ioctl VIDIOC_SUBDEV_G_SELECTION, VIDIOC_SUBDEV_S_SELECTION

&manvol;

VIDIOC_SUBDEV_G_SELECTION

VIDIOC_SUBDEV_S_SELECTION

Get or set selection rectangles on a subdev pad

    	int ioctl
    	int fd
    	int request
    	struct v4l2_subdev_selection *argp

## Arguments

`fd`

- &fd;

`request`

- VIDIOC_SUBDEV_G_SELECTION, VIDIOC_SUBDEV_S_SELECTION

`argp`

## Description

### Experimental

This is an experimental interface and may change in the future.

The selections are used to configure various image processing functionality performed by the subdevs which affect the image size. This currently includes cropping, scaling and composition.

The selection API replaces the old subdev crop API. All the function of the crop API, and more, are supported by the selections API.

See subdev for more information on how each selection target affects the image processing pipeline inside the subdevice.

### Types of selection targets

There are two types of selection targets: actual and bounds. The actual targets are the targets which configure the hardware. The BOUNDS target will return a rectangle that contain all possible actual rectangles.

### Discovering supported features

To discover which targets are supported, the user can perform `VIDIOC_SUBDEV_G_SELECTION` on them. Any unsupported target will return `EINVAL`.

Selection targets and flags are documented in v4l2-selections-common.

### struct v4l2_subdev_selection

&cs-str;
__u32 | which | Active or try selection, from &v4l2-subdev-format-whence;.
__u32 | pad | Pad number as reported by the media framework.
__u32 | target | Target selection rectangle. See v4l2-selections-common.
__u32 | flags | Flags. See v4l2-selection-flags.
&v4l2-rect; | rect | Selection rectangle, in pixels.
__u32 | reserved[8] | Reserved for future extensions. Applications and drivers must set the array to zero.

&return-value;

EBUSY

- The selection rectangle can't be changed because the pad is currently busy. This can be caused, for instance, by an active video stream on the pad. The ioctl must not be retried without performing another action to fix the problem first. Only returned by `VIDIOC_SUBDEV_S_SELECTION`

EINVAL

- The &v4l2-subdev-selection; pad references a non-existing pad, the which field references a non-existing format, or the selection target is not supported on the given subdev pad.