Pure, const and malloc attributes to libavutil.
[libav.git] / libavutil / common.h
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 common.h
23 * common internal and external API header
24 */
25
26 #ifndef FFMPEG_COMMON_H
27 #define FFMPEG_COMMON_H
28
29 #include <inttypes.h>
30
31 #ifdef HAVE_AV_CONFIG_H
32 /* only include the following when compiling package */
33 # include "config.h"
34
35 # include <stdlib.h>
36 # include <stdio.h>
37 # include <string.h>
38 # include <ctype.h>
39 # include <limits.h>
40 # include <errno.h>
41 # include <math.h>
42 #endif /* HAVE_AV_CONFIG_H */
43
44 #ifndef av_always_inline
45 #if defined(__GNUC__) && (__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ > 0)
46 # define av_always_inline __attribute__((always_inline)) inline
47 #else
48 # define av_always_inline inline
49 #endif
50 #endif
51
52 #ifndef av_noinline
53 #if defined(__GNUC__) && (__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ > 0)
54 # define av_noinline __attribute__((noinline))
55 #else
56 # define av_noinline
57 #endif
58 #endif
59
60 #ifndef av_pure
61 #if defined(__GNUC__) && (__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ > 0)
62 # define av_pure __attribute__((pure))
63 #else
64 # define av_pure
65 #endif
66 #endif
67
68 #ifndef av_const
69 #if defined(__GNUC__) && (__GNUC__ > 2 || __GNUC__ == 2 && __GNUC_MINOR__ > 5)
70 # define av_const __attribute__((const))
71 #else
72 # define av_const
73 #endif
74 #endif
75
76 #ifdef HAVE_AV_CONFIG_H
77 # include "internal.h"
78 #endif /* HAVE_AV_CONFIG_H */
79
80 #ifndef attribute_deprecated
81 #if defined(__GNUC__) && (__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ > 0)
82 # define attribute_deprecated __attribute__((deprecated))
83 #else
84 # define attribute_deprecated
85 #endif
86 #endif
87
88 #ifndef av_unused
89 #if defined(__GNUC__)
90 # define av_unused __attribute__((unused))
91 #else
92 # define av_unused
93 #endif
94 #endif
95
96 #include "mem.h"
97
98 //rounded divison & shift
99 #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
100 /* assume b>0 */
101 #define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
102 #define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
103 #define FFSIGN(a) ((a) > 0 ? 1 : -1)
104
105 #define FFMAX(a,b) ((a) > (b) ? (a) : (b))
106 #define FFMIN(a,b) ((a) > (b) ? (b) : (a))
107
108 #define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
109
110 /* misc math functions */
111 extern const uint8_t ff_log2_tab[256];
112
113 static inline av_const int av_log2(unsigned int v)
114 {
115 int n = 0;
116 if (v & 0xffff0000) {
117 v >>= 16;
118 n += 16;
119 }
120 if (v & 0xff00) {
121 v >>= 8;
122 n += 8;
123 }
124 n += ff_log2_tab[v];
125
126 return n;
127 }
128
129 static inline av_const int av_log2_16bit(unsigned int v)
130 {
131 int n = 0;
132 if (v & 0xff00) {
133 v >>= 8;
134 n += 8;
135 }
136 n += ff_log2_tab[v];
137
138 return n;
139 }
140
141 /* median of 3 */
142 static inline av_const int mid_pred(int a, int b, int c)
143 {
144 #ifdef HAVE_CMOV
145 int i=b;
146 asm volatile(
147 "cmp %2, %1 \n\t"
148 "cmovg %1, %0 \n\t"
149 "cmovg %2, %1 \n\t"
150 "cmp %3, %1 \n\t"
151 "cmovl %3, %1 \n\t"
152 "cmp %1, %0 \n\t"
