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

#include <log.h>

Public Attributes
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.

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.

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.).

Member Data Documentation

§ 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)

§ 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.

§ get_category

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

Callback to return the category.

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

§ 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

§ 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()

§ 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.

§ 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)

§ 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.

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

libavutil/log.h

Public Attributes