avutil.h 9.3 KB

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  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. #ifndef AVUTIL_AVUTIL_H
  21. #define AVUTIL_AVUTIL_H
  22. /**
  23. * @file
  24. * @ingroup lavu
  25. * Convenience header that includes @ref lavu "libavutil"'s core.
  26. */
  27. /**
  28. * @mainpage
  29. *
  30. * @section ffmpeg_intro Introduction
  31. *
  32. * This document describes the usage of the different libraries
  33. * provided by FFmpeg.
  34. *
  35. * @li @ref libavc "libavcodec" encoding/decoding library
  36. * @li @ref lavfi "libavfilter" graph-based frame editing library
  37. * @li @ref libavf "libavformat" I/O and muxing/demuxing library
  38. * @li @ref lavd "libavdevice" special devices muxing/demuxing library
  39. * @li @ref lavu "libavutil" common utility library
  40. * @li @ref lswr "libswresample" audio resampling, format conversion and mixing
  41. * @li @ref lpp "libpostproc" post processing library
  42. * @li @ref libsws "libswscale" color conversion and scaling library
  43. *
  44. * @section ffmpeg_versioning Versioning and compatibility
  45. *
  46. * Each of the FFmpeg libraries contains a version.h header, which defines a
  47. * major, minor and micro version number with the
  48. * <em>LIBRARYNAME_VERSION_{MAJOR,MINOR,MICRO}</em> macros. The major version
  49. * number is incremented with backward incompatible changes - e.g. removing
  50. * parts of the public API, reordering public struct members, etc. The minor
  51. * version number is incremented for backward compatible API changes or major
  52. * new features - e.g. adding a new public function or a new decoder. The micro
  53. * version number is incremented for smaller changes that a calling program
  54. * might still want to check for - e.g. changing behavior in a previously
  55. * unspecified situation.
  56. *
  57. * FFmpeg guarantees backward API and ABI compatibility for each library as long
  58. * as its major version number is unchanged. This means that no public symbols
  59. * will be removed or renamed. Types and names of the public struct members and
  60. * values of public macros and enums will remain the same (unless they were
  61. * explicitly declared as not part of the public API). Documented behavior will
  62. * not change.
  63. *
  64. * In other words, any correct program that works with a given FFmpeg snapshot
  65. * should work just as well without any changes with any later snapshot with the
  66. * same major versions. This applies to both rebuilding the program against new
  67. * FFmpeg versions or to replacing the dynamic FFmpeg libraries that a program
  68. * links against.
  69. *
  70. * However, new public symbols may be added and new members may be appended to
  71. * public structs whose size is not part of public ABI (most public structs in
  72. * FFmpeg). New macros and enum values may be added. Behavior in undocumented
  73. * situations may change slightly (and be documented). All those are accompanied
  74. * by an entry in doc/APIchanges and incrementing either the minor or micro
  75. * version number.
  76. */
  77. /**
  78. * @defgroup lavu libavutil
  79. * Common code shared across all FFmpeg libraries.
  80. *
  81. * @note
  82. * libavutil is designed to be modular. In most cases, in order to use the
  83. * functions provided by one component of libavutil you must explicitly include
  84. * the specific header containing that feature. If you are only using
  85. * media-related components, you could simply include libavutil/avutil.h, which
  86. * brings in most of the "core" components.
  87. *
  88. * @{
  89. *
  90. * @defgroup lavu_crypto Crypto and Hashing
  91. *
  92. * @{
  93. * @}
  94. *
  95. * @defgroup lavu_math Mathematics
  96. * @{
  97. *
  98. * @}
  99. *
  100. * @defgroup lavu_string String Manipulation
  101. *
  102. * @{
  103. *
  104. * @}
  105. *
  106. * @defgroup lavu_mem Memory Management
  107. *
  108. * @{
  109. *
  110. * @}
  111. *
  112. * @defgroup lavu_data Data Structures
  113. * @{
  114. *
  115. * @}
  116. *
  117. * @defgroup lavu_video Video related
  118. *
  119. * @{
  120. *
  121. * @}
  122. *
  123. * @defgroup lavu_audio Audio related
  124. *
  125. * @{
  126. *
  127. * @}
  128. *
  129. * @defgroup lavu_error Error Codes
  130. *
  131. * @{
  132. *
  133. * @}
  134. *
  135. * @defgroup lavu_log Logging Facility
  136. *
  137. * @{
  138. *
  139. * @}
  140. *
  141. * @defgroup lavu_misc Other
  142. *
  143. * @{
  144. *
  145. * @defgroup preproc_misc Preprocessor String Macros
  146. *
  147. * @{
  148. *
  149. * @}
  150. *
  151. * @defgroup version_utils Library Version Macros
  152. *
  153. * @{
  154. *
  155. * @}
  156. */
  157. /**
  158. * @addtogroup lavu_ver
  159. * @{
  160. */
  161. /**
  162. * Return the LIBAVUTIL_VERSION_INT constant.
  163. */
  164. unsigned avutil_version(void);
  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. * Return the libavutil build-time configuration.
  173. */
  174. const char *avutil_configuration(void);
  175. /**
  176. * Return the libavutil license.
