common.h (11426B)
1 /* 2 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> 3 * 4 * This file is part of Libav. 5 * 6 * Libav 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 * Libav 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 Libav; 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 23 * common internal and external API header 24 */ 25 26 #ifndef AVUTIL_COMMON_H 27 #define AVUTIL_COMMON_H 28 29 #include <ctype.h> 30 #include <errno.h> 31 #include <inttypes.h> 32 #include <limits.h> 33 #include <math.h> 34 #include <stdio.h> 35 #include <stdlib.h> 36 #include <string.h> 37 #include "attributes.h" 38 #include "libavutil/avconfig.h" 39 40 #if AV_HAVE_BIGENDIAN 41 # define AV_NE(be, le) (be) 42 #else 43 # define AV_NE(be, le) (le) 44 #endif 45 46 //rounded division & shift 47 #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b)) 48 /* assume b>0 */ 49 #define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b)) 50 #define FFABS(a) ((a) >= 0 ? (a) : (-(a))) 51 #define FFSIGN(a) ((a) > 0 ? 1 : -1) 52 53 #define FFMAX(a,b) ((a) > (b) ? (a) : (b)) 54 #define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c) 55 #define FFMIN(a,b) ((a) > (b) ? (b) : (a)) 56 #define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c) 57 58 #define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0) 59 #define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0])) 60 #define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1)) 61 62 /* misc math functions */ 63 extern const uint8_t ff_log2_tab[256]; 64 65 extern const uint8_t av_reverse[256]; 66 67 static av_always_inline av_const int av_log2_c(unsigned int v) 68 { 69 int n = 0; 70 if (v & 0xffff0000) { 71 v >>= 16; 72 n += 16; 73 } 74 if (v & 0xff00) { 75 v >>= 8; 76 n += 8; 77 } 78 n += ff_log2_tab[v]; 79 80 return n; 81 } 82 83 static av_always_inline av_const int av_log2_16bit_c(unsigned int v) 84 { 85 int n = 0; 86 if (v & 0xff00) { 87 v >>= 8; 88 n += 8; 89 } 90 n += ff_log2_tab[v]; 91 92 return n; 93 } 94 95 #ifdef HAVE_AV_CONFIG_H 96 # include "config.h" 97 # include "intmath.h" 98 #endif 99 100 /* Pull in unguarded fallback defines at the end of this file. */ 101 #include "common.h" 102 103 /** 104 * Clip a signed integer value into the amin-amax range. 105 * @param a value to clip 106 * @param amin minimum value of the clip range 107 * @param amax maximum value of the clip range 108 * @return clipped value 109 */ 110 static av_always_inline av_const int av_clip_c(int a, int amin, int amax) 111 { 112 if (a < amin) return amin; 113 else if (a > amax) return amax; 114 else return a; 115 } 116 117 /** 118 * Clip a signed integer value into the 0-255 range. 119 * @param a value to clip 120 * @return clipped value 121 */ 122 static av_always_inline av_const uint8_t av_clip_uint8_c(int a) 123 { 124 if (a&(~0xFF)) return (-a)>>31; 125 else return a; 126 } 127 128 /** 129 * Clip a signed integer value into the -128,127 range. 130 * @param a value to clip 131 * @return clipped value 132 */ 133 static av_always_inline av_const int8_t av_clip_int8_c(int a) 134 { 135 if ((a+0x80) & ~0xFF) return (a>>31) ^ 0x7F; 136 else return a; 137 } 138 139 /** 140 * Clip a signed integer value into the 0-65535 range. 141 * @param a value to clip 142 * @return clipped value 143 */ 144 static av_always_inline av_const uint16_t av_clip_uint16_c(int a) 145 { 146 if (a&(~0xFFFF)) return (-a)>>31; 147 else return a; 148 } 149 150 /** 151 * Clip a signed integer value into the -32768,32767 range. 152 * @param a value to clip 153 * @return clipped value 154 */ 155 static av_always_inline av_const int16_t av_clip_int16_c(int a) 156 { 157 if ((a+0x8000) & ~0xFFFF) return (a>>31) ^ 0x7FFF; 158 else return a; 159 } 160 161 /** 162 * Clip a signed 64-bit integer value into the -2147483648,2147483647 range. 163 * @param a value to clip 164 * @return clipped value 165 */ 166 static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a) 167 { 168 if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (a>>63) ^ 0x7FFFFFFF; 169 else return a; 170 } 171 172 /** 173 * Clip a signed integer to an unsigned power of two range. 174 * @param a value to clip 175 * @param p bit position to clip at 176 * @return clipped value 177 */ 178 static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p) 179 { 180 if (a & ~((1<<p) - 1)) return -a >> 31 & ((1<<p) - 1); 181 else return a; 182 } 183 184 /** 185 * Clip a float value into the amin-amax range. 186 * @param a value to clip 187 * @param amin minimum value of the clip range 188 * @param amax maximum value of the clip range 189 * @return clipped value 190 */ 191 static av_always_inline av_const float av_clipf_c(float a, float amin, float amax) 192 { 193 if (a < amin) return amin; 194 else if (a > amax) return amax; 195 else return a; 196 } 197 198 /** Compute ceil(log2(x)). 199 * @param x value used to compute ceil(log2(x)) 200 * @return computed ceiling of log2(x) 201 */ 202 static av_always_inline av_const int av_ceil_log2_c(int x) 203 { 204 return av_log2((x - 1) << 1); 205 } 206 207 /** 208 * Count number of bits set to one in x 209 * @param x value to count bits of 210 * @return the number of bits set to one in x 211 */ 212 static av_always_inline av_const int av_popcount_c(uint32_t x) 213 { 214 x -= (x >> 1) & 0x55555555; 215 x = (x & 0x33333333) + ((x >> 2) & 0x33333333); 216 x = (x + (x >> 4)) & 0x0F0F0F0F; 217 x += x >> 8; 218 return (x + (x >> 16)) & 0x3F; 219 } 220 221 /** 222 * Count number of bits set to one in x 223 * @param x value to count bits of 224 * @return the number of bits set to one in x 225 */ 226 static av_always_inline av_const int av_popcount64_c(uint64_t x) 227 { 228 return av_popcount(x) + av_popcount(x >> 32); 229 } 230 231 #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24)) 232 #define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24)) 233 234 /** 235 * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form. 236 * 237 * @param val Output value, must be an lvalue of type uint32_t. 238 * @param GET_BYTE Expression reading one byte from the input. 239 * Evaluated up to 7 times (4 for the currently 240 * assigned Unicode range). With a memory buffer 241 * input, this could be *ptr++. 242 * @param ERROR Expression to be evaluated on invalid input, 243 * typically a goto statement. 244 */ 245 #define GET_UTF8(val, GET_BYTE, ERROR)\ 246 val= GET_BYTE;\ 247 {\ 248 int ones= 7 - av_log2(val ^ 255);\ 249 if(ones==1)\ 250 ERROR\ 251 val&= 127>>ones;\ 252 while(--ones > 0){\ 253 int tmp= GET_BYTE - 128;\ 254 if(tmp>>6)\ 255 ERROR\ 256 val= (val<<6) + tmp;\ 257 }\ 258 } 259 260 /** 261 * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form. 262 * 263 * @param val Output value, must be an lvalue of type uint32_t. 264 * @param GET_16BIT Expression returning two bytes of UTF-16 data converted 265 * to native byte order. Evaluated one or two times. 266 * @param ERROR Expression to be evaluated on invalid input, 267 * typically a goto statement. 268 */ 269 #define GET_UTF16(val, GET_16BIT, ERROR)\ 270 val = GET_16BIT;\ 271 {\ 272 unsigned int hi = val - 0xD800;\ 273 if (hi < 0x800) {\ 274 val = GET_16BIT - 0xDC00;\ 275 if (val > 0x3FFU || hi > 0x3FFU)\ 276 ERROR\ 277 val += (hi<<10) + 0x10000;\ 278 }\ 279 }\ 280 281 /** 282 * @def PUT_UTF8(val, tmp, PUT_BYTE) 283 * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long). 