avutil.h (8783B)
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 #ifndef AVUTIL_AVUTIL_H 22 #define AVUTIL_AVUTIL_H 23 24 /** 25 * @file 26 * external API header 27 */ 28 29 /** 30 * @mainpage 31 * 32 * @section ffmpeg_intro Introduction 33 * 34 * This document describes the usage of the different libraries 35 * provided by FFmpeg. 36 * 37 * @li @ref libavc "libavcodec" encoding/decoding library 38 * @li @ref lavfi "libavfilter" graph-based frame editing library 39 * @li @ref libavf "libavformat" I/O and muxing/demuxing library 40 * @li @ref lavd "libavdevice" special devices muxing/demuxing library 41 * @li @ref lavu "libavutil" common utility library 42 * @li @ref lswr "libswresample" audio resampling, format conversion and mixing 43 * @li @ref lpp "libpostproc" post processing library 44 * @li @ref libsws "libswscale" color conversion and scaling library 45 * 46 * @section ffmpeg_versioning Versioning and compatibility 47 * 48 * Each of the FFmpeg libraries contains a version.h header, which defines a 49 * major, minor and micro version number with the 50 * <em>LIBRARYNAME_VERSION_{MAJOR,MINOR,MICRO}</em> macros. The major version 51 * number is incremented with backward incompatible changes - e.g. removing 52 * parts of the public API, reordering public struct members, etc. The minor 53 * version number is incremented for backward compatible API changes or major 54 * new features - e.g. adding a new public function or a new decoder. The micro 55 * version number is incremented for smaller changes that a calling program 56 * might still want to check for - e.g. changing behavior in a previously 57 * unspecified situation. 58 * 59 * FFmpeg guarantees backward API and ABI compatibility for each library as long 60 * as its major version number is unchanged. This means that no public symbols 61 * will be removed or renamed. Types and names of the public struct members and 62 * values of public macros and enums will remain the same (unless they were 63 * explicitly declared as not part of the public API). Documented behavior will 64 * not change. 65 * 66 * In other words, any correct program that works with a given FFmpeg snapshot 67 * should work just as well without any changes with any later snapshot with the 68 * same major versions. This applies to both rebuilding the program against new 69 * FFmpeg versions or to replacing the dynamic FFmpeg libraries that a program 70 * links against. 71 * 72 * However, new public symbols may be added and new members may be appended to 73 * public structs whose size is not part of public ABI (most public structs in 74 * FFmpeg). New macros and enum values may be added. Behavior in undocumented 75 * situations may change slightly (and be documented). All those are accompanied 76 * by an entry in doc/APIchanges and incrementing either the minor or micro 77 * version number. 78 */ 79 80 /** 81 * @defgroup lavu Common utility functions 82 * 83 * @brief 84 * libavutil contains the code shared across all the other FFmpeg 85 * libraries 86 * 87 * @note In order to use the functions provided by avutil you must include 88 * the specific header. 89 * 90 * @{ 91 * 92 * @defgroup lavu_crypto Crypto and Hashing 93 * 94 * @{ 95 * @} 96 * 97 * @defgroup lavu_math Maths 98 * @{ 99 * 100 * @} 101 * 102 * @defgroup lavu_string String Manipulation 103 * 104 * @{ 105 * 106 * @} 107 * 108 * @defgroup lavu_mem Memory Management 109 * 110 * @{ 111 * 112 * @} 113 * 114 * @defgroup lavu_data Data Structures 115 * @{ 116 * 117 * @} 118 * 119 * @defgroup lavu_audio Audio related 120 * 121 * @{ 122 * 123 * @} 124 * 125 * @defgroup lavu_error Error Codes 126 * 127 * @{ 128 * 129 * @} 130 * 131 * @defgroup lavu_log Logging Facility 132 * 133 * @{ 134 * 135 * @} 136 * 137 * @defgroup lavu_misc Other 138 * 139 * @{ 140 * 141 * @defgroup preproc_misc Preprocessor String Macros 142 * 143 * @{ 144 * 145 * @} 146 * 147 * @defgroup version_utils Library Version Macros 148 * 149 * @{ 150 * 151 * @} 152 */ 153 154 155 /** 156 * @addtogroup lavu_ver 157 * @{ 158 */ 159 160 /** 161 * Return the LIBAVUTIL_VERSION_INT constant. 162 */ 163 unsigned avutil_version(void); 164 165 /** 166 * Return an informative version string. This usually is the actual release 167 * version number or a git commit description. This string has no fixed format 168 * and can change any time. It should never be parsed by code. 169 */ 170 const char *av_version_info(void); 171 172 /** 173 * Return the libavutil build-time configuration. 174 */ 175 const char *avutil_configuration(void); 176 177 /** 178 * Return the libavutil license. 179 */ 180 const char *avutil_license(void); 181 182 /** 183 * @} 184 */ 185 186 /** 187 * @addtogroup lavu_media Media Type 188 * @brief Media Type 189 */ 190 191 enum AVMediaType { 192 AVMEDIA_TYPE_UNKNOWN = -1, ///< Usually treated as AVMEDIA_TYPE_DATA 193 AVMEDIA_TYPE_VIDEO, 194 AVMEDIA_TYPE_AUDIO, 195 AVMEDIA_TYPE_DATA, ///< Opaque data information usually continuous 196 AVMEDIA_TYPE_SUBTITLE, 197 AVMEDIA_TYPE_ATTACHMENT, ///< Opaque data information usually sparse 198 AVMEDIA_TYPE_NB 199 }; 200 201 /** 202 * Return a string describing the media_type enum, NULL if media_type 203 * is unknown. 204 */ 205 const char *av_get_media_type_string(enum AVMediaType media_type); 206 207 /** 208 * @defgroup lavu_const Constants 209 * @{ 210 * 211 * @defgroup lavu_enc Encoding specific 212 * 213 * @note those definition should move to avcodec 214 * @{ 215 */ 216 217 #define FF_LAMBDA_SHIFT 7 218 #define FF_LAMBDA_SCALE (1<<FF_LAMBDA_SHIFT) 219 #define FF_QP2LAMBDA 118 ///< factor to convert from H.263 QP to lambda 220 #define FF_LAMBDA_MAX (256*128-1) 221 222 #define FF_QUALITY_SCALE FF_LAMBDA_SCALE //FIXME maybe remove 223 224 /** 225 * @} 226 * @defgroup lavu_time Timestamp specific 227 * 228 * FFmpeg internal timebase and timestamp definitions 229 * 230 * @{ 231 */ 232 233 /** 234 * @brief Undefined timestamp value 235 * 236 * Usually reported by demuxer that work on containers that do not provide 237 * either pts or dts. 238 */ 239 240 #define AV_NOPTS_VALUE ((int64_t)UINT64_C(0x8000000000000000)) 241 242 /** 243 * Internal time base represented as integer 244 */ 245 246 #define AV_TIME_BASE 1000000 247 248 /** 249 * Internal time base represented as fractional value 250 */ 251 252 #define AV_TIME_BASE_Q (AVRational){1, AV_TIME_BASE} 253 254 /** 255 * @} 256 * @} 257 * @defgroup lavu_picture Image related 258 * 259 * AVPicture types, pixel formats and basic image planes manipulation. 260 * 261 * @{ 262 */ 263 264 enum AVPictureType { 265 AV_PICTURE_TYPE_NONE = 0, ///< Undefined 266 AV_PICTURE_TYPE_I, ///< Intra 267 AV_PICTURE_TYPE_P, ///< Predicted 268 AV_PICTURE_TYPE_B, ///< Bi-dir predicted 269 AV_PICTURE_TYPE_S, ///< S(GMC)-VOP MPEG4 270 AV_PICTURE_TYPE_SI, ///< Switching Intra 271 AV_PICTURE_TYPE_SP, ///< Switching Predicted 272 AV_PICTURE_TYPE_BI, ///< BI type 273 }; 274 275 /** 276 * Return a single letter to describe the given picture type 277 * pict_type. 278 * 279 * @param[in] pict_type the picture type @return a single character 280 * representing the picture type, '?' if pict_type is unknown 281 */ 282 char av_get_picture_type_char(enum AVPictureType pict_type); 283 284 /** 285 * @} 286 */ 287 288 #include "common.h" 289 #include "error.h" 290 #include "rational.h" 291 #include "version.h" 292 #include "macros.h" 293 #include "mathematics.h" 294 #include "log.h" 295 #include "pixfmt.h" 296 297 /** 298 * Return x default pointer in case p is NULL. 299 */ 300 static inline void *av_x_if_null(const void *p, const void *x) 301 { 302 return (void *)(intptr_t)(p ? p : x); 303 } 304 305 /** 306 * Compute the length of an integer list. 307 * 308 * @param elsize size in bytes of each list element (only 1, 2, 4 or 8) 309 * @param term list terminator (usually 0 or -1) 310 * @param list pointer to the list 311 * @return length of the list, in elements, not counting the terminator 312 */ 313 unsigned av_int_list_length_for_size(unsigned elsize, 314 const void *list, uint64_t term) av_pure; 315 316 /** 317 * Compute the length of an integer list. 318 * 319 * @param term list terminator (usually 0 or -1) 320 * @param list pointer to the list 321 * @return length of the list, in elements, not counting the terminator 322 */ 323 #define av_int_list_length(list, term) \ 324 av_int_list_length_for_size(sizeof(*(list)), list, term) 325 326 /** 327 * Open a file using a UTF-8 filename. 328 * The API of this function matches POSIX fopen(), errors are returned through 329 * errno. 330 */ 331 FILE *av_fopen_utf8(const char *path, const char *mode); 332 333 /** 334 * Return the fractional representation of the internal time base. 335 */ 336 AVRational av_get_time_base_q(void); 337 338 /** 339 * @} 340 * @} 341 */ 342 343 #endif /* AVUTIL_AVUTIL_H */