8.9. ioctl VIDIOC_DV_TIMINGS_CAP, VIDIOC_SUBDEV_DV_TIMINGS_CAP¶
8.9.1. Name¶
VIDIOC_DV_TIMINGS_CAP - VIDIOC_SUBDEV_DV_TIMINGS_CAP - The capabilities of the Digital Video receiver/transmitter
8.9.3. Arguments¶
fd
- File descriptor returned by open().
request
- VIDIOC_DV_TIMINGS_CAP, VIDIOC_SUBDEV_DV_TIMINGS_CAP
argp
8.9.4. 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.
__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. |
__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] |
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. |
8.9.5. 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.