1V4L2_FIELD_ANY 2V4L2_FIELD_NONE 3V4L2_FIELD_TOP 4V4L2_FIELD_BOTTOM 5V4L2_FIELD_INTERLACED 6V4L2_FIELD_SEQ_TB 7V4L2_FIELD_SEQ_BT 8V4L2_FIELD_ALTERNATE 9V4L2_FIELD_INTERLACED_TB 10V4L2_FIELD_INTERLACED_BT 11