AVClass Struct Reference

Describe the class of an AVClass context structure. More...

#include <log.h>

Data Fields

const char * class_name
 The name of the class; usually it is the same name as the context structure type to which the AVClass is associated. More...
 
const char *(* item_name )(void *ctx)
 A pointer to a function which returns the name of a context instance ctx associated with the class. More...
 
const struct AVOptionoption
 a pointer to the first option specified in the class if any or NULL More...
 
int version
 LIBAVUTIL_VERSION with which this structure was created. More...
 
int log_level_offset_offset
 Offset in the structure where log_level_offset is stored. More...
 
int parent_log_context_offset
 Offset in the structure where a pointer to the parent context for logging is stored. More...
 
void *(* child_next )(void *obj, void *prev)
 Return next AVOptions-enabled child or NULL. More...
 
const struct AVClass *(* child_class_next )(const struct AVClass *prev)
 Return an AVClass corresponding to the next potential AVOptions-enabled child. More...
 

Detailed Description

Describe the class of an AVClass context structure.

That is an arbitrary struct of which the first field is a pointer to an AVClass struct (e.g. AVCodecContext, AVFormatContext etc.).

Definition at line 34 of file log.h.

Field Documentation

◆ class_name

const char* AVClass::class_name

The name of the class; usually it is the same name as the context structure type to which the AVClass is associated.

Definition at line 39 of file log.h.

◆ item_name

const char*(* AVClass::item_name) (void *ctx)

A pointer to a function which returns the name of a context instance ctx associated with the class.

Definition at line 45 of file log.h.

◆ option

const struct AVOption* AVClass::option

a pointer to the first option specified in the class if any or NULL

See also
av_set_default_options()

Definition at line 52 of file log.h.

◆ version

int AVClass::version

LIBAVUTIL_VERSION with which this structure was created.

This is used to allow fields to be added without requiring major version bumps everywhere.

Definition at line 60 of file log.h.

◆ log_level_offset_offset

int AVClass::log_level_offset_offset

Offset in the structure where log_level_offset is stored.

0 means there is no such variable

Definition at line 66 of file log.h.

◆ parent_log_context_offset

int AVClass::parent_log_context_offset

Offset in the structure where a pointer to the parent context for logging is stored.

For example a decoder could pass its AVCodecContext to eval as such a parent context, which an av_log() implementation could then leverage to display the parent context. The offset can be NULL.

Definition at line 75 of file log.h.

◆ child_next

void*(* AVClass::child_next) (void *obj, void *prev)

Return next AVOptions-enabled child or NULL.

Definition at line 80 of file log.h.

◆ child_class_next

const struct AVClass*(* AVClass::child_class_next) (const struct AVClass *prev)

Return an AVClass corresponding to the next potential AVOptions-enabled child.

The difference between child_next and this is that child_next iterates over already existing objects, while child_class_next iterates over all possible children.

Definition at line 90 of file log.h.


The documentation for this struct was generated from the following file: