AVClass

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.).

Members

Variables

category
AVClassCategory 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
AVClass* function(const AVClass* prev) child_class_next;

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

child_next
void* function(void* obj, void* prev) child_next;

Return next AVOptions-enabled child or NULL

class_name
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.

get_category
AVClassCategory function(void* ctx) get_category;

Callback to return the category. available since version (51 << 16 | 59 << 8 | 100)

item_name
char* function(void* ctx) item_name;

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

log_level_offset_offset
int log_level_offset_offset;

Offset in the structure where log_level_offset is stored. 0 means there is no such variable

option
AVOption* option;

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

parent_log_context_offset
int 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

query_ranges
int function(AVOptionRanges**, void* obj, const char* key, int flags) query_ranges;

Callback to return the supported/allowed ranges. available since version (52.12)

ver
int ver;

LIBAVUTIL_VERSION with which this structure was created. This is used to allow fields to be added without requiring major version bumps everywhere.

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