* of a filtergraph, only a convenience function to help drain a filtergraph
* in a balanced way under normal circumstances.
*
- * @return the return value of ff_request_frame,
- * or AVERROR_EOF of all links returned AVERROR_EOF.
+ * Also note that AVERROR_EOF does not mean that frames did not arrive on
+ * some of the sinks during the process.
+ * When there are multiple sink links, in case the requested link
+ * returns an EOF, this may cause a filter to flush pending frames
+ * which are sent to another sink link, although unrequested.
+ *
+ * @return the return value of ff_request_frame(),
+ * or AVERROR_EOF if all links returned AVERROR_EOF
*/
int avfilter_graph_request_oldest(AVFilterGraph *graph);