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

#include <libavutil/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 AVOption *	option
	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...

AVClassCategory	category
	Category used for visualization (like color) This is only set if the category is equal for all objects using this class. More...

AVClassCategory(*	get_category )(void *ctx)
	Callback to return the category. More...

int(*	query_ranges )(struct AVOptionRanges *, void obj, const char *key, int flags)
	Callback to return the supported/allowed ranges. 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 67 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 72 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 78 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 85 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 93 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 99 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 108 of file log.h.

◆ child_next

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

Return next AVOptions-enabled child or NULL.

Definition at line 113 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 123 of file log.h.

◆ category

AVClassCategory AVClass::category

Category used for visualization (like color) This is only set if the category is equal for all objects using this class.

available since version (51 << 16 | 56 << 8 | 100)

Definition at line 130 of file log.h.

◆ get_category

AVClassCategory(* AVClass::get_category) (void *ctx)

Callback to return the category.

available since version (51 << 16 | 59 << 8 | 100)

Definition at line 136 of file log.h.

◆ query_ranges

int(* AVClass::query_ranges) (struct AVOptionRanges **, void *obj, const char *key, int flags)

Callback to return the supported/allowed ranges.

available since version (52.12)

Definition at line 142 of file log.h.

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

libavutil/log.h

Data Fields