* @param f0 used to return the main frame
* @param f1 used to return the second frame, or NULL if disabled
* @return >=0 for success or AVERROR code
+ * @note The frame returned in f0 belongs to the caller (get = 1 in
+ * ff_framesync_get_frame()) while the frame returned in f1 is still owned
+ * by the framesync structure.
*/
int ff_framesync_dualinput_get(FFFrameSync *fs, AVFrame **f0, AVFrame **f1);