a temporary variable and should be of type uint16_t. It
324 * represents an intermediate value during conversion that is to be
325 * output by PUT_16BIT.
326 * @param PUT_16BIT writes the converted UTF-16 data to any proper destination
327 * in desired endianness. It could be a function or a statement, and uses tmp
328 * as the input byte. For example, PUT_BYTE could be "*output++ = tmp;"
329 * PUT_BYTE will be executed 1 or 2 times depending on input character.
330 */
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
399