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);



File descriptor returned by open().





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 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

__u32min_widthMinimum width of the active video in pixels.
__u32max_widthMaximum width of the active video in pixels.
__u32min_heightMinimum height of the active video in lines.
__u32max_heightMaximum height of the active video in lines.
__u64min_pixelclockMinimum pixelclock frequency in Hz.
__u64max_pixelclockMaximum pixelclock frequency in Hz.
__u32standardsThe video standard(s) supported by the hardware. See Table A.60, “DV BT Timing standards” for a list of standards.
__u32capabilitiesSeveral flags giving more information about the capabilities. See Table A.23, “DV BT Timing capabilities” for a description of the flags.
__u32reserved[16]Reserved for future extensions. Drivers must set the array to zero.

Table A.22. struct v4l2_dv_timings_cap

__u32typeType of DV timings as listed in Table A.59, “DV Timing types”. 
__u32padPad 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. 
__u32reserved[2]Reserved for future extensions. Drivers and applications must set the array to zero. 
 struct v4l2_bt_timings_capbtBT.656/1120 timings capabilities of the hardware.

Table A.23. DV BT Timing capabilities

V4L2_DV_BT_CAP_INTERLACEDInterlaced formats are supported.
V4L2_DV_BT_CAP_PROGRESSIVEProgressive formats are supported.
V4L2_DV_BT_CAP_REDUCED_BLANKINGCVT/GTF specific: the timings can make use of reduced blanking (CVT) or the 'Secondary GTF' curve (GTF).
V4L2_DV_BT_CAP_CUSTOMCan support non-standard timings, i.e. timings not belonging to the standards set in the standards field.

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.