153 "cmovg %1, %0 \n\t"
154 :"+&r"(i), "+&r"(a)
155 :"r"(b), "r"(c)
156 );
157 return i;
158 #elif 0
159 int t= (a-b)&((a-b)>>31);
160 a-=t;
161 b+=t;
162 b-= (b-c)&((b-c)>>31);
163 b+= (a-b)&((a-b)>>31);
164
165 return b;
166 #else
167 if(a>b){
168 if(c>b){
169 if(c>a) b=a;
170 else b=c;
171 }
172 }else{
173 if(b>c){
174 if(c>a) b=c;
175 else b=a;
176 }
177 }
178 return b;
179 #endif
180 }
181
182 /**
183 * clip a signed integer value into the amin-amax range
184 * @param a value to clip
185 * @param amin minimum value of the clip range
186 * @param amax maximum value of the clip range
187 * @return clipped value
188 */
189 static inline av_const int av_clip(int a, int amin, int amax)
190 {
191 if (a < amin) return amin;
192 else if (a > amax) return amax;
193 else return a;
194 }
195
196 /**
197 * clip a signed integer value into the 0-255 range
198 * @param a value to clip
199 * @return clipped value
200 */
201 static inline av_const uint8_t av_clip_uint8(int a)
202 {
203 if (a&(~255)) return (-a)>>31;
204 else return a;
205 }
206
207 /**
208 * clip a signed integer value into the -32768,32767 range
209 * @param a value to clip
210 * @return clipped value
211 */
212 static inline av_const int16_t av_clip_int16(int a)
213 {
214 if ((a+32768) & ~65535) return (a>>31) ^ 32767;
215 else return a;
216 }
217
218 /* math */
219 int64_t av_const ff_gcd(int64_t a, int64_t b);
220
221 /**
222 * converts fourcc string to int
223 */
224 static inline av_pure int ff_get_fourcc(const char *s){
225 #ifdef HAVE_AV_CONFIG_H
226 assert( strlen(s)==4 );
227 #endif
228
229 return (s[0]) + (s[1]<<8) + (s[2]<<16) + (s[3]<<24);
230 }
231
232 #define MKTAG(a,b,c,d) (a | (b << 8) | (c << 16) | (d << 24))
233 #define MKBETAG(a,b,c,d) (d | (c << 8) | (b << 16) | (a << 24))
234
235 /*!
236 * \def GET_UTF8(val, GET_BYTE, ERROR)
237 * converts a UTF-8 character (up to 4 bytes long) to its 32-bit UCS-4 encoded form
238 * \param val is the output and should be of type uint32_t. It holds the converted
239 * UCS-4 character and should be a left value.
240 * \param GET_BYTE gets UTF-8 encoded bytes from any proper source. It can be
241 * a function or a statement whose return value or evaluated value is of type
242 * uint8_t. It will be executed up to 4 times for values in the valid UTF-8 range,
243 * and up to 7 times in the general case.
244 * \param ERROR action that should be taken when an invalid UTF-8 byte is returned
245 * from GET_BYTE. It should be a statement that jumps out of the macro,
246 * like exit(), goto, return, break, or continue.
247 */
248 #define GET_UTF8(val, GET_BYTE, ERROR)\
249 val= GET_BYTE;\
250 {\
251 int ones= 7 - av_log2(val ^ 255);\
252 if(ones==1)\
253 ERROR\
254 val&= 127>>ones;\
255 while(--ones > 0){\
256 int tmp= GET_BYTE - 128;\
257 if(tmp>>6)\
258 ERROR\
259 val= (val<<6) + tmp;\
260 }\
261 }
262
263 /*!
264 * \def PUT_UTF8(val, tmp, PUT_BYTE)
265 * converts a 32-bit unicode character to its UTF-8 encoded form (up to 4 bytes long).
266 * \param val is an input only argument and should be of type uint32_t. It holds
267 * a ucs4 encoded unicode character that is to be converted to UTF-8. If
268 * val is given as a function it's executed only once.
