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 */
av_x_if_null(const void * p,const void * x)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 */
344