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
 120 /* misc math functions */
 121 extern const uint8_t ff_log2_tab[256];
 122
 123 static inline av_const int av_log2(unsigned int v)
 124 {
 125     int n = 0;
 126     if (v & 0xffff0000) {
 127         v >>= 16;
 128         n += 16;
 129     }
 130     if (v & 0xff00) {
 131         v >>= 8;
 132         n += 8;
 133     }
 134     n += ff_log2_tab[v];
 135
 136     return n;
 137 }
 138
 139 static inline av_const int av_log2_16bit(unsigned int v)
 140 {
 141     int n = 0;
 142     if (v & 0xff00) {
 143         v >>= 8;
 144         n += 8;
 145     }
 146     n += ff_log2_tab[v];
 147
 148     return n;
 149 }
 150
 151 /* median of 3 */
 152 static inline av_const int mid_pred(int a, int b, int c)
 153 {
 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)
 166     );
 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);
 174
 175     return b;
 176 #else
 177     if(a>b){
 178         if(c>b){
 179             if(c>a) b=a;
 180             else    b=c;
 181         }
 182     }else{
 183         if(b>c){
 184             if(c>a) b=c;
 185             else    b=a;
 186         }
 187     }
 188     return b;
 189 #endif
 190 }
 191
 192 /**
 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
 198  */
 199 static inline av_const int av_clip(int a, int amin, int amax)
 200 {
 201     if      (a < amin) return amin;
 202     else if (a > amax) return amax;
 203     else               return a;
 204 }
 205
 206 /**
 207  * clip a signed integer value into the 0-255 range
 208  * @param a value to clip
 209  * @return clipped value
 210  */
 211 static inline av_const uint8_t av_clip_uint8(int a)
 212 {
 213     if (a&(~255)) return (-a)>>31;
 214     else          return a;
 215 }
 216
 217 /**
 218  * clip a signed integer value into the -32768,32767 range
 219  * @param a value to clip
 220  * @return clipped value
 221  */
 222 static inline av_const int16_t av_clip_int16(int a)
 223 {
 224     if ((a+32768) & ~65535) return (a>>31) ^ 32767;
 225     else                    return a;
 226 }
 227
 228 /**
 229  * clip a float value into the amin-amax range
 230  * @param a value to clip
 231  * @param amin minimum value of the clip range
 232  * @param amax maximum value of the clip range
 233  * @return clipped value
 234  */
 235 static inline av_const float av_clipf(float a, float amin, float amax)
 236 {
 237     if      (a < amin) return amin;
 238     else if (a > amax) return amax;
 239     else               return a;
 240 }
 241
 242 /* math */
 243 int64_t av_const ff_gcd(int64_t a, int64_t b);
 244
 245 /**
 246  * converts fourcc string to int
 247  */
 248 static inline av_pure int ff_get_fourcc(const char *s){
 249 #ifdef HAVE_AV_CONFIG_H
 250     assert( strlen(s)==4 );
 251 #endif
 252
 253     return (s[0]) + (s[1]<<8) + (s[2]<<16) + (s[3]<<24);
 254 }
 255
 256 #define MKTAG(a,b,c,d) (a | (b << 8) | (c << 16) | (d << 24))
 257 #define MKBETAG(a,b,c,d) (d | (c << 8) | (b << 16) | (a << 24))
 258
 259 /*!
 260  * \def GET_UTF8(val, GET_BYTE, ERROR)
 261  * converts a UTF-8 character (up to 4 bytes long) to its 32-bit UCS-4 encoded form
 262  * \param val is the output and should be of type uint32_t. It holds the converted
 263  * UCS-4 character and should be a left value.
 264  * \param GET_BYTE gets UTF-8 encoded bytes from any proper source. It can be
 265  * a function or a statement whose return value or evaluated value is of type
 266  * uint8_t. It will be executed up to 4 times for values in the valid UTF-8 range,
 267  * and up to 7 times in the general case.
 268  * \param ERROR action that should be taken when an invalid UTF-8 byte is returned
 269  * from GET_BYTE. It should be a statement that jumps out of the macro,
 270  * like exit(), goto, return, break, or continue.
 271  */
 272 #define GET_UTF8(val, GET_BYTE, ERROR)\
 273     val= GET_BYTE;\
 274     {\
 275         int ones= 7 - av_log2(val ^ 255);\
 276         if(ones==1)\
 277             ERROR\
 278         val&= 127>>ones;\
 279         while(--ones > 0){\
 280             int tmp= GET_BYTE - 128;\
 281             if(tmp>>6)\
 282                 ERROR\
 283             val= (val<<6) + tmp;\
 284         }\
 285     }
 286
 287 /*!
 288  * \def PUT_UTF8(val, tmp, PUT_BYTE)
 289  * converts a 32-bit unicode character to its UTF-8 encoded form (up to 4 bytes long).
 290  * \param val is an input only argument and should be of type uint32_t. It holds
 291  * a ucs4 encoded unicode character that is to be converted to UTF-8. If
 292  * val is given as a function it's executed only once.
 293  * \param tmp is a temporary variable and should be of type uint8_t. It
 294  * represents an intermediate value during conversion that is to be
 295  * outputted by PUT_BYTE.
 296  * \param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
 297  * It could be a function or a statement, and uses tmp as the input byte.
 298  * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
 299  * executed up to 4 times for values in the valid UTF-8 range and up to
 300  * 7 times in the general case, depending on the length of the converted
 301  * unicode character.
 302  */
 303 #define PUT_UTF8(val, tmp, PUT_BYTE)\
 304     {\
 305         int bytes, shift;\
 306         uint32_t in = val;\
 307         if (in < 0x80) {\
 308             tmp = in;\
 309             PUT_BYTE\
 310         } else {\
 311             bytes = (av_log2(in) + 4) / 5;\
 312             shift = (bytes - 1) * 6;\
 313             tmp = (256 - (256 >> bytes)) | (in >> shift);\
 314             PUT_BYTE\
 315             while (shift >= 6) {\
 316                 shift -= 6;\
 317                 tmp = 0x80 | ((in >> shift) & 0x3f);\
 318                 PUT_BYTE\
 319             }\
 320         }\
 321     }
 322
 323 #if defined(ARCH_X86) || defined(ARCH_POWERPC) || defined(ARCH_BFIN)
 324 #define AV_READ_TIME read_time
 325 #if defined(ARCH_X86_64)
 326 static inline uint64_t read_time(void)
 327 {
 328     uint64_t a, d;
 329     asm volatile("rdtsc\n\t"
 330                  : "=a" (a), "=d" (d));
 331     return (d << 32) | (a & 0xffffffff);
 332 }
 333 #elif defined(ARCH_X86_32)
 334 static inline long long read_time(void)
 335 {
 336     long long l;
 337     asm volatile("rdtsc\n\t"
 338                  : "=A" (l));
 339     return l;
 340 }
 341 #elif ARCH_BFIN
 342 static inline uint64_t read_time(void)
 343 {
 344     union {
 345         struct {
 346             unsigned lo;
 347             unsigned hi;
 348         } p;
 349         unsigned long long c;
 350     } t;
 351     asm volatile ("%0=cycles; %1=cycles2;" : "=d" (t.p.lo), "=d" (t.p.hi));
 352     return t.c;
 353 }
 354 #else //FIXME check ppc64
 355 static inline uint64_t read_time(void)
 356 {
 357     uint32_t tbu, tbl, temp;
 358
 359      /* from section 2.2.1 of the 32-bit PowerPC PEM */
 360      asm volatile(
 361          "1:\n"
 362          "mftbu  %2\n"
 363          "mftb   %0\n"
 364          "mftbu  %1\n"
 365          "cmpw   %2,%1\n"
 366          "bne    1b\n"
 367      : "=r"(tbl), "=r"(tbu), "=r"(temp)
 368      :
 369      : "cc");
 370
 371      return (((uint64_t)tbu)<<32) | (uint64_t)tbl;
 372 }
 373 #endif
 374 #elif defined(HAVE_GETHRTIME)
 375 #define AV_READ_TIME gethrtime
 376 #endif
 377
 378 #ifdef AV_READ_TIME
 379 #define START_TIMER \
 380 uint64_t tend;\
 381 uint64_t tstart= AV_READ_TIME();\
 382
 383 #define STOP_TIMER(id) \
 384 tend= AV_READ_TIME();\
 385 {\
 386     static uint64_t tsum=0;\
 387     static int tcount=0;\
 388     static int tskip_count=0;\
 389     if(tcount<2 || tend - tstart < FFMAX(8*tsum/tcount, 2000)){\
 390         tsum+= tend - tstart;\
 391         tcount++;\
 392     }else\
 393         tskip_count++;\
 394     if(((tcount+tskip_count)&(tcount+tskip_count-1))==0){\
 395         av_log(NULL, AV_LOG_ERROR, "%"PRIu64" dezicycles in %s, %d runs, %d skips\n",\
 396                tsum*10/tcount, id, tcount, tskip_count);\
 397     }\
 398 }
 399 #else
 400 #define START_TIMER
 401 #define STOP_TIMER(id) {}
 402 #endif
 403
 404 /**
 405  * Returns NULL if CONFIG_SMALL is defined otherwise the argument
 406  * without modifications, used to disable the definition of strings
 407  * (for example AVCodec long_names).
 408  */
 409 #ifdef CONFIG_SMALL
 410 #   define NULL_IF_CONFIG_SMALL(x) NULL
 411 #else
 412 #   define NULL_IF_CONFIG_SMALL(x) x
 413 #endif
 414
 415 #endif /* AVUTIL_COMMON_H */