VIDIOC_DV_TIMINGS_CAP, VIDIOC_SUBDEV_DV_TIMINGS_CAP — The capabilities of the Digital Video receiver/transmitter
int ioctl( | int fd, |
| int request, | |
struct v4l2_dv_timings_cap *argp); |
fdFile descriptor returned by open().
requestVIDIOC_DV_TIMINGS_CAP, VIDIOC_SUBDEV_DV_TIMINGS_CAP
argpTo 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 that 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.
Table A.21. 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 Table A.60, “DV BT Timing standards” for a list of standards. |
| __u32 | capabilities | Several flags giving more information about the capabilities. See Table A.23, “DV BT Timing capabilities” for a description of the flags. |
| __u32 | reserved[16] | Reserved for future extensions. Drivers must set the array to zero. |
Table A.22. struct v4l2_dv_timings_cap
| __u32 | type | Type of DV timings as listed in Table A.59, “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] |
Table A.23. 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.
|
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.