284 * @param val is an input-only argument and should be of type uint32_t. It holds 285 * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If 286 * val is given as a function it is executed only once. 287 * @param tmp is a temporary variable and should be of type uint8_t. It 288 * represents an intermediate value during conversion that is to be 289 * output by PUT_BYTE. 290 * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination. 291 * It could be a function or a statement, and uses tmp as the input byte. 292 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be 293 * executed up to 4 times for values in the valid UTF-8 range and up to 294 * 7 times in the general case, depending on the length of the converted 295 * Unicode character. 296 */ 297 #define PUT_UTF8(val, tmp, PUT_BYTE)\ 298 {\ 299 int bytes, shift;\ 300 uint32_t in = val;\ 301 if (in < 0x80) {\ 302 tmp = in;\ 303 PUT_BYTE\ 304 } else {\ 305 bytes = (av_log2(in) + 4) / 5;\ 306 shift = (bytes - 1) * 6;\ 307 tmp = (256 - (256 >> bytes)) | (in >> shift);\ 308 PUT_BYTE\ 309 while (shift >= 6) {\ 310 shift -= 6;\ 311 tmp = 0x80 | ((in >> shift) & 0x3f);\ 312 PUT_BYTE\ 313 }\ 314 }\ 315 } 316 317 /** 318 * @def PUT_UTF16(val, tmp, PUT_16BIT) 319 * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes). 320 * @param val is an input-only argument and should be of type uint32_t. It holds 321 * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If 322 * val is given as a function it is executed only once. 323 * @param tmp is a temporary variable and should be of type uint16_t. It 324 * represents an intermediate value during conversion that is to be 325 * output by PUT_16BIT. 326 * @param PUT_16BIT writes the converted UTF-16 data to any proper destination 327 * in desired endianness. It could be a function or a statement, and uses tmp 328 * as the input byte. For example, PUT_BYTE could be "*output++ = tmp;" 329 * PUT_BYTE will be executed 1 or 2 times depending on input character. 330 */ 331 #define PUT_UTF16(val, tmp, PUT_16BIT)\ 332 {\ 333 uint32_t in = val;\ 334 if (in < 0x10000) {\ 335 tmp = in;\ 336 PUT_16BIT\ 337 } else {\ 338 tmp = 0xD800 | ((in - 0x10000) >> 10);\ 339 PUT_16BIT\ 340 tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\ 341 PUT_16BIT\ 342 }\ 343 }\ 344 345 346 347 #include "mem.h" 348 349 #ifdef HAVE_AV_CONFIG_H 350 # include "internal.h" 351 #endif /* HAVE_AV_CONFIG_H */ 352 353 #endif /* AVUTIL_COMMON_H */ 354 355 /* 356 * The following definitions are outside the multiple inclusion guard 357 * to ensure they are immediately available in intmath.h. 358 */ 359 360 #ifndef av_log2 361 # define av_log2 av_log2_c 362 #endif 363 #ifndef av_log2_16bit 364 # define av_log2_16bit av_log2_16bit_c 365 #endif 366 #ifndef av_ceil_log2 367 # define av_ceil_log2 av_ceil_log2_c 368 #endif 369 #ifndef av_clip 370 # define av_clip av_clip_c 371 #endif 372 #ifndef av_clip_uint8 373 # define av_clip_uint8 av_clip_uint8_c 374 #endif 375 #ifndef av_clip_int8 376 # define av_clip_int8 av_clip_int8_c 377 #endif 378 #ifndef av_clip_uint16 379 # define av_clip_uint16 av_clip_uint16_c 380 #endif 381 #ifndef av_clip_int16 382 # define av_clip_int16 av_clip_int16_c 383 #endif 384 #ifndef av_clipl_int32 385 # define av_clipl_int32 av_clipl_int32_c 386 #endif 387 #ifndef av_clip_uintp2 388 # define av_clip_uintp2 av_clip_uintp2_c 389 #endif 390 #ifndef av_clipf 391 # define av_clipf av_clipf_c 392 #endif 393 #ifndef av_popcount 394 # define av_popcount av_popcount_c 395 #endif 396 #ifndef av_popcount64 397 # define av_popcount64 av_popcount64_c 398 #endif