955040350345dc5fdedcaae79a429a24aecc5755
[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 COMMON_H
27 #define 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 #ifdef HAVE_AV_CONFIG_H
61 # include "internal.h"
62 #endif /* HAVE_AV_CONFIG_H */
63
64 #ifndef attribute_deprecated
65 #if defined(__GNUC__) && (__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ > 0)
66 # define attribute_deprecated __attribute__((deprecated))
67 #else
68 # define attribute_deprecated
69 #endif
70 #endif
71
72 #ifndef av_unused
73 #if defined(__GNUC__)
74 # define av_unused __attribute__((unused))
75 #else
76 # define av_unused
77 #endif
78 #endif
79
80 #include "mem.h"
81
82 //rounded divison & shift
83 #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
84 /* assume b>0 */
85 #define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
86 #define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
87 #define FFSIGN(a) ((a) > 0 ? 1 : -1)
88
89 #define FFMAX(a,b) ((a) > (b) ? (a) : (b))
90 #define FFMIN(a,b) ((a) > (b) ? (b) : (a))
91
92 #define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
93
94 /* misc math functions */
95 extern const uint8_t ff_log2_tab[256];
96
97 static inline int av_log2(unsigned int v)
98 {
99 int n;
100
101 n = 0;
102 if (v & 0xffff0000) {
103 v >>= 16;
104 n += 16;
105 }
106 if (v & 0xff00) {
107 v >>= 8;
108 n += 8;
109 }
110 n += ff_log2_tab[v];
111
112 return n;
113 }
114
115 static inline int av_log2_16bit(unsigned int v)
116 {
117 int n;
118
119 n = 0;
120 if (v & 0xff00) {
121 v >>= 8;
122 n += 8;
123 }
124 n += ff_log2_tab[v];
125
126 return n;
127 }
128
129 /* median of 3 */
130 static inline int mid_pred(int a, int b, int c)
131 {
132 #ifdef HAVE_CMOV
133 int i=b;
134 asm volatile(
135 "cmp %2, %1 \n\t"
136 "cmovg %1, %0 \n\t"
137 "cmovg %2, %1 \n\t"
138 "cmp %3, %1 \n\t"
139 "cmovl %3, %1 \n\t"
140 "cmp %1, %0 \n\t"
141 "cmovg %1, %0 \n\t"
142 :"+&r"(i), "+&r"(a)
143 :"r"(b), "r"(c)
144 );
145 return i;
146 #elif 0
147 int t= (a-b)&((a-b)>>31);
148 a-=t;
149 b+=t;
150 b-= (b-c)&((b-c)>>31);
151 b+= (a-b)&((a-b)>>31);
152
153 return b;
154 #else
155 if(a>b){
156 if(c>b){
157 if(c>a) b=a;
158 else b=c;
159 }
160 }else{
161 if(b>c){
162 if(c>a) b=c;
163 else b=a;
164 }
165 }
166 return b;
167 #endif
168 }
169
170 /**
171 * clip a signed integer value into the amin-amax range
172 * @param a value to clip
173 * @param amin minimum value of the clip range
174 * @param amax maximum value of the clip range
175 * @return clipped value
176 */
177 static inline int av_clip(int a, int amin, int amax)
178 {
179 if (a < amin) return amin;
180 else if (a > amax) return amax;
181 else return a;
182 }
183
184 /**
185 * clip a signed integer value into the 0-255 range
186 * @param a value to clip
187 * @return clipped value
188 */
189 static inline uint8_t av_clip_uint8(int a)
190 {
191 if (a&(~255)) return (-a)>>31;
192 else return a;
193 }
194
195 /**
196 * clip a signed integer value into the -32768,32767 range
197 * @param a value to clip
198 * @return clipped value
199 */
200 static inline int16_t av_clip_int16(int a)
201 {
202 if ((a+32768) & ~65535) return (a>>31) ^ 32767;
203 else return a;
204 }
205
206 /* math */
207 int64_t ff_gcd(int64_t a, int64_t b);
208
209 /**
210 * converts fourcc string to int
211 */
212 static inline int ff_get_fourcc(const char *s){
213 #ifdef HAVE_AV_CONFIG_H
214 assert( strlen(s)==4 );
215 #endif
216
217 return (s[0]) + (s[1]<<8) + (s[2]<<16) + (s[3]<<24);
218 }
219
220 #define MKTAG(a,b,c,d) (a | (b << 8) | (c << 16) | (d << 24))
221 #define MKBETAG(a,b,c,d) (d | (c << 8) | (b << 16) | (a << 24))
222
223 /*!
224 * \def GET_UTF8(val, GET_BYTE, ERROR)
225 * converts a UTF-8 character (up to 4 bytes long) to its 32-bit UCS-4 encoded form
226 * \param val is the output and should be of type uint32_t. It holds the converted
227 * UCS-4 character and should be a left value.
228 * \param GET_BYTE gets UTF-8 encoded bytes from any proper source. It can be
229 * a function or a statement whose return value or evaluated value is of type
230 * uint8_t. It will be executed up to 4 times for values in the valid UTF-8 range,
231 * and up to 7 times in the general case.
