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¶

VIDIOC_DV_TIMINGS_CAP¶

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

VIDIOC_SUBDEV_DV_TIMINGS_CAP¶

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 {	(anonymous)
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.