7.9. ioctl VIDIOC_DV_TIMINGS_CAP, VIDIOC_SUBDEV_DV_TIMINGS_CAP

7.9.1. Name

VIDIOC_DV_TIMINGS_CAP - VIDIOC_SUBDEV_DV_TIMINGS_CAP - The capabilities of the Digital Video receiver/transmitter

7.9.2. Synopsis

int ioctl(int fd, VIDIOC_DV_TIMINGS_CAP, struct v4l2_dv_timings_cap *argp)

int ioctl(int fd, VIDIOC_SUBDEV_DV_TIMINGS_CAP, struct v4l2_dv_timings_cap *argp)

7.9.3. Arguments

fd

File descriptor returned by open().

argp

Pointer to struct v4l2_dv_timings_cap.

7.9.4. Description

To query the capabilities of the DV receiver/transmitter applications initialize the pad field to 0, zero the reserved array of struct v4l2_dv_timings_cap and call the VIDIOC_DV_TIMINGS_CAP ioctl on a video node and the driver will fill in the structure.

Note

Drivers may return different values after switching the video input or output.

When implemented by the driver DV capabilities of subdevices can be queried by calling the VIDIOC_SUBDEV_DV_TIMINGS_CAP ioctl directly on a subdevice node. The capabilities are specific to inputs (for DV receivers) or outputs (for DV transmitters), applications must specify the desired pad number in the struct v4l2_dv_timings_cap pad field and zero the reserved array. Attempts to query capabilities on a pad that doesn’t support them will return an EINVAL error code.

v4l2_bt_timings_cap

struct v4l2_bt_timings_cap

__u32	min_width	Minimum width of the active video in pixels.
__u32	max_width	Maximum width of the active video in pixels.
__u32	min_height	Minimum height of the active video in lines.
__u32	max_height	Maximum height of the active video in lines.
__u64	min_pixelclock	Minimum pixelclock frequency in Hz.
__u64	max_pixelclock	Maximum pixelclock frequency in Hz.
__u32	standards	The video standard(s) supported by the hardware. See DV BT Timing standards for a list of standards.
__u32	capabilities	Several flags giving more information about the capabilities. See DV BT Timing capabilities for a description of the flags.
__u32	reserved[16]	Reserved for future extensions. Drivers must set the array to zero.

v4l2_dv_timings_cap

struct v4l2_dv_timings_cap

__u32	type	Type of DV timings as listed in DV Timing types.
__u32	pad	Pad number as reported by the media controller API. This field is only used when operating on a subdevice node. When operating on a video node applications must set this field to zero.
__u32	reserved[2]	Reserved for future extensions. Drivers and applications must set the array to zero.
union
	struct v4l2_bt_timings_cap	bt	BT.656/1120 timings capabilities of the hardware.
	__u32	raw_data[32]

DV BT Timing capabilities

Flag	Description
V4L2_DV_BT_CAP_INTERLACED	Interlaced formats are supported.
V4L2_DV_BT_CAP_PROGRESSIVE	Progressive formats are supported.
V4L2_DV_BT_CAP_REDUCED_BLANKING	CVT/GTF specific: the timings can make use of reduced blanking (CVT) or the ‘Secondary GTF’ curve (GTF).
V4L2_DV_BT_CAP_CUSTOM	Can support non-standard timings, i.e. timings not belonging to the standards set in the standards field.

7.9.5. 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.