67 typedef struct AVClass {  struct
72     const char* class_name;
78     const char* (*item_name)(void* ctx);
85     const struct AVOption *option;
93     int version;
117      * Return an AVClass corresponding to the next potential  argument
125     const struct AVClass* (*child_class_next)(const struct AVClass *prev);  argument
133     AVClassCategory category;  argument
139     AVClassCategory (*get_category)(void* ctx);  argument
153      * @return AVClass for the next AVOptions-enabled child or NULL if there are  argument
160     const struct AVClass* (*child_class_iterate)(void **iter);  argument
161 } AVClass;  typedef