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libavutil/common.h

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00001 /*
00002  * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
00003  *
00004  * This file is part of FFmpeg.
00005  *
00006  * FFmpeg is free software; you can redistribute it and/or
00007  * modify it under the terms of the GNU Lesser General Public
00008  * License as published by the Free Software Foundation; either
00009  * version 2.1 of the License, or (at your option) any later version.
00010  *
00011  * FFmpeg is distributed in the hope that it will be useful,
00012  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014  * Lesser General Public License for more details.
00015  *
00016  * You should have received a copy of the GNU Lesser General Public
00017  * License along with FFmpeg; if not, write to the Free Software
00018  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00019  */
00020 
00026 #ifndef AVUTIL_COMMON_H
00027 #define AVUTIL_COMMON_H
00028 
00029 #include <ctype.h>
00030 #include <errno.h>
00031 #include <inttypes.h>
00032 #include <limits.h>
00033 #include <math.h>
00034 #include <stdio.h>
00035 #include <stdlib.h>
00036 #include <string.h>
00037 #include "attributes.h"
00038 #include "libavutil/avconfig.h"
00039 
00040 #if AV_HAVE_BIGENDIAN
00041 #   define AV_NE(be, le) (be)
00042 #else
00043 #   define AV_NE(be, le) (le)
00044 #endif
00045 
00046 //rounded division & shift
00047 #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
00048 /* assume b>0 */
00049 #define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
00050 #define FFUDIV(a,b) (((a)>0 ?(a):(a)-(b)+1) / (b))
00051 #define FFUMOD(a,b) ((a)-(b)*FFUDIV(a,b))
00052 #define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
00053 #define FFSIGN(a) ((a) > 0 ? 1 : -1)
00054 
00055 #define FFMAX(a,b) ((a) > (b) ? (a) : (b))
00056 #define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
00057 #define FFMIN(a,b) ((a) > (b) ? (b) : (a))
00058 #define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)
00059 
00060 #define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
00061 #define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
00062 #define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1))
00063 
00064 /* misc math functions */
00065 extern const uint8_t ff_log2_tab[256];
00066 
00067 extern const uint8_t av_reverse[256];
00068 
00069 static av_always_inline av_const int av_log2_c(unsigned int v)
00070 {
00071     int n = 0;
00072     if (v & 0xffff0000) {
00073         v >>= 16;
00074         n += 16;
00075     }
00076     if (v & 0xff00) {
00077         v >>= 8;
00078         n += 8;
00079     }
00080     n += ff_log2_tab[v];
00081 
00082     return n;
00083 }
00084 
00085 static av_always_inline av_const int av_log2_16bit_c(unsigned int v)
00086 {
00087     int n = 0;
00088     if (v & 0xff00) {
00089         v >>= 8;
00090         n += 8;
00091     }
00092     n += ff_log2_tab[v];
00093 
00094     return n;
00095 }
00096 
00097 #ifdef HAVE_AV_CONFIG_H
00098 #   include "config.h"
00099 #   include "intmath.h"
00100 #endif
00101 
00102 /* Pull in unguarded fallback defines at the end of this file. */
00103 #include "common.h"
00104 
00112 static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
00113 {
00114     if      (a < amin) return amin;
00115     else if (a > amax) return amax;
00116     else               return a;
00117 }
00118 
00124 static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
00125 {
00126     if (a&(~0xFF)) return (-a)>>31;
00127     else           return a;
00128 }
00129 
00135 static av_always_inline av_const int8_t av_clip_int8_c(int a)
00136 {
00137     if ((a+0x80) & ~0xFF) return (a>>31) ^ 0x7F;
00138     else                  return a;
00139 }
00140 
00146 static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
00147 {
00148     if (a&(~0xFFFF)) return (-a)>>31;
00149     else             return a;
00150 }
00151 
00157 static av_always_inline av_const int16_t av_clip_int16_c(int a)
00158 {
00159     if ((a+0x8000) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
00160     else                      return a;
00161 }
00162 
00168 static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
00169 {
00170     if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (a>>63) ^ 0x7FFFFFFF;
00171     else                                         return a;
