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 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 39//rounded division & shift 40#define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b)) 41/* assume b>0 */ 42#define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b)) 43#define FFABS(a) ((a) >= 0 ? (a) : (-(a))) 44#define FFSIGN(a) ((a) > 0 ? 1 : -1) 45 46#define FFMAX(a,b) ((a) > (b) ? (a) : (b)) 47#define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c) 48#define FFMIN(a,b) ((a) > (b) ? (b) : (a)) 49#define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c) 50 51#define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0) 52#define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0])) 53#define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1)) 54 55/* misc math functions */ 56extern const uint8_t ff_log2_tab[256]; 57 58extern const uint8_t av_reverse[256]; 59 60static inline av_const int av_log2_c(unsigned int v) 61{ 62 int n = 0; 63 if (v & 0xffff0000) { 64 v >>= 16; 65 n += 16; 66 } 67 if (v & 0xff00) { 68 v >>= 8; 69 n += 8; 70 } 71 n += ff_log2_tab[v]; 72 73 return n; 74} 75 76static inline av_const int av_log2_16bit_c(unsigned int v) 77{ 78 int n = 0; 79 if (v & 0xff00) { 80 v >>= 8; 81 n += 8; 82 } 83 n += ff_log2_tab[v]; 84 85 return n; 86} 87 88#ifdef HAVE_AV_CONFIG_H 89# include "config.h" 90# include "intmath.h" 91#endif 92 93#ifndef av_log2 94# define av_log2 av_log2_c 95#endif 96#ifndef av_log2_16bit 97# define av_log2_16bit av_log2_16bit_c 98#endif 99 100/** 101 * Clips a signed integer value into the amin-amax range. 102 * @param a value to clip 103 * @param amin minimum value of the clip range 104 * @param amax maximum value of the clip range 105 * @return clipped value 106 */ 107static inline av_const int av_clip(int a, int amin, int amax) 108{ 109 if (a < amin) return amin; 110 else if (a > amax) return amax; 111 else return a; 112} 113 114/** 115 * Clips a signed integer value into the 0-255 range. 116 * @param a value to clip 117 * @return clipped value 118 */ 119static inline av_const uint8_t av_clip_uint8(int a) 120{ 121 if (a&(~0xFF)) return (-a)>>31; 122 else return a; 123} 124 125/** 126 * Clips a signed integer value into the 0-65535 range. 127 * @param a value to clip 128 * @return clipped value 129 */ 130static inline av_const uint16_t av_clip_uint16(int a) 131{ 132 if (a&(~0xFFFF)) return (-a)>>31; 133 else return a; 134} 135 136/** 137 * Clips a signed integer value into the -32768,32767 range. 138 * @param a value to clip 139 * @return clipped value 140 */ 141static inline av_const int16_t av_clip_int16(int a) 142{ 143 if ((a+0x8000) & ~0xFFFF) return (a>>31) ^ 0x7FFF; 144 else return a; 145} 146 147/** 148 * Clips a signed 64-bit integer value into the -2147483648,2147483647 range. 149 * @param a value to clip 150 * @return clipped value 151 */ 152static inline av_const int32_t av_clipl_int32(int64_t a) 153{ 154 if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (a>>63) ^ 0x7FFFFFFF; 155 else return a; 156} 157 158/** 159 * Clips a float value into the amin-amax range. 160 * @param a value to clip 161 * @param amin minimum value of the clip range 162 * @param amax maximum value of the clip range 163 * @return clipped value 164 */ 165static inline av_const float av_clipf(float a, float amin, float amax) 166{ 167 if (a < amin) return amin; 168 else if (a > amax) return amax; 169 else return a; 170} 171 172/** Computes ceil(log2(x)). 173 * @param x value used to compute ceil(log2(x)) 174 * @return computed ceiling of log2(x) 175 */ 176static inline av_const int av_ceil_log2(int x) 177{ 178 return av_log2((x - 1) << 1); 179} 180 181#define MKTAG(a,b,c,d) (a | (b << 8) | (c << 16) | (d << 24)) 182#define MKBETAG(a,b,c,d) (d | (c << 8) | (b << 16) | (a << 24)) 183 184/*! 185 * \def GET_UTF8(val, GET_BYTE, ERROR) 186 * Converts a UTF-8 character (up to 4 bytes long) to its 32-bit UCS-4 encoded form 187 * \param val is the output and should be of type uint32_t. It holds the converted 188 * UCS-4 character and should be a left value. 189 * \param GET_BYTE gets UTF-8 encoded bytes from any proper source. It can be 190 * a function or a statement whose return value or evaluated value is of type 191 * uint8_t. It will be executed up to 4 times for values in the valid UTF-8 range, 192 * and up to 7 times in the general case. 193 * \param ERROR action that should be taken when an invalid UTF-8 byte is returned 194 * from GET_BYTE. It should be a statement that jumps out of the macro, 195 * like exit(), goto, return, break, or continue. 196 */ 197#define GET_UTF8(val, GET_BYTE, ERROR)\ 198 val= GET_BYTE;\ 199 {\ 200 int ones= 7 - av_log2(val ^ 255);\ 201 if(ones==1)\ 202 ERROR\ 203 val&= 127>>ones;\ 204 while(--ones > 0){\ 205 int tmp= GET_BYTE - 128;\ 206 if(tmp>>6)\ 207 ERROR\ 208 val= (val<<6) + tmp;\ 209 }\ 210 } 211 212/*! 213 * \def GET_UTF16(val, GET_16BIT, ERROR) 214 * Converts a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form 215 * \param val is the output and should be of type uint32_t. It holds the converted 216 * UCS-4 character and should be a left value. 217 * \param GET_16BIT gets two bytes of UTF-16 encoded data converted to native endianness. 218 * It can be a function or a statement whose return value or evaluated value is of type 219 * uint16_t. It will be executed up to 2 times. 220 * \param ERROR action that should be taken when an invalid UTF-16 surrogate is 221 * returned from GET_BYTE. It should be a statement that jumps out of the macro, 222 * like exit(), goto, return, break, or continue. 223 */ 224#define GET_UTF16(val, GET_16BIT, ERROR)\ 225 val = GET_16BIT;\ 226 {\ 227 unsigned int hi = val - 0xD800;\ 228 if (hi < 0x800) {\ 229 val = GET_16BIT - 0xDC00;\ 230 if (val > 0x3FFU || hi > 0x3FFU)\ 231 ERROR\ 232 val += (hi<<10) + 0x10000;\ 233 }\ 234 }\ 235 236/*! 237 * \def PUT_UTF8(val, tmp, PUT_BYTE) 238 * Converts a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long). 239 * \param val is an input-only argument and should be of type uint32_t. It holds 240 * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If 241 * val is given as a function it is executed only once. 242 * \param tmp is a temporary variable and should be of type uint8_t. It 243 * represents an intermediate value during conversion that is to be 244 * output by PUT_BYTE. 245 * \param PUT_BYTE writes the converted UTF-8 bytes to any proper destination. 246 * It could be a function or a statement, and uses tmp as the input byte. 247 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be 248 * executed up to 4 times for values in the valid UTF-8 range and up to 249 * 7 times in the general case, depending on the length of the converted 250 * Unicode character. 251 */ 252#define PUT_UTF8(val, tmp, PUT_BYTE)\ 253 {\ 254 int bytes, shift;\ 255 uint32_t in = val;\ 256 if (in < 0x80) {\ 257 tmp = in;\ 258 PUT_BYTE\ 259 } else {\ 260 bytes = (av_log2(in) + 4) / 5;\ 261 shift = (bytes - 1) * 6;\ 262 tmp = (256 - (256 >> bytes)) | (in >> shift);\ 263 PUT_BYTE\ 264 while (shift >= 6) {\ 265 shift -= 6;\ 266 tmp = 0x80 | ((in >> shift) & 0x3f);\ 267 PUT_BYTE\ 268 }\ 269 }\ 270 } 271 272/*! 273 * \def PUT_UTF16(val, tmp, PUT_16BIT) 274 * Converts a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes). 275 * \param val is an input-only argument and should be of type uint32_t. It holds 276 * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If 277 * val is given as a function it is executed only once. 278 * \param tmp is a temporary variable and should be of type uint16_t. It 279 * represents an intermediate value during conversion that is to be 280 * output by PUT_16BIT. 281 * \param PUT_16BIT writes the converted UTF-16 data to any proper destination 282 * in desired endianness. It could be a function or a statement, and uses tmp 283 * as the input byte. For example, PUT_BYTE could be "*output++ = tmp;" 284 * PUT_BYTE will be executed 1 or 2 times depending on input character. 285 */ 286#define PUT_UTF16(val, tmp, PUT_16BIT)\ 287 {\ 288 uint32_t in = val;\ 289 if (in < 0x10000) {\ 290 tmp = in;\ 291 PUT_16BIT\ 292 } else {\ 293 tmp = 0xD800 | ((in - 0x10000) >> 10);\ 294 PUT_16BIT\ 295 tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\ 296 PUT_16BIT\ 297 }\ 298 }\ 299 300 301 302#include "mem.h" 303 304#ifdef HAVE_AV_CONFIG_H 305# include "internal.h" 306#endif /* HAVE_AV_CONFIG_H */ 307 308#endif /* AVUTIL_COMMON_H */ 309