V4L2_CID_BASE      39 extra_lib/include/avcap/linux/uvc_compat.h #undef	V4L2_CID_BASE
V4L2_CID_BASE      40 extra_lib/include/avcap/linux/uvc_compat.h #define V4L2_CID_BASE			(V4L2_CTRL_CLASS_USER | 0x900)