*/
void avfilter_formats_unref(AVFilterFormats **ref);
-int avfilter_poll_frame(AVFilterLink *link);
-
/**
* A filter pad used for either input or output.
*/
int avfilter_request_frame(AVFilterLink *link);
/**
+ * Poll a frame from the filter chain.
+ * @param link the input link
+ * @return the number of imediately available frames
+ */
+int avfilter_poll_frame(AVFilterLink *link);
+
+/**
* Notify the next filter of the start of a frame.
* @param link the output link the frame will be sent over
* @param picref A reference to the frame about to be sent. The data for this