Libav 0.7.1
libavutil/common.h
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00001 /*
00002  * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
00003  *
00004  * This file is part of Libav.
00005  *
00006  * Libav 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  * Libav 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 Libav; 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 FFABS(a) ((a) >= 0 ? (a) : (-(a)))
00051 #define FFSIGN(a) ((a) > 0 ? 1 : -1)
00052 
00053 #define FFMAX(a,b) ((a) > (b) ? (a) : (b))
00054 #define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
00055 #define FFMIN(a,b) ((a) > (b) ? (b) : (a))
00056 #define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)
00057 
00058 #define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
00059 #define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
00060 #define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1))
00061 
00062 /* misc math functions */
00063 extern const uint8_t ff_log2_tab[256];
00064 
00065 extern const uint8_t av_reverse[256];
00066 
00067 static av_always_inline av_const int av_log2_c(unsigned int v)
00068 {
00069     int n = 0;
00070     if (v & 0xffff0000) {
00071         v >>= 16;
00072         n += 16;
00073     }
00074     if (v & 0xff00) {
00075         v >>= 8;
00076         n += 8;
00077     }
00078     n += ff_log2_tab[v];
00079 
00080     return n;
00081 }
00082 
00083 static av_always_inline av_const int av_log2_16bit_c(unsigned int v)
00084 {
00085     int n = 0;
00086     if (v & 0xff00) {
00087         v >>= 8;
00088         n += 8;
00089     }
00090     n += ff_log2_tab[v];
00091 
00092     return n;
00093 }
00094 
00095 #ifdef HAVE_AV_CONFIG_H
00096 #   include "config.h"
00097 #   include "intmath.h"
00098 #endif
00099 
00100 /* Pull in unguarded fallback defines at the end of this file. */
00101 #include "common.h"
00102 
00110 static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
00111 {
00112     if      (a < amin) return amin;
00113     else if (a > amax) return amax;
00114     else               return a;
00115 }
00116 
00122 static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
00123 {
00124     if (a&(~0xFF)) return (-a)>>31;
00125     else           return a;
00126 }
00127 
00133 static av_always_inline av_const int8_t av_clip_int8_c(int a)
00134 {
00135     if ((a+0x80) & ~0xFF) return (a>>31) ^ 0x7F;
00136     else                  return a;
00137 }
00138 
00144 static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
00145 {
00146     if (a&(~0xFFFF)) return (-a)>>31;
00147     else             return a;
00148 }
00149 
00155 static av_always_inline av_const int16_t av_clip_int16_c(int a)
00156 {
00157     if ((a+0x8000) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
00158     else                      return a;
00159 }
00160 
00166 static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
00167 {
00168     if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (a>>63) ^ 0x7FFFFFFF;
00169     else                                         return a;
00170 }
00171 
00178 static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
00179 {
00180     if (a & ~((1<<p) - 1)) return -a >> 31 & ((1<<p) - 1);
00181     else                   return  a;
00182 }
00183 
00191 static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
00192 {
00193     if      (a < amin) return amin;
00194     else if (a > amax) return amax;
00195     else               return a;
00196 }
00197 
00202 static av_always_inline av_const int av_ceil_log2_c(int x)
00203 {
00204     return av_log2((x - 1) << 1);
00205 }
00206 
00212 static av_always_inline av_const int av_popcount_c(uint32_t x)
00213 {
00214     x -= (x >> 1) & 0x55555555;
00215     x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
00216     x = (x + (x >> 4)) & 0x0F0F0F0F;
00217     x += x >> 8;
00218     return (x + (x >> 16)) & 0x3F;
00219 }
00220 
00221 #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((d) << 24))
00222 #define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((a) << 24))
00223 
00235 #define GET_UTF8(val, GET_BYTE, ERROR)\
00236     val= GET_BYTE;\
00237     {\
00238         int ones= 7 - av_log2(val ^ 255);\
00239         if(ones==1)\
00240             ERROR\
00241         val&= 127>>ones;\
00242         while(--ones > 0){\
00243             int tmp= GET_BYTE - 128;\
00244             if(tmp>>6)\
00245                 ERROR\
00246             val= (val<<6) + tmp;\
00247         }\
00248     }
00249 
00259 #define GET_UTF16(val, GET_16BIT, ERROR)\
00260     val = GET_16BIT;\
00261     {\
00262         unsigned int hi = val - 0xD800;\
00263         if (hi < 0x800) {\
00264             val = GET_16BIT - 0xDC00;\
00265             if (val > 0x3FFU || hi > 0x3FFU)\
00266                 ERROR\
00267             val += (hi<<10) + 0x10000;\
00268         }\
00269     }\
00270 
00271 
00287 #define PUT_UTF8(val, tmp, PUT_BYTE)\
00288     {\
00289         int bytes, shift;\
00290         uint32_t in = val;\
00291         if (in < 0x80) {\
00292             tmp = in;\
00293             PUT_BYTE\
00294         } else {\
00295             bytes = (av_log2(in) + 4) / 5;\
00296             shift = (bytes - 1) * 6;\
00297             tmp = (256 - (256 >> bytes)) | (in >> shift);\
00298             PUT_BYTE\
00299             while (shift >= 6) {\
00300                 shift -= 6;\
00301                 tmp = 0x80 | ((in >> shift) & 0x3f);\
00302                 PUT_BYTE\
00303             }\
00304         }\
00305     }
00306 
00321 #define PUT_UTF16(val, tmp, PUT_16BIT)\
00322     {\
00323         uint32_t in = val;\
00324         if (in < 0x10000) {\
00325             tmp = in;\
00326             PUT_16BIT\
00327         } else {\
00328             tmp = 0xD800 | ((in - 0x10000) >> 10);\
00329             PUT_16BIT\
00330             tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
00331             PUT_16BIT\
00332         }\
00333     }\
00334 
00335 
00336 
00337 #include "mem.h"
00338 
00339 #ifdef HAVE_AV_CONFIG_H
00340 #    include "internal.h"
00341 #endif /* HAVE_AV_CONFIG_H */
00342 
00343 #endif /* AVUTIL_COMMON_H */
00344 
00345 /*
00346  * The following definitions are outside the multiple inclusion guard
00347  * to ensure they are immediately available in intmath.h.
00348  */
00349 
00350 #ifndef av_log2
00351 #   define av_log2       av_log2_c
00352 #endif
00353 #ifndef av_log2_16bit
00354 #   define av_log2_16bit av_log2_16bit_c
00355 #endif
00356 #ifndef av_ceil_log2
00357 #   define av_ceil_log2     av_ceil_log2_c
00358 #endif
00359 #ifndef av_clip
00360 #   define av_clip          av_clip_c
00361 #endif
00362 #ifndef av_clip_uint8
00363 #   define av_clip_uint8    av_clip_uint8_c
00364 #endif
00365 #ifndef av_clip_int8
00366 #   define av_clip_int8     av_clip_int8_c
00367 #endif
00368 #ifndef av_clip_uint16
00369 #   define av_clip_uint16   av_clip_uint16_c
00370 #endif
00371 #ifndef av_clip_int16
00372 #   define av_clip_int16    av_clip_int16_c
00373 #endif
00374 #ifndef av_clipl_int32
00375 #   define av_clipl_int32   av_clipl_int32_c
00376 #endif
00377 #ifndef av_clip_uintp2
00378 #   define av_clip_uintp2   av_clip_uintp2_c
00379 #endif
00380 #ifndef av_clipf
00381 #   define av_clipf         av_clipf_c
00382 #endif
00383 #ifndef av_popcount
00384 #   define av_popcount      av_popcount_c
00385 #endif