Rename var
[FFMpeg-mirror/DVCPRO-HD.git] / libavutil / common.h
blob5a56832eebc3057f6fb4c369eacbadf6cb80b7e4
1 /*
2 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
4 * This file is part of FFmpeg.
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.
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.
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
21 /**
22 * @file common.h
23 * common internal and external API header
26 #ifndef FFMPEG_COMMON_H
27 #define FFMPEG_COMMON_H
29 #include <inttypes.h>
31 #ifdef HAVE_AV_CONFIG_H
32 /* only include the following when compiling package */
33 # include "config.h"
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 */
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
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
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
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
76 #ifndef av_cold
77 #if defined(__GNUC__) && (__GNUC__ > 4 || __GNUC__ == 4 && __GNUC_MINOR__ > 2)
78 # define av_cold __attribute__((cold))
79 #else
80 # define av_cold
81 #endif
82 #endif
84 #ifdef HAVE_AV_CONFIG_H
85 # include "internal.h"
86 #endif /* HAVE_AV_CONFIG_H */
88 #ifndef attribute_deprecated
89 #if defined(__GNUC__) && (__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ > 0)
90 # define attribute_deprecated __attribute__((deprecated))
91 #else
92 # define attribute_deprecated
93 #endif
94 #endif
96 #ifndef av_unused
97 #if defined(__GNUC__)
98 # define av_unused __attribute__((unused))
99 #else
100 # define av_unused
101 #endif
102 #endif
104 #include "mem.h"
106 //rounded divison & shift
107 #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
108 /* assume b>0 */
109 #define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
110 #define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
111 #define FFSIGN(a) ((a) > 0 ? 1 : -1)
113 #define FFMAX(a,b) ((a) > (b) ? (a) : (b))
114 #define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
115 #define FFMIN(a,b) ((a) > (b) ? (b) : (a))
116 #define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)
118 #define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
120 /* misc math functions */
121 extern const uint8_t ff_log2_tab[256];
123 static inline av_const int av_log2(unsigned int v)
125 int n = 0;
126 if (v & 0xffff0000) {
127 v >>= 16;
128 n += 16;
130 if (v & 0xff00) {
131 v >>= 8;
132 n += 8;
134 n += ff_log2_tab[v];
136 return n;
139 static inline av_const int av_log2_16bit(unsigned int v)
141 int n = 0;
142 if (v & 0xff00) {
143 v >>= 8;
144 n += 8;
146 n += ff_log2_tab[v];
148 return n;
151 /* median of 3 */
152 static inline av_const int mid_pred(int a, int b, int c)
154 #ifdef HAVE_CMOV
155 int i=b;
156 asm volatile(
157 "cmp %2, %1 \n\t"
158 "cmovg %1, %0 \n\t"
159 "cmovg %2, %1 \n\t"
160 "cmp %3, %1 \n\t"
161 "cmovl %3, %1 \n\t"
162 "cmp %1, %0 \n\t"
163 "cmovg %1, %0 \n\t"
164 :"+&r"(i), "+&r"(a)
165 :"r"(b), "r"(c)
167 return i;
168 #elif 0
169 int t= (a-b)&((a-b)>>31);
170 a-=t;
171 b+=t;
172 b-= (b-c)&((b-c)>>31);
173 b+= (a-b)&((a-b)>>31);
175 return b;
176 #else
177 if(a>b){
178 if(c>b){
179 if(c>a) b=a;
180 else b=c;
182 }else{
183 if(b>c){
184 if(c>a) b=c;
185 else b=a;
188 return b;
189 #endif
193 * clip a signed integer value into the amin-amax range
194 * @param a value to clip
195 * @param amin minimum value of the clip range
196 * @param amax maximum value of the clip range
197 * @return clipped value
199 static inline av_const int av_clip(int a, int amin, int amax)
201 if (a < amin) return amin;
202 else if (a > amax) return amax;
203 else return a;
207 * clip a signed integer value into the 0-255 range
208 * @param a value to clip
209 * @return clipped value
211 static inline av_const uint8_t av_clip_uint8(int a)
213 if (a&(~255)) return (-a)>>31;
214 else return a;
218 * clip a signed integer value into the -32768,32767 range
219 * @param a value to clip
220 * @return clipped value
222 static inline av_const int16_t av_clip_int16(int a)
224 if ((a+32768) & ~65535) return (a>>31) ^ 32767;
225 else return a;
228 /* math */
229 int64_t av_const ff_gcd(int64_t a, int64_t b);
232 * converts fourcc string to int
234 static inline av_pure int ff_get_fourcc(const char *s){
235 #ifdef HAVE_AV_CONFIG_H
236 assert( strlen(s)==4 );
237 #endif
239 return (s[0]) + (s[1]<<8) + (s[2]<<16) + (s[3]<<24);
242 #define MKTAG(a,b,c,d) (a | (b << 8) | (c << 16) | (d << 24))
243 #define MKBETAG(a,b,c,d) (d | (c << 8) | (b << 16) | (a << 24))
246 * \def GET_UTF8(val, GET_BYTE, ERROR)
247 * converts a UTF-8 character (up to 4 bytes long) to its 32-bit UCS-4 encoded form
248 * \param val is the output and should be of type uint32_t. It holds the converted
249 * UCS-4 character and should be a left value.
