VIDIOC_QUERY_DV_PRESET — Sense the DV preset received by the current input
int ioctl( | int fd, |
int request, | |
struct v4l2_dv_preset *argp) ; |
The hardware may be able to detect the current DV preset
automatically, similar to sensing the video standard. To do so, applications
call VIDIOC_QUERY_DV_PRESET
with a pointer to a
struct v4l2_dv_preset type. Once the hardware detects a preset, that preset is
returned in the preset field of struct v4l2_dv_preset. When detection is not
possible or fails, the value V4L2_DV_INVALID is returned.