269 * \param tmp is a temporary variable and should be of type uint8_t. It
270 * represents an intermediate value during conversion that is to be
271 * outputted by PUT_BYTE.
272 * \param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
273 * It could be a function or a statement, and uses tmp as the input byte.
274 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
275 * executed up to 4 times for values in the valid UTF-8 range and up to
276 * 7 times in the general case, depending on the length of the converted
277 * unicode character.
278 */
279 #define PUT_UTF8(val, tmp, PUT_BYTE)\
280 {\
281 int bytes, shift;\
282 uint32_t in = val;\
283 if (in < 0x80) {\
284 tmp = in;\
285 PUT_BYTE\
286 } else {\
287 bytes = (av_log2(in) + 4) / 5;\
288 shift = (bytes - 1) * 6;\
289 tmp = (256 - (256 >> bytes)) | (in >> shift);\
290 PUT_BYTE\
291 while (shift >= 6) {\
292 shift -= 6;\
293 tmp = 0x80 | ((in >> shift) & 0x3f);\
294 PUT_BYTE\
295 }\
296 }\
297 }
298
299 #if defined(ARCH_X86) || defined(ARCH_POWERPC) || defined(ARCH_BFIN)
300 #define AV_READ_TIME read_time
301 #if defined(ARCH_X86_64)
302 static inline uint64_t read_time(void)
303 {
304 uint64_t a, d;
305 asm volatile("rdtsc\n\t"
306 : "=a" (a), "=d" (d));
307 return (d << 32) | (a & 0xffffffff);
308 }
309 #elif defined(ARCH_X86_32)
310 static inline long long read_time(void)
311 {
312 long long l;
313 asm volatile("rdtsc\n\t"
314 : "=A" (l));
315 return l;
316 }
317 #elif ARCH_BFIN
318 static inline uint64_t read_time(void)
319 {
320 union {
321 struct {
322 unsigned lo;
323 unsigned hi;
324 } p;
325 unsigned long long c;
326 } t;
327 asm volatile ("%0=cycles; %1=cycles2;" : "=d" (t.p.lo), "=d" (t.p.hi));
328 return t.c;
329 }
330 #else //FIXME check ppc64
331 static inline uint64_t read_time(void)
332 {
333 uint32_t tbu, tbl, temp;
334
335 /* from section 2.2.1 of the 32-bit PowerPC PEM */
336 __asm__ __volatile__(
337 "1:\n"
338 "mftbu %2\n"
339 "mftb %0\n"
340 "mftbu %1\n"
341 "cmpw %2,%1\n"
342 "bne 1b\n"
343 : "=r"(tbl), "=r"(tbu), "=r"(temp)
344 :
345 : "cc");
346
347 return (((uint64_t)tbu)<<32) | (uint64_t)tbl;
348 }
349 #endif
350 #elif defined(HAVE_GETHRTIME)
351 #define AV_READ_TIME gethrtime
352 #endif
353
354 #ifdef AV_READ_TIME
355 #define START_TIMER \
356 uint64_t tend;\
357 uint64_t tstart= AV_READ_TIME();\
358
359 #define STOP_TIMER(id) \
360 tend= AV_READ_TIME();\
361 {\
362 static uint64_t tsum=0;\
363 static int tcount=0;\
364 static int tskip_count=0;\
365 if(tcount<2 || tend - tstart < FFMAX(8*tsum/tcount, 2000)){\
366 tsum+= tend - tstart;\
367 tcount++;\
368 }else\
369 tskip_count++;\
370 if(((tcount+tskip_count)&(tcount+tskip_count-1))==0){\
371 av_log(NULL, AV_LOG_DEBUG, "%"PRIu64" dezicycles in %s, %d runs, %d skips\n",\
372 tsum*10/tcount, id, tcount, tskip_count);\
373 }\
374 }
375 #else
376 #define START_TIMER
377 #define STOP_TIMER(id) {}
378 #endif
379
380 #endif /* FFMPEG_COMMON_H */