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avutil.h
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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 
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 
192  AVMEDIA_TYPE_UNKNOWN = -1, ///< Usually treated as AVMEDIA_TYPE_DATA
195  AVMEDIA_TYPE_DATA, ///< Opaque data information usually continuous
197  AVMEDIA_TYPE_ATTACHMENT, ///< Opaque data information usually sparse
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 
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  */
337 
338 /**
339  * @}
340  * @}
341  */
342 
343 #endif /* AVUTIL_AVUTIL_H */
BI type.
Definition: avutil.h:272
S(GMC)-VOP MPEG4.
Definition: avutil.h:269
const char * avutil_configuration(void)
Return the libavutil build-time configuration.
Definition: utils.c:68
#define av_pure
Definition: attributes.h:70
FILE * av_fopen_utf8(const char *path, const char *mode)
Open a file using a UTF-8 filename.
Definition: file_open.c:154
Undefined.
Definition: avutil.h:265
Switching Intra.
Definition: avutil.h:270
Opaque data information usually continuous.
Definition: avutil.h:195
mode
Definition: f_perms.c:27
char av_get_picture_type_char(enum AVPictureType pict_type)
Return a single letter to describe the given picture type pict_type.
Definition: utils.c:91
static void * av_x_if_null(const void *p, const void *x)
Return x default pointer in case p is NULL.
Definition: avutil.h:300
Utility Preprocessor macros.
unsigned avutil_version(void)
Return the LIBAVUTIL_VERSION_INT constant.
Definition: utils.c:38
error code definitions
unsigned av_int_list_length_for_size(unsigned elsize, const void *list, uint64_t term) av_pure
Compute the length of an integer list.
Definition: utils.c:105
Libavutil version macros.
const char * av_version_info(void)
Return an informative version string.
Definition: utils.c:33
Usually treated as AVMEDIA_TYPE_DATA.
Definition: avutil.h:192
Opaque data information usually sparse.
Definition: avutil.h:197
const char * avutil_license(void)
Return the libavutil license.
Definition: utils.c:73
Switching Predicted.
Definition: avutil.h:271
rational number numerator/denominator
Definition: rational.h:43
AVMediaType
Definition: avutil.h:191
AVPictureType
Definition: avutil.h:264
AVRational av_get_time_base_q(void)
Return the fractional representation of the internal time base.
Definition: utils.c:124
const char * av_get_media_type_string(enum AVMediaType media_type)
Return a string describing the media_type enum, NULL if media_type is unknown.
Definition: utils.c:79
common internal and external API header
rational numbers
Bi-dir predicted.
Definition: avutil.h:268
pixel format definitions
Predicted.
Definition: avutil.h:267