ioctl VIDIOC_G_STD, VIDIOC_S_STD &manvol; VIDIOC_G_STD VIDIOC_S_STD Query or select the video standard of the current input int ioctl int fd int request v4l2_std_id *argp int ioctl int fd int request const v4l2_std_id *argp fd &fd; request VIDIOC_G_STD, VIDIOC_S_STD argp To query and select the current video standard applications use the VIDIOC_G_STD and VIDIOC_S_STD ioctls which take a pointer to a &v4l2-std-id; type as argument. VIDIOC_G_STD can return a single flag or a set of flags as in &v4l2-standard; field id. The flags must be unambiguous such that they appear in only one enumerated v4l2_standard structure. VIDIOC_S_STD accepts one or more flags, being a write-only ioctl it does not return the actual new standard as VIDIOC_G_STD does. When no flags are given or the current input does not support the requested standard the driver returns an &EINVAL;. When the standard set is ambiguous drivers may return EINVAL or choose any of the requested standards. &return-value; EINVAL The VIDIOC_S_STD parameter was unsuitable.