ioctl VIDIOC_ENUM_DV_TIMINGS, VIDIOC_SUBDEV_ENUM_DV_TIMINGS
&manvol;
VIDIOC_ENUM_DV_TIMINGS
VIDIOC_SUBDEV_ENUM_DV_TIMINGS
Enumerate supported Digital Video timings
int ioctl
int fd
int request
struct v4l2_enum_dv_timings *argp
Arguments
fd
&fd;
request
VIDIOC_ENUM_DV_TIMINGS, VIDIOC_SUBDEV_ENUM_DV_TIMINGS
argp
Description
While some DV receivers or transmitters support a wide range of timings, others
support only a limited number of timings. With this ioctl applications can enumerate a list
of known supported timings. Call &VIDIOC-DV-TIMINGS-CAP; to check if it also supports other
standards or even custom timings that are not in this list.
To query the available timings, applications initialize the
index field, set the pad field to 0,
zero the reserved array of &v4l2-enum-dv-timings; and call the
VIDIOC_ENUM_DV_TIMINGS ioctl on a video node with a
pointer to this structure. Drivers fill the rest of the structure or return an
&EINVAL; when the index is out of bounds. To enumerate all supported DV timings,
applications shall begin at index zero, incrementing by one until the
driver returns EINVAL. Note that drivers may enumerate a
different set of DV timings after switching the video input or
output.
When implemented by the driver DV timings of subdevices can be queried
by calling the VIDIOC_SUBDEV_ENUM_DV_TIMINGS ioctl directly
on a subdevice node. The DV timings are specific to inputs (for DV receivers) or
outputs (for DV transmitters), applications must specify the desired pad number
in the &v4l2-enum-dv-timings; pad field. Attempts to
enumerate timings on a pad that doesn't support them will return an &EINVAL;.
struct v4l2_enum_dv_timings
&cs-str;
__u32
index
Number of the DV timings, set by the
application.
__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.
&v4l2-dv-timings;
timings
The timings.
&return-value;
EINVAL
The &v4l2-enum-dv-timings; index
is out of bounds or the pad number is invalid.
ENODATA
Digital video presets are not supported for this input or output.