+
+ /**
+ * Return next AVOptions-enabled child or NULL
+ */
+ void* (*child_next)(void *obj, void *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.
+ */
+ const struct AVClass* (*child_class_next)(const struct AVClass *prev);