Name

VIDIOC_QUERY_DV_PRESET — Sense the DV preset received by the current input

Synopsis

int ioctl(int fd,
 int request,
 struct v4l2_dv_preset *argp);
 

Arguments

fd

File descriptor returned by open().

request

VIDIOC_QUERY_DV_PRESET

argp

Description

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. If the preset could not be detected because there was no signal, or the signal was unreliable, or the signal did not map to a supported preset, then the value V4L2_DV_INVALID is returned.

Return Value

On success 0 is returned, on error -1 and the errno variable is set appropriately. The generic error codes are described at the Generic Error Codes chapter.