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 AVUTIL_COMMON_H
  27 #define AVUTIL_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 #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
  83
  84 #ifdef HAVE_AV_CONFIG_H
  85 #    include "internal.h"
  86 #endif /* HAVE_AV_CONFIG_H */
  87
  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
  95
  96 #ifndef av_unused
  97 #if defined(__GNUC__)
  98 #    define av_unused __attribute__((unused))
  99 #else
 100 #    define av_unused
 101 #endif
 102 #endif
 103
 104 #include "mem.h"
 105
 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)
 112
 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)
 117
 118 #define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
 119 #define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
 120
 121 /* misc math functions */
 122 extern const uint8_t ff_log2_tab[256];
 123
 124 static inline av_const int av_log2(unsigned int v)
 125 {
 126     int n = 0;
 127     if (v & 0xffff0000) {
 128         v >>= 16;
 129         n += 16;
 130     }
 131     if (v & 0xff00) {
 132         v >>= 8;
 133         n += 8;
 134     }
 135     n += ff_log2_tab[v];
 136
 137     return n;
 138 }
 139
 140 static inline av_const int av_log2_16bit(unsigned int v)
 141 {
 142     int n = 0;
 143     if (v & 0xff00) {
 144         v >>= 8;
 145         n += 8;
 146     }
 147     n += ff_log2_tab[v];
 148
 149     return n;
 150 }
 151
 152 /* median of 3 */
 153 static inline av_const int mid_pred(int a, int b, int c)
 154 {
 155 #ifdef HAVE_CMOV
 156     int i=b;
 157     __asm__ volatile(
 158         "cmp    %2, %1 \n\t"
 159         "cmovg  %1, %0 \n\t"
 160         "cmovg  %2, %1 \n\t"
 161         "cmp    %3, %1 \n\t"
 162         "cmovl  %3, %1 \n\t"
 163         "cmp    %1, %0 \n\t"
 164         "cmovg  %1, %0 \n\t"
 165         :"+&r"(i), "+&r"(a)
 166         :"r"(b), "r"(c)
 167     );
 168     return i;
 169 #elif 0
 170     int t= (a-b)&((a-b)>>31);
 171     a-=t;
 172     b+=t;
 173     b-= (b-c)&((b-c)>>31);
 174     b+= (a-b)&((a-b)>>31);
 175
 176     return b;
 177 #else
 178     if(a>b){
 179         if(c>b){
 180             if(c>a) b=a;
 181             else    b=c;
 182         }
 183     }else{
 184         if(b>c){
 185             if(c>a) b=c;
 186             else    b=a;
 187         }
 188     }
 189     return b;
 190 #endif
 191 }
 192
 193 /**
 194  * clip a signed integer value into the amin-amax range
 195  * @param a value to clip
 196  * @param amin minimum value of the clip range
 197  * @param amax maximum value of the clip range
 198  * @return clipped value
 199  */
 200 static inline av_const int av_clip(int a, int amin, int amax)
 201 {
 202     if      (a < amin) return amin;
 203     else if (a > amax) return amax;
 204     else               return a;
 205 }
 206
 207 /**
 208  * clip a signed integer value into the 0-255 range
 209  * @param a value to clip
 210  * @return clipped value
 211  */
 212 static inline av_const uint8_t av_clip_uint8(int a)
 213 {
 214     if (a&(~255)) return (-a)>>31;
 215     else          return a;
 216 }
 217
 218 /**
 219  * clip a signed integer value into the -32768,32767 range
 220  * @param a value to clip
 221  * @return clipped value
 222  */
 223 static inline av_const int16_t av_clip_int16(int a)
 224 {
 225     if ((a+32768) & ~65535) return (a>>31) ^ 32767;
 226     else                    return a;
 227 }
 228
 229 /**
 230  * clip a float value into the amin-amax range
 231  * @param a value to clip
 232  * @param amin minimum value of the clip range
 233  * @param amax maximum value of the clip range
 234  * @return clipped value
 235  */
 236 static inline av_const float av_clipf(float a, float amin, float amax)
 237 {
 238     if      (a < amin) return amin;
 239     else if (a > amax) return amax;
 240     else               return a;
 241 }
 242
 243 /* math */
 244 int64_t av_const ff_gcd(int64_t a, int64_t b);
 245
 246 /**
 247  * converts fourcc string to int
 248  */
 249 static inline av_pure int ff_get_fourcc(const char *s){
 250 #ifdef HAVE_AV_CONFIG_H
 251     assert( strlen(s)==4 );
 252 #endif
 253
 254     return (s[0]) + (s[1]<<8) + (s[2]<<16) + (s[3]<<24);
 255 }
 256
 257 #define MKTAG(a,b,c,d) (a | (b << 8) | (c << 16) | (d << 24))
 258 #define MKBETAG(a,b,c,d) (d | (c << 8) | (b << 16) | (a << 24))
 259
 260 /*!
 261  * \def GET_UTF8(val, GET_BYTE, ERROR)
 262  * converts a UTF-8 character (up to 4 bytes long) to its 32-bit UCS-4 encoded form
 263  * \param val is the output and should be of type uint32_t. It holds the converted
 264  * UCS-4 character and should be a left value.
 265  * \param GET_BYTE gets UTF-8 encoded bytes from any proper source. It can be
 266  * a function or a statement whose return value or evaluated value is of type
 267  * uint8_t. It will be executed up to 4 times for values in the valid UTF-8 range,
 268  * and up to 7 times in the general case.