00172 }
00173 
00180 static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
00181 {
00182     if (a & ~((1<<p) - 1)) return -a >> 31 & ((1<<p) - 1);
00183     else                   return  a;
00184 }
00185 
00193 static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
00194 {
00195     if      (a < amin) return amin;
00196     else if (a > amax) return amax;
00197     else               return a;
00198 }
00199 
00204 static av_always_inline av_const int av_ceil_log2_c(int x)
00205 {
00206     return av_log2((x - 1) << 1);
00207 }
00208 
00214 static av_always_inline av_const int av_popcount_c(uint32_t x)
00215 {
00216     x -= (x >> 1) & 0x55555555;
00217     x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
00218     x = (x + (x >> 4)) & 0x0F0F0F0F;
00219     x += x >> 8;
00220     return (x + (x >> 16)) & 0x3F;
00221 }
00222 
00223 #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((d) << 24))
00224 #define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((a) << 24))
00225 
00237 #define GET_UTF8(val, GET_BYTE, ERROR)\
00238     val= GET_BYTE;\
00239     {\
00240         int ones= 7 - av_log2(val ^ 255);\
00241         if(ones==1)\
00242             ERROR\
00243         val&= 127>>ones;\
00244         while(--ones > 0){\
00245             int tmp= GET_BYTE - 128;\
00246             if(tmp>>6)\
00247                 ERROR\
00248             val= (val<<6) + tmp;\
00249         }\
00250     }
00251 
00261 #define GET_UTF16(val, GET_16BIT, ERROR)\
00262     val = GET_16BIT;\
00263     {\
00264         unsigned int hi = val - 0xD800;\
00265         if (hi < 0x800) {\
00266             val = GET_16BIT - 0xDC00;\
00267             if (val > 0x3FFU || hi > 0x3FFU)\
00268                 ERROR\
00269             val += (hi<<10) + 0x10000;\
00270         }\
00271     }\
00272 
00273 
00289 #define PUT_UTF8(val, tmp, PUT_BYTE)\
00290     {\
00291         int bytes, shift;\
00292         uint32_t in = val;\
00293         if (in < 0x80) {\
00294             tmp = in;\
00295             PUT_BYTE\
00296         } else {\
00297             bytes = (av_log2(in) + 4) / 5;\
00298             shift = (bytes - 1) * 6;\
00299             tmp = (256 - (256 >> bytes)) | (in >> shift);\
00300             PUT_BYTE\
00301             while (shift >= 6) {\
00302                 shift -= 6;\
00303                 tmp = 0x80 | ((in >> shift) & 0x3f);\
00304                 PUT_BYTE\
00305             }\
00306         }\
00307     }
00308 
00323 #define PUT_UTF16(val, tmp, PUT_16BIT)\
00324     {\
00325         uint32_t in = val;\
00326         if (in < 0x10000) {\
00327             tmp = in;\
00328             PUT_16BIT\
00329         } else {\
00330             tmp = 0xD800 | ((in - 0x10000) >> 10);\
00331             PUT_16BIT\
00332             tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
00333             PUT_16BIT\
00334         }\
00335     }\
00336 
00337 
00338 
00339 #include "mem.h"
00340 
00341 #ifdef HAVE_AV_CONFIG_H
00342 #    include "internal.h"
00343 #endif /* HAVE_AV_CONFIG_H */
00344 
00345 #endif /* AVUTIL_COMMON_H */
00346 
00347 /*
00348  * The following definitions are outside the multiple inclusion guard
00349  * to ensure they are immediately available in intmath.h.
00350  */
00351 
00352 #ifndef av_log2
00353 #   define av_log2       av_log2_c
00354 #endif
00355 #ifndef av_log2_16bit
00356 #   define av_log2_16bit av_log2_16bit_c
00357 #endif
00358 #ifndef av_ceil_log2
00359 #   define av_ceil_log2     av_ceil_log2_c
00360 #endif
00361 #ifndef av_clip
00362 #   define av_clip          av_clip_c
00363 #endif
00364 #ifndef av_clip_uint8
00365 #   define av_clip_uint8    av_clip_uint8_c
00366 #endif
00367 #ifndef av_clip_int8
00368 #   define av_clip_int8     av_clip_int8_c
00369 #endif
00370 #ifndef av_clip_uint16
00371 #   define av_clip_uint16   av_clip_uint16_c
00372 #endif
00373 #ifndef av_clip_int16
00374 #   define av_clip_int16    av_clip_int16_c
00375 #endif
00376 #ifndef av_clipl_int32
00377 #   define av_clipl_int32   av_clipl_int32_c
00378 #endif
00379 #ifndef av_clip_uintp2
00380 #   define av_clip_uintp2   av_clip_uintp2_c
00381 #endif
00382 #ifndef av_clipf
00383 #   define av_clipf         av_clipf_c
00384 #endif
00385 #ifndef av_popcount
00386 #   define av_popcount      av_popcount_c
00387 #endif

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