ffmpeg/libavutil/avutil.h

345 lines
8.4 KiB
C

/*
* copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVUTIL_AVUTIL_H
#define AVUTIL_AVUTIL_H
/**
* @file
* external API header
*/
/**
* @mainpage
*
* @section ffmpeg_intro Introduction
*
* This document describes the usage of the different libraries
* provided by FFmpeg.
*
* @li @ref libavc "libavcodec" encoding/decoding library
* @li @ref lavfi "libavfilter" graph-based frame editing library
* @li @ref libavf "libavformat" I/O and muxing/demuxing library
* @li @ref lavd "libavdevice" special devices muxing/demuxing library
* @li @ref lavu "libavutil" common utility library
* @li @ref lswr "libswresample" audio resampling, format conversion and mixing
* @li @ref lpp "libpostproc" post processing library
* @li @ref libsws "libswscale" color conversion and scaling library
*
* @section ffmpeg_versioning Versioning and compatibility
*
* Each of the FFmpeg libraries contains a version.h header, which defines a
* major, minor and micro version number with the
* <em>LIBRARYNAME_VERSION_{MAJOR,MINOR,MICRO}</em> macros. The major version
* number is incremented with backward incompatible changes - e.g. removing
* parts of the public API, reordering public struct members, etc. The minor
* version number is incremented for backward compatible API changes or major
* new features - e.g. adding a new public function or a new decoder. The micro
* version number is incremented for smaller changes that a calling program
* might still want to check for - e.g. changing behavior in a previously
* unspecified situation.
*
* FFmpeg guarantees backward API and ABI compatibility for each library as long
* as its major version number is unchanged. This means that no public symbols
* will be removed or renamed. Types and names of the public struct members and
* values of public macros and enums will remain the same (unless they were
* explicitly declared as not part of the public API). Documented behavior will
* not change.
*
* In other words, any correct program that works with a given FFmpeg snapshot
* should work just as well without any changes with any later snapshot with the
* same major versions. This applies to both rebuilding the program against new
* FFmpeg versions or to replacing the dynamic FFmpeg libraries that a program
* links against.
*
* However, new public symbols may be added and new members may be appended to
* public structs whose size is not part of public ABI (most public structs in
* FFmpeg). New macros and enum values may be added. Behavior in undocumented
* situations may change slightly (and be documented). All those are accompanied
* by an entry in doc/APIchanges and incrementing either the minor or micro
* version number.
*/
/**
* @defgroup lavu Common utility functions
*
* @brief
* libavutil contains the code shared across all the other FFmpeg
* libraries
*
* @note In order to use the functions provided by avutil you must include
* the specific header.
*
* @{
*
* @defgroup lavu_crypto Crypto and Hashing
*
* @{
* @}
*
* @defgroup lavu_math Maths
* @{
*
* @}
*
* @defgroup lavu_string String Manipulation
*
* @{
*
* @}
*
* @defgroup lavu_mem Memory Management
*
* @{
*
* @}
*
* @defgroup lavu_data Data Structures
* @{
*
* @}
*
* @defgroup lavu_audio Audio related
*
* @{
*
* @}
*
* @defgroup lavu_error Error Codes
*
* @{
*
* @}
*
* @defgroup lavu_log Logging Facility
*
* @{
*
* @}
*
* @defgroup lavu_misc Other
*
* @{
*
* @defgroup lavu_internal Internal
*
* Not exported functions, for internal usage only
*
* @{
*
* @}
*
* @defgroup preproc_misc Preprocessor String Macros
*
* @{
*
* @}
*
* @defgroup version_utils Library Version Macros
*
* @{
*
* @}
*/
/**
* @addtogroup lavu_ver
* @{
*/
/**
* Return the LIBAVUTIL_VERSION_INT constant.
*/
unsigned avutil_version(void);
/**
* Return the libavutil build-time configuration.
*/
const char *avutil_configuration(void);
/**
* Return the libavutil license.
