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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 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 
00226 static av_always_inline av_const int av_popcount64_c(uint64_t x)
00227 {
00228     return av_popcount(x) + av_popcount(x >> 32);
00229 }
00230 
00231 #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
00232 #define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))
00233 
00245 #define GET_UTF8(val, GET_BYTE, ERROR)\
00246     val= GET_BYTE;\
00247     {\
00248         int ones= 7 - av_log2(val ^ 255);\
00249         if(ones==1)\
00250             ERROR\
00251         val&= 127>>ones;\
00252         while(--ones > 0){\
00253             int tmp= GET_BYTE - 128;\
00254             if(tmp>>6)\
00255                 ERROR\
00256             val= (val<<6) + tmp;\
00257         }\
00258     }
00259 
00269 #define GET_UTF16(val, GET_16BIT, ERROR)\
00270     val = GET_16BIT;\
00271     {\
00272         unsigned int hi = val - 0xD800;\
00273         if (hi < 0x800) {\
00274             val = GET_16BIT - 0xDC00;\
00275             if (val > 0x3FFU || hi > 0x3FFU)\
00276                 ERROR\
00277             val += (hi<<10) + 0x10000;\
00278         }\
00279     }\
00280 
00281 
00297 #define PUT_UTF8(val, tmp, PUT_BYTE)\
00298     {\
00299         int bytes, shift;\
00300         uint32_t in = val;\
00301         if (in < 0x80) {\
00302             tmp = in;\
00303             PUT_BYTE\
00304         } else {\
00305             bytes = (av_log2(in) + 4) / 5;\
00306             shift = (bytes - 1) * 6;\
00307             tmp = (256 - (256 >> bytes)) | (in >> shift);\
00308             PUT_BYTE\
00309             while (shift >= 6) {\
00310                 shift -= 6;\
00311                 tmp = 0x80 | ((in >> shift) & 0x3f);\
00312                 PUT_BYTE\
00313             }\
00314         }\
00315     }
00316 
00331 #define PUT_UTF16(val, tmp, PUT_16BIT)\
00332     {\
00333         uint32_t in = val;\
00334         if (in < 0x10000) {\
00335             tmp = in;\
00336             PUT_16BIT\
00337         } else {\
00338             tmp = 0xD800 | ((in - 0x10000) >> 10);\
00339             PUT_16BIT\
00340             tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
00341             PUT_16BIT\
00342         }\
00343     }\
00344 
00345 
00346 
00347 #include "mem.h"
00348 
00349 #ifdef HAVE_AV_CONFIG_H
00350 #    include "internal.h"
00351 #endif /* HAVE_AV_CONFIG_H */
00352 
00353 #endif /* AVUTIL_COMMON_H */
00354 
00355 /*
00356  * The following definitions are outside the multiple inclusion guard
00357  * to ensure they are immediately available in intmath.h.
00358  */
00359 
00360 #ifndef av_log2
00361 #   define av_log2       av_log2_c
00362 #endif
00363 #ifndef av_log2_16bit
00364 #   define av_log2_16bit av_log2_16bit_c
00365 #endif
00366 #ifndef av_ceil_log2
00367 #   define av_ceil_log2     av_ceil_log2_c
00368 #endif
00369 #ifndef av_clip
00370 #   define av_clip          av_clip_c
00371 #endif
00372 #ifndef av_clip_uint8
00373 #   define av_clip_uint8    av_clip_uint8_c
00374 #endif
00375 #ifndef av_clip_int8
00376 #   define av_clip_int8     av_clip_int8_c
00377 #endif
00378 #ifndef av_clip_uint16
00379 #   define av_clip_uint16   av_clip_uint16_c
00380 #endif
00381 #ifndef av_clip_int16
00382 #   define av_clip_int16    av_clip_int16_c
00383 #endif
00384 #ifndef av_clipl_int32
00385 #   define av_clipl_int32   av_clipl_int32_c
00386 #endif
00387 #ifndef av_clip_uintp2
00388 #   define av_clip_uintp2   av_clip_uintp2_c
00389 #endif
00390 #ifndef av_clipf
00391 #   define av_clipf         av_clipf_c
00392 #endif
00393 #ifndef av_popcount
00394 #   define av_popcount      av_popcount_c
00395 #endif
00396 #ifndef av_popcount64
00397 #   define av_popcount64    av_popcount64_c
00398 #endif
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