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 lsws "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_misc Other
132 *
133 * @{
134 *
135 * @defgroup lavu_internal Internal
136 *
137 * Not exported functions, for internal usage only
138 *
139 * @{
140 *
141 * @}
142 */
143
144
145 /**
146 * @addtogroup lavu_ver
147 * @{
148 */
149
150 /**
151 * Return the LIBAVUTIL_VERSION_INT constant.
152 */
153 unsigned avutil_version(void);
154
155 /**
156 * Return the libavutil build-time configuration.
157 */
158 const char *avutil_configuration(void);
159
160 /**
161 * Return the libavutil license.
162 */
163 const char *avutil_license(void);
164
165 /**
166 * @}
167 */
168
169 /**
170 * @addtogroup lavu_media Media Type
171 * @brief Media Type
172 */
173
174 enum AVMediaType {
175 AVMEDIA_TYPE_UNKNOWN = -1, ///< Usually treated as AVMEDIA_TYPE_DATA
176 AVMEDIA_TYPE_VIDEO,
177 AVMEDIA_TYPE_AUDIO,
178 AVMEDIA_TYPE_DATA, ///< Opaque data information usually continuous
179 AVMEDIA_TYPE_SUBTITLE,
180 AVMEDIA_TYPE_ATTACHMENT, ///< Opaque data information usually sparse
181 AVMEDIA_TYPE_NB
182 };
183
184 /**
185 * Return a string describing the media_type enum, NULL if media_type
186 * is unknown.
187 */
188 const char *av_get_media_type_string(enum AVMediaType media_type);
189
190 /**
191 * @defgroup lavu_const Constants
192 * @{
193 *
194 * @defgroup lavu_enc Encoding specific
195 *
196 * @note those definition should move to avcodec
197 * @{
198 */
199
200 #define FF_LAMBDA_SHIFT 7
201 #define FF_LAMBDA_SCALE (1<<FF_LAMBDA_SHIFT)
202 #define FF_QP2LAMBDA 118 ///< factor to convert from H.263 QP to lambda
203 #define FF_LAMBDA_MAX (256*128-1)
204
205 #define FF_QUALITY_SCALE FF_LAMBDA_SCALE //FIXME maybe remove
206
207 /**
208 * @}
209 * @defgroup lavu_time Timestamp specific
210 *
211 * FFmpeg internal timebase and timestamp definitions
212 *
213 * @{
214 */
215
216 /**
217 * @brief Undefined timestamp value
218 *
219 * Usually reported by demuxer that work on containers that do not provide
220 * either pts or dts.
221 */
222
223 #define AV_NOPTS_VALUE ((int64_t)UINT64_C(0x8000000000000000))
224
225 /**
226 * Internal time base represented as integer
227 */
228
229 #define AV_TIME_BASE 1000000
230
231 /**
232 * Internal time base represented as fractional value
233 */
234
235 #define AV_TIME_BASE_Q (AVRational){1, AV_TIME_BASE}
236
237 /**
238 * @}
239 * @}
240 * @defgroup lavu_picture Image related
241 *
242 * AVPicture types, pixel formats and basic image planes manipulation.
243 *
244 * @{
245 */
246
247 enum AVPictureType {
248 AV_PICTURE_TYPE_NONE = 0, ///< Undefined
249 AV_PICTURE_TYPE_I, ///< Intra
250 AV_PICTURE_TYPE_P, ///< Predicted
251 AV_PICTURE_TYPE_B, ///< Bi-dir predicted
252 AV_PICTURE_TYPE_S, ///< S(GMC)-VOP MPEG4
253 AV_PICTURE_TYPE_SI, ///< Switching Intra
254 AV_PICTURE_TYPE_SP, ///< Switching Predicted
255 AV_PICTURE_TYPE_BI, ///< BI type
256 };
257
258 /**
259 * Return a single letter to describe the given picture type
260 * pict_type.
261 *
262 * @param[in] pict_type the picture type @return a single character
263 * representing the picture type, '?' if pict_type is unknown
264 */
265 char av_get_picture_type_char(enum AVPictureType pict_type);
266
267 /**
268 * @}
269 */
270
271 #include "common.h"
272 #include "error.h"
273 #include "version.h"
274 #include "mathematics.h"
275 #include "rational.h"
276 #include "intfloat_readwrite.h"
277 #include "log.h"
278 #include "pixfmt.h"
279
280 /**
281 * Return x default pointer in case p is NULL.
282 */
av_x_if_null(const void * p,const void * x)283 static inline void *av_x_if_null(const void *p, const void *x)
284 {
285 return (void *)(intptr_t)(p ? p : x);
286 }
287
288 /**
289 * Compute the length of an integer list.
290 *
291 * @param elsize size in bytes of each list element (only 1, 2, 4 or 8)
292 * @param term list terminator (usually 0 or -1)
293 * @param list pointer to the list
294 * @return length of the list, in elements, not counting the terminator
295 */
296 unsigned av_int_list_length_for_size(unsigned elsize,
297 const void *list, uint64_t term) av_pure;
298
299 /**
300 * Compute the length of an integer list.
301 *
302 * @param term list terminator (usually 0 or -1)
303 * @param list pointer to the list
304 * @return length of the list, in elements, not counting the terminator
305 */
306 #define av_int_list_length(list, term) \
307 av_int_list_length_for_size(sizeof(*(list)), list, term)
308
309 /**
310 * @}
311 * @}
312 */
313
314 #endif /* AVUTIL_AVUTIL_H */
315