*/
const char *avutil_license(void);
/**
* @}
*/
/**
* @addtogroup lavu_media Media Type
* @brief Media Type
*/
enum AVMediaType {
AVMEDIA_TYPE_UNKNOWN = -1, ///< Usually treated as AVMEDIA_TYPE_DATA
AVMEDIA_TYPE_VIDEO,
AVMEDIA_TYPE_AUDIO,
AVMEDIA_TYPE_DATA, ///< Opaque data information usually continuous
AVMEDIA_TYPE_SUBTITLE,
AVMEDIA_TYPE_ATTACHMENT, ///< Opaque data information usually sparse
AVMEDIA_TYPE_NB
};
/**
* Return a string describing the media_type enum, NULL if media_type
* is unknown.
*/
const char *av_get_media_type_string(enum AVMediaType media_type);
/**
* @defgroup lavu_const Constants
* @{
*
* @defgroup lavu_enc Encoding specific
*
* @note those definition should move to avcodec
* @{
*/
#define FF_LAMBDA_SHIFT 7
#define FF_LAMBDA_SCALE (1<<FF_LAMBDA_SHIFT)
#define FF_QP2LAMBDA 118 ///< factor to convert from H.263 QP to lambda
#define FF_LAMBDA_MAX (256*128-1)
#define FF_QUALITY_SCALE FF_LAMBDA_SCALE //FIXME maybe remove
/**
* @}
* @defgroup lavu_time Timestamp specific
*
* FFmpeg internal timebase and timestamp definitions
*
* @{
*/
/**
* @brief Undefined timestamp value
*
* Usually reported by demuxer that work on containers that do not provide
* either pts or dts.
*/
#define AV_NOPTS_VALUE ((int64_t)UINT64_C(0x8000000000000000))
/**
* Internal time base represented as integer
*/
#define AV_TIME_BASE 1000000
/**
* Internal time base represented as fractional value
*/
#define AV_TIME_BASE_Q (AVRational){1, AV_TIME_BASE}
/**
* @}
* @}
* @defgroup lavu_picture Image related
*
* AVPicture types, pixel formats and basic image planes manipulation.
*
* @{
*/
enum AVPictureType {
AV_PICTURE_TYPE_NONE = 0, ///< Undefined
AV_PICTURE_TYPE_I, ///< Intra
AV_PICTURE_TYPE_P, ///< Predicted
AV_PICTURE_TYPE_B, ///< Bi-dir predicted
AV_PICTURE_TYPE_S, ///< S(GMC)-VOP MPEG4
AV_PICTURE_TYPE_SI, ///< Switching Intra
AV_PICTURE_TYPE_SP, ///< Switching Predicted
AV_PICTURE_TYPE_BI, ///< BI type
};
/**
* Return a single letter to describe the given picture type
* pict_type.
*
* @param[in] pict_type the picture type @return a single character
* representing the picture type, '?' if pict_type is unknown
*/
char av_get_picture_type_char(enum AVPictureType pict_type);
/**
* @}
*/
#include "common.h"
#include "error.h"
#include "rational.h"
#include "version.h"
#include "macros.h"
#include "mathematics.h"
#include "log.h"
#include "pixfmt.h"
/**
* Return x default pointer in case p is NULL.
*/
static inline void *av_x_if_null(const void *p, const void *x)
{
return (void *)(intptr_t)(p ? p : x);
}
/**
* Compute the length of an integer list.
*
* @param elsize size in bytes of each list element (only 1, 2, 4 or 8)
* @param term list terminator (usually 0 or -1)
* @param list pointer to the list
* @return length of the list, in elements, not counting the terminator
*/
unsigned av_int_list_length_for_size(unsigned elsize,
const void *list, uint64_t term) av_pure;
/**
* Compute the length of an integer list.
*
* @param term list terminator (usually 0 or -1)
* @param list pointer to the list
* @return length of the list, in elements, not counting the terminator
*/
#define av_int_list_length(list, term) \
av_int_list_length_for_size(sizeof(*(list)), list, term)
/**
* Open a file using a UTF-8 filename.
* The API of this function matches POSIX fopen(), errors are returned through
* errno.
*/
FILE *av_fopen_utf8(const char *path, const char *mode);
/**
* Return the fractional representation of the internal time base.
*/
AVRational av_get_time_base_q(void);
/**
* @}
* @}
*/
#endif /* AVUTIL_AVUTIL_H */