*/
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);
-
/**
* Category used for visualization (like color)
* This is only set if the category is equal for all objects using this class.
* available since version (52.12)
*/
int (*query_ranges)(struct AVOptionRanges **, void *obj, const char *key, int flags);
+
+ /**
+ * Iterate over the AVClasses corresponding to potential AVOptions-enabled
+ * children.
+ *
+ * @param iter pointer to opaque iteration state. The caller must initialize
+ * *iter to NULL before the first call.
+ * @return AVClass for the next AVOptions-enabled child or NULL if there are
+ * no more such children.
+ *
+ * @note The difference between child_next and this is that child_next
+ * iterates over _already existing_ objects, while child_class_iterate
+ * iterates over _all possible_ children.
+ */
+ const struct AVClass* (*child_class_iterate)(void **iter);
} AVClass;
/**
*/
void av_log(void *avcl, int level, const char *fmt, ...) av_printf_format(3, 4);
+/**
+ * Send the specified message to the log once with the initial_level and then with
+ * the subsequent_level. By default, all logging messages are sent to
+ * stderr. This behavior can be altered by setting a different logging callback
+ * function.
+ * @see av_log
+ *
+ * @param avcl A pointer to an arbitrary struct of which the first field is a
+ * pointer to an AVClass struct or NULL if general log.
+ * @param initial_level importance level of the message expressed using a @ref
+ * lavu_log_constants "Logging Constant" for the first occurance.
+ * @param subsequent_level importance level of the message expressed using a @ref
+ * lavu_log_constants "Logging Constant" after the first occurance.
+ * @param fmt The format string (printf-compatible) that specifies how
+ * subsequent arguments are converted to output.
+ * @param state a variable to keep trak of if a message has already been printed
+ * this must be initialized to 0 before the first use. The same state
+ * must not be accessed by 2 Threads simultaneously.
+ */
+void av_log_once(void* avcl, int initial_level, int subsequent_level, int *state, const char *fmt, ...) av_printf_format(5, 6);
+
/**
* Send the specified message to the log if the level is less than or equal