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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  * @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 lpp "libpostproc" post processing library
45  * @li @ref libsws "libswscale" color conversion and scaling library
46  *
47  * @section ffmpeg_versioning Versioning and compatibility
48  *
49  * Each of the FFmpeg libraries contains a version.h header, which defines a
50  * major, minor and micro version number with the
51  * <em>LIBRARYNAME_VERSION_{MAJOR,MINOR,MICRO}</em> macros. The major version
52  * number is incremented with backward incompatible changes - e.g. removing
53  * parts of the public API, reordering public struct members, etc. The minor
54  * version number is incremented for backward compatible API changes or major
55  * new features - e.g. adding a new public function or a new decoder. The micro
56  * version number is incremented for smaller changes that a calling program
57  * might still want to check for - e.g. changing behavior in a previously
58  * unspecified situation.
59  *
60  * FFmpeg guarantees backward API and ABI compatibility for each library as long
61  * as its major version number is unchanged. This means that no public symbols
62  * will be removed or renamed. Types and names of the public struct members and
63  * values of public macros and enums will remain the same (unless they were
64  * explicitly declared as not part of the public API). Documented behavior will
65  * not change.
66  *
67  * In other words, any correct program that works with a given FFmpeg snapshot
68  * should work just as well without any changes with any later snapshot with the
69  * same major versions. This applies to both rebuilding the program against new
70  * FFmpeg versions or to replacing the dynamic FFmpeg libraries that a program
71  * links against.
72  *
73  * However, new public symbols may be added and new members may be appended to
74  * public structs whose size is not part of public ABI (most public structs in
75  * FFmpeg). New macros and enum values may be added. Behavior in undocumented
76  * situations may change slightly (and be documented). All those are accompanied
77  * by an entry in doc/APIchanges and incrementing either the minor or micro
78  * version number.
79  */
80 
81 /**
82  * @defgroup lavu libavutil
83  * Common code shared across all FFmpeg libraries.
84  *
85  * @note
86  * libavutil is designed to be modular. In most cases, in order to use the
87  * functions provided by one component of libavutil you must explicitly include
88  * the specific header containing that feature. If you are only using
89  * media-related components, you could simply include libavutil/avutil.h, which
90  * brings in most of the "core" components.
91  *
92  * @{
93  *
94  * @defgroup lavu_crypto Crypto and Hashing
95  *
96  * @{
97  * @}
98  *
99  * @defgroup lavu_math Mathematics
100  * @{
101  *
102  * @}
103  *
104  * @defgroup lavu_string String Manipulation
105  *
106  * @{
107  *
108  * @}
109  *
110  * @defgroup lavu_mem Memory Management
111  *
112  * @{
113  *
114  * @}
115  *
116  * @defgroup lavu_data Data Structures
117  * @{
118  *
119  * @}
120  *
121  * @defgroup lavu_audio Audio related
122  *
123  * @{
124  *
125  * @}
126  *
127  * @defgroup lavu_error Error Codes
128  *
129  * @{
130  *
131  * @}
132  *
133  * @defgroup lavu_log Logging Facility
134  *
135  * @{
136  *
137  * @}
138  *
139  * @defgroup lavu_misc Other
140  *
141  * @{
142  *
143  * @defgroup preproc_misc Preprocessor String Macros
144  *
145  * @{
146  *
147  * @}
148  *
149  * @defgroup version_utils Library Version Macros
150  *
151  * @{
152  *
153  * @}
154  */
155 
156 
157 /**
158  * @addtogroup lavu_ver
159  * @{
160  */
161 
162 /**
163  * Return the LIBAVUTIL_VERSION_INT constant.
164  */
165 unsigned avutil_version(void);
166 
167 /**
168  * Return an informative version string. This usually is the actual release
169  * version number or a git commit description. This string has no fixed format
170  * and can change any time. It should never be parsed by code.
171  */
172 const char *av_version_info(void);
173 
174 /**
175  * Return the libavutil build-time configuration.
176  */
177 const char *avutil_configuration(void);
178 
179 /**
180  * Return the libavutil license.
181  */
182 const char *avutil_license(void);
183 
184 /**
185  * @}
186  */
187 
188 /**
189  * @addtogroup lavu_media Media Type
190  * @brief Media Type
191  */
192 
194  AVMEDIA_TYPE_UNKNOWN = -1, ///< Usually treated as AVMEDIA_TYPE_DATA
197  AVMEDIA_TYPE_DATA, ///< Opaque data information usually continuous
199  AVMEDIA_TYPE_ATTACHMENT, ///< Opaque data information usually sparse
201 };
202 
203 /**
204  * Return a string describing the media_type enum, NULL if media_type
205  * is unknown.