250 * \param GET_BYTE gets UTF-8 encoded bytes from any proper source. It can be
251 * a function or a statement whose return value or evaluated value is of type
252 * uint8_t. It will be executed up to 4 times for values in the valid UTF-8 range,
253 * and up to 7 times in the general case.
254 * \param ERROR action that should be taken when an invalid UTF-8 byte is returned
255 * from GET_BYTE. It should be a statement that jumps out of the macro,
256 * like exit(), goto, return, break, or continue.
258 #define GET_UTF8(val, GET_BYTE, ERROR)\
259 val= GET_BYTE;\
261 int ones= 7 - av_log2(val ^ 255);\
262 if(ones==1)\
263 ERROR\
264 val&= 127>>ones;\
265 while(--ones > 0){\
266 int tmp= GET_BYTE - 128;\
267 if(tmp>>6)\
268 ERROR\
269 val= (val<<6) + tmp;\
274 * \def PUT_UTF8(val, tmp, PUT_BYTE)
275 * converts a 32-bit unicode character to its UTF-8 encoded form (up to 4 bytes long).
276 * \param val is an input only argument and should be of type uint32_t. It holds
277 * a ucs4 encoded unicode character that is to be converted to UTF-8. If
278 * val is given as a function it's executed only once.
279 * \param tmp is a temporary variable and should be of type uint8_t. It
280 * represents an intermediate value during conversion that is to be
281 * outputted by PUT_BYTE.
282 * \param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
283 * It could be a function or a statement, and uses tmp as the input byte.
284 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
285 * executed up to 4 times for values in the valid UTF-8 range and up to
286 * 7 times in the general case, depending on the length of the converted
287 * unicode character.
289 #define PUT_UTF8(val, tmp, PUT_BYTE)\
291 int bytes, shift;\
292 uint32_t in = val;\
293 if (in < 0x80) {\
294 tmp = in;\
295 PUT_BYTE\
296 } else {\
297 bytes = (av_log2(in) + 4) / 5;\
298 shift = (bytes - 1) * 6;\
299 tmp = (256 - (256 >> bytes)) | (in >> shift);\
300 PUT_BYTE\
301 while (shift >= 6) {\
302 shift -= 6;\
303 tmp = 0x80 | ((in >> shift) & 0x3f);\
304 PUT_BYTE\
309 #if defined(ARCH_X86) || defined(ARCH_POWERPC) || defined(ARCH_BFIN)
310 #define AV_READ_TIME read_time
311 #if defined(ARCH_X86_64)
312 static inline uint64_t read_time(void)
314 uint64_t a, d;
315 asm volatile("rdtsc\n\t"
316 : "=a" (a), "=d" (d));
317 return (d << 32) | (a & 0xffffffff);
319 #elif defined(ARCH_X86_32)
320 static inline long long read_time(void)
322 long long l;
323 asm volatile("rdtsc\n\t"
324 : "=A" (l));
325 return l;
327 #elif ARCH_BFIN
328 static inline uint64_t read_time(void)
330 union {
331 struct {
332 unsigned lo;
333 unsigned hi;
334 } p;
335 unsigned long long c;
336 } t;
337 asm volatile ("%0=cycles; %1=cycles2;" : "=d" (t.p.lo), "=d" (t.p.hi));
338 return t.c;
340 #else //FIXME check ppc64
341 static inline uint64_t read_time(void)
343 uint32_t tbu, tbl, temp;
345 /* from section 2.2.1 of the 32-bit PowerPC PEM */
346 asm volatile(
347 "1:\n"
348 "mftbu %2\n"
349 "mftb %0\n"
350 "mftbu %1\n"
351 "cmpw %2,%1\n"
352 "bne 1b\n"
353 : "=r"(tbl), "=r"(tbu), "=r"(temp)
355 : "cc");
357 return (((uint64_t)tbu)<<32) | (uint64_t)tbl;
359 #endif
360 #elif defined(HAVE_GETHRTIME)
361 #define AV_READ_TIME gethrtime
362 #endif
364 #ifdef AV_READ_TIME
365 #define START_TIMER \
366 uint64_t tend;\
367 uint64_t tstart= AV_READ_TIME();\
369 #define STOP_TIMER(id) \
370 tend= AV_READ_TIME();\
372 static uint64_t tsum=0;\
373 static int tcount=0;\
374 static int tskip_count=0;\
375 if(tcount<2 || tend - tstart < FFMAX(8*tsum/tcount, 2000)){\
376 tsum+= tend - tstart;\
377 tcount++;\
378 }else\
379 tskip_count++;\
380 if(((tcount+tskip_count)&(tcount+tskip_count-1))==0){\
381 av_log(NULL, AV_LOG_ERROR, "%"PRIu64" dezicycles in %s, %d runs, %d skips\n",\
382 tsum*10/tcount, id, tcount, tskip_count);\
385 #else
386 #define START_TIMER
387 #define STOP_TIMER(id) {}
388 #endif
391 * Returns NULL if CONFIG_SMALL is defined otherwise the argument
392 * without modifications, used to disable the definition of strings
393 * (for example AVCodec long_names).
395 #ifdef CONFIG_SMALL
396 # define NULL_IF_CONFIG_SMALL(x) NULL
397 #else
398 # define NULL_IF_CONFIG_SMALL(x) x
399 #endif
401 #endif /* FFMPEG_COMMON_H */