232 * \param ERROR action that should be taken when an invalid UTF-8 byte is returned
233 * from GET_BYTE. It should be a statement that jumps out of the macro,
234 * like exit(), goto, return, break, or continue.
235 */
236 #define GET_UTF8(val, GET_BYTE, ERROR)\
237 val= GET_BYTE;\
238 {\
239 int ones= 7 - av_log2(val ^ 255);\
240 if(ones==1)\
241 ERROR\
242 val&= 127>>ones;\
243 while(--ones > 0){\
244 int tmp= GET_BYTE - 128;\
245 if(tmp>>6)\
246 ERROR\
247 val= (val<<6) + tmp;\
248 }\
249 }
250
251 /*!
252 * \def PUT_UTF8(val, tmp, PUT_BYTE)
253 * converts a 32-bit unicode character to its UTF-8 encoded form (up to 4 bytes long).
254 * \param val is an input only argument and should be of type uint32_t. It holds
255 * a ucs4 encoded unicode character that is to be converted to UTF-8. If
256 * val is given as a function it's executed only once.
257 * \param tmp is a temporary variable and should be of type uint8_t. It
258 * represents an intermediate value during conversion that is to be
259 * outputted by PUT_BYTE.
260 * \param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
261 * It could be a function or a statement, and uses tmp as the input byte.
262 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
263 * executed up to 4 times for values in the valid UTF-8 range and up to
264 * 7 times in the general case, depending on the length of the converted
265 * unicode character.
266 */
267 #define PUT_UTF8(val, tmp, PUT_BYTE)\
268 {\
269 int bytes, shift;\
270 uint32_t in = val;\
271 if (in < 0x80) {\
272 tmp = in;\
273 PUT_BYTE\
274 } else {\
275 bytes = (av_log2(in) + 4) / 5;\
276 shift = (bytes - 1) * 6;\
277 tmp = (256 - (256 >> bytes)) | (in >> shift);\
278 PUT_BYTE\
279 while (shift >= 6) {\
280 shift -= 6;\
281 tmp = 0x80 | ((in >> shift) & 0x3f);\
282 PUT_BYTE\
283 }\
284 }\
285 }
286
287 #if defined(ARCH_X86) || defined(ARCH_POWERPC) || defined(ARCH_BFIN)
288 #define AV_READ_TIME read_time
289 #if defined(ARCH_X86_64)
290 static inline uint64_t read_time(void)
291 {
292 uint64_t a, d;
293 asm volatile( "rdtsc\n\t"
294 : "=a" (a), "=d" (d)
295 );
296 return (d << 32) | (a & 0xffffffff);
297 }
298 #elif defined(ARCH_X86_32)
299 static inline long long read_time(void)
300 {
301 long long l;
302 asm volatile( "rdtsc\n\t"
303 : "=A" (l)
304 );
305 return l;
306 }
307 #elif ARCH_BFIN
308 static inline uint64_t read_time(void)
309 {
310 union {
311 struct {
312 unsigned lo;
313 unsigned hi;
314 } p;
315 unsigned long long c;
316 } t;
317 asm volatile ("%0=cycles; %1=cycles2;" : "=d" (t.p.lo), "=d" (t.p.hi));
318 return t.c;
319 }
320 #else //FIXME check ppc64
321 static inline uint64_t read_time(void)
322 {
323 uint32_t tbu, tbl, temp;
324
325 /* from section 2.2.1 of the 32-bit PowerPC PEM */
326 __asm__ __volatile__(
327 "1:\n"
328 "mftbu %2\n"
329 "mftb %0\n"
330 "mftbu %1\n"
331 "cmpw %2,%1\n"
332 "bne 1b\n"
333 : "=r"(tbl), "=r"(tbu), "=r"(temp)
334 :
335 : "cc");
336
337 return (((uint64_t)tbu)<<32) | (uint64_t)tbl;
338 }
339 #endif
340 #elif defined(HAVE_GETHRTIME)
341 #define AV_READ_TIME gethrtime
342 #endif
343
344 #ifdef AV_READ_TIME
345 #define START_TIMER \
346 uint64_t tend;\
347 uint64_t tstart= AV_READ_TIME();\
348
349 #define STOP_TIMER(id) \
350 tend= AV_READ_TIME();\
351 {\
352 static uint64_t tsum=0;\
353 static int tcount=0;\
354 static int tskip_count=0;\
355 if(tcount<2 || tend - tstart < FFMAX(8*tsum/tcount, 2000)){\
356 tsum+= tend - tstart;\
357 tcount++;\
358 }else\
359 tskip_count++;\
360 if(((tcount+tskip_count)&(tcount+tskip_count-1))==0){\
361 av_log(NULL, AV_LOG_DEBUG, "%"PRIu64" dezicycles in %s, %d runs, %d skips\n", tsum*10/tcount, id, tcount, tskip_count);\
362 }\
363 }
364 #else
365 #define START_TIMER
366 #define STOP_TIMER(id) {}
367 #endif
368
369 #endif /* COMMON_H */