 269  * \param ERROR action that should be taken when an invalid UTF-8 byte is returned
 270  * from GET_BYTE. It should be a statement that jumps out of the macro,
 271  * like exit(), goto, return, break, or continue.
 272  */
 273 #define GET_UTF8(val, GET_BYTE, ERROR)\
 274     val= GET_BYTE;\
 275     {\
 276         int ones= 7 - av_log2(val ^ 255);\
 277         if(ones==1)\
 278             ERROR\
 279         val&= 127>>ones;\
 280         while(--ones > 0){\
 281             int tmp= GET_BYTE - 128;\
 282             if(tmp>>6)\
 283                 ERROR\
 284             val= (val<<6) + tmp;\
 285         }\
 286     }
 287
 288 /*!
 289  * \def PUT_UTF8(val, tmp, PUT_BYTE)
 290  * converts a 32-bit unicode character to its UTF-8 encoded form (up to 4 bytes long).
 291  * \param val is an input only argument and should be of type uint32_t. It holds
 292  * a ucs4 encoded unicode character that is to be converted to UTF-8. If
 293  * val is given as a function it's executed only once.
 294  * \param tmp is a temporary variable and should be of type uint8_t. It
 295  * represents an intermediate value during conversion that is to be
 296  * outputted by PUT_BYTE.
 297  * \param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
 298  * It could be a function or a statement, and uses tmp as the input byte.
 299  * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
 300  * executed up to 4 times for values in the valid UTF-8 range and up to
 301  * 7 times in the general case, depending on the length of the converted
 302  * unicode character.
 303  */
 304 #define PUT_UTF8(val, tmp, PUT_BYTE)\
 305     {\
 306         int bytes, shift;\
 307         uint32_t in = val;\
 308         if (in < 0x80) {\
 309             tmp = in;\
 310             PUT_BYTE\
 311         } else {\
 312             bytes = (av_log2(in) + 4) / 5;\
 313             shift = (bytes - 1) * 6;\
 314             tmp = (256 - (256 >> bytes)) | (in >> shift);\
 315             PUT_BYTE\
 316             while (shift >= 6) {\
 317                 shift -= 6;\
 318                 tmp = 0x80 | ((in >> shift) & 0x3f);\
 319                 PUT_BYTE\
 320             }\
 321         }\
 322     }
 323
 324 #if defined(ARCH_X86) || defined(ARCH_POWERPC) || defined(ARCH_BFIN)
 325 #define AV_READ_TIME read_time
 326 #if defined(ARCH_X86)
 327 static inline uint64_t read_time(void)
 328 {
 329     uint32_t a, d;
 330     __asm__ volatile("rdtsc\n\t"
 331                  : "=a" (a), "=d" (d));
 332     return ((uint64_t)d << 32) + a;
 333 }
 334 #elif ARCH_BFIN
 335 static inline uint64_t read_time(void)
 336 {
 337     union {
 338         struct {
 339             unsigned lo;
 340             unsigned hi;
 341         } p;
 342         unsigned long long c;
 343     } t;
 344     __asm__ volatile ("%0=cycles; %1=cycles2;" : "=d" (t.p.lo), "=d" (t.p.hi));
 345     return t.c;
 346 }
 347 #else //FIXME check ppc64
 348 static inline uint64_t read_time(void)
 349 {
 350     uint32_t tbu, tbl, temp;
 351
 352      /* from section 2.2.1 of the 32-bit PowerPC PEM */
 353      __asm__ volatile(
 354          "1:\n"
 355          "mftbu  %2\n"
 356          "mftb   %0\n"
 357          "mftbu  %1\n"
 358          "cmpw   %2,%1\n"
 359          "bne    1b\n"
 360      : "=r"(tbl), "=r"(tbu), "=r"(temp)
 361      :
 362      : "cc");
 363
 364      return (((uint64_t)tbu)<<32) | (uint64_t)tbl;
 365 }
 366 #endif
 367 #elif defined(HAVE_GETHRTIME)
 368 #define AV_READ_TIME gethrtime
 369 #endif
 370
 371 #ifdef AV_READ_TIME
 372 #define START_TIMER \
 373 uint64_t tend;\
 374 uint64_t tstart= AV_READ_TIME();\
 375
 376 #define STOP_TIMER(id) \
 377 tend= AV_READ_TIME();\
 378 {\
 379     static uint64_t tsum=0;\
 380     static int tcount=0;\
 381     static int tskip_count=0;\
 382     if(tcount<2 || tend - tstart < FFMAX(8*tsum/tcount, 2000)){\
 383         tsum+= tend - tstart;\
 384         tcount++;\
 385     }else\
 386         tskip_count++;\
 387     if(((tcount+tskip_count)&(tcount+tskip_count-1))==0){\
 388         av_log(NULL, AV_LOG_ERROR, "%"PRIu64" dezicycles in %s, %d runs, %d skips\n",\
 389                tsum*10/tcount, id, tcount, tskip_count);\
 390     }\
 391 }
 392 #else
 393 #define START_TIMER
 394 #define STOP_TIMER(id) {}
 395 #endif
 396
 397 /**
 398  * Returns NULL if CONFIG_SMALL is defined otherwise the argument
 399  * without modifications, used to disable the definition of strings
 400  * (for example AVCodec long_names).
 401  */
 402 #ifdef CONFIG_SMALL
 403 #   define NULL_IF_CONFIG_SMALL(x) NULL
 404 #else
 405 #   define NULL_IF_CONFIG_SMALL(x) x
 406 #endif
 407
 408 #endif /* AVUTIL_COMMON_H */