1V4L2_CTRL_CLASS_USER
2V4L2_CTRL_CLASS_MPEG
3V4L2_CTRL_CLASS_CAMERA
4V4L2_CTRL_CLASS_FM_TX
5V4L2_CTRL_CLASS_FLASH
6V4L2_CTRL_CLASS_JPEG
7V4L2_CTRL_CLASS_IMAGE_SOURCE
8V4L2_CTRL_CLASS_IMAGE_PROC
9V4L2_CTRL_CLASS_FM_RX
10