  177. */
  178. const char *avutil_license(void);
  179. /**
  180. * @}
  181. */
  182. /**
  183. * @addtogroup lavu_media Media Type
  184. * @brief Media Type
  185. */
  186. enum AVMediaType {
  187. AVMEDIA_TYPE_UNKNOWN = -1, ///< Usually treated as AVMEDIA_TYPE_DATA
  188. AVMEDIA_TYPE_VIDEO,
  189. AVMEDIA_TYPE_AUDIO,
  190. AVMEDIA_TYPE_DATA, ///< Opaque data information usually continuous
  191. AVMEDIA_TYPE_SUBTITLE,
  192. AVMEDIA_TYPE_ATTACHMENT, ///< Opaque data information usually sparse
  193. AVMEDIA_TYPE_NB
  194. };
  195. /**
  196. * Return a string describing the media_type enum, NULL if media_type
  197. * is unknown.
  198. */
  199. const char *av_get_media_type_string(enum AVMediaType media_type);
  200. /**
  201. * @defgroup lavu_const Constants
  202. * @{
  203. *
  204. * @defgroup lavu_enc Encoding specific
  205. *
  206. * @note those definition should move to avcodec
  207. * @{
  208. */
  209. #define FF_LAMBDA_SHIFT 7
  210. #define FF_LAMBDA_SCALE (1<<FF_LAMBDA_SHIFT)
  211. #define FF_QP2LAMBDA 118 ///< factor to convert from H.263 QP to lambda
  212. #define FF_LAMBDA_MAX (256*128-1)
  213. #define FF_QUALITY_SCALE FF_LAMBDA_SCALE //FIXME maybe remove
  214. /**
  215. * @}
  216. * @defgroup lavu_time Timestamp specific
  217. *
  218. * FFmpeg internal timebase and timestamp definitions
  219. *
  220. * @{
  221. */
  222. /**
  223. * @brief Undefined timestamp value
  224. *
  225. * Usually reported by demuxer that work on containers that do not provide
  226. * either pts or dts.
  227. */
  228. #define AV_NOPTS_VALUE ((int64_t)UINT64_C(0x8000000000000000))
  229. /**
  230. * Internal time base represented as integer
  231. */
  232. #define AV_TIME_BASE 1000000
  233. /**
  234. * Internal time base represented as fractional value
  235. */
  236. #ifdef __cplusplus
  237. /* ISO C++ forbids compound-literals. */
  238. #define AV_TIME_BASE_Q av_make_q(1, AV_TIME_BASE)
  239. #else
  240. #define AV_TIME_BASE_Q (AVRational){1, AV_TIME_BASE}
  241. #endif
  242. /**
  243. * @}
  244. * @}
  245. * @defgroup lavu_picture Image related
  246. *
  247. * AVPicture types, pixel formats and basic image planes manipulation.
  248. *
  249. * @{
  250. */
  251. enum AVPictureType {
  252. AV_PICTURE_TYPE_NONE = 0, ///< Undefined
  253. AV_PICTURE_TYPE_I, ///< Intra
  254. AV_PICTURE_TYPE_P, ///< Predicted
  255. AV_PICTURE_TYPE_B, ///< Bi-dir predicted
  256. AV_PICTURE_TYPE_S, ///< S(GMC)-VOP MPEG-4
  257. AV_PICTURE_TYPE_SI, ///< Switching Intra
  258. AV_PICTURE_TYPE_SP, ///< Switching Predicted
  259. AV_PICTURE_TYPE_BI, ///< BI type
  260. };
  261. /**
  262. * Return a single letter to describe the given picture type
  263. * pict_type.
  264. *
  265. * @param[in] pict_type the picture type @return a single character
  266. * representing the picture type, '?' if pict_type is unknown
  267. */
  268. char av_get_picture_type_char(enum AVPictureType pict_type);
  269. /**
  270. * @}
  271. */
  272. #include "common.h"
  273. #include "rational.h"
  274. #include "version.h"
  275. #include "macros.h"
  276. #include "mathematics.h"
  277. #include "log.h"
  278. #include "pixfmt.h"
  279. /**
  280. * Return x default pointer in case p is NULL.
  281. */
  282. static inline void *av_x_if_null(const void *p, const void *x)
  283. {
  284. return (void *)(intptr_t)(p ? p : x);
  285. }
  286. /**
  287. * Compute the length of an integer list.
  288. *
  289. * @param elsize size in bytes of each list element (only 1, 2, 4 or 8)
  290. * @param term list terminator (usually 0 or -1)
  291. * @param list pointer to the list
  292. * @return length of the list, in elements, not counting the terminator
  293. */
  294. unsigned av_int_list_length_for_size(unsigned elsize,
  295. const void *list, uint64_t term) av_pure;
  296. /**
  297. * Compute the length of an integer list.
  298. *
  299. * @param term list terminator (usually 0 or -1)
  300. * @param list pointer to the list
  301. * @return length of the list, in elements, not counting the terminator
  302. */
  303. #define av_int_list_length(list, term) \
  304. av_int_list_length_for_size(sizeof(*(list)), list, term)
  305. /**
  306. * Return the fractional representation of the internal time base.
  307. */
  308. AVRational av_get_time_base_q(void);
  309. #define AV_FOURCC_MAX_STRING_SIZE 32
  310. #define av_fourcc2str(fourcc) av_fourcc_make_string((char[AV_FOURCC_MAX_STRING_SIZE]){0}, fourcc)
  311. /**
  312. * Fill the provided buffer with a string containing a FourCC (four-character
  313. * code) representation.
  314. *
  315. * @param buf a buffer with size in bytes of at least AV_FOURCC_MAX_STRING_SIZE
  316. * @param fourcc the fourcc to represent
  317. * @return the buffer in input
  318. */
  319. char *av_fourcc_make_string(char *buf, uint32_t fourcc);
  320. /**
  321. * @}
  322. * @}
  323. */
  324. #endif /* AVUTIL_AVUTIL_H */