206  */
207 const char *av_get_media_type_string(enum AVMediaType media_type);
208 
209 /**
210  * @defgroup lavu_const Constants
211  * @{
212  *
213  * @defgroup lavu_enc Encoding specific
214  *
215  * @note those definition should move to avcodec
216  * @{
217  */
218 
219 #define FF_LAMBDA_SHIFT 7
220 #define FF_LAMBDA_SCALE (1<<FF_LAMBDA_SHIFT)
221 #define FF_QP2LAMBDA 118 ///< factor to convert from H.263 QP to lambda
222 #define FF_LAMBDA_MAX (256*128-1)
223 
224 #define FF_QUALITY_SCALE FF_LAMBDA_SCALE //FIXME maybe remove
225 
226 /**
227  * @}
228  * @defgroup lavu_time Timestamp specific
229  *
230  * FFmpeg internal timebase and timestamp definitions
231  *
232  * @{
233  */
234 
235 /**
236  * @brief Undefined timestamp value
237  *
238  * Usually reported by demuxer that work on containers that do not provide
239  * either pts or dts.
240  */
241 
242 #define AV_NOPTS_VALUE ((int64_t)UINT64_C(0x8000000000000000))
243 
244 /**
245  * Internal time base represented as integer
246  */
247 
248 #define AV_TIME_BASE 1000000
249 
250 /**
251  * Internal time base represented as fractional value
252  */
253 
254 #define AV_TIME_BASE_Q (AVRational){1, AV_TIME_BASE}
255 
256 /**
257  * @}
258  * @}
259  * @defgroup lavu_picture Image related
260  *
261  * AVPicture types, pixel formats and basic image planes manipulation.
262  *
263  * @{
264  */
265 
267  AV_PICTURE_TYPE_NONE = 0, ///< Undefined
268  AV_PICTURE_TYPE_I, ///< Intra
269  AV_PICTURE_TYPE_P, ///< Predicted
270  AV_PICTURE_TYPE_B, ///< Bi-dir predicted
271  AV_PICTURE_TYPE_S, ///< S(GMC)-VOP MPEG-4
272  AV_PICTURE_TYPE_SI, ///< Switching Intra
273  AV_PICTURE_TYPE_SP, ///< Switching Predicted
274  AV_PICTURE_TYPE_BI, ///< BI type
275 };
276 
277 /**
278  * Return a single letter to describe the given picture type
279  * pict_type.
280  *
281  * @param[in] pict_type the picture type @return a single character
282  * representing the picture type, '?' if pict_type is unknown
283  */
284 char av_get_picture_type_char(enum AVPictureType pict_type);
285 
286 /**
287  * @}
288  */
289 
290 #include "common.h"
291 #include "error.h"
292 #include "rational.h"
293 #include "version.h"
294 #include "macros.h"
295 #include "mathematics.h"
296 #include "log.h"
297 #include "pixfmt.h"
298 
299 /**
300  * Return x default pointer in case p is NULL.
301  */
302 static inline void *av_x_if_null(const void *p, const void *x)
303 {
304  return (void *)(intptr_t)(p ? p : x);
305 }
306 
307 /**
308  * Compute the length of an integer list.
309  *
310  * @param elsize size in bytes of each list element (only 1, 2, 4 or 8)
311  * @param term list terminator (usually 0 or -1)
312  * @param list pointer to the list
313  * @return length of the list, in elements, not counting the terminator
314  */
315 unsigned av_int_list_length_for_size(unsigned elsize,
316  const void *list, uint64_t term) av_pure;
317 
318 /**
319  * Compute the length of an integer list.
320  *
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 #define av_int_list_length(list, term) \
326  av_int_list_length_for_size(sizeof(*(list)), list, term)
327 
328 /**
329  * Open a file using a UTF-8 filename.
330  * The API of this function matches POSIX fopen(), errors are returned through
331  * errno.
332  */
333 FILE *av_fopen_utf8(const char *path, const char *mode);
334 
335 /**
336  * Return the fractional representation of the internal time base.
337  */
339 
340 /**
341  * @}
342  * @}
343  */
344 
345 #endif /* AVUTIL_AVUTIL_H */
BI type.
Definition: avutil.h:274
S(GMC)-VOP MPEG-4.
Definition: avutil.h:271
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:267
Switching Intra.
Definition: avutil.h:272
Opaque data information usually continuous.
Definition: avutil.h:197
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:302
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:194
Opaque data information usually sparse.
Definition: avutil.h:199
const char * avutil_license(void)
Return the libavutil license.
Definition: utils.c:73
Switching Predicted.
Definition: avutil.h:273
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AVMediaType
Definition: avutil.h:193
AVPictureType
Definition: avutil.h:266
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
Utilties for rational number calculation.
Bi-dir predicted.
Definition: avutil.h:270
pixel format definitions
mode
Use these values in ebur128_init (or'ed).
Definition: ebur128.h:83
Predicted.
Definition: avutil.h:269