+/**
+ * The option is inteded for exporting values to the caller.
+ */
+#define AV_OPT_FLAG_EXPORT 64
+/**
+ * The option may not be set through the AVOptions API, only read.
+ * This flag only makes sense when AV_OPT_FLAG_EXPORT is also set.
+ */
+#define AV_OPT_FLAG_READONLY 128