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

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 33 of file log.h.

Field Documentation

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

Return an AVClass corresponding to 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 88 of file log.h.

Referenced by av_opt_child_class_next().

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

Return next AVOptions-enabled child or NULL.

Definition at line 78 of file log.h.

Referenced by av_opt_child_next().

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 38 of file log.h.

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 44 of file log.h.

Referenced by av_log_default_callback(), and http_av_log().

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 65 of file log.h.

Referenced by av_log().

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 51 of file log.h.

Referenced by av_find_opt(), and av_opt_next().

int AVClass::parent_log_context_offset

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

for example a decoder that uses eval.c could pass its AVCodecContext to eval as such parent context. And a av_log() implementation could then display the parent context can be NULL of course

Definition at line 73 of file log.h.

Referenced by av_log_default_callback().

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 59 of file log.h.

Referenced by av_log().


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