libavutil/avutil.h

   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  * @ingroup lavu
  27  * Convenience header that includes @ref lavu "libavutil"'s core.
  28  */
  29
  30 /**
  31  * @mainpage
  32  *
  33  * @section ffmpeg_intro Introduction
  34  *
  35  * This document describes the usage of the different libraries
  36  * provided by FFmpeg.
  37  *
  38  * @li @ref libavc "libavcodec" encoding/decoding library
  39  * @li @ref lavfi "libavfilter" graph-based frame editing library
  40  * @li @ref libavf "libavformat" I/O and muxing/demuxing library
  41  * @li @ref lavd "libavdevice" special devices muxing/demuxing library
  42  * @li @ref lavu "libavutil" common utility library
  43  * @li @ref lswr "libswresample" audio resampling, format conversion and mixing
  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 libavutil
  82  * Common code shared across all FFmpeg libraries.
  83  *
  84  * @note
  85  * libavutil is designed to be modular. In most cases, in order to use the
  86  * functions provided by one component of libavutil you must explicitly include
  87  * the specific header containing that feature. If you are only using
  88  * media-related components, you could simply include libavutil/avutil.h, which
  89  * brings in most of the "core" components.
  90  *
  91  * @{
  92  *
  93  * @defgroup lavu_crypto Crypto and Hashing
  94  *
  95  * @{
  96  * @}
  97  *
  98  * @defgroup lavu_math Mathematics
  99  * @{
 100  *
 101  * @}
 102  *
 103  * @defgroup lavu_string String Manipulation
 104  *
 105  * @{
 106  *
 107  * @}
 108  *
 109  * @defgroup lavu_mem Memory Management
 110  *
 111  * @{
 112  *
 113  * @}
 114  *
 115  * @defgroup lavu_data Data Structures
 116  * @{
 117  *
 118  * @}
 119  *
 120  * @defgroup lavu_video Video related
 121  *
 122  * @{
 123  *
 124  * @}
 125  *
 126  * @defgroup lavu_audio Audio related
 127  *
 128  * @{
 129  *
 130  * @}
 131  *
 132  * @defgroup lavu_error Error Codes
 133  *
 134  * @{
 135  *
 136  * @}
 137  *
 138  * @defgroup lavu_log Logging Facility
 139  *
 140  * @{
 141  *
 142  * @}
 143  *
 144  * @defgroup lavu_misc Other
 145  *
 146  * @{
 147  *
 148  * @defgroup preproc_misc Preprocessor String Macros
 149  *
 150  * @{
 151  *
 152  * @}
 153  *
 154  * @defgroup version_utils Library Version Macros
 155  *
 156  * @{
 157  *
 158  * @}
 159  */
 160
 161
 162 /**
 163  * @addtogroup lavu_ver
 164  * @{
 165  */
 166
 167 /**
 168  * Return the LIBAVUTIL_VERSION_INT constant.
 169  */
 170 unsigned avutil_version(void);
 171
 172 /**
 173  * Return an informative version string. This usually is the actual release
 174  * version number or a git commit description. This string has no fixed format
 175  * and can change any time. It should never be parsed by code.
 176  */
 177 const char *av_version_info(void);
 178
 179 /**
 180  * Return the libavutil build-time configuration.
 181  */
 182 const char *avutil_configuration(void);
 183
 184 /**
 185  * Return the libavutil license.
 186  */
 187 const char *avutil_license(void);
 188
 189 /**
 190  * @}
 191  */
 192
 193 /**
 194  * @addtogroup lavu_media Media Type
 195  * @brief Media Type
 196  */
 197
 198 enum AVMediaType {
 199     AVMEDIA_TYPE_UNKNOWN = -1,  ///< Usually treated as AVMEDIA_TYPE_DATA
 200     AVMEDIA_TYPE_VIDEO,
 201     AVMEDIA_TYPE_AUDIO,
 202     AVMEDIA_TYPE_DATA,          ///< Opaque data information usually continuous
 203     AVMEDIA_TYPE_SUBTITLE,
 204     AVMEDIA_TYPE_ATTACHMENT,    ///< Opaque data information usually sparse
 205     AVMEDIA_TYPE_NB
 206 };
 207
 208 /**
 209  * Return a string describing the media_type enum, NULL if media_type
 210  * is unknown.
 211  */
 212 const char *av_get_media_type_string(enum AVMediaType media_type);
 213
 214 /**
 215  * @defgroup lavu_const Constants
 216  * @{
 217  *
 218  * @defgroup lavu_enc Encoding specific
 219  *
 220  * @note those definition should move to avcodec
 221  * @{
 222  */
 223
 224 #define FF_LAMBDA_SHIFT 7
 225 #define FF_LAMBDA_SCALE (1<<FF_LAMBDA_SHIFT)
 226 #define FF_QP2LAMBDA 118 ///< factor to convert from H.263 QP to lambda
 227 #define FF_LAMBDA_MAX (256*128-1)
 228
 229 #define FF_QUALITY_SCALE FF_LAMBDA_SCALE //FIXME maybe remove
 230
 231 /**
 232  * @}
 233  * @defgroup lavu_time Timestamp specific
 234  *
 235  * FFmpeg internal timebase and timestamp definitions
 236  *
 237  * @{
 238  */
 239
 240 /**
 241  * @brief Undefined timestamp value
 242  *
 243  * Usually reported by demuxer that work on containers that do not provide
 244  * either pts or dts.
 245  */
 246
 247 #define AV_NOPTS_VALUE          ((int64_t)UINT64_C(0x8000000000000000))
 248
 249 /**
 250  * Internal time base represented as integer
 251  */
 252
 253 #define AV_TIME_BASE            1000000
 254
 255 /**
 256  * Internal time base represented as fractional value
 257  */
 258
 259 #ifdef __cplusplus
 260 /* ISO C++ forbids compound-literals. */
 261 #define AV_TIME_BASE_Q          av_make_q(1, AV_TIME_BASE)
 262 #else
 263 #define AV_TIME_BASE_Q          (AVRational){1, AV_TIME_BASE}
 264 #endif
 265
 266 /**
 267  * @}
 268  * @}
 269  * @defgroup lavu_picture Image related
 270  *
 271  * AVPicture types, pixel formats and basic image planes manipulation.
 272  *
 273  * @{
 274  */
 275
 276 enum AVPictureType {
 277     AV_PICTURE_TYPE_NONE = 0, ///< Undefined
 278     AV_PICTURE_TYPE_I,     ///< Intra
 279     AV_PICTURE_TYPE_P,     ///< Predicted
 280     AV_PICTURE_TYPE_B,     ///< Bi-dir predicted
 281     AV_PICTURE_TYPE_S,     ///< S(GMC)-VOP MPEG-4
 282     AV_PICTURE_TYPE_SI,    ///< Switching Intra
 283     AV_PICTURE_TYPE_SP,    ///< Switching Predicted
 284     AV_PICTURE_TYPE_BI,    ///< BI type
 285 };
 286
 287 /**
 288  * Return a single letter to describe the given picture type
 289  * pict_type.
 290  *
 291  * @param[in] pict_type the picture type @return a single character
 292  * representing the picture type, '?' if pict_type is unknown
 293  */
 294 char av_get_picture_type_char(enum AVPictureType pict_type);
 295
 296 /**
 297  * @}
 298  */
 299
 300 #include "common.h"
 301 #include "rational.h"
 302 #include "version.h"
 303 #include "macros.h"
 304 #include "mathematics.h"
 305 #include "log.h"
 306 #include "pixfmt.h"
 307
 308 /**
 309  * Return x default pointer in case p is NULL.
 310  */
 311 static inline void *av_x_if_null(const void *p, const void *x)
 312 {
 313     return (void *)(intptr_t)(p ? p : x);
 314 }
 315
 316 #if FF_API_OPT_INT_LIST
 317 /**
 318  * Compute the length of an integer list.
 319  *
 320  * @param elsize  size in bytes of each list element (only 1, 2, 4 or 8)
 321  * @param term    list terminator (usually 0 or -1)
 322  * @param list    pointer to the list
 323  * @return  length of the list, in elements, not counting the terminator
 324  */
 325 attribute_deprecated
 326 unsigned av_int_list_length_for_size(unsigned elsize,
 327                                      const void *list, uint64_t term) av_pure;
 328
 329 /**
 330  * Compute the length of an integer list.
 331  *
 332  * @param term  list terminator (usually 0 or -1)
 333  * @param list  pointer to the list
 334  * @return  length of the list, in elements, not counting the terminator
 335  */
 336 #define av_int_list_length(list, term) \
 337     av_int_list_length_for_size(sizeof(*(list)), list, term)
 338 #endif
 339
 340 /**
 341  * Return the fractional representation of the internal time base.
 342  */
 343 AVRational av_get_time_base_q(void);
 344
 345 #define AV_FOURCC_MAX_STRING_SIZE 32
 346
 347 #define av_fourcc2str(fourcc) av_fourcc_make_string((char[AV_FOURCC_MAX_STRING_SIZE]){0}, fourcc)
 348
 349 /**
 350  * Fill the provided buffer with a string containing a FourCC (four-character
 351  * code) representation.
 352  *
 353  * @param buf    a buffer with size in bytes of at least AV_FOURCC_MAX_STRING_SIZE
 354  * @param fourcc the fourcc to represent
 355  * @return the buffer in input
 356  */
 357 char *av_fourcc_make_string(char *buf, uint32_t fourcc);
 358
 359 /**
 360  * @}
 361  * @}
 362  */
 363
 364 #endif /* AVUTIL_AVUTIL_H */