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 AVOption *	option
	An array of options for the structure or NULL. More...

int	version
	LIBAVUTIL_VERSION with which this structure was created. More...

int	log_level_offset_offset
	Offset in the structure where the 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...

AVClassCategory	category
	Category used for visualization (like color). More...

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

int(*	query_ranges )(struct AVOptionRanges *, void obj, const char *key, int flags)
	Callback to return the supported/allowed ranges. More...

void (	child_next )(void obj, void prev)
	Return next AVOptions-enabled child or NULL. More...

const struct AVClass (	child_class_iterate )(void **iter)
	Iterate over the AVClasses corresponding to potential AVOptions-enabled children. More...

int	state_flags_offset
	When non-zero, offset in the object to an unsigned int holding object state flags, a combination of AVClassStateFlags values. 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 75 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 80 of file log.h.

Referenced by av_parse_cpu_caps(), ff_vk_init(), ist_add(), of_parse_group_token(), opt_abort_on(), opt_cpucount(), show_format_opts(), and vs2av_log().

◆ 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 86 of file log.h.

Referenced by item_name(), log_callback(), and log_slave().

◆ option

const struct AVOption* AVClass::option

An array of options for the structure or NULL.

When non-NULL, the array must be terminated by an option with a NULL name.

See also: av_set_default_options()

Definition at line 95 of file log.h.

Referenced by priv_data_size_wrong().

◆ version

int AVClass::version

LIBAVUTIL_VERSION with which this structure was created.

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

Definition at line 103 of file log.h.

Referenced by av_vlog(), and get_category().

◆ log_level_offset_offset

int AVClass::log_level_offset_offset

Offset in the structure where the log level offset is stored.

The log level offset is an int added to the log level for logging with this object as the context.

0 means there is no such variable.

Definition at line 112 of file log.h.

Referenced by av_vlog().

◆ 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.

When the pointer is NULL, or this offset is zero, the object is assumed to have no parent.

Definition at line 123 of file log.h.

Referenced by format_line(), and log_callback().

◆ category

AVClassCategory AVClass::category

Category used for visualization (like color).

Only used when get_category() is NULL. Use this field when all instances of this class have the same category, use get_category() otherwise.

Definition at line 132 of file log.h.

Referenced by ff_alloc_input_device_context(), get_category(), is_device(), log_callback(), next_input(), and next_output().

◆ get_category

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

Callback to return the instance category.

Use this callback when different instances of this class may have different categories, category otherwise.

Definition at line 139 of file log.h.

Referenced by get_category(), and log_callback().

◆ query_ranges

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

Callback to return the supported/allowed ranges.

Definition at line 144 of file log.h.

◆ child_next

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

Return next AVOptions-enabled child or NULL.

Definition at line 149 of file log.h.

◆ child_class_iterate

const struct AVClass*(* AVClass::child_class_iterate) (void **iter)

Iterate over the AVClasses corresponding to potential AVOptions-enabled children.

Parameters

iter	pointer to opaque iteration state. The caller must initialize *iter to NULL before the first call.

Returns: AVClass for the next AVOptions-enabled child or NULL if there are no more such children.

Note: The difference between child_next() and child_class_iterate() is that child_next() iterates over actual children of an existing object instance, while child_class_iterate() iterates over the classes of all potential children of any possible instance of this class.

Definition at line 166 of file log.h.

Referenced by av_opt_child_class_iterate().

◆ state_flags_offset

int AVClass::state_flags_offset

When non-zero, offset in the object to an unsigned int holding object state flags, a combination of AVClassStateFlags values.

The flags are updated by the object to signal its state to the generic code.

Added in version 59.41.100.

Definition at line 175 of file log.h.

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

libavutil/log.h

Data Fields