V4L2_CTRL_CLASS_USER 827 include/linux/videodev2.h #define V4L2_CID_BASE (V4L2_CTRL_CLASS_USER | 0x900) V4L2_CTRL_CLASS_USER 832 include/linux/videodev2.h #define V4L2_CID_USER_CLASS (V4L2_CTRL_CLASS_USER | 1)