mj2_video_target::set_field_order

For interlaced video tracks, call this function to indicate the order of the two fields. If order is KDU_FIELDS_NONE, each frame has a progressive scan, with only one field (this is the default). Otherwise, order must be one of KDU_FIELDS_TOP_FIRST or KDU_FIELDS_TOP_SECOND. In the former case, the first field in temporal sequence also holds the first line in its frame. Otherwise, the second field of each frame holds the top line of the frame.

It is illegal to call this function after the first call to open_image.

order [kdu_field_order]