fd1d00c7b36cc7defc09d823bc01ea631704de37
[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 #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 = 0;
100 if (v & 0xffff0000) {
101 v >>= 16;
102 n += 16;
103 }
104 if (v & 0xff00) {
105 v >>= 8;
106 n += 8;
107 }
108 n += ff_log2_tab[v];
109
110 return n;
111 }
112
113 static inline int av_log2_16bit(unsigned int v)
114 {
115 int n = 0;
116 if (v & 0xff00) {
117 v >>= 8;
118 n += 8;
119 }
120 n += ff_log2_tab[v];
121
122 return n;
123 }
124
125 /* median of 3 */
126 static inline int mid_pred(int a, int b, int c)
127 {
128 #ifdef HAVE_CMOV
129 int i=b;
130 asm volatile(
131 "cmp %2, %1 \n\t"
132 "cmovg %1, %0 \n\t"
133 "cmovg %2, %1 \n\t"
134 "cmp %3, %1 \n\t"
135 "cmovl %3, %1 \n\t"
136 "cmp %1, %0 \n\t"
137 "cmovg %1, %0 \n\t"
138 :"+&r"(i), "+&r"(a)
139 :"r"(b), "r"(c)
140 );
141 return i;
142 #elif 0
143 int t= (a-b)&((a-b)>>31);
144 a-=t;
145 b+=t;
146 b-= (b-c)&((b-c)>>31);
147 b+= (a-b)&((a-b)>>31);
148
149 return b;
150 #else
151 if(a>b){
152 if(c>b){
153 if(c>a) b=a;
154 else b=c;
155 }
156 }else{
157 if(b>c){
158 if(c>a) b=c;
159 else b=a;
160 }
161 }
162 return b;
163 #endif
164 }
165
166 /**
167 * clip a signed integer value into the amin-amax range
168 * @param a value to clip
169 * @param amin minimum value of the clip range
170 * @param amax maximum value of the clip range
171 * @return clipped value
172 */
173 static inline int av_clip(int a, int amin, int amax)
174 {
175 if (a < amin) return amin;
176 else if (a > amax) return amax;
177 else return a;
178 }
179
180 /**
181 * clip a signed integer value into the 0-255 range
182 * @param a value to clip
183 * @return clipped value
184 */
185 static inline uint8_t av_clip_uint8(int a)
186 {
187 if (a&(~255)) return (-a)>>31;
188 else return a;
189 }
190
191 /**
192 * clip a signed integer value into the -32768,32767 range
193 * @param a value to clip
194 * @return clipped value
195 */
196 static inline int16_t av_clip_int16(int a)
197 {
198 if ((a+32768) & ~65535) return (a>>31) ^ 32767;
199 else return a;
200 }
201
202 /* math */
203 int64_t ff_gcd(int64_t a, int64_t b);
204
205 /**
206 * converts fourcc string to int
207 */
208 static inline int ff_get_fourcc(const char *s){
209 #ifdef HAVE_AV_CONFIG_H
210 assert( strlen(s)==4 );
211 #endif
212
213 return (s[0]) + (s[1]<<8) + (s[2]<<16) + (s[3]<<24);
214 }
215
216 #define MKTAG(a,b,c,d) (a | (b << 8) | (c << 16) | (d << 24))
217 #define MKBETAG(a,b,c,d) (d | (c << 8) | (b << 16) | (a << 24))
218
219 /*!
220 * \def GET_UTF8(val, GET_BYTE, ERROR)
221 * converts a UTF-8 character (up to 4 bytes long) to its 32-bit UCS-4 encoded form
222 * \param val is the output and should be of type uint32_t. It holds the converted
223 * UCS-4 character and should be a left value.
224 * \param GET_BYTE gets UTF-8 encoded bytes from any proper source. It can be
225 * a function or a statement whose return value or evaluated value is of type
226 * uint8_t. It will be executed up to 4 times for values in the valid UTF-8 range,
227 * and up to 7 times in the general case.
228 * \param ERROR action that should be taken when an invalid UTF-8 byte is returned
229 * from GET_BYTE. It should be a statement that jumps out of the macro,
230 * like exit(), goto, return, break, or continue.
231 */
232 #define GET_UTF8(val, GET_BYTE, ERROR)\
233 val= GET_BYTE;\
234 {\
235 int ones= 7 - av_log2(val ^ 255);\
236 if(ones==1)\
237 ERROR\
238 val&= 127>>ones;\
239 while(--ones > 0){\
240 int tmp= GET_BYTE - 128;\
241 if(tmp>>6)\
242 ERROR\
243 val= (val<<6) + tmp;\
244 }\
245 }
246
247 /*!
248 * \def PUT_UTF8(val, tmp, PUT_BYTE)
249 * converts a 32-bit unicode character to its UTF-8 encoded form (up to 4 bytes long).
250 * \param val is an input only argument and should be of type uint32_t. It holds
251 * a ucs4 encoded unicode character that is to be converted to UTF-8. If
252 * val is given as a function it's executed only once.
253 * \param tmp is a temporary variable and should be of type uint8_t. It
254 * represents an intermediate value during conversion that is to be
255 * outputted by PUT_BYTE.
256 * \param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
257 * It could be a function or a statement, and uses tmp as the input byte.
258 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
259 * executed up to 4 times for values in the valid UTF-8 range and up to
260 * 7 times in the general case, depending on the length of the converted
261 * unicode character.
262 */
263 #define PUT_UTF8(val, tmp, PUT_BYTE)\
264 {\
265 int bytes, shift;\
266 uint32_t in = val;\
267 if (in < 0x80) {\
268 tmp = in;\
269 PUT_BYTE\
270 } else {\
271 bytes = (av_log2(in) + 4) / 5;\
272 shift = (bytes - 1) * 6;\
273 tmp = (256 - (256 >> bytes)) | (in >> shift);\
274 PUT_BYTE\
275 while (shift >= 6) {\
276 shift -= 6;\
277 tmp = 0x80 | ((in >> shift) & 0x3f);\
278 PUT_BYTE\
279 }\
280 }\
281 }
282
283 #if defined(ARCH_X86) || defined(ARCH_POWERPC) || defined(ARCH_BFIN)
284 #define AV_READ_TIME read_time
285 #if defined(ARCH_X86_64)
286 static inline uint64_t read_time(void)
287 {
288 uint64_t a, d;
289 asm volatile("rdtsc\n\t"
290 : "=a" (a), "=d" (d));
291 return (d << 32) | (a & 0xffffffff);
292 }
293 #elif defined(ARCH_X86_32)
294 static inline long long read_time(void)
295 {
296 long long l;
297 asm volatile("rdtsc\n\t"
298 : "=A" (l));
299 return l;
300 }
301 #elif ARCH_BFIN
302 static inline uint64_t read_time(void)
303 {
304 union {
305 struct {
306 unsigned lo;
307 unsigned hi;
308 } p;
309 unsigned long long c;
310 } t;
311 asm volatile ("%0=cycles; %1=cycles2;" : "=d" (t.p.lo), "=d" (t.p.hi));
312 return t.c;
313 }
314 #else //FIXME check ppc64
315 static inline uint64_t read_time(void)
316 {
317 uint32_t tbu, tbl, temp;
318
319 /* from section 2.2.1 of the 32-bit PowerPC PEM */
320 __asm__ __volatile__(
321 "1:\n"
322 "mftbu %2\n"
323 "mftb %0\n"
324 "mftbu %1\n"
325 "cmpw %2,%1\n"
326 "bne 1b\n"
327 : "=r"(tbl), "=r"(tbu), "=r"(temp)
328 :
329 : "cc");
330
331 return (((uint64_t)tbu)<<32) | (uint64_t)tbl;
332 }
333 #endif
334 #elif defined(HAVE_GETHRTIME)
335 #define AV_READ_TIME gethrtime
336 #endif
337
338 #ifdef AV_READ_TIME
339 #define START_TIMER \
340 uint64_t tend;\
341 uint64_t tstart= AV_READ_TIME();\
342
343 #define STOP_TIMER(id) \
344 tend= AV_READ_TIME();\
345 {\
346 static uint64_t tsum=0;\
347 static int tcount=0;\
348 static int tskip_count=0;\
349 if(tcount<2 || tend - tstart < FFMAX(8*tsum/tcount, 2000)){\
350 tsum+= tend - tstart;\
351 tcount++;\
352 }else\
353 tskip_count++;\
354 if(((tcount+tskip_count)&(tcount+tskip_count-1))==0){\
355 av_log(NULL, AV_LOG_DEBUG, "%"PRIu64" dezicycles in %s, %d runs, %d skips\n",\
356 tsum*10/tcount, id, tcount, tskip_count);\
357 }\
358 }
359 #else
360 #define START_TIMER
361 #define STOP_TIMER(id) {}
362 #endif
363
364 #endif /* FFMPEG